guided vs unguided?

[neil groves]

What is guided exactly? if I set up my AVX mount and let it track an object for a few mins while I make an exposure, is that guided? or is it something more complex?

Neil.

[rowan46]

another camera is locked onto a star in the general are of where you are imaging. the output from the camera is fed into the autoguider port on the mount and this then results in more accurate tracking.

[Leveye]

The term guided usually refers to using a small scope attached to the main imaging scope that has a camera attached to it. You then hook the camera/scope up to a computer and then run another connection from the computer back to the mount. The "guidescope" can then be used with a program like PHD to guide on a star and if the star moves in pixel counts the program will send a message to the mount to correct it. This way the main telescope can track an object for much longer times aiding in imaging it.

[Pete Presland]

unguided for me was the difference between 30 second exposures and exposures as long as the pollution would permit. PHD really is a fantastic programme

[swag72]

Guiding is probably one of the biggest improvements you will see in your imaging. Yes you need a mount with the correct motors in it, and a separate camera and scope for guiding (there's a couple of other approaches as well) - You will find that with tracking alone, depending on your focal length and PA you can get up to a few minutes of error free exposure. By error free I mean that the stars are round and show no elongation. With guiding, and as long as it works well, you can get exposures of as long as the sky will allow. My narrowband subs for example are 30 minutes long.

Hope that helps.

[IanL]

Read this:

http://stargazerslounge.com/topic/188777-phd-guiding-basic-use-and-troubleshooting/

[Redshift48]

I agree with the above comments. In my experience, even with accurate polar alignment, I rarely can go beyond 5 minute subs without some motion distortion if I am not guiding. When you see good images composed of 10 or 20 minute subs, you can be certain that they were guiding. And PhD is a wonderful (free) program!

Robert

[neil groves]

If in the future I discover I need to guide then I am best getting the AVX mount instead of the astrotrac, I have heard of laptops overheating in the field so I am not inspired by that thought unless I can use a tablet instead?

Neil.

[ollypenrice]

I think that even in California you'd be unlikely to overheat a laptop too badly on a clear night. I remember it cooling off even in the central valley on clear August nights. Laptops and guiding are routine throught the world.

Olly