Digiscoping w/ the Sony a9 - 21 Oct 2020
I find it amazing that I've had the Sony Alpha a9 Full-Frame camera for over a year and have not tried it for digiscoping until now. My current digiscoping camera, the Sony Alpha a7III is so good that I've not felt the desire to look for newer and better. But with my recent acquisition of a Digidapter(tm) DLM adapter that attaches directly to the lens threads of my Zeiss 35/2.8 it is now as easy as swapping camera bodies. So I decided to see if the autofocus-master a9 would work in front of a spotting scope eyepiece. It does, and impressively!
The 24 Mpx stacked CMOS sensor delivers a blazing-fast 20 fps silent-shooting without rolling-shutter issues. This makes the camera perfect for fast-action sports and wildlife shooting. I was curious to see how well the industry-leading autofocus worked w/ the camera attached to the Swarovski STX85 and 25-60X zoom eyepiece (at 25X).
The first thing I noticed is how back-heavy the rig is. I have my slide plate on the Manfrotto 501HDV fluid-head as far forward as it will go, but the camera (plus battery pack) is noticeably back-heavy. If I remove the battery pack then the system is perfectly balanced.
I found that autofocus worked great, but requires "manual-assisted" autofocus operation. That means that I have to get close enough with the manual focus for the autofocus to lock on, otherwise the camera has a tendency to want to hunt focus. I found that having my thumb on the back-button focus while rolling focus w/ the scope's focusing ring the camera automatically locked on (green focusing boxes appear in the viewfinder) for razor-sharp captures.
I planted myself at the edge of the house w/ the scope leveled on the thistle feeder waiting for Pine Siskins to visit (they have been around by the dozen for the past 3 days). An American Goldfinch flew in about 20' away and I was able to fire off a quick burst.
But I was interested in seeing how well the Auto-focus worked, so I kept it in Zone. I have to say I was happy with the outcome. When the Pine Siskins showed up I waited for the squabbling birds to land on nearby branches of the River Birch tree so that I could get some fall-foliage shots.
The Sony a9 did not disappoint!
Image quality was every bit as good as I get w/ the Sony a7III with possibly a slight advantage in the image sharpness department. I have to say that it definitely was much easier (and faster) using manual-assisted autofocus than it is to operate in focus-peaking mode.
The camera worked great for up-close subjects, but how about farther-out subjects? A male White-crowned Sparrow appeared about 30' away at the edge of the yard, so I tried to see how autofocus worked for longer-distance subjects. Though light was now beginning to drop (1/125 sec exposures at ISO 3200 f/2.8) I still managed quite a few sharp, feather-detailed images without the need for focus-peaking.
When my back-pension comes in I'll definitely replace my Sony a7III w/ a Sony a9, but in the meantime I'll keep it attached to my 100-400mm GM for BIF's. For those of you with an unlimited budget the Sony a9 is about the best you can get in a digiscoping camera. For those of you with a less-than-unlimited budget you will still do just fine with a camera like a Sony a7III or even a smaller/cheaper APS-C camera or M43 camera for your digiscoping camera.