Thank you. This is exactly what I needed to know. I have just been putting my camera up to the eyepiece and shooting. I usualy get one good picture out a hundred shots. This helpful information should increase the frequency of my obtaining good pictures.
good video But IMO shows a large k of of understanding in terms of camera technology. I'll explain my reasons for thinking this. the human eye has one lense with a focal length of about 50mm. the compact cameras have multiple lenses in them used for focusing so straight away is unlike the human eye. the optical zoom on the compact cameras can be far more powerful then the human eyes fixed 50mm. a dslr camera however with a cropped sensor is roughly 28.5mm focal length but being cropped is more accurate to a 50mm focal length hence closer the human eye. also by not having any glass/lenses between the sensor and scope the eyepiece it self works as the eyes lense and therefore uses the scope to its best abilities without the zoom of compact cameras effecting the results. this is my understanding of things and if I'm wrong please correct me explaining why so we can all learn. thank you.
+Anthony Hawkins Hi Anthony, and thanks for your invitation to clarify and expand a few points. I would have posted a shorter answer but I haven’t got the time so I posted a long one (with apologies to Pascal). To have a focal length of 50mm the human proportions would need to be stretched more than a little. In fact the average human being would need to be about 12 feet high! The focal length of the human eye is in the range of 18 to 24mm. You’re probably confusing the technical specification of the eye with the long established but incorrect SLR (now DSLR) rubric that a 50mm lens is a good match for the visual field of the human eye. The 50mm is/was regarded as the ‘standard lens’ for 35mm SLR film cameras for this reason. The problem with this is that this judgement is grounded in the subjectivity of perception; whereas we need to get to grips with the design features of the relevant optics. Telescope eyepieces, unless indicated otherwise, are designed to be employed by the human eye. Just looking at focal length and aperture, the human eye is a fairly poor camera by modern standards; (but of course it has some fairly nifty high-tech features that so far defy any attempt to mimic on a camera!). By using a camera that is a good analogue for the eye - ie, small diameter lens (1cm or less) with a limited focal length - so a typical 12MP+ compact camera - ideally with either a modest internal zoom (to tackle vignetting) or at least one that extends out of the body by no more than a couple of centimetres or so. Such a camera would be regarded as a ‘good’ analogue for the human eye for our purposes. I say good in irritating inverted commas like that because it could be a little better or a little worse, and have more or less lens elements and still work OK. Rather like ‘democracy’ - it can be better or worse and still function satisfactorily. Ultimately, the camera that more closely resembles a human eye works so well on a spotting scope simply because of the narrow design limitations of the spotting scope ocular. It was designed to work with little lenses and not big ones - the mistaken utility of the spotting scope stems from forgetting what it was designed for. The spotting scope was designed to work with ‘cameras’ right enough - but it’s the cameras we have in our heads only that the designer had in mind. If the attached camera can approximate the human eye the results can be almost magical. The lure of the bigger better camera will always be in play. If I can get good to great results with a little pocket camera then surely I can get fantastic results if I put my expensive top-spec DSLR on my spotting scope instead? It is not an unreasonable assumption on the face of it - experience will have confirmed time after time that the better the primary specification and competence of the tools we use the better the finished work is likely to be. But not always, and not this time. The DSLR/projection method, does not lack for visible support, and seems to still be well endorsed by the spotting scope manufacturers to a large extent. Many spotting scopes are still supplied with T thread fitting points - usually at the base of the eyepiece - a few - e.g., the Acuter Natureview's - have the thread under the eyecup on some models. But really this idea is the best part of a decade out of date now - with the necessary projection tube seen on sale less and less. Previous to about eight or nine years ago I only ever recommended SLR/DSLRs for use with spotting scopes, telescopes and microscopes - it’s what everybody did in my industry. But as small cameras improved and became commonplace and cheap, the digi-scoping method became the standard procedure for attaching cameras to any optical aids with fitted eyepieces - especially when compromised by weight constraints etc. The growing dominance of the method was simply based on the ease with which superior results could be achieved with the small ‘eye-analogue’ cameras. Superior that is to the results achieved with DSLRs employing the eyepiece projection method. So what’s wrong with mating of a great removable lens camera (DSLR or mirrorless) with a great spotting scope? Well first off, how will you actually fit the camera? If you adopt eyepiece projection you will need to fit a, typically, screw on projection barrel fitted with a marque specific T mounting ring. You will need to remove the lens and fit the camera body directly to the T ring (and remember, are you going to do this operation next to a reed bed full of summer ticks and mud or, to avoid calamity, do it all in the boot of your car before setting off?). Then there’s the results to consider - generally, the imaging plane of a DSLR is over 40mm from the lens flange but you may not get a decent focused image just attaching the body to the T ring - the chances are you’ll see a dark band along the top of the display screen and you will need T thread extension tubes to push the imaging plane further away from the first lens of the telescope’s ocular. But that can be done readily enough - if you can find T extension tubes or the rather dearer marque specific ones. But there are still other problems to contend with - and one of the most irritating with the eyepiece projection method is that you effectively lose the use of your scope. Are you really going to keep taking the body on and off the projection tube every time you want view something? Typically you’ll need to unscrew the tube off the scope to have unhindered access for your eye. So maybe you go the afocal or digiscoping route with your DSLR or mid removable lens camera? There is no reason in principle why a DSLR or other removable lens camera fitted with a standard lens can’t be used - none in principle maybe, but lots in practice. Most DSLR and other cameras with removable lenses have large front elements on their standard lenses - gone are the days of the 50mm f3.5 standard Leica lens with small front element! So the plumbing pipes just won’t fit together in a favourable way. Most spotting scopes have eye lenses (the first lens nearest the eye) of under 25mm in diameter (well under in fact) - hardly surprising when you think of the human eye it needs to mate with. And most camera lenses are going to exceed this diameter - there is no chance of blocking extraneous light (where the lenses meet) by just kissing the smaller camera lens barral into the eyepieces eye-cup (as in the case of small eye-analogue camera) - so you’ll need to add a cardboard tube or something to achieve this (don’t forget the diameter of the lens is one thing - you will also have to contend with the physical external size of the lens barrel). In the end the camera image will include the outer rim of the eyepiece and you’ll need to zoom in to correct this. Then there’s the weight of all this. The spotting scope has a tripod mounting foot situated to balance and support the scope alone - OK when it has a little compact camera and holder attached, not so good when it has a big camera attached. But you can upgrade the tripod if necessary and add a balance bar to the scope to move the mounting point towards the camera. But even if you master all these inconveniences you will not be rewarded with superior results to the small camera digi scoping method; at best you’ll get the same results but you’ll have worked a lot harder and spent more to get them. This is simply because there is a low ceiling created by the telescope optics - and we keep coming back to the same logic - because it was designed to function with the living human eye. And the small ‘eye-analogue’ camera simply harvests all the gravy, the image detail and quality, that there is to get: and it does it with the minimum operational fuss. If the points I’ve outlined aren’t fatal enough for the old eyepiece projection method - and frankly, this battle is long lost in favour of digi scoping - just take a look at the readers photos in the backs of Birding magazines or online forums in the UK where birdwatching is a big hobby. The top pictures are taken with either an interchangeable lens camera fitted with a long focus photographic lens or a small compact - what I’m calling an eye-analogue - camera attached using the digiscoping method to a spotting scope. Direct pairings of interchangeable lens cameras and spotting scopes are increasingly rare - and for many good reasons in my view. I hope this helps understand why I favour small cameras and why the digi-scoping method has been so widely adopted. Thanks for giving me the chance to expand some of the points raised in the video. KR RJD ANTV
+Astronomy and Nature TV thanks for your reply. yes I see where your coming from and I'm sure some of what was saying was wrong in respect of focal length. I currently have my dslr attached to my celestron scope via a t mount adaptor but will defo get a small compact and compare results. thanks a lot valuable advice received.
+Anthony Hawkins Well if your Celestron scope is designed for astronomy and has a 1.25" eyepiece holder then you should explore using that fitting. My observations were really directed at the contest between eyepiece projection employing removable lens cameras and the digi scoping strategy (employing good human eye analogue compact cameras) when attempting photography with fixed eyepiece optical aids. The moment the eyepiece is removable all bets are off. The projection method becomes the outright favourite. You say a brand name but no model details so you still may need to take into consideration weight bearing factors such that if the telescope is small and light you may still be better off with the digi scoping method (or afocal method as it was usually known in astro photo circles!) on purely mechanical stability grounds. I hope this helps. KR RJD ANTV
OK, this is an old video, but if you are still around, thank you, it has been really helpful to me.
Thank you for sharing and really gave me a total understanding on how it works.Great Video!
Thank you. This is exactly what I needed to know. I have just been putting my camera up to the eyepiece and shooting. I usualy get one good picture out a hundred shots. This helpful information should increase the frequency of my obtaining good pictures.
Thank You mr.Dalby, for this excellent explanation about the ins and outs of Digiscoping! Great!
Thanks I’m just starting out and this info has been really helpful ❤️
These videos are so great
Very informative. Thanks for sharing.
A very big thank you, you make me save money :)
Extremely helpful video :)
Great video ... thanks
Brilliant ! So I need a smaller camera I think ?... I was using a Camcorder with x50 zoom and it was looking inside the Scope !
Well Done
Very useful, objective advice, thank you. :)
Thanks. Very helpful.
This explains a bit about why my nicer Nikon with a 28mm lens makes a huge vignetting effect.
Thanks for this!
Soooooo actually a small cheap camera with small focal length is best for digiscoping.
Awesome!
good video But IMO shows a large k of of understanding in terms of camera technology. I'll explain my reasons for thinking this. the human eye has one lense with a focal length of about 50mm. the compact cameras have multiple lenses in them used for focusing so straight away is unlike the human eye. the optical zoom on the compact cameras can be far more powerful then the human eyes fixed 50mm. a dslr camera however with a cropped sensor is roughly 28.5mm focal length but being cropped is more accurate to a 50mm focal length hence closer the human eye. also by not having any glass/lenses between the sensor and scope the eyepiece it self works as the eyes lense and therefore uses the scope to its best abilities without the zoom of compact cameras effecting the results. this is my understanding of things and if I'm wrong please correct me explaining why so we can all learn. thank you.
+Anthony Hawkins Hi Anthony, and thanks for your invitation to clarify and expand a few points. I would have posted a shorter answer but I haven’t got the time so I posted a long one (with apologies to Pascal).
To have a focal length of 50mm the human proportions would need to be stretched more than a little. In fact the average human being would need to be about 12 feet high! The focal length of the human eye is in the range of 18 to
24mm. You’re probably confusing the technical specification of the eye with the long established but incorrect SLR (now DSLR) rubric that a 50mm lens is a good match for the visual field of the human eye. The 50mm is/was regarded as the ‘standard lens’ for 35mm SLR film cameras for this reason. The problem with this is that this judgement is grounded in the subjectivity of perception; whereas we need to get to grips with the design features of the relevant optics. Telescope eyepieces, unless indicated otherwise, are designed to be employed by the human eye. Just looking at focal length and aperture, the human eye is a fairly poor camera by modern standards; (but of course it has some fairly nifty high-tech features that so far defy any attempt to mimic on a camera!).
By using a camera that is a good analogue for the eye - ie, small diameter lens (1cm or less) with a limited focal length - so a typical 12MP+ compact camera - ideally with either a modest internal zoom (to tackle vignetting) or at least one that extends out of the body by no more than a couple of centimetres or so. Such a camera would be regarded as a ‘good’ analogue for the human eye for our purposes. I say good in irritating inverted commas like that because it could be a little better or a little worse, and have more or less lens elements and still work OK. Rather like ‘democracy’ - it can be better or worse and still function satisfactorily. Ultimately, the camera that more closely resembles a human eye works so well on a spotting scope simply because of the narrow design limitations of the spotting scope ocular. It was designed to work with little lenses and not big ones - the mistaken utility of the spotting scope stems from forgetting what it was designed for. The spotting scope was designed to work with ‘cameras’ right enough - but it’s the cameras we have in our heads only that the designer had in mind. If the attached camera can approximate the human eye the results can be almost magical.
The lure of the bigger better camera will always be in play. If I can get good to great results with a little pocket
camera then surely I can get fantastic results if I put my expensive top-spec DSLR on my spotting scope instead? It is
not an unreasonable assumption on the face of it - experience will have confirmed time after time that the better the primary specification and competence of the tools we use the better the finished work is likely to be.
But not always, and not this time.
The DSLR/projection method, does not lack for visible support, and seems to still be well endorsed by the spotting scope manufacturers to a large extent. Many spotting scopes are still supplied with T thread fitting points - usually at the base of the eyepiece - a few - e.g., the Acuter Natureview's - have the thread under the eyecup on some models. But really this idea is the best part of a decade out of date now - with the necessary projection tube seen on sale less and less. Previous to about eight or nine years ago I only ever recommended SLR/DSLRs for use with spotting scopes, telescopes and microscopes - it’s what everybody did in my industry. But as small cameras improved and became commonplace and cheap, the digi-scoping method became the standard procedure for attaching cameras to any optical aids with fitted eyepieces - especially when compromised by weight constraints etc. The growing dominance of the method was simply based on the ease with which superior results could be achieved with the small ‘eye-analogue’ cameras. Superior that is to the results achieved with DSLRs employing the eyepiece projection method.
So what’s wrong with mating of a great removable lens camera (DSLR or mirrorless) with a great spotting scope?
Well first off, how will you actually fit the camera? If you adopt eyepiece projection you will need to fit a, typically,
screw on projection barrel fitted with a marque specific T mounting ring. You will need to remove the lens and fit the camera body directly to the T ring (and remember, are you going to do this operation next to a reed bed full of
summer ticks and mud or, to avoid calamity, do it all in the boot of your car before setting off?). Then there’s the results to consider - generally, the imaging plane of a DSLR is over 40mm from the lens flange but you may not get a
decent focused image just attaching the body to the T ring - the chances are you’ll see a dark band along the top of the display screen and you will need T thread extension tubes to push the imaging plane further away from the first
lens of the telescope’s ocular. But that can be done readily enough - if you can find T extension tubes or the rather dearer marque specific ones. But there are still other problems to contend with - and one of the most irritating with the eyepiece projection method is that you effectively lose the use of your scope. Are you really going to keep taking the body on and off the projection tube every time you want view something? Typically you’ll need to unscrew the tube off the scope to have unhindered access for your eye. So maybe you go the afocal or digiscoping route with your DSLR or mid removable lens camera?
There is no reason in principle why a DSLR or other removable lens camera fitted with a standard lens can’t be used -
none in principle maybe, but lots in practice. Most DSLR and other cameras with removable lenses have large front elements on their standard lenses - gone are the days of the 50mm f3.5 standard Leica lens with small front element!
So the plumbing pipes just won’t fit together in a favourable way. Most spotting scopes have eye lenses (the first lens
nearest the eye) of under 25mm in diameter (well under in fact) - hardly surprising when you think of the human eye it needs to mate with. And most camera lenses are going to exceed this diameter - there is no chance of blocking extraneous light (where the lenses meet) by just kissing the smaller camera lens barral into the eyepieces eye-cup (as in the case of small eye-analogue camera) - so you’ll need to add a cardboard tube or something to achieve this (don’t forget the diameter of the lens is one thing - you will also have to contend with the physical external size of the lens barrel). In the end the camera image will include the outer rim of the eyepiece and you’ll need to zoom in to correct this.
Then there’s the weight of all this. The spotting scope has a tripod mounting foot situated to balance and support the
scope alone - OK when it has a little compact camera and holder attached, not so good when it has a big camera attached. But you can upgrade the tripod if necessary and add a balance bar to the scope to move the mounting point towards the camera.
But even if you master all these inconveniences you will not be rewarded with superior results to the small
camera digi scoping method; at best you’ll get the same results but you’ll have worked a lot harder and spent more to get them. This is simply because there is a low ceiling created by the telescope optics - and we keep coming back to the same logic - because it was designed to function with the living human eye. And the small ‘eye-analogue’ camera simply harvests all the gravy, the image detail and quality, that there is to get: and it does it with the minimum operational fuss.
If the points I’ve outlined aren’t fatal enough for the old eyepiece projection method - and frankly, this battle is long
lost in favour of digi scoping - just take a look at the readers photos in the backs of Birding magazines or online forums in the UK where birdwatching is a big hobby. The top pictures are taken with either an interchangeable lens camera fitted with a long focus photographic lens or a small compact - what I’m calling an eye-analogue - camera attached using the digiscoping method to a spotting scope. Direct pairings of interchangeable lens cameras and spotting scopes are increasingly rare - and for many good reasons in my view.
I hope this helps understand why I favour small cameras and why the digi-scoping method has been so widely adopted. Thanks for giving me the chance to expand some of the points raised in the video. KR RJD ANTV
+Astronomy and Nature TV thanks for your reply. yes I see where your coming from and I'm sure some of what was saying was wrong in respect of focal length. I currently have my dslr attached to my celestron scope via a t mount adaptor but will defo get a small compact and compare results. thanks a lot valuable advice received.
+Anthony Hawkins Well if your Celestron scope is designed for astronomy and has a 1.25" eyepiece holder then you should explore using that fitting. My observations were really directed at the contest between eyepiece projection employing removable lens cameras and the digi scoping strategy (employing good human eye analogue compact cameras) when attempting photography with fixed eyepiece optical aids. The moment the eyepiece is removable all bets are off. The projection method becomes the outright favourite. You say a brand name but no model details so you still may need to take into consideration weight bearing factors such that if the telescope is small and light you may still be better off with the digi scoping method (or afocal method as it was usually known in astro photo circles!) on purely mechanical stability grounds. I hope this helps. KR RJD ANTV
How about that.. XD 2021 and you don't need digital camera for digiscoping anymore haha