spc900n

[Pete Presland]

i am a bit new to astrophotography game i have a spc900n what are the best settings using qfocus to get the images.i seem to never be able to get the focus correct.

[michael.h.f.wilkinson]

How are you attaching the spc900 to the telescope?

I have the same webcam, and use k3ccdtools for image acquisition. I first maximize exposure time (minimize shutter speed) given the frame rate chosen, and reduce gain until contrast is optimal (background not quite black, no saturation). Focusing is then done visually (and is still frequently a pain).

[beamish]

You could use "Bahtinov Grabber " app but you'd need to make a mask.

[michael.h.f.wilkinson]

I made a mask recently, but have not used it yet. I will report on my findings when I do.

[Pete Presland]

You could use "Bahtinov Grabber " app but you'd need to make a mask.

thanks, good idea

i have downloaded the template now the cutting out bit looks like a steady hand is needed!

[kookoo_gr]

bunny i assume u use a 1.25'' adapter to place the camera at the focuser. btw are you using a crayford or rack focuser?

in order to focus do as michael says. also if u are taking photos of jupiter or saturn try using any visible moons on the camera as focus aids. when they are pin points then you have a good focus.

seeing is also very important. if you have bad seeing then focusing is very difficult.

finally when you have the best focus possible mark the point of focus with a marker at the focuser tube. the next time it will be much easier to focus. also try the wxastrocapture software, it is very good for planetary photographs

[michael.h.f.wilkinson]

I had a quick shot with my Bahtinov mask recently, no time for a thorough trial, but had some difficulty with extended objects as planets. Bright point sources are better I think. I still use the original focuser of the C8, so marking the tube is not an option, alas. Besides, thermal expansion can throw the focus quite considerably, so a fixed mark would help only within a limited temperature range.

[Glider]

I don't bother trying to focus on the planet at all. Pick a bright star like Capella, focus using a mask, then lock the focuser and go back to your planet.

[michael.h.f.wilkinson]

Works usually, however, I have some mirror flop to contend with (typical old SCT problem, bleh)