SharpCap Forums

Hi All,
I know this is sort of a nebulous question, pun intended but does anyone have some broad strokes advice on how long I should gather information (data) on a DSO to get a decent image that I can enlarge to say 24”X36”. I’m not trying to outdo Hubble or JWT, just some good data to work with. I have a Celestron CPC800, a wedge, a Hyperstar and a ZWO 533 camera. What should I be looking for as a decent benchmark to have quality data to process? I understand it varies from target to target but pick one that you have done with a similar setup and let me know how many frames, how long each is and total frame count. That should get me in the ballpark anyway. Thanks!
Reid

I use a 533 with a 12” dob and .75 coma corrector. At 100 gain I usually go between 15 to 30 sec. The 533 has a square sensor so remember that for enlarging. For a bright galaxy I use 30 min integration. Using a hyper star you won’t need near as much time as me. Hopefully someone with a hyper star will answer.

Hi,

as George says, with the hyperstar, it won't take nearly as long as it would with a typical f/5 imaging refractor, let alone an SCT without hyperstar at f/10. In the end, it all comes down to how much noise you are happy with in the final enlarged image - try 15 to 60 minutes on a target (depending on whether bright or dim) and then process the data and see how it looks when blown up to roughly the right size. If the noise is still troublesome, you need to take more data (4x as long total capture time will drop the noise by a factor of 2).

cheers,

Robin

Thank you guys for the point in the right direction. My initial guess was about an hour on a target but fainter stuff like the Veil Nebula would take much longer I'm sure. My first quick and dirty was M42 with a two star alignment and no polar alignment but both the suggested target stars came up right in the middle of the screen on my computer so beginners luck eh? The winds are howling here today so no chance to work tonight but I'll start with a polar alignment when I can and then do the two star alignment. Hopefully with that, my image will be stabile enough to shoot for perhaps two hours and gather enough data to do a decent enlargement. I'll keep my fingers crossed, steady by jerks is what my mantra is!
Reid