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Are Smartphones as good as m4/3s? (1 Viewer)

dalat

...
Switzerland
Hi,
since a while, I use the Samsung S6 for digiscoping on my Swaro ATM-HD 80 scope. It is still one of the best smartphone cameras out there I think, and handling with the Kowa adapter is very easy.

Recently, I bought a m4/3 camera, the Pana G81 (or 85 or 80), and now I also got the 20 mm 1.7 pancake lense, which has a good reputation for digiscoping. It works well, I can use it with the Swaro DCA adapter. Handling is good, but defintly more clumsy than with the phone, just because everything is bigger and heavier.

I made a couple of test shots, and I was quite surprised, and a bit dissapointed: the m4/3 set-up isn't really better than the smartphone, it actually looks worse.

See below of a summary of test shots. I used a pole behind my flat, distance about 25 m. The upper pics were made in dim light on a cloudy evening, the below row is in the evening sun. Left ist the Panasonic, right is the Samsung.

So, do you have similar experience? Are small sensor smartphone cameras really as good or better as bigger sensors for digiscoping? And if so, why is that?
 

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Here the exif data for the four test shots:

Upper left: Panasonic G81 (16 MP) + 20 mm 1.7 (equiv 40 mm), 1/60, 1.7, ISO 1600
Upper right: Samsung S6, 16 MP, 4.3 mm (equiv 28 mm), 1/50, 1.9, ISO 80
Lower left: G81 + 20 mm, 1/160, 1.7, ISO 200
Lower right: S6, 1/500, 1.9 / ISO 40

All are heavy crops of the central part of the image, no further processing besides resizing...
 
Dalat,

I haven't used m4/3, but have been mulling over similar and related questions.

In my gallery, the photo titled "Narcissus" was taken with my Samsung Note 3 hand aligned (hence the heavy vignetting in one corner) through one barrel of my Zen-Ray 8x43 ED3 binoculars, reasonably late in the arvo. As far as the IQ is concerned I have to say that I was rather pleasantly surprised! :t: :king:

As an always on you bit of kit, it is something I will explore again with another set of bins (have had in mind 10x for some time, but I think the Canon 12x36 IS III would also be interesting), in concert with a new smartphone (I will probably trade up soon, especially if someone makes a decent sized mobile sensor for a 2x or proper 50mm equivalent optical telephoto [maybe even with IS] - Note 9 perhaps?) and use the setup with a dedicated adapter.


Chosun :gh:
 
Dalat,
I use the G85 version of the camera but has not used it for digiscoping. What are your settings for AF on the camera?

Niels
 
For this test, I used AFS, and tried different different Af fields (point, smallest centre field, 4 fields). I used shutter release via the screen tip function (determine focus point and take picture, with a slight touch on the screen), and also with remote controle (via app). I also tried manual focus. For the comparison above, I took the best shot of the set, but actually there was not a big difference between the methods...

I didn't use the G85 for digiscoping in real life yet, except for some deer behind the house, but the Samsung gave better results for those as well...
 
I made a couple of test shots, and I was quite surprised, and a bit dissapointed: the m4/3 set-up isn't really better than the smartphone, it actually looks worse.
(---)
So, do you have similar experience? Are small sensor smartphone cameras really as good or better as bigger sensors for digiscoping? And if so, why is that?

The scope's exit pupil should be at least as big as the camera's lens aperture in order not to reduce effective aperture and get too long exposure times.
Imagine your phone is a f/2 and in a certain light your exposure time is 1/500 s. The aperture is 2 mm.
If the exit pupil of the scope is 2 mm and you manage to center the phone or pocket camera perfectly, your exposure time should be quite close to when used outside of the scope. Only the scope's light transmission will cause some light loss.

But if your camera has a 20 mm focal length and you use it at f/2.0, the aperture will be 10 mm used outside the scope. When digiscoping, the 2 mm exit pupil of the scope will effectively stop down the camera to f/10 which means you need a considerably higher ISO setting to use the same exposure times.
If you're shooting at Auto ISO and have no maximum exposure time set, you will either see shake or the adverse effects of the higher ISO or both.

//L
 
Many thanks! I was suspecting something like this, but I'm too clueless about optics and camera theoretics to spell it out.

The exit pupil of my scope at 50 X is indeed 1,6 mm. I don't know the aperture of my phone, but it looks like somewhere between 1 and 2 mm, so is indeed close to the scope's EP.

Large scopes like the Swaro 95 also give only small EPs of < 2 mm at 50 x or higher. Can we make it a general rule then, that phones or small sensor compacts are better suited for those EP than m4/3 or APS-C cameras, or do I miss something?

I'll try a test at lower mag (25x) as well. However, at lower mag, discoping looses its range advantage compared to camera and lens, so does not make that much sense any more...
 
TWhen digiscoping, the 2 mm exit pupil of the scope will effectively stop down the camera to f/10 which means you need a considerably higher ISO setting to use the same exposure times.

One more thought: I seem to have read somewhere that diffraction is an issue when highly stopped down. Could it be that because of the small exit pupil, diffrations affects image quality of the m4/3, but not so much the smaller sensor/lens of the phone?
 
One more thought: I seem to have read somewhere that diffraction is an issue when highly stopped down. Could it be that because of the small exit pupil, diffrations affects image quality of the m4/3, but not so much the smaller sensor/lens of the phone?

I thought of that too, but decided diffraction probably would be a non-issue compared to shake.

//L
 
Many thanks! I was suspecting something like this, but I'm too clueless about optics and camera theoretics to spell it out.
You're welcome!

Large scopes like the Swaro 95 also give only small EPs of < 2 mm at 50 x or higher. Can we make it a general rule then, that phones or small sensor compacts are better suited for those EP than m4/3 or APS-C cameras, or do I miss something?
Most likely. I had some incredibly good results with a Lumix TZ40 and my Fieldscopes (ED82A and ED50A). Using a very large scope like this may seem senseless, but compared to a small sensor ultrazoom like the Nikon P900 it will yield better results. Unfortunately the practical aspects come into play.
A P900 is more usable for birds in flight than a digiscoping setup.

I'll try a test at lower mag (25x) as well. However, at lower mag, discoping looses its range advantage compared to camera and lens, so does not make that much sense any more...
Good luck!

//L
 
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