+1 there is no way I will ever have a use case for a Duo unless it's on a short and fast scope. Especially now that I use 2.5nm filters. I like the idea of having the guide camera peek over the filters.
SBIG tried the two-sensor cameras back in the old days as the ST-7.
http://www.company7....oducts/st7.html
https://patents.goog...t/US5525793A/en
I mentioned the camera to Sam in an email a couple of years ago, but warned him that it is not useful for narrowband filters (i.e., serious astroimagers). But he ran with it anyway; I think ZWO is after "convienience" for the novice ("Easy as 1,2,3"), rather than performance for serious hobbyists. More money in that.
SBIG wised up and gave up on that diversion, and later cameras include a camera combo that integrated a main camera, filter wheel and a guide camera which is not obstructed by filters. E.g. the STF series
https://diffractionl.../06/AAS_STF.pdf
Pretty complex set of prisms, though. But a small sensor can probably be placed inside the filter wheel itself, and avoid any additional optical elements.
(I still have my SBIG ST-8300, but not the "F," though :-).
Instead of adding a guide sensor to a main camera, a filter wheel that includes a guide camera might make sense as a product (again stealing half the idea from SBIG). But don't tell Sam I mentioned it, since he might want to make money off of such an idea too, without testing all scenerios out :-)
Chen
Edited by w7ay, 01 March 2025 - 10:35 PM.