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Question: Spotting scope vs. super telephoto lens (1 Viewer)

vd Berg

Active member
Hello,

Not with standing a price-, weight- difference.
I was wondering, what is the difference in sharpness, image quality between a digiscoping and super telephoto lens (from 500mm) setup, for birds (waders, birds of prey) at a long distance (from about 70m)?
I mean waders and birds of prey at difficult/non reachable places.

Regards, vd Berg
 

marcsantacurz

Well-known member
I find focusing a spotting scope much slower than an autofocus camera lens. If things are moving around (even if not too fast), you'll struggle with critical focus. If the f/stop is large enough to give you some DoF, you could still get passable shots, but not if you're going to crop a lot or make big enlargements.

Depending on the camera adapter, you might be looking at an 800mm - 1200mm equivalent focal length, but only with a 65mm - 80mm lens. So your f/stop is going to be like f/10 - f/16. At those focal lengths, without IS (unless you get something from IBIS), you'll need shutter speeds like 1/1200 - 1/2000 (depending on wind and tripod stability), so you'll really be bumping up the ISO.

If you use something more like MFT, you could use the lower magnification adapters to get better f/stop while still getting some of that range back.

A mirrorless camera with focus peaking or EVF zoom helps a lot.

I am not sure if there's any difference in CA or field curvature or asymmetric focus. Modern (non-film) lenses are designed for a very flat sensor (whereas film is more forgiving of alignment issues because there is more depth to the film emulsion). If the spotting scope is not equally well calibrated to a flat sensor, there may be CA issues or lens symmetry.

A lower resolution camera (larger pixel pitch) would do better with the high f/stops because it will be less sensitive to diffraction at f/10 or above. Of course, that's all relative to sensor size. Though I expect lack of critical focus would dominate the IQ rather than diffraction.

Marc
 

vd Berg

Active member
Hello,

Do you have two photos showing the difference/result between digiscoping (with a spotting scope) and a super telephoto lens (from 500mm), for the same bird at a long distance?

Regards, vd Berg
 

marcsantacurz

Well-known member
I don't have anything like that readily available. If I get a chance this weekend, I could try comparing a 32x Opticon MM4 (1600mm equivalent) w/ an 800mm f/5.6 lens shot on micro 4/3 (1600mm equivalent).

Marc
 

vd Berg

Active member
I don't have anything like that readily available. If I get a chance this weekend, I could try comparing a 32x Opticon MM4 (1600mm equivalent) w/ an 800mm f/5.6 lens shot on micro 4/3 (1600mm equivalent).

Marc

Hello Marc,

Okay if you could try that preferably from about 70m for (the size of) a bird.
I found an old Lensrentals "digiscoping and super telephoto lens" comparison test. A comparison test at 90 feet (27meter) between a Swarovski ATX 95mm and a Canon 800mm f/5.6 IS with a Canon 7D (https://www.lensrentals.com/blog/2012/10/scoping-out-digiscoping/). Not the comparison test for (the size of) a bird at a long distance where I'm searching for, but the comparison gives already an indication.

Regards, vd Berg
 
Last edited:

h14nha

Well-known member
Hello,

Not with standing a price-, weight- difference.
I was wondering, what is the difference in sharpness, image quality between a digiscoping and super telephoto lens (from 500mm) setup, for birds (waders, birds of prey) at a long distance (from about 70m)?
I mean waders and birds of prey at difficult/non reachable places.

Regards, vd Berg

I used to do a bit of digiscoping in the early days, things have moved on since then I know, but you can't compare a digiscoping set up to a 500mm/4. Perched birds will give you the opportunity to fine tune focus, but anything on the move gives the advantage to the 500mm/4
 

lmans66

Out Birding....
Supporter
United States
In many cases the image from a 500-600mm lens will be superb over that of the scope. Now, in long distances, perhaps not so, especially if you start cropping the lens images.

But ....to me....to me......there is something to be had by Digiscoping...the intangible. I love waiting for the shot and taking the time to get my (1 shot), as opposed to just snapping off 10-15 images per second and one of them is bound to come out well using a camera+ lens.

To me....cameras and lens zoom have gotten SO GOOD.....that there is no skill in taking a picture, in flight, or perched or whatever. Really, just about anyone that can hold the camera and has any idea of bird behavior can capture an award winning shot. So the skill factor needed is low. To me, the intangible aspect of having skill to digiscope goes way beyond the image. It is the skill, the fun, the attitude I have when Digiscoping, the mindset, the ability to think on my feel and improvise and be creative etc.... Digi-scoping to me is hands-down more skillful and a personal level of satisfaction attained by doing so. My camera and lens? It sits in the closet!!!!!
 

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