A forum member PM'd me and asked if I could send him some examples of the level of vignetting with my G3 attached to my telescope with the MaxView eyepiece and Digi-T adaptor.
I thought that more people may be interested so I posted my reply here
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It's a pretty warm day today in Minnesota, and there's a fresh breeze from the south. I'm shooting across an unplanted corn field, so there's a lot of heat waves. I didn't try to get perfect focus. The subject is a tornado siren.
Note that I have an Orion StarMax102 telescope. It's a Maksutov-Cassegrain, not unlike a catadioptric telephoto lens.
For those not familiar with this type of scope:
I make this point because anything less than about 15mm of zoom you'll start to see the front mirror, not to mention the vignetting gets pretty bad.
I show five images: full zoom (28mm), 20mm, 15mm, and full wide (7mm). I also included an image at full zoom without the scope. You'll see the siren in the center of the picture.
My scope is f/12.7 at 1300mm focal length. The MaxView eyepiece is 40mm. I would think that a different scope may have a different level of vignetting.
By my math, at full zoom, it's about a 91x magnification. 1300mm/40mm = 32.5. The G3 has a 35-140mm equivalent lens. 140mm/50mm = 2.8 32.5 x 2.8 = 91
FWIW... YMMV.



