It seems like my life is controlled by A) Back Focus and B) the lack of available items in various supply chains. Like a lot of us…
I recently picked up a QHY286C cooled color camera. The intent is to use it with my C11 EdgeHD OTA with Feather Touch Crayford focuser.
The C11 EdgeHD has a 146.5mm overall Back Focus requirement. The included plates in the QHY268C were of course almost there, but around 7 mm short. I managed to locate and buy one of the last “M54 all in one” adapter kits in the US. That arrived today and I inserted the remaining 7mm of spacers into the stack.
OABF stack of 146.95 or 1/2 mm short, but I think I can live with that as when I add a filter into the mix it increases BF requirements by 1mm.…
Or will 1/2 mm cause an issue? The kit does have a .5mm shim.
But that leads me to my next question. With the OAG in the stack, does it make any difference where it's place in the imaging path? Presently it’s right up against the “center tilt switch” for the camera.
Stack: QHY268C + "center tilt switch" + OAG + 12mm spacers + Filter drawer + 2” nose piece. So it’s as close to the imaging chip as possible. Can it be farther away from the imaging chip, or will that lead to vignetting issues?
The "center tilt switch" is the unit that locks onto the camera via 3 screws and allows for camera rotation independent of the rest of the stack. Everything else screws into it, I have no idea why they call it a "center tilt switch"...
Thanks in advance!
Bryan
