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Old 14-06-2010, 10:43 AM
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gregbradley
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gregbradley is offline
 
Join Date: Feb 2006
Location: Sydney
Posts: 18,174
Hey what game is this? Say how bad the conditions were and then put up an image that is actually quite good

Nice colours in the neb itself and quite a bit of detail.

Did you try the darken layer and offset filter technique to round the stars up?

It sometimes damages the neb if you have to work at it too hard so you can select the stars as a layer and do only them or lassoo them and only do stars not in the neb or do it as a hidden layer and rub through only the areas where it doesn't effect neb details.

What was the problem you had with autoguiding?

My little Astrotech66ED and ST402ME continues to be a simple and effective autoguiding solution up to 1260mm focal length so far.
Always lots of guide stars always sharp enough and not so long focal length that the autoguider is chasing the seeing too much.
I can get it down to .5 second or less exposure times on a good night and get slightly better results than 1 second guide exposures.
Autoguiding is usually as good as your polar alignment, your balance of your OTA/camera and squareness. After that it can be further tweaked. I find you can get considerably different autoguiding errors from different guide stars in the same field. If I find the errors higher than normal my first action is to select another gudie star and see how that one goes. Not sure why that is. Some stars are binaries and when the guidescope doesn't split them they look a bit elongated on one side. I usually select the brightest sharpest looking star. Not one that is too bright and bleeding over in the image but one that will survive a small light cloud passing through the field.

I use 1 second guide exposures or less. For my setup that is ideal. Longer exposure times means the PE builds up too much. And my Tak NJP mount has low PE to start with (about 3.5 arc seconds or less last I checked). At the end of the day you will also need to get the PE down with PE software or work on your mount to get it lower (better worms, coatings that are available for the gears). Or if feasible a better mount. I like the Tak as it is user friendly and very simple to use. One or 2 synchs and it does its go-tos. I usually park it after use so I simply turn it on and off I go with the free driver by Chuck Faranda.

Greg.
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