Location: Collingwood Park, Ipswich, Queensland,...
Posts: 76
Anyone using a C6 SCT?
I'm looking for a second scope with a bit more reach. Mount is a belt modded HEQ5 that gives me good tracking with 7kg payload on it at the moment.
I'm thinking a C6 SCT with a 6.3 reducer would suit my setup quite well. That would be double the focal length I'm running now and well within the weight limits of my mount. I think a C8 would be a reach too far for this mount.
Anyone running similar? Would love to hear your thougts on the scope.
Location: Collingwood Park, Ipswich, Queensland,...
Posts: 76
Quote:
Originally Posted by Camelopardalis
The challenge is not so much the weight with that mount but the focal length.
I have a C6 and the reducer, and either combination are good for visual. But the field isn't flat enough for something like a DSLR, say.
Hmm that could be a problem as I image with a 071mc pro APS size sensor. From what I'm reading with the 6.3 reducer the diameter be for vignetting is 24mm and the sensor I have is 28mm. I now realise that will vignette some but too much to be corrected by flats?
Vignetting will be a problem... the baffle tube diameter on the C6 is only 27mm. On the C8 it's 38mm.
But also bear in mind that the reducer was designed a long time ago for the C8, so slightly different optical parameters, and it doesn't work optimally. The difference in field curvature makes the stars out towards the edges look less than great.
There are alternative reducers that appear to do a better job though... the Optec one for example, and Starizona are prepping a new 0.4x product (for smaller sensors though).
FWIW, the C8 is only 1.x kg heavier... but there may be better options, depending on what targets you're interested in...?
Edit: another FWIW, folk get some pretty amazing images with the ever-popular 130mm f/5 newt...you'd need a coma corrector to go with it too, and note that it needs to be the imaging-compatible version (where the mirror is positioned so it can come to focus with a camera), but they're fairly inexpensive.