I am a Sony shooter and have up until this year was never happy with the results with teleconverters. No good on the 200-600 zoom, and even on the 400 and 600 primes I was not enthusiastic with the results, only using if absolutely necessary. Then this year Sony brought out the 300 F2.8 GM. I think that lens has the best glass of all Sony lenses and seems to have been optimised for use with the 1.4x and 2x teleconverters. I now use teleconverters daily on that lens with superb results, taking out the 300 +2x in preference to the 600. I really cannot see loss of quality even pixel peeping, and at half the weight it is so much more pleasurable and easy to use. My attitude to teleconverters has entirely changed, I now consider I have a 300 F2.8, 420 F4 or 600 F5.6 prime lens all in one.
Hi Tom,great video I have been considering the 1.4 for my 180-600 but have been resorting to dx recently and now that I have the z8 I have the megapixels to play with so I have put the purchase on hold your video was great timing as o have found the images taken in dx mode have been quite sufficient ,keep up the ok the good work glad to see more videos coming out cheers John
Yes, absolutely, glad the timing worked out! Yes the 180-600 is a great pairing with the Z8 and a 1.4 would be OK, but if the DX mode gives you enough reach, I’d stick to that!
I find TCs immensely useful and i don't hesitate to use them on any of my lenses. Some caveats: 2x i only use on my best glass, for the reasons you mention, and even then not very often. The 1.4 goes fine anytime on my fast glass and on my second-tier glass (which i only really carry if i need to save weight). I think that what you are referring to as 'Prosumer' is usually good enough optically for 1.4s. I also think it's important also to consider that the vast majority of photographers are not waiting to upgrade to Pro telephotos - it's not in the budgetary equation. A 1.4 for these people provides them with great flexibility while saving them, quite literally, many thousands of pounds in upgrades. Another point i'll make is that, while there are certainly some people (not many) who exclusively photograph wildlife during Blue Hour, most people are using their gear for a wider range of tasks. I shoot very little in the way of fast-moving wildlife in challenging light, so i rarely experience most of the problems you're talking about in using a TC because there's a lot more latitude for balancing aperture and shutter-speed - probably 70% of the time losing a stop or two isn't critical - and the response time to a situation is easily long enough to attach a TC. All that said, i'm familiar with the frustration of getting caught with a TC on when something fast comes hurtling toward me and my whole frame turns into a bit of board and a surfer's feet - it just doesn't happen often enough to nullify the advantages of owning one. Cheers and all the best.
Thank you for a very useful video on this topic. And presentation style I might add (to the point, with no annoying music or transitions). As a birder I often find my subjects to be far enough so that even DX cropping on my Nikon camera is not enough and I end up cropping further in postprocessing. This using a prime Z800 mm lens. I do have a 1.4 teleconverter but not enough experience to know which is better when needing to frame my subject tighter than the DX mode in the final photo: 1. Use DX mode + teleconverter or 2. Use DX and crop further in postprocessing. My feeling so far has been that #2 is better, even with plenty of available light as use of the teleconverter (Z 1.4) results in softer image. But this is just my feeling, I am yet to do an objective test comparison. Would appreciate your thoughts on this, thank you.
So with the 800mm PF I would almost always look to use without the TC. If you are working with a Z8/Z9 I would feel the route of using the DX crop is best, however if a subject is really distant, you may want use the TC in good light to ensure you still me more pixels on your subject. You'll loose some sharpness but ultimately the choice will depend on final usage. If you are aiming to print you might want a bit more resolution , where as for smaller web use, cropping might be fine for final delivery. In my experience I would go Bare lens - cropping in camera - TC. But if I had loads of light and could stop down even further once the TC was added I might use it then for the extra MP on my subject. Cheers, Tom
I've never understood why they don't make front connected teleconvertors. Many years ago I had a janky setup which consisted of a 45-175mm lumix lens that had an old bridge camera teleconvertor attached to it by means of a step up ring. This made it an almost 300mm lens BUT only lost a third of a stop of light! If only we could do this for all lenses!
Contrary to what the video says, TC's do work by increasing the combined FL, since FL and magnification are tightly related by the lens equation. The so-called 'light loss' of a TC is due to the fact that the FL is increased but the aperture (meaning size of entrance pupil - entrance pupil, meaning size of the aperture stop seen through the front of the lens) remains the same - so the f-number, FL divided by aperture, must increase. A front mounted TC puts glass in front of the lens, so can change the size of the entrance pupil as well as increasing the FL. To do so it needs to be big enough. Suppose we have a 200/2.8 - that has an aperture of 71mm. We design a 1.4x front mounted TC, that converts it to a 280/2.8. To keep the f-number the same, the aperture of the combined lens will need to be 280mm/2.8 = 100mm. So our TC will need to have a rear element size of at least 71mm and a front element greater than 100mm. It's going to be a big and expensive piece of glass. In addition, it's limited in the lenses that you can fit it onto. Then there's the economics. The expensive part of a long lens is all that glass in the front - so this TC will cost the best part of the cost of a complete lens, and you'd probably prefer the complete lens. The rear-mounted TC is small, compact and (relatively) inexpensive, so for most it's the better choice.
@BobN54 Thank you for your detailed information. I'm surprised I couldn't think of this myself but of course M43 is always quite small anyway so never considered that!
@@BobN54 Great explanation. I'd only add 2 things (the first of which is implicit in your description, but can be stated more plainly for less technical readers): 1/ A magnifying glass is still just a lens with a focal length. Thus, adding a magnifying glass into a light path _necessarily_ changes the total focal length (and, as you described, the lens can be designed to compensate for that change in focal length in order to keep the same focal ratio). 2/ TCs have multiple optical elements in multiple groups, so "magnifying glass" (by definition, a single convex lens) isn't a fair description.
@@davidg5898 Thanks for the simpler explanation - as you say, simpler for the non-technically minded. I'd just clarify that a TC isn't a 'magnifying glass', it's actually got negative optical power like a concave lens, so it lengthens the focal length. A magnifying lens converter is a so-called 'speed booster' or 'focal reducer' that you can put behind a lens to shorten the focal length and reduce the f-number to put on a camera with a smaller sensor than the lens was designed for. You can do some interesting things with those. I have a Mk 1 Sigma 50-150/2.8 which I use with a 1.4x 'speed booster' to make a compact 35-100/2 on an mFT camera.
Great video Tom! Something I’ve noticed is just how much better teleconverters are now than they were when I first got one - the Z 1.4x is just astonishing, as is the one in my 400mm TC lens.. Until the in-built TC it was always an uneasy relationship though risking dust / rain and missing action when changing over. I always felt it gave better images than cropping but that wasn’t always worth the faff!
Yes the new TCs are certainly a BIG improvement over the older models and for sure the built in ones are just another level up again! We are rather lucky these days with the new lenses coming out and I can’t wait to see more tele option in the future. I SO want a 300mm 2.8 Z TC!
Very nice explanation, with excellent reasoning behind it… I was thinking on buying a x1.4… but now I’m definitely going to wait for a better brighter lens 👍🙏
Glad it was helpful! I know so many people who have picked up extenders to find them underwhelming to then return to them later on pro glass and see where they should truly be utilised! I think at the cost they are - especially if we are talking about new Z mount versions, for most people putting that money towards top end glass is a better move!
I have a gen II TC and the 1.4 is fine however the III has a few upgrades over the II, with optic upgrade and better chromatic abrasion control, increased ergonomics and most importantly full control with FL lenses and E mount lenses, that have full electric aperture control
Since adding a Z8 i utilise the dx crop (programmed to a button) rather than using my 1.4tc on my 500mm f4. Only if i absolutely cannot get any nearer to a subject will i then use the 1.4tc or if I'm at a hide etc on a decent day light wise.
Yes, same here when it comes to my TC use, I just find the wide open lens not only creates more pleasing images but gives me more flexibility to work with the light. TC's as you say are only for when I really can't get any closer!
I had the 1.4 with my 400mm f4.5 but I just found it so much quicker and easier to drop to DX crop and then if I needed extra resolution, use Gigapixel. The TC works fine and very little IQ loss but it’s just a hassle. Been shooting like that for 6 months and zero complaints with dozens of prints sold using that method. Even at 20x30 inches
100% the hassle of the TC can very often cause you to miss images, and these days with high MP sensors often there is no need to use one! The 400mm 4.5 is a great lens and has wonderful IQ, and for sure if you’re not seeing any issues in print, then it a great way to work!
When I had my 600 F4 I had a 1.4 Tele converter for it but now I have changed system and the 500 F4 is ridiculously out of my price range will not get one for my 200 to 600 mm lens prefer to use crop mode in camera or the basic heavily cropped the image I feel that teleconverters these days are for prime lens only or they come built in
I have the 180-600mm with 1.4tc....z8.....drifted away from using tc...except for doing shore birds at low tide on a bright day...won't get the best images but not too bad
Yes, on a really bright day with loads of light the 1.4 can certainly work on a slower lens, but as a general rule, I find cropping to give a far better quality!
Yes the 1.7 TC is not a great TC and I too have always found it never hit the spot, probably why Nikon never made a Z mount one! Although you never know whats coming!
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Do you mean it is worth trying the 1.4 and the 2.0 tc with the 300 2.8 VR?
I personally don't like them.And they are a pain, and I never felt they are sharp. Great video. As you mentioned, they magnify problems that exist from the beginning. Greg
Yes they are a double edge sword one must use carefully and sparingly! I always find the images I'm drawn to on my catalogue are always those shot with the bare lenses - i tend to only use them when my hands are tied!
Thanks for the time and effort put into this video. It's a little unfortunate that the click-bait title leads into you making a mistake which really gets carried on and amplified through the video, leading to conclusions that I couldn't recommend. Your assumption seems to be that people think that a TC increases focal length when that's wrong. Sorry, it's exactly right. A 300mm lens with a 1.4x TC is indeed a 420mm lens. All you've done is add a few more elements to increase the focal length. Magnification and focal length are directly related. If you increase magnification you increase the FL, there's no way round that. On the point that you're also magnifying the lens aberrations - not necessarily, because the extra elements can actually be used to correct aberrations if the designer knows what they are, that's what was called a 'matched multiplier' and will certainly apply to built-in TC's. It's also a reason why OEM TC's can be a better bet than independents, the designers knew the characteristics of the most likely lenses to which it would be fitted. A TC is not a 'magnifying glass', it actually has negative optical power - it's what astronomers would call a 'Barlow lens'. Also, the magnification of faults only applies to the lens, not the camera, as you implied. The change in f-number has nothing to do with the amount of extra lens elements. For a few extra elements to reduce the light by a stop it would need to be smoked glass, not quality coated optical glass. Here's what's going on. The aperture of the lens (the diameter of the entrance pupil) remains the same. Putting a TC on the back of the lens can't do anything to the light going in. But the FL of the lens has been increased by the TC (yes, it really has). The f-number is the focal length divided by the aperture. So, taking your example. If you had a 300mm f/2.8 lens, that has an aperture of 107mm. (300mm/2.8). Now you put on a 1.4x TC. Now it has a FL of 420mm. The aperture is still 107mm, so now the f-number is 420mm/107mm = 4. It's now a 420mm f/4 lens. Have a thought about this. What I say explains why every single 1.4x TC results in a 1-stop rise of f-number and every single 2x results in a rise of 2-stops. For your 'extra glass' argument to work, every single 1,4x TC would need to have the same glass loss, and it would be half the glass loss of every single 2x converter. That's hardly likely, is it? There's also some confusion here about the relative effects of a TC and cropping. Apart from the one-button convenience, your 'added benefits' of cropping are illusory. You say it doesn't have any impact on the optical quality of your lenses, but of course when you view the image you'll have to enlarge the image 1.5 times more, which will magnify all the lens' faults, just like a TC does. Then you say it means the aperture of your lens doesn't drop. As above, with a TC, the aperture remains the same, the f-number 'drops' - actually increases (they are different - and this is not just pedantry, because getting them confused is causing some of the mistakes here) - but the amount of light captured in the image is 'dropping' in just the same way as it would with a TC. It means that at the same shutter speed you'll end up with just the same image noise as you would have had you used the TC and raised the ISO to compensate for the different f-number. The same goes for DOF, you'll end up with the same DOF whether you use a TC or crop. You later amplified this when you discussed using the built-in TC versus cropping when you said that cropping 'allowed you to retain a higher shutter speed'. Of course, it didn't. You could have had the same shutter speed with the TC, you'd have to have gone up a stop in ISO, but the outcome IQ-wise would have been the same - probably better because you'd have more pixels on the duck. You do need to to disabuse youself of the notion that cropping 'lets more light in that a TC. The light that makes it into the image is exactly the same. All you're 'have to have enough light' arguments fail because of this. I'm not at all sure about your argument about cropping being more suitable for low end lenses. The actual loss of resolution of a good TC is minimal, most of the resolution loss is due to enlargement. You still get that enlargement loss with cropping, and in addition you get resolution reduction due to reduced pixel count. I've done experiments on TC versus cropping on quite a few lenses and cameras, and cropping tends to win if you have a high-pixel count sensor, the TC is better if it's lower - even with lower end lenses. So I can't agree with your buying advice, TC's can be useful even for people with 'prosumer' lenses.
I'm more than happy to "agree to disagree" as with years of testing on some of the best and prosumer lenses, I know from experience that adding TC's almost always leads to a reduction in quality of the final image. The amplification of lens flaws is easily visible and I think you largely miss my points about light... When I'm talking about a loss in light, I'm talking about the "workable aperture" for the cameras and how adding the TC's drop this. When attached you are no longer able to work wide open, restricting your ability to effectively retain shutter speeds when necessary - and this is independent of ISO because I doubt anyone would be daft enough to keep TC's on when the light really drops and your jacking up the ISO, as the AF would already be suffering. Adding a TC does remove a stop of light "Functionally" - this largely has a greater effect when we are talking about smaller apertures as this is where lens systems really start to take their toll on AF. When it comes to cropping this is also a key principle you seem to miss, as the effect of a 1.4 TC V a 1.5 crop gives the same rough "focal length equivalent" however on the cropping method you are still able to shoot wide open, aiding both shutter speed and AF functionality!
@@TomMasonPhoto I'm not happy agreeing to disagree when it's matters of fact that are at stake. Your opening line, that a TC doesn't change the FL is simply wrong, according to optics. Of course, it does. So that, at least needs to be corrected. I'm missing nothing about working 'wide open'. Of course when you add a teleconverter you're still working 'wide open', it's just a higher f-number because the focal length is longer. The light coming into the lens is just the same, you're just getting less of it on the sensor because the angle of view has been reduced. In fact, you're getting exactly the same light as if you had selected the same part of the image by cropping. So, what' going to determine your shutter speed? The image quality (i.e. amount of noise you're going to get) you end up with. Noise mostly depends on amount of light energy collected, which is the same - so the noise will be the same - except that for most cameras the electronic (read) noise, which is the rest of the noise, reduces a bit at higher iSOs, so in the end the version with the ISO raised to allow the same shatter speed at the higher f-number might be a bit better. You have a point about AF, that does depend to an extent on sensor illuminance, and therefore f-number. However, that's to an extent, going from f/2.8 to f/4 won't make a load of difference with most modern cameras unless the light is very low, and of course if you use the full frame you'll get more AFD points available. Swings and roundabouts, I'd say. But AF is the only real advantage in terms of light that cropping has over taking the hit in f-number and raising the ISO as needed. To get this requires knowing about ISO and noise and what causes it - a hint, ISO is not what you think it is. The other fact that you got wrong is suggesting that the so-called 'light-loss' of TCs is due to glass loss. Simply not true. Opinions we can differ on, but you need to get the facts right.
@ I’m sorry but the teleconverter does not change the physical focal length of the original lens. It increases the magnification factor to provide the same view as the new lens mm stated when added. This additional glass reduces the light transmission from the original lens to the camera and also magnifies unfavourable lens characteristics, such as chromatic aberrations and a lack of true sharpness. The loss of light transmission and reduction in the cameras ability to retain a wide open aperture has effects on the available options for exposure and reduces the available light for AF. This is far more of a problem in consumer lenses where sharpness is already not perfect and apertures are already not largely wide f6.3 for example. These are the points I’m making. Yes raising ISO can help combat the issue of shutter speed however won’t do anything to improve the lens IQ that’s being reduced from the TC. ISO is simple sensor gain and doesn’t have any effect on actual light coming into the system. The loss off aperture then does have rather large implication for lower tier lenses - rather the main point in making here!
@@TomMasonPhoto Sure it doesn't change the focal length of the original lens, but the two together make a lens with a longer focal length. A 200mm with a 1.4x TC is physically a 280mm lens, it's just that the back part is demountable. The 'magnification factor' is achieved by means of lengthening the focal length. The amount of light transmission lost due to the TC is minimal. Think of it, a properly coated lens element has a transmission north of 99%.A Nikon Z 2x TC has 8 elements (in 5 groups) even if each one causes a 1% light loss that's a total light transmission of 92% or about 1/10th of a stop loss. Not worth worrying about. On the question of quality reduction caused by the TC verses the quality reduction of reducing the pixel count by cropping - which one wins depends on quite e few factors. Firstly the extra aberrations caused by a good TC are pretty small, and by a bad one quite a bit. As I said, a TC can sometimes even reduce aberrations. A negative element at the back of the lens (which is what a TC is) tends to act as a field flattener, so if the host lens has a bit of field curvature (as do many cheaper lenses) then the TC might help it a bit in this respect. On the other hand, if it has a flat field (as do better lenses) a TC might make it a bit worse. It depends very much on the TC and the lens. You really have to test out each combination rather than making generalisations. On the other hand reducing pixel count always reduces quality. So which is best varies from case to case. I once did a series of experiments comparing an APS-C lens (actually a Sigma consumer zoom) mounted on a Canon EOS 650 (8MP) versus it mounted on a 5D (13MP) both native and used cropped or with a good 1.4x TC, which allowed it to cover the full frame. The worst result was the cropped 5D, the best was the 5D full frame with TC. It went with pixel count. I would expect the difference to be less pronounced with higher pixel counts, because you're getting to sensor resolutions where the lenses aren't rendering a high MTF, but I still don't see a general rule there. I think that the relative degradation of a TC on a 'consumer lens' is liable to be smaller than that of one on a high grade lens, since the aberrations of the TC will be swamped by those of the cheaper lens, so in that case the pixel advantage might well be the determining factor. It depends. ISO isn't 'sensor gain' (I said it wasn't what you thought it was). That's another common misconception that gets bandied around the internet. I have the ISO standard and know it in detail, and it doesn't define changes in gain. However variable voltage gain is used in most cameras and its effect is to reduce the amount of electronic (read) noise added as the ISO is increased. That's why it's there, trading highlight capability for shadow noise when you're in low light. The point is that the predominant noise is what is called photon shot noise, which depends on how many photons are captured in the image. Think of it as pointillism, where an image is built up of random dots. The more dots you have the smoother the image will look. In the end the amount of light (as in number of photons) is identical for a photo taken with a TC and one taken with the original lens and cropped (at the same shutter speed), so both will be equally noisy and have the same IQ - except that the one with the higher ISO might have slightly less shadow noise due to the effect mentioned above. That depends on the camera. You have a point about AF, but modern AF systems (particularly Nikon) work in crazy low light, so I'm not sure how critical that would be. Just as a last point, I mentioned that aperture/f-number confusion can sometimes cause conceptualisation problems. You say that problems can be caused when 'apertures are already not largely wide f6.3 for example.' So lets take a 300mm f/6.3 lens. Its aperture is 47.6mm. You put a 1.4x TC on the back. The aperture is still 47.6mm, putting a TC on the back doesn't change it. The f-number however is now larger, at f/9 due to teh FL being increased. But it's still as 'wide' because it's still the same width. You can only say that an f-number is 'wider' if the focal length is the same. More importantly, since the hole collecting the light from the scene is the same, the amount of light collected from the scene will be the same. It doesn't matter whether the framing is achieved by cropping or putting a TC on the back.
YT won't let me add the Canon URL, but it is essentially speaking in similar terms to the Nikon page: "Extenders are a relatively cheap and convenient way of enhancing your telephoto capability. But using them to increase focal length comes at a cost − reduced maximum aperture. The 1.4x Extender causes a decrease of one stop in the maximum aperture of the lens, while the 2x Extender causes a loss of two stops. This means you gain extra focal length at the expense of losing some light. If you attach a 1.4x Extender to an EF 70-200mm f/2.8L IS III USM lens, for example, it will become in effect a 98-280mm f/4 lens".
The thing I don't understand (and maybe its a physics problem), is why camera companies don't build the "switch" to turn a TC on and off the way you can on a 400 2.8 and 600 2.8 into the normal TCs? Also, the big thing I always like to remind people of in regards to TCs is that this is where having a lens that outresolves your sensor becomes important. If you compare say the 180-600 to the 600 prime both look roughly the same sharpness because both are resolving above the resolution of the sensor. However, the zoom is just "barely" outresolving the sensor, while the prime has much higher resolving power. Thus when you magnify the image from the zoom, you hit the zoom's limit and image quality drops off hard while with the prime, it is still handling the magnification just fine. Its kinda like if you compare a Lambo to an F-150 on a road with an 80kmph max. Both seems to perform similarly but if you move them both to the autobahn the Lambo leaves the F-150 in the dust. Finally one small pro tip, is that for a fraction of the price of a TC on a modern camera that costs like $550usd, you could just buy Topaz Gigapixel AI which in many cases will yield better results simply upscaling your image than the TC would have doing it optically.
I’ve always wanted a 1.4 TC that has the switch! So you can add it to any lens and have the option of the TC going in or out! It would be amazing to have it, with multiple tc options - like a 1.4 + 1.7 TC you could scroll through!! And yes to your comment about high end lenses offering better resolving power to start, the magnification of this aspect is key when thinking about TC’s!
@@TomMasonPhoto The only reason I can think of why they don't do it is because either the physics make it impossible for a TC that needs to play nice with any lens OR they believe we should need to buy flagship tier exotics to access this sort of convenience.
It has to do with how an integrated TC works. The light path is designed so that they can put the TC in the middle of the lens body, where the light path is narrowest, allowing them to use narrower diameter lenses for the TC. The switch physically moves the narrow TC assembly entirely out of the light path. An add-on rear-mounted TC can't be made to function that way for 2 reasons: 1/ If you slide the TC lenses out of the light path, you're still left with an extension tube that isn't returning your lens to its original specs -- not to mention that not all lenses play well with extension tubes. 2/ An assembly that slides the TC lenses out of the way and leaves it as an extension tube _could_ be manufactured but it would be 1.5x-2x as wide as a normal TC because the optics have to slide somewhere. And because add-on TCs are mounted outside of the original lens, the glass necessarily has to be at least as large as the original lens' back glass.
@ he’s having spoken to some of the Nikon engineers about this I know it’s sadly something we won’t see! The extension tube problem is a key thing as you then lack the ability to focus at infinity!
I am a Sony shooter and have up until this year was never happy with the results with teleconverters. No good on the 200-600 zoom, and even on the 400 and 600 primes I was not enthusiastic with the results, only using if absolutely necessary. Then this year Sony brought out the 300 F2.8 GM. I think that lens has the best glass of all Sony lenses and seems to have been optimised for use with the 1.4x and 2x teleconverters. I now use teleconverters daily on that lens with superb results, taking out the 300 +2x in preference to the 600. I really cannot see loss of quality even pixel peeping, and at half the weight it is so much more pleasurable and easy to use. My attitude to teleconverters has entirely changed, I now consider I have a 300 F2.8, 420 F4 or 600 F5.6 prime lens all in one.
For sure the new 300mm 2.8 GM looks a lovely lens, I'm really looking forward to a new Nikon Z 300mm, would be a dream for me! The newer high end optics certainly shine more with TC's more than optics of past generations and especially more consumer glass! so glad you've got a set-up you love!
I am a Sony shooter and have up until this year was never happy with the results with teleconverters. No good on the 200-600 zoom, and even on the 400 and 600 primes I was not enthusiastic with the results, only using if absolutely necessary. Then this year Sony brought out the 300 F2.8 GM. I think that lens has the best glass of all Sony lenses and seems to have been optimised for use with the 1.4x and 2x teleconverters. I now use teleconverters daily on that lens with superb results, taking out the 300 +2x in preference to the 600. I really cannot see loss of quality even pixel peeping, and at half the weight it is so much more pleasurable and easy to use. My attitude to teleconverters has entirely changed, I now consider I have a 300 F2.8, 420 F4 or 600 F5.6 prime lens all in one.
Really worthwhile content Tom & made a lot of sense - thank you for your thoughts👌
Glad you enjoyed it!
Great to see that you start posting more videos! 👍
More to come! I’m going to try keep them on the regular!
Hi Tom,great video I have been considering the 1.4 for my 180-600 but have been resorting to dx recently and now that I have the z8 I have the megapixels to play with so I have put the purchase on hold your video was great timing as o have found the images taken in dx mode have been quite sufficient ,keep up the ok the good work glad to see more videos coming out cheers John
Yes, absolutely, glad the timing worked out! Yes the 180-600 is a great pairing with the Z8 and a 1.4 would be OK, but if the DX mode gives you enough reach, I’d stick to that!
I find TCs immensely useful and i don't hesitate to use them on any of my lenses. Some caveats: 2x i only use on my best glass, for the reasons you mention, and even then not very often. The 1.4 goes fine anytime on my fast glass and on my second-tier glass (which i only really carry if i need to save weight). I think that what you are referring to as 'Prosumer' is usually good enough optically for 1.4s. I also think it's important also to consider that the vast majority of photographers are not waiting to upgrade to Pro telephotos - it's not in the budgetary equation. A 1.4 for these people provides them with great flexibility while saving them, quite literally, many thousands of pounds in upgrades. Another point i'll make is that, while there are certainly some people (not many) who exclusively photograph wildlife during Blue Hour, most people are using their gear for a wider range of tasks. I shoot very little in the way of fast-moving wildlife in challenging light, so i rarely experience most of the problems you're talking about in using a TC because there's a lot more latitude for balancing aperture and shutter-speed - probably 70% of the time losing a stop or two isn't critical - and the response time to a situation is easily long enough to attach a TC. All that said, i'm familiar with the frustration of getting caught with a TC on when something fast comes hurtling toward me and my whole frame turns into a bit of board and a surfer's feet - it just doesn't happen often enough to nullify the advantages of owning one. Cheers and all the best.
I appreciate the point you keep stressing in this video: don't expect great results from a TC unless you're starting with a great lens.
Yes. 100%. Hopefully I get that home 😂
Thank you for a very useful video on this topic. And presentation style I might add (to the point, with no annoying music or transitions).
As a birder I often find my subjects to be far enough so that even DX cropping on my Nikon camera is not enough and I end up cropping further in postprocessing.
This using a prime Z800 mm lens.
I do have a 1.4 teleconverter but not enough experience to know which is better when needing to frame my subject tighter than the DX mode in the final photo:
1. Use DX mode + teleconverter or
2. Use DX and crop further in postprocessing.
My feeling so far has been that #2 is better, even with plenty of available light as use of the teleconverter (Z 1.4) results in softer image.
But this is just my feeling, I am yet to do an objective test comparison.
Would appreciate your thoughts on this, thank you.
So with the 800mm PF I would almost always look to use without the TC.
If you are working with a Z8/Z9 I would feel the route of using the DX crop is best, however if a subject is really distant, you may want use the TC in good light to ensure you still me more pixels on your subject. You'll loose some sharpness but ultimately the choice will depend on final usage. If you are aiming to print you might want a bit more resolution , where as for smaller web use, cropping might be fine for final delivery.
In my experience I would go Bare lens - cropping in camera - TC. But if I had loads of light and could stop down even further once the TC was added I might use it then for the extra MP on my subject. Cheers, Tom
I've never understood why they don't make front connected teleconvertors. Many years ago I had a janky setup which consisted of a 45-175mm lumix lens that had an old bridge camera teleconvertor attached to it by means of a step up ring. This made it an almost 300mm lens BUT only lost a third of a stop of light! If only we could do this for all lenses!
Contrary to what the video says, TC's do work by increasing the combined FL, since FL and magnification are tightly related by the lens equation. The so-called 'light loss' of a TC is due to the fact that the FL is increased but the aperture (meaning size of entrance pupil - entrance pupil, meaning size of the aperture stop seen through the front of the lens) remains the same - so the f-number, FL divided by aperture, must increase. A front mounted TC puts glass in front of the lens, so can change the size of the entrance pupil as well as increasing the FL. To do so it needs to be big enough. Suppose we have a 200/2.8 - that has an aperture of 71mm. We design a 1.4x front mounted TC, that converts it to a 280/2.8. To keep the f-number the same, the aperture of the combined lens will need to be 280mm/2.8 = 100mm. So our TC will need to have a rear element size of at least 71mm and a front element greater than 100mm. It's going to be a big and expensive piece of glass. In addition, it's limited in the lenses that you can fit it onto. Then there's the economics. The expensive part of a long lens is all that glass in the front - so this TC will cost the best part of the cost of a complete lens, and you'd probably prefer the complete lens. The rear-mounted TC is small, compact and (relatively) inexpensive, so for most it's the better choice.
@BobN54 Thank you for your detailed information. I'm surprised I couldn't think of this myself but of course M43 is always quite small anyway so never considered that!
@@BobN54 Great explanation. I'd only add 2 things (the first of which is implicit in your description, but can be stated more plainly for less technical readers):
1/ A magnifying glass is still just a lens with a focal length. Thus, adding a magnifying glass into a light path _necessarily_ changes the total focal length (and, as you described, the lens can be designed to compensate for that change in focal length in order to keep the same focal ratio).
2/ TCs have multiple optical elements in multiple groups, so "magnifying glass" (by definition, a single convex lens) isn't a fair description.
@@davidg5898 Thanks for the simpler explanation - as you say, simpler for the non-technically minded. I'd just clarify that a TC isn't a 'magnifying glass', it's actually got negative optical power like a concave lens, so it lengthens the focal length. A magnifying lens converter is a so-called 'speed booster' or 'focal reducer' that you can put behind a lens to shorten the focal length and reduce the f-number to put on a camera with a smaller sensor than the lens was designed for. You can do some interesting things with those. I have a Mk 1 Sigma 50-150/2.8 which I use with a 1.4x 'speed booster' to make a compact 35-100/2 on an mFT camera.
@@BobN54 Good point re: focal extender vs. reducer!
I also use a speedbooster with EF mount lenses on my MFT.
Great video Tom! Something I’ve noticed is just how much better teleconverters are now than they were when I first got one - the Z 1.4x is just astonishing, as is the one in my 400mm TC lens.. Until the in-built TC it was always an uneasy relationship though risking dust / rain and missing action when changing over. I always felt it gave better images than cropping but that wasn’t always worth the faff!
Yes the new TCs are certainly a BIG improvement over the older models and for sure the built in ones are just another level up again! We are rather lucky these days with the new lenses coming out and I can’t wait to see more tele option in the future. I SO want a 300mm 2.8 Z TC!
@@TomMasonPhotoyeah, that would be very nice, especially if it was lightweight..!
@ yes indeed that would be my dream combo!
Very nice explanation, with excellent reasoning behind it… I was thinking on buying a x1.4… but now I’m definitely going to wait for a better brighter lens 👍🙏
Glad it was helpful! I know so many people who have picked up extenders to find them underwhelming to then return to them later on pro glass and see where they should truly be utilised! I think at the cost they are - especially if we are talking about new Z mount versions, for most people putting that money towards top end glass is a better move!
Can you explain why everyon‘s recommendation is to only use gen. III teleconverters and not I and II?
I have a gen II TC and the 1.4 is fine however the III has a few upgrades over the II, with optic upgrade and better chromatic abrasion control, increased ergonomics and most importantly full control with FL lenses and E mount lenses, that have full electric aperture control
@
Thank you.
Great explanation 👌
Thank you 🙂
10/10, no brainer!
Cheers!
Since adding a Z8 i utilise the dx crop (programmed to a button) rather than using my 1.4tc on my 500mm f4. Only if i absolutely cannot get any nearer to a subject will i then use the 1.4tc or if I'm at a hide etc on a decent day light wise.
Yes, same here when it comes to my TC use, I just find the wide open lens not only creates more pleasing images but gives me more flexibility to work with the light. TC's as you say are only for when I really can't get any closer!
Have my ftz adapter Mark ii plus f mount lenses as i don't have z mount lenses
Has someone experience with a Nikkor 500mm F4/G and a 1.4 TC III and can tell something about it?
I had the 1.4 with my 400mm f4.5 but I just found it so much quicker and easier to drop to DX crop and then if I needed extra resolution, use Gigapixel.
The TC works fine and very little IQ loss but it’s just a hassle. Been shooting like that for 6 months and zero complaints with dozens of prints sold using that method. Even at 20x30 inches
100% the hassle of the TC can very often cause you to miss images, and these days with high MP sensors often there is no need to use one! The 400mm 4.5 is a great lens and has wonderful IQ, and for sure if you’re not seeing any issues in print, then it a great way to work!
Teleconversters are not weapons of choice, but a great option to make a backpack lighter. I enjoy DX + TC17 + 70-200 lens. It doest make sense. ✌️
When I had my 600 F4 I had a 1.4 Tele converter for it but now I have changed system and the 500 F4 is ridiculously out of my price range will not get one for my 200 to 600 mm lens prefer to use crop mode in camera or the basic heavily cropped the image I feel that teleconverters these days are for prime lens only or they come built in
Yes I agree that TC's are best left for prime lenses, especially the built in types as they are co-designed to really make the best of the image!
I have the 180-600mm with 1.4tc....z8.....drifted away from using tc...except for doing shore birds at low tide on a bright day...won't get the best images but not too bad
Yes, on a really bright day with loads of light the 1.4 can certainly work on a slower lens, but as a general rule, I find cropping to give a far better quality!
2X works fine on my 300 GM...
Yes I know the new GM has some updated optics - I’m hoping to see a Z 300mm!
I’ve tried the 1.7 Tc with my 300 2.8 VR, unfortunately it degrades the image too much.
Yes the 1.7 TC is not a great TC and I too have always found it never hit the spot, probably why Nikon never made a Z mount one! Although you never know whats coming!
Do you mean it is worth trying the 1.4 and the 2.0 tc with the 300 2.8 VR?
To say it short:
- you better need an exceptional good lens to use TCs at all
- 1.4x is OK, 2x I will not use any more
That's the one!
extenders gie you more pixels for the subject on the sensor, this is not the case with crop where you remove pixels.
I personally don't like them.And they are a pain, and I never felt they are sharp. Great video. As you mentioned, they magnify problems that exist from the beginning. Greg
Yes they are a double edge sword one must use carefully and sparingly! I always find the images I'm drawn to on my catalogue are always those shot with the bare lenses - i tend to only use them when my hands are tied!
That's the kick up the backside I needed to convince me not to buy one, thanks again.
No worries!
Thanks for the time and effort put into this video. It's a little unfortunate that the click-bait title leads into you making a mistake which really gets carried on and amplified through the video, leading to conclusions that I couldn't recommend. Your assumption seems to be that people think that a TC increases focal length when that's wrong. Sorry, it's exactly right.
A 300mm lens with a 1.4x TC is indeed a 420mm lens. All you've done is add a few more elements to increase the focal length. Magnification and focal length are directly related. If you increase magnification you increase the FL, there's no way round that. On the point that you're also magnifying the lens aberrations - not necessarily, because the extra elements can actually be used to correct aberrations if the designer knows what they are, that's what was called a 'matched multiplier' and will certainly apply to built-in TC's. It's also a reason why OEM TC's can be a better bet than independents, the designers knew the characteristics of the most likely lenses to which it would be fitted. A TC is not a 'magnifying glass', it actually has negative optical power - it's what astronomers would call a 'Barlow lens'. Also, the magnification of faults only applies to the lens, not the camera, as you implied. The change in f-number has nothing to do with the amount of extra lens elements. For a few extra elements to reduce the light by a stop it would need to be smoked glass, not quality coated optical glass. Here's what's going on. The aperture of the lens (the diameter of the entrance pupil) remains the same. Putting a TC on the back of the lens can't do anything to the light going in. But the FL of the lens has been increased by the TC (yes, it really has). The f-number is the focal length divided by the aperture. So, taking your example. If you had a 300mm f/2.8 lens, that has an aperture of 107mm. (300mm/2.8). Now you put on a 1.4x TC. Now it has a FL of 420mm. The aperture is still 107mm, so now the f-number is 420mm/107mm = 4. It's now a 420mm f/4 lens. Have a thought about this. What I say explains why every single 1.4x TC results in a 1-stop rise of f-number and every single 2x results in a rise of 2-stops. For your 'extra glass' argument to work, every single 1,4x TC would need to have the same glass loss, and it would be half the glass loss of every single 2x converter. That's hardly likely, is it?
There's also some confusion here about the relative effects of a TC and cropping. Apart from the one-button convenience, your 'added benefits' of cropping are illusory. You say it doesn't have any impact on the optical quality of your lenses, but of course when you view the image you'll have to enlarge the image 1.5 times more, which will magnify all the lens' faults, just like a TC does. Then you say it means the aperture of your lens doesn't drop. As above, with a TC, the aperture remains the same, the f-number 'drops' - actually increases (they are different - and this is not just pedantry, because getting them confused is causing some of the mistakes here) - but the amount of light captured in the image is 'dropping' in just the same way as it would with a TC. It means that at the same shutter speed you'll end up with just the same image noise as you would have had you used the TC and raised the ISO to compensate for the different f-number. The same goes for DOF, you'll end up with the same DOF whether you use a TC or crop. You later amplified this when you discussed using the built-in TC versus cropping when you said that cropping 'allowed you to retain a higher shutter speed'. Of course, it didn't. You could have had the same shutter speed with the TC, you'd have to have gone up a stop in ISO, but the outcome IQ-wise would have been the same - probably better because you'd have more pixels on the duck. You do need to to disabuse youself of the notion that cropping 'lets more light in that a TC. The light that makes it into the image is exactly the same. All you're 'have to have enough light' arguments fail because of this.
I'm not at all sure about your argument about cropping being more suitable for low end lenses. The actual loss of resolution of a good TC is minimal, most of the resolution loss is due to enlargement. You still get that enlargement loss with cropping, and in addition you get resolution reduction due to reduced pixel count. I've done experiments on TC versus cropping on quite a few lenses and cameras, and cropping tends to win if you have a high-pixel count sensor, the TC is better if it's lower - even with lower end lenses. So I can't agree with your buying advice, TC's can be useful even for people with 'prosumer' lenses.
I'm more than happy to "agree to disagree" as with years of testing on some of the best and prosumer lenses, I know from experience that adding TC's almost always leads to a reduction in quality of the final image. The amplification of lens flaws is easily visible and I think you largely miss my points about light...
When I'm talking about a loss in light, I'm talking about the "workable aperture" for the cameras and how adding the TC's drop this. When attached you are no longer able to work wide open, restricting your ability to effectively retain shutter speeds when necessary - and this is independent of ISO because I doubt anyone would be daft enough to keep TC's on when the light really drops and your jacking up the ISO, as the AF would already be suffering. Adding a TC does remove a stop of light "Functionally" - this largely has a greater effect when we are talking about smaller apertures as this is where lens systems really start to take their toll on AF. When it comes to cropping this is also a key principle you seem to miss, as the effect of a 1.4 TC V a 1.5 crop gives the same rough "focal length equivalent" however on the cropping method you are still able to shoot wide open, aiding both shutter speed and AF functionality!
@@TomMasonPhoto I'm not happy agreeing to disagree when it's matters of fact that are at stake. Your opening line, that a TC doesn't change the FL is simply wrong, according to optics. Of course, it does. So that, at least needs to be corrected. I'm missing nothing about working 'wide open'. Of course when you add a teleconverter you're still working 'wide open', it's just a higher f-number because the focal length is longer. The light coming into the lens is just the same, you're just getting less of it on the sensor because the angle of view has been reduced. In fact, you're getting exactly the same light as if you had selected the same part of the image by cropping. So, what' going to determine your shutter speed? The image quality (i.e. amount of noise you're going to get) you end up with. Noise mostly depends on amount of light energy collected, which is the same - so the noise will be the same - except that for most cameras the electronic (read) noise, which is the rest of the noise, reduces a bit at higher iSOs, so in the end the version with the ISO raised to allow the same shatter speed at the higher f-number might be a bit better.
You have a point about AF, that does depend to an extent on sensor illuminance, and therefore f-number. However, that's to an extent, going from f/2.8 to f/4 won't make a load of difference with most modern cameras unless the light is very low, and of course if you use the full frame you'll get more AFD points available. Swings and roundabouts, I'd say. But AF is the only real advantage in terms of light that cropping has over taking the hit in f-number and raising the ISO as needed. To get this requires knowing about ISO and noise and what causes it - a hint, ISO is not what you think it is.
The other fact that you got wrong is suggesting that the so-called 'light-loss' of TCs is due to glass loss. Simply not true.
Opinions we can differ on, but you need to get the facts right.
@ I’m sorry but the teleconverter does not change the physical focal length of the original lens. It increases the magnification factor to provide the same view as the new lens mm stated when added. This additional glass reduces the light transmission from the original lens to the camera and also magnifies unfavourable lens characteristics, such as chromatic aberrations and a lack of true sharpness. The loss of light transmission and reduction in the cameras ability to retain a wide open aperture has effects on the available options for exposure and reduces the available light for AF. This is far more of a problem in consumer lenses where sharpness is already not perfect and apertures are already not largely wide f6.3 for example. These are the points I’m making. Yes raising ISO can help combat the issue of shutter speed however won’t do anything to improve the lens IQ that’s being reduced from the TC. ISO is simple sensor gain and doesn’t have any effect on actual light coming into the system. The loss off aperture then does have rather large implication for lower tier lenses - rather the main point in making here!
@@TomMasonPhoto Sure it doesn't change the focal length of the original lens, but the two together make a lens with a longer focal length. A 200mm with a 1.4x TC is physically a 280mm lens, it's just that the back part is demountable. The 'magnification factor' is achieved by means of lengthening the focal length. The amount of light transmission lost due to the TC is minimal. Think of it, a properly coated lens element has a transmission north of 99%.A Nikon Z 2x TC has 8 elements (in 5 groups) even if each one causes a 1% light loss that's a total light transmission of 92% or about 1/10th of a stop loss. Not worth worrying about.
On the question of quality reduction caused by the TC verses the quality reduction of reducing the pixel count by cropping - which one wins depends on quite e few factors. Firstly the extra aberrations caused by a good TC are pretty small, and by a bad one quite a bit. As I said, a TC can sometimes even reduce aberrations. A negative element at the back of the lens (which is what a TC is) tends to act as a field flattener, so if the host lens has a bit of field curvature (as do many cheaper lenses) then the TC might help it a bit in this respect. On the other hand, if it has a flat field (as do better lenses) a TC might make it a bit worse. It depends very much on the TC and the lens. You really have to test out each combination rather than making generalisations. On the other hand reducing pixel count always reduces quality. So which is best varies from case to case. I once did a series of experiments comparing an APS-C lens (actually a Sigma consumer zoom) mounted on a Canon EOS 650 (8MP) versus it mounted on a 5D (13MP) both native and used cropped or with a good 1.4x TC, which allowed it to cover the full frame. The worst result was the cropped 5D, the best was the 5D full frame with TC. It went with pixel count. I would expect the difference to be less pronounced with higher pixel counts, because you're getting to sensor resolutions where the lenses aren't rendering a high MTF, but I still don't see a general rule there. I think that the relative degradation of a TC on a 'consumer lens' is liable to be smaller than that of one on a high grade lens, since the aberrations of the TC will be swamped by those of the cheaper lens, so in that case the pixel advantage might well be the determining factor. It depends.
ISO isn't 'sensor gain' (I said it wasn't what you thought it was). That's another common misconception that gets bandied around the internet. I have the ISO standard and know it in detail, and it doesn't define changes in gain. However variable voltage gain is used in most cameras and its effect is to reduce the amount of electronic (read) noise added as the ISO is increased. That's why it's there, trading highlight capability for shadow noise when you're in low light. The point is that the predominant noise is what is called photon shot noise, which depends on how many photons are captured in the image. Think of it as pointillism, where an image is built up of random dots. The more dots you have the smoother the image will look. In the end the amount of light (as in number of photons) is identical for a photo taken with a TC and one taken with the original lens and cropped (at the same shutter speed), so both will be equally noisy and have the same IQ - except that the one with the higher ISO might have slightly less shadow noise due to the effect mentioned above. That depends on the camera.
You have a point about AF, but modern AF systems (particularly Nikon) work in crazy low light, so I'm not sure how critical that would be.
Just as a last point, I mentioned that aperture/f-number confusion can sometimes cause conceptualisation problems. You say that problems can be caused when 'apertures are already not largely wide f6.3 for example.' So lets take a 300mm f/6.3 lens. Its aperture is 47.6mm. You put a 1.4x TC on the back. The aperture is still 47.6mm, putting a TC on the back doesn't change it. The f-number however is now larger, at f/9 due to teh FL being increased. But it's still as 'wide' because it's still the same width. You can only say that an f-number is 'wider' if the focal length is the same. More importantly, since the hole collecting the light from the scene is the same, the amount of light collected from the scene will be the same. It doesn't matter whether the framing is achieved by cropping or putting a TC on the back.
YT won't let me add the Canon URL, but it is essentially speaking in similar terms to the Nikon page: "Extenders are a relatively cheap and convenient way of enhancing your telephoto capability. But using them to increase focal length comes at a cost − reduced maximum aperture. The 1.4x Extender causes a decrease of one stop in the maximum aperture of the lens, while the 2x Extender causes a loss of two stops. This means you gain extra focal length at the expense of losing some light. If you attach a 1.4x Extender to an EF 70-200mm f/2.8L IS III USM lens, for example, it will become in effect a 98-280mm f/4 lens".
The thing I don't understand (and maybe its a physics problem), is why camera companies don't build the "switch" to turn a TC on and off the way you can on a 400 2.8 and 600 2.8 into the normal TCs?
Also, the big thing I always like to remind people of in regards to TCs is that this is where having a lens that outresolves your sensor becomes important. If you compare say the 180-600 to the 600 prime both look roughly the same sharpness because both are resolving above the resolution of the sensor. However, the zoom is just "barely" outresolving the sensor, while the prime has much higher resolving power. Thus when you magnify the image from the zoom, you hit the zoom's limit and image quality drops off hard while with the prime, it is still handling the magnification just fine. Its kinda like if you compare a Lambo to an F-150 on a road with an 80kmph max. Both seems to perform similarly but if you move them both to the autobahn the Lambo leaves the F-150 in the dust.
Finally one small pro tip, is that for a fraction of the price of a TC on a modern camera that costs like $550usd, you could just buy Topaz Gigapixel AI which in many cases will yield better results simply upscaling your image than the TC would have doing it optically.
I’ve always wanted a 1.4 TC that has the switch! So you can add it to any lens and have the option of the TC going in or out! It would be amazing to have it, with multiple tc options - like a 1.4 + 1.7 TC you could scroll through!!
And yes to your comment about high end lenses offering better resolving power to start, the magnification of this aspect is key when thinking about TC’s!
@@TomMasonPhoto The only reason I can think of why they don't do it is because either the physics make it impossible for a TC that needs to play nice with any lens OR they believe we should need to buy flagship tier exotics to access this sort of convenience.
It has to do with how an integrated TC works. The light path is designed so that they can put the TC in the middle of the lens body, where the light path is narrowest, allowing them to use narrower diameter lenses for the TC. The switch physically moves the narrow TC assembly entirely out of the light path.
An add-on rear-mounted TC can't be made to function that way for 2 reasons:
1/ If you slide the TC lenses out of the light path, you're still left with an extension tube that isn't returning your lens to its original specs -- not to mention that not all lenses play well with extension tubes.
2/ An assembly that slides the TC lenses out of the way and leaves it as an extension tube _could_ be manufactured but it would be 1.5x-2x as wide as a normal TC because the optics have to slide somewhere. And because add-on TCs are mounted outside of the original lens, the glass necessarily has to be at least as large as the original lens' back glass.
@ he’s having spoken to some of the Nikon engineers about this I know it’s sadly something we won’t see! The extension tube problem is a key thing as you then lack the ability to focus at infinity!
I am a Sony shooter and have up until this year was never happy with the results with teleconverters. No good on the 200-600 zoom, and even on the 400 and 600 primes I was not enthusiastic with the results, only using if absolutely necessary. Then this year Sony brought out the 300 F2.8 GM. I think that lens has the best glass of all Sony lenses and seems to have been optimised for use with the 1.4x and 2x teleconverters. I now use teleconverters daily on that lens with superb results, taking out the 300 +2x in preference to the 600. I really cannot see loss of quality even pixel peeping, and at half the weight it is so much more pleasurable and easy to use. My attitude to teleconverters has entirely changed, I now consider I have a 300 F2.8, 420 F4 or 600 F5.6 prime lens all in one.
For sure the new 300mm 2.8 GM looks a lovely lens, I'm really looking forward to a new Nikon Z 300mm, would be a dream for me! The newer high end optics certainly shine more with TC's more than optics of past generations and especially more consumer glass! so glad you've got a set-up you love!