"Infinity Focus" and Fixing a Rokinon 135 f/2
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- Опубліковано 4 лис 2021
- What exactly is "Infinity Focus" and what are the potential problems with a hard stop for infinity on a lens? This video also addresses how to modify a Rokinon 135mm f/2 camera lens if you are having trouble reaching infinity focus on the stars.
Screwdriver set: amzn.to/2YfTTjc
Magnetic Project Mat: amzn.to/3wk7ZwQ
Camera Modifications: www.astrogear.net/?ref=nebula...
Week 24 of appreciating Five Minute Fridays
Just completed my surgery on my brand new Rokinon 135mm F2 to fix the focus and it worked great. I now have a perfect focus range for astrophotography.
Just tried it out on a Rokinon I had given up on and it worked like a charm! Thanks so much for this and all your other super helpful videos.
Thank you Nico. Did the surgery today and it works lika a charm 🤩🙏
Good morning.
Watched your video and followed it to the letter.
Fixed my lens focus problem a treat!
Thanks very much!!
Thanks, Nico. I have the same lens but have not had an infinity focus issue yet. Great video in case I need to fix.
Thanks for showing how to fix the infinity point. Appreciated!
Brilliant, that worked a treat. Many thanks for a clear and concise set of instructions 👍
Another short and excellent video Nico!!
Thank you very very much Nico!. I've a Samyang 8mm f3.5 lens that has some infinity focus problems. I was even trying to sand the mount piece to reduce the distance for that lens to achieve a better focus, but, in the end, after watching this video, fount that the 8mm lens has the same screws for adjusting!
This will make that lens interesting to me again. Thanks!
No more problem after removing the hard stop. Very easy Thank you so much. Dominique
Very informative video as always Nico! I actually went the opposite route and adjusted the sensor on my Rebel T3 to its maximum forward adjustment, which overcame the focus issue. That route was NOT easy and takes a lot of patience due to the complexity and inner workings of DSLR's. Unfortunately, that camera decided recently to give up the ghost. I think this time around I'll go this route when the replacement modified camera arrives. The 135 Rokinon has been a staple for my Astro images but excels in the daytime as well!
Thanks for sharing this Nico. I also had the problem with this lens and my Sony A7S and ended up sending it to an official service to fix it. Thanks again!
Such an easy solution for such FRUSTRATING problem!
I bought a vintage Pentax SMC 200mm for my mod Canon M3, using a Pentax K to EOS-M adapter, I still didn't have a Bahtinov (and no experience) and I sure I was doing something wrong.
It took me while to figure out that this was a focus issue, because I could focus to "infinity" in day time. Then, I replaced the cheap adapter with another one. Only after getting a Bahtinov mask I knew for sure that the problem is the focus. Asked in CN and most people suggested to add a clear lens in front of the sensor, only one person suggested to adjust the lens, which was super easy.
After the adjustment I can tell for sure that adding a glass wouldn't have fixed the problem, and I love having that extra place to play with the focus.
The value of a good set of mini screwdriver is underestimated in this case!
Great content a always!
Great tutorial, Nico! Worked perfectly for me.
Good morning Nico. I followed your instructions to the letter and problem is resolved 💯%
Many thanks and keep well.
Warm regards,
Mupanga
Lusaka, Zambia
I love this Tair 300 f4.5! I have it and made a nice shot of orion using my 7D. But I didn't use stacking, it is only single exposure.
Just the video I was looking for. My 135mm f/2 can't focus properly and I will surely give your solution a go.
I just did this open heart surgery. I opened the lens and my heart stopped :). I used the lens on a full spectrum mod and it really does have an issue of hard stop just before the infinity focus when modding. Thanks for the tutorial!
Awesome video because I bought an off brand oshiro 135mm f2.8 lens and the infinity has been giving me a problem for lack of better terms. Clears skies in the NORTHEAST 🇺🇸 TONIGHT.
You're a life saver Nico! I actually bought a used lens myself a few days ago at an incredibly cheap price (less than half if new) for a like new lens - just that it has this issue. I'm having a hard time noticing bad focus myself (bad eyes probably lol), but my bahtinov mask says it doesn't quite reach focus.
Just to clarify, before removing the screws I'm suppose to put it as far to infinity as it goes, as in, reach the stop?
But yea, seems pretty easy and I'm gonna have a hell of a good time with it after it's fixed
Thank you for that tutorial! I am not sure if it's a good idea but instead of removing the stop entirely, I moved it one screw to the right. This way I can go slightly past infinity, and still have a hard stop for safety.
Super stoked I came across this comment as I was in the middle of doing this to mine. I saw what you were saying and just moved the stop 1 screw over. The other screw will go in in the middle of the stop. It let me hit focus last night and still had a little room yet until the stop. But I like having that hard stop. I feel this is the proper way to do it. Thanks!
Just did this myself, good catch!
I am not sure this is necessary. I am no expert but when I followed the directions the lens still hard stops, just a little further away
There is another internal hard stop. Better remove the external one entirely.
Many thanks! Great simple tutorial that worked.
Tips: gently heat up the focuser rubber with a small heat gun (emphasis on gently) and slide it down instead than up. Completely remove the stop. It is actually a "pre-stop". There is another internal stop once it is removed.
Thanks. Great video. I had just received my Rokinon 135 mm yesterday and noticed there was zero play beyond the infinity focus. I thought that was very strange and worrisome until I came upon your video. I just did this mod using your instructions. Just a couple of observations from the experience I had. Some things that weren't said or immediately obvious although they were certainly shown in the video.
1) Even with the right screw driver some of the first three screws were overtightened at the factory and tough to get out. I really had to press hard to prevent the PH00 from climbing out of the grooves and damaging the screws
2) As shown in the video its important to make sure you get the rubber grip pushed all the way to the end of the lens in order to get to the hard stop
3) Also as shown in the video, going around the grip in a circular fashion with fingers under the trailing edge is the best way to get it to slide down otherwise it can be tough to move.
4) When replacing the three screws at the end I was having a hard time lining up the screw holes but playing the video back at half speed was helpful there.
Thanks again. I probably wouldn't have done this without the video
I just had a friend 3d print me a bahtinov mask for the lens hood for the Rokinon 135 and it works perfect.
Very informative and helpful. Thank You!
Interesting, my solution to this exact issue was opening up the camera and shifting the sensor forward.
When you shifted the sensor forward, how much, in terms of screw turns? one full turn or more than that? I just pulled the IR cut filter from my 600D
Would love to hear more about this as well. I have an astro-modded Canon camera, performed Nico's fix, but just about (or not, checking with a Bahtinov mask soon) hitting focus. There's already an SvBony CLS clip-in filter inside (~1.8mm glass thickness).
Great Tutorial Nico!!
Cool, I've got that 300mm lens, I have the full Zenit photosniper kit it came in including the gun stock for it which is why the focuser is part way down the lens body :)
A great tutorial. I bought the Samyang 135mm lens this last summer and tried it out quite recently with my modified Canon 600D and a Bahtinov mask. I reached perfect focus at the hard stop which was fortunate because I couldn’t go beyond that to go slightly out of focus, if that makes sense. Then I put an Optolong L-Pro clip in filter into the camera. I found that with the filter I could rotate into and out of focus perfectly at F2.8 which seems to be the sweet spot for this lens. This may help others with a similar problem without having to ‘surgically’ adjust the lens.
Maybe I should get one. I need a manual telephoto because my camera decides it’s gonna change focus when I touch the screen. Lost an hour of exposures because of that.
@@13_cmi Sounds like you're camera was in autofocus mode with touch focus enabled? If not, you may want to use electrical tape to tape down the focus ring, once you have focus set properly, so it doesn't move when you shake the camera. Good luck!
It worked for me! Thanks!
Excellent tip! Now i just need to buy this lens :)
Fantastic, clear and precise. As Usual! DG New Forest U.K.
After fixing my 135mm F2 following this method, I tried it on my Samyang 24mm F1.4. However the 24mm has a different construction so it requires starting from the back end and removing the mount ring and aperture ring. It's a more complicated process, but still achievable using the same tools.
Thanks for the info.... my Samyang 135mm F2 is now operating as it should have to begin with.
Awesome 👏 this worked for me Thank you 🙏 🔭🤩📸
Thanks for this. I could never understand why you couldn't just turn the lens to infinity and the stars would be in focus. Now I know :-)
Especially complex lens designs with ED, UD glass elements change shift in focal length / focus shift due to temperature changes.
Hmmm...wonder if I will have this problem when I finally go to use my Samyang 135mm with my ASI294MC Pro. I know what to do now, if I do...great video, Nico!
thumbs up for the TAIR-3 :D
Thanks Nico, great video as always, and an interesting tip :-)
Do you have any plans to do a 5min Friday on backfocus, as you mentioned in this video? Especially for dedicated astro camera (eg ZWO ASI 533), reducers / telescope combos (eg. William Optics 6A III) ... it's so challenging to understand which set of measurements etc. to utilise from each device.....
Thank you for the tutorial! So removing the silver hard stop piece is the solution. That's a much better option than moving the camera sensor
I agree. It's really not too bad for a lens mod, and I've had great success with these lenses after doing it.
The missing sensor glass / ir Pass filters of astromodified cameras prolong the light path to the point of convergence by 1/3 of their thickness as a rule of thumb. I had to learn it the hard way on my Sony a7rII. I still have some lenses with which I cannot reach infinity focus fully open. This is really helpful advice and luckily an easy procedure on one of the cooky cutter lenses for ap :)
Exactly what happened to me when I removed the filter of my olympus cam. Works for telescopes, but with the 135's little brother, the 85mm f/1.8 ED, i cant reach infinity focus anymore. I'm probably gonna try this, but its still gonna be hard since MFT has a 3mm glass in the path. That's a lot to cover for the extra focusing path.
One way to avoid this is with an astro-mod is to replace the removed IR cut filter with clear optical glass to preserve the optical geometry.
The removed filter otherwise affects not only infinity focus but also auto-focus (unless it's a mirrorless camera) and depth of field calibration on all your lenses.
who modded you're A7R II? do you experience that ir light bleed/leak during long exposures? I'd like to maybe mod one of mine
@@kalef1234 I had it modded by Markus Mehl in Germany. Although the IRPass filter was replaced with a baader filter replacement there is still some ir leakage from the service led inside the shutter mechanism. There has been an instruction how to shield it and I intend to let Merkus try to improve the situation. With the current glow I must take darks in order to get decent results. I will link to Markus' page and the instructions for shielding once I am at a desktop pc.
@@benjaminolry5849 oh yeah i guess dark frames would subtract it out, i didn't even think about that!
the hardest part is the rubber. Thanks for the guide :)
Hey Nico ! Thanks for the video!! My Rokinon lens stops at the backwards " L ". Nowhere near the infinity symbol. I will order the magnetic pad, screw driver set and fix my lens.
Same. Did you find out why?
@@user-ys6gs8sn2j mine is the exact same, did it work for you?
hi Nico, question about the stopper that you removed. Is there any risk of over focusing and damaging the lens if you dont put it back in? eg. if you twist the focus ring past its intended infinity point and collide some of the internal optics? or is this not an issue? cheers
This is super helpful! Are you aware of any difference in the process on the cine (other than the rubber not being there? Not sure which screws to pull
i have a samyang 50mm f1.4 and a 14mm f2.8 Series II that don't focus to infinity on my astro-modded 6D....they unfortunately don't have this same 'stopping mechanism' so I guess I'll have to sell them
EDIT: fixed the 50mm f/1.4 Samyang's focus, it's a bit more involved but definitely doable. had to take the back mount ring off, the aperture ring and ball bearing out, and then completely slide the focus plastic ring off after loosening the same screws featured in this video. then you remove the white sliders, rotate the focus around once to get past infinity, then re-assemble.
Спасибо за ролик!!))) Ваш преданный подписчик)!
Very Helpful, Thank you very much, now my question would be, would tfor my APSC and my full frame camera?
Yes, it works for this lens for any camera you are using.
Nice move Doctor.
:)
I wonder if this could be useful for my canon 50mm nifty fifty, with my astro modified 6D I'm just slightly out of focus at the hard stop.
Great Video Nico! you should be a teacher
My Rokinon has infinity focus about 3mm to the right of the. indicator on the lens.
Always yours.
That works perfectly for my 135mm,but I have the Samyang 50mm,where there is not a ring that I can pull after unscrewing those 3 small screws. Anybody any idea or link to a description that helps me with my 50mm?
Thank you. My Samyang arrived this week and I was anxious about this very issue. My focus ring does not rotate all the way to the infinity symbol...but I tested it out with my DSLR on a tree that I know to be over a mile away. Looks like I can just go slightly past true infinity focus....on my DSLR. I'm going to be using it with my ASI183MC Pro and the last of my adapters arrives today. Once I have that, I will test the focus out using FireCapture and follow your tutorial if I notice I can't get there. We're forecasted for 3 clear, moonless nights in a row, starting tomorrow night.
Does this inability to reach infinity focus get better or worse as temperature decreases? Intuitively, I would think that it's worse at warm temps but maybe I'm backwards on my thinking.
Don't quote me on this, but I think you are right that it get's worse at warmer temperatures. I noticed that pairing this Rokinon 135 f/2 to my Canon EOS Ra had no problems when I first tried that combo (winter), but remember finding being just shy of perfect focus shooting polaris in warmer weather. It was close enough that I went ahead with the shoot, but excited to try the lens again now that I have it fixed.
@@NebulaPhotos good thing it’s extremely cold when my favorite nebulas are out. 😂
you don't place back the hard stop screws?
thanks, i was able to do this with ease. Thanks...was finally able to focus in landscape test. Now for some clear skies...
Hi Nico, thank you for another informative video. For clarification, in step 3, you took off the small silver piece. Do you replace that afterwards or does that prevent you from making the adjustment? Thanks again. Clear skies! Narrie (The Nar Side).
In my case, I didn't put back the silver piece as it was preventing the focus ring from move far enough in that direction to reach focus. After I put the three small screws back in, the focus ring worked well and still stopped turning on both ends of the range. I'm not really sure what the purpose of the silver piece is other than creating an artificial hard stop for the focus ring.
@@NebulaPhotos thanks. I thought that might be the case. I think if you turned it too hard without the silver piece, you could overcome the resistance the three set screws provide by themselves. Though I don't own that lens, I knew I would learn something from your video. I look forward to using your in-depth post processing videos tutorials to help me make better images and hopefully a better astrophotographer. Clear skies! Nar
@@NMagturo i had the same question. in the end I removed the silver stopper but replaced the tiny screws so as not to misplace them...
@@totoantibes thanks!
I tried this mod but one of the three screws was too tight and I was unable to get it out. Lens was returned.
I wonder if this works with my 8mm fisheye..
Awesome info, Nico!
One question, are you saying you could adjust the aperture to fix this.? Stop down and achieve infinity?
That won't help my situation, however., as I have this problem with a fixed aperture lens. :(
I just discovered my 14 mm Rokinon doesn't reach infinity on my Pentax. Very disappointed about this, especially on the wider lens... Why not make the travel go well past infinity? What are they trying to avoid by making it such a narrow range of movement?
Thanks Nico! I thought I was going to have to return the lens. I'm not sure I'm ready to perform surgery on my own, but will be talking to my local repair shop.
Clear skies...
N
Yes, sometimes! When you stop down the critical focus zone expands and in some cases you may enter perfect focus after being out of the CFZ at faster aperture. Good luck with your repair. Clear skies, Nico
In my experience the 14mm samyang/rokinons are very hard to adjsut past infinity. I did it to my samyang 50mm with relative ease but I just can't seem to slide the black plastic focus ring off the lens to get to the internal stoppers on the 14mm
@@kalef1234 Thanks for the info. I still haven't taken this to the shop, but I'll mention it to them.
(I'm not brave enough to try it myself!)
@@SkySailor75 I totally understand. My 14mm was also 'decentered' so I didn't have anything to lose haha. I fixed taht as well so now it's quite sharp and I'm excited to try some milkyway shots with it. Hope it all works out for ya!
ua-cam.com/video/Q2189HvL7E4/v-deo.html try watch one bro, I believe it is exactly what you need.
I just bought this lens and found the same problem. As this is a known issue, how can it pass muster at the factory? I tried focusing on some distant mountains and could not get that last ounce of clarity as the infinity symbol would not his the last mark. I'm going to mod my "Brand New Lens". Makes no sense.
Would you recommend the same approach with the Rokinon 14mm f/2.8? Thanks!!
If you are having trouble reaching focus at infinity with it, then I think it would be worth a shot. I can't tell you if the system is the same, as I've never 'looked under the hood' with that lens.
Hi
Hey, Nico! I have the Samyang 135mm f/2.0 and I am having the issue you've mentioned in this video. The lens won't focus all the way to infinity. I peeled back the rubber grip of the focus ring, however, the screws that I need to unscrew are extremely tight. I don't want to risk breaking the lens (from using force to undo the screws). Is this issue specific to the 135mm or does it vary? I am wondering whether to send the lens back in exchange for a new one but I don't want to do that if the issue will persist. Any thoughts?
It seems super common for this lens not to come to focus with modified cameras, so even if you return the one you have you may need to do the modification on the new one (but maybe the screws will be easier to turn?)
@@NebulaPhotos Thanks for the quick reply. The camera I use (Sony a6000) is not modified but I suppose it just depends on the camera lens combination. I think I might try and take the lens to a camera shop. They might have better tools there
I had the same issue today. At first I couldn't get the one of the screws to turn. Make sure you have the right phillips head 00 but you also have to apply a good amount of pressure while turning the screw driver so it doesn't climb out of the grooves and strip the screw. The screws seem pretty tough though.
Do you have to put the silver piece that controls hard stop back after testing or not?
I didn't. The focus ring still stops on both ends without it (i.e. it doesn't just keep turning). I think in my case, I needed to keep that piece out to put the infinity focus position where I wanted it. I did save it in case I need to put it back for some reason.
@@NebulaPhotos thanks Nico! I'll try this out.
What would happen if we go to far beyond Infinity focus without hard stop ?🙈
I know this video is older now. I just ordered this lens, and was wondering what the purpose of infinity focus was for astrophotography (I'm new to AP)? What are the use cases for it? Thanks all! Clear skies!
All astrophotography is at ‘infinity focus’. For a lens, infinity is just the ‘hyper focal distance’ the point at which everything is in focus. For a wide angle lens, infinity can mean 5 feet. For most telephoto lenses, it’s more like 100 feet. The issue with Rokinon lenses is sometimes they won’t focus to infinity especially after a camera has been modified. So this is a fix for that
@@NebulaPhotos Thank you, Nico. You're the best at explaining everything. It's thanks to your videos, as well as Trevor Jones, that I have just started dipping my toes into AP. Shooting my first deep sky this coming weekend. Andromeda. Thank you so much for everything you do, Clear skies!
Did you do or plan to do a project with TAIR 3? I have the same, and it looks to me that it is not able to reach infinity after it gets cold. Do you know if there is a way to modify it to go a bit over infinity?
Yes, I've already modified mine and plan to do more with it on the channel
You're joking 😯 I have had this lens for 3 weeks, battled with the infinity issue continuously. Thought it was faulty, so have just returned it 😒
Really wanted to try this because even after going for repair couple of months it came back with same issue....but I had to quit before really getting started. 2 out of 3 screws weren't moving...hope I didn't strip them entirely. Any hints to get them loose?
Ah, that's the worst - sorry! I've never run into that with this lens, but with other projects I have stripped screws and had to turn to screw extraction techniques. I'm not sure if I would try those here. Other than what I showed, the only other option to reach focus is to move the sensor inside your camera. There are some screws in there too if you take it apart. I've never done this, just relaying the info.
Good info. But what is interesting (maybe my lens is older or newer) but my Rokinon f/2 135mm has a different labeling setup. Meaning, as seen at this video (3:30) your label is L then the infinity symbol and then m. On my lens... its m infinity symbol and then L. Does this make any difference in regards to doing this tweak?
Are you having trouble focusing to infinity? If not, I don’t recommend doing this. If you are, I think this tweak is worth a shot.
Thanks. I just got the lens. Snow expected (big surprise) so it will be awhile before I can see if it's an issue.@@NebulaPhotos
Hi Nico, I did the fix this morning but when I reach the infinit icon i lost the focus on the ground, maybe I did it wrong?
The markings on the barrel will no longer be accurate, but you will definitely still have full range of focus, it will just be expanded. I doubt you did the modification wrong, but you can’t expect to just move to the infinity icon and be in focus, focus using live view and you should be fine.
Hi Nico can you recommend some laptop software to control a dslr settings so I don't have to touch the camera once guiding?
BackyardEOS or BackyardNikon are good paid options. NINA is a good free option. All are windows only I believe
@@NebulaPhotos thanks Nico will download NINA and give it a go.
I have a question About focus. When im shooting The stars, i bump Up all my settings to max - 30sec exposure, F1.8 and iso 1600 (thats max on my camera)
I focus using live view at that settings.
Will my focus change, When i change my f value or aby setting? Thank you for reply😊
Your focal position should not change by closing the iris (aperture) or changing ISO/shutter speed. The only setting that could result in a focus shift is zoom. Many zoom lenses do not hold the same focus through the zoom range.
@@NebulaPhotos thank you Nico! I just finished shooting Orion withou worries and fear❤️
Это Таир-300фс в начале?)
Heres a question. Do you just remove the little mmetal clip all together?
I did, it’s not the only stop, there is another one internally. I think it’s fine to remove it entirely.
@@NebulaPhotos brill. Thanks for the reply.
Question 🙋🏻♂️ once the hard stop is removed can the lens be damaged by someone turning it way past infinity? I wouldn’t but a child might or a drop incident.
I am not an expert on this topic, but from my limited experience, here are my thoughts:
1. On this Rokinon lens, I thought removing the hard stop might mean I can just keep turning the focus barrel and it would just keep going 'way past infinity' as you say. In reality, it didn't work this way. The focus travel still stopped on both ends of the range, but I was able to move where infinity focus was achieved on that range.
2. I suspect the hard stop is indeed there to prevent damage to the lens. I could see how by removing it, if I twisted the lens barrel too fast to one end now, I could potentially break off the small screws providing that resistance. So yes, I think you may be right that removing it might make the lens more susceptible to damage from someone mishandling it (exerting too much force on the focus barrel). If you drop it, I'd be more worried about miscollimation of the lenses than anything related to this mod.
I'm having big dramas with my recently astro modded Sony A7C when using wide lenses like the 14 and 24mm GM. They do no longer reach infinity focus at all when wide open or anywhere near wide open. Kind of looks acceptable past f4, but that defeats the purpose of an f1.4-f1.8 lens hey. 135mm GM at f1.8 works fine. Very disappointing experience thus far.
Sorry to hear that. I don't have any experience with astro-modified Sonys. Did you do it yourself or send it somewhere?
So, my lens doesn't go that far to the left of infinity. Am I just position the screw position on the left side of the small slot instead of the right now?
It's hard to say as I don't think the markings are consistently lined up with the ring from copy to copy. You just need to make your best guess, then test the lens, and keep repeating that process until you can comfortably reach infinity focus with some room to spare before you run out of focus travel.
@@NebulaPhotos I think it might have something to do with when each was made. Your inside looked ever so slightly different, but it was a little hard to see. I was only able to put the screws back in one of two positions. I do think it still worked, so thank you for this video.
Can you clean the Samyang 135mm f2 inside?
Like the inner surface of the lenses? I've never tried. Do you think yours have dust?
@@NebulaPhotos i would like to see how to clean inside too, i have 2 fungus spot inside, probably on second or third element.
Niko, when I tried these steps, it just moves by a couple of mm off Infinity mark. But continues to lock after that. Is that all the extra turn we get?
Yes, it is not a huge change, but with all of the Rokinon lenses I've done it on (4 now), it's all that was necessary to consistly reach focus at infinity.
@@NebulaPhotos thank you. I own a samyang 135 for Nikon mount. And am not successful with this. I still get blurred stars. When I use the lens with dslr I get tact sharp stars. So lens is fine. Am not sure if I did the surgery right. Is there a way I can get in touch with you on email offline? I will need some help please... been struck with this for more than a week now.
@@sreeshab4093 I'm not sure I understand. If your stars were tact sharp, why did you perform the surgery? Yes, you can email me: nicocarver at gmail dot com
@@NebulaPhotos They were tact sharp with Nikon DSLR body, not with astro camera 071MC
@@sreeshab4093 Ah, okay, in that case. The lens is likely fine as-is, and you just have to fine-tune the spacing between the astro camera and lens with spacers.
I bought a Rokinon 135mm F2.2 ED UMC thinking it was a 135mm F2 lens. I want to use mine for astrophotography. Is there much difference? Also, I cannot select F2.2. Stops @ F4. Nor can I select Infinity. Is this normal? Thanks for your videos. Much appreciated. Mike
Is it perhaps the T2.2? If so that's just the cinema version and should be optically identical, just a different housing designed for cinematographers.
@@NebulaPhotos Yes it's a f2.2. But I still cannot get to F2.2 .stops btw F4 and F2.8. Nor can I adjust focus to Infinity. Thx for the reply
If you are still within the return period, I'd return it. If not, when you say it won't focus to infinity are you just talking about the marking on the lens or have you actually tested it on a subject at infinity focus? I'm not sure I understand about the aperture values, the Rokinon cinema lenses I've had have a clickless aperture ring so can be set anywhere. Turning it all the way to the right would give a T Stop (transmission stop) of T2.2 which is equivalent to an f/ratio of f/2.0.
@@NebulaPhotos It does have " clickless" aperture ring. It just will not travel any further than between F4 and F2.8. No where near F2.2. I have not tried the focus on infinity, will do today. but again, I cannot turn the focus ring anywhere near even the "L" never mind infinity. Thx for the reply. I was hoping to attach photos but no luck. Mike
@@1clancym It could just be that the markings are way off; I've seen that before on manual lenses. If you turn the aperture ring as wide open as it will go (between T4 and T2.8) can you see the blades of the iris when you look down the front of the lens? When a lens is wide open, you typically can't really see the iris. If you can't see it, than my guess is that position between 4 and 2.8 is actually 2.2
Hi Nico. Don’t suppose you actually know the screw size. Tried with screwdriver I have with no joy. Need to get a decent set
I'm afraid I don't remember off-hand, probably Phillips #00 or maybe #000. You can get a pretty cheap set on Amazon that has all the options for precision bits: amzn.to/3I7QmYX
there’s no way that this manual focus lens will consistently serve you with accurate focus, the way an AF-lens on a mirrorless camera using contrast based autofocus will. i have great results, as an example, uaing a Fuji GFX 50R with the 32-64 mm GF lens at f4, also for astro.
Time to get rid of the covid hair.
Thank you!! I was nervous about operating on my lens, but after watching a few times I gave it a go, and all went smoothly!