Ngc 253

[doppler]

Continuing with the short exposure and subs theme, here is a quick NGC 253 pic. I am looking forward to getting some imaging time on this one in the coming weeks as it moves out of the city light glow and into my darker northwestern sky.
13 X 15second subs, equal amount of darks at iso 3200, canon 1100d, 10"f4.7 newt, no guiding, stacked in DSS.

[RobF]

G'day Rick.
That's a cracking effort for unguided and 15 sec subs! Really shows the power of the 10".
Just be careful of a dangerous breed of IIS'ers that will try to reprocess your image for you.

I just happened to have Pixinsight running and couldn't resist a bit more stretching and colour tweaking sorry :)
Bit too blue in this rendering, but definitely worth adding to your data and working it a bit harder when you get time.

[doppler]

[QUOTE=RobF;1132989]G'day Rick.
That's a cracking effort for unguided and 15 sec subs! Really shows the power of the 10".
Just be careful of a dangerous breed of IIS'ers that will try to reprocess your image for you. QUOTE]

All good, its a bit hard to do anything with the compressed jpg files that you can post here though.
I am still using an old 1970's cave mount which can handle the weight of the ota etc ok but it's not the easiest to balance in some positions especially straight up (the 4" f7 finder scope throws it right out of wack). It works better with a load on the drive motor. Once ngc 453 is past the zenith I should be able to drop the iso and increase the sub length.
Cheers Rick

[cometcatcher]

Nice shot for just under 4 minutes!

I need to get hold of an RA drive for my Samson mount so I can use some bigger canons on it, like you are doing.

[doppler]

Thanks Kevin,
The big toys are better, just harder to drive lol, unless of course you are rich and can afford a high tech computerised engine. Unfortunatly I can only do street drags not formula 1.

[RickS]

Very nice for a quick NGC 253, Rick!

[cometcatcher]

That's a sticking point with me too, hence why I want to get a motor for the Samson. My HEQ5 will only do up to an 8".

How long a sub can you do before RA trailing unguided?

[doppler]

Too short a time to get any usefull data, probably 1 second. I tried 4 seconds with the last lunar eclipse (10" at 1200mm focal length) and the background stars were starting to trail and that was with tracking, just bad polar alignment. I do use a drive corrector to adjust the tracking speed it helps to tame the PE in the drive.

[Rex]

Nice Rick, Can't wait to see how it pans out when you get some more data. looking forward to it.