Howdy. Have upgraded my dslr to fullframe for non-astro stuff and have recently been trying it on my refractor. After a few shots of M33 something was obviously amiss.

Previous configuration was a 450d or 7d on a william optics 90mm + a William Optics .8x Flattener/Reducer. I'm not sure if it was the MkII or MkIII. Worked pretty well anyway. But there was HUGE vignetting with the full frame. I did expect quite a bit but the amount shocked me. Here's a flat sample CI took against a lighted wall. First is with the reducer, second is without.




Minimal vignetting on the second but the field isn't flat unfortunately.

Loving the camera though - this is the first light M33 with the edges cropped out. Will need to try and find a suitable flattener.


www.flickr.com/photos/thelunarscape/8271507533/in/photostream

Trev

Hi Trev,
I might be wrong with this post.but have you checked whats the correct distance for your cameras from reducer to your chip?

Hi Nerro, yep I checked the chip distance. Should be just over 5cm. Turns out that flattener was only designed for aps-c sized sensors. Hadn't even occurred to me to check before trying the camera. It's no big deal though, the field of view is so wide I'll probably be cropping alot anyway.