|
Cheers guys. Yep, Ray, I've been under the impression that 1/2 - 1/3 the seeing in "/px is what you should aim for, but Suavi's earlier comments have me wondering, specifically in regard to the assumption that a bigger aperture is going to mean better resolution: what if it does the opposite because the optics suck?
As mentioned earlier, my "best common case" seeing is about 1.8" with a 120mm scope and 0.6" RMS guide error. We established earlier that puts my actual seeing (approx) between about 1.6" and 1.8".
So lets say I want to make the most of it, err on the side of resolution and oversampling so we'll use 1.6". Again erring on the side of oversampling, I'll go with 1/3 of the seeing in "/px - that tells me I want to be sampling at about 0.53" / px
Given the above, an RC8 combined with the ASI 1600 looks like a good fit. Increasing the aperture (assuming all else is precisely equal) should have reduced my FWHM to 1.6" instead of 1.8"... but how can I be sure that the RC8 is going to be a good choice? What if it's just plain "not sharp"? What metric can I use to compare my options before making such a purchase?
Funny thing this hobby... the longer I'm involved with it, the more I realise what I don't know.
|