As I go through galaxy season fighting to find a guide star with my remote OAG setup (can't rotate anything) that keeps my target framed, I'm debating upgrading from my QHY5L-II M to an IMX178 based guide camera. That will give me roughly twice the total area (7.4 x 5 mm vs. 4.83 x 3.63 mm), but with 4x the pixel resolution. If I can successfully marry this with the 0.5x focal reducer I have (that wouldn't reach focus on the end of the 5L-II tube) and still have enough mirror FOV in the OAG, I should be able to guide with equivalent accuracy but have about 8X the FOV! Assuming the pixels are more sensitive to boot and I should have plenty of stars to work with.
I'm currently using the ASI178MC for my all sky camera and getting pretty good results. I'd generally prefer to have a tube format similar to the 5L-II, but the 290MM doesn't really give me any more sensor area over what I have now. I realize there's also the 174MM, which would give me the area but without the resolution, and at a considerably higher price point. I'd also like to be able to do some narrow band (e.g. solar) imaging with the camera, which I believe would be much better supported by the 178MM. It's also unfortunate that the mini's are back to USB 2.0 speeds, although given I never had good results with my 178MC at USB 3.0 speeds, it may not do me much good to have USB 3.0.
As far as physical setup, I'm imaging on a Celestron 11" Edge HD OTA with a Taurus Tracker III OAG, which has ~ 1/2" pick-off mirror. At any rate, I'd appreciate some quick feedback before the sale's over. Unfortunately there's not enough information (e.g. QE) on the 290 and 178 sensors to easily compare what I'm considering, so any direction from the pros is appreciated.
Thanks,
Beo
