question about "finding" objects on my CCD
Posted 15 June 2013 - 08:01 PM
i mean, i can find it without any problem with an eyepiece and my eye, it's just when i switch to my camera, i can't find the object again, or it takes a really long time to figure out where it is again. it's really frustrating.
how do you solve this problem? a really good finder scope? a wide field autoguider of some sort?
Posted 15 June 2013 - 10:44 PM
how do you do it?
Posted 15 June 2013 - 11:55 PM
Posted 16 June 2013 - 02:43 AM
I have a CG-5 and generally after two star alignment and 1 calibration star the object is in the center of the field of view (0.4-0.5 degree). I use also a e-finder that is more or less aligned with the main scope and I never switch to eyepieces.
Posted 16 June 2013 - 06:59 AM
Make sure you are Polar Aligned properly first, then do a good Star Alignment.
The only way you'll have trouble finding an object after that is if you are at too high a magnification (eg: f10) and the object is just slightly off centre, putting it out of the FOV.
Widen your FOV with a faster scope or use a Focal Reducer (or both is even better).
Posted 16 June 2013 - 07:45 AM
Why don't you allocate one cam as an e-finder with wideangle lens and forget the regular [optical] finder. Under my severe LP only the brighter alignment stars are easily visible in the latter - certainly none of the faint fuzzies but an e-finder makes short work of them with 1s-2s exp in display loop! Checkout my e-finder
i've started playing around with several different cameras......
Posted 16 June 2013 - 07:53 AM
As an example when I did the AL's Double Star program I used a C14. A goto would get me close but still a bit away from the actual object. I'd find it in the finderscope and center. A 40mm eyepiece on the C14 gave me a fov of about 30 arcminutes and I'd center the double in the eyepiece (no cross hair on the ep so it was a judgement guess on centering). Switching to my SDC-435 camera gave a fov of 2x4 arcminutes and the double was almost always in the fov of the camera. Without the flip mirror finding the double with that small fov would have driven me crazy. It usually took less than a minute from the end of the goto to centered on the SDC-435.
Posted 16 June 2013 - 11:05 AM
Posted 16 June 2013 - 11:32 AM
My original eFinder...
Posted 18 June 2013 - 01:01 AM
Posted 18 June 2013 - 01:12 AM
It's easiest to do the parfocal on daytime targets; later at night focus should be done with a bright star on the camera, and then swap out to the eyepiece and fine-tune by moving the ep up and down a little.
Posted 25 June 2013 - 10:14 AM
Next step for me is a focal reducer to increase FOV. I didn't think of doing the alignment with the video -- going to try that, too.
Posted 26 June 2013 - 04:47 PM
Posted 27 June 2013 - 10:06 AM
Seeking in Ebay i saw these interesting lcd monitor with video input, few with autonomous batteries, light and cheap,possibly very useful for astro camera
I can speak highly for the first link.
Those little monitors work great with our AstroVideo cameras.
A friend of mine uses one with a Video camera as his finderscope.
As for the other 2 links, I've never seen them before.
Posted 27 June 2013 - 11:16 AM