Here's another NGC 253

[p medcraft]

This image is a little over 20 minutes total exposure at 30 seconds and ISO800.
The camera is a Canon 300D and the scope a 14" Celestron Schmidt cassegrain on a CGE mount. Way to little time for a galaxy but got some detail none the less. The scope was at F7 and was unguided.

Paul Medcraft

[iceman (Mike)]

Looks great Paul, nice to see another 253 shot!

Welcome back too, haven't seen you around for ages!

[atalas]

Nice detail Paul !

[RB (Andrew)]

Great shot Paul,

I like this method of lots of short exposures stacked into a final image.

[ving (David)]

sweet stuff
does lots of short images stacked give less noise?

[Striker (Tony)]

Yes ving......the more exposure stacked lower's the noise ratio

Nice Paul...you have been busy

[p medcraft]

I moved my family to Perth earlier this year and tackled a new job, usual story, not a lot of spare time. I am hoping to get some good imaging in over the Christmas break.

[Itchy]

Hi Paul,


Nice Shot!

It seemed to me that you should have got more than that from 20 min of exposure at F7 so I took the liberty of downloading and having a fiddle. I hope you don't mind. If you do, I'll remove it.

Indeed there was more. It is a pitty that you have clipped the bottom end other wise there may be more still. Did you use dark frames on this? There was some residual amp glow that made it difficult to stretch any further.

Again, hope you don't mind.

Cheers

[p medcraft]

Hi Tony, no problems working on the image. Yes there is more but I am a little (LOT) unskilled with Photoshop. I didn't take any dark frames so there is a some additional noise.

[seeker372011 (Narayan)]

that amp glow for such short exposures is a surprise...I dont think I get anything like thattill I go to say 8 or 10 min exposures...Itchy, anyone else..is this normal with your Canon 300D?

[Itchy]

Originally Posted by seeker372011

that amp glow for such short exposures is a surprise...I dont think I get anything like thattill I go to say 8 or 10 min exposures...Itchy, anyone else..is this normal with your Canon 300D?

The amp glow is dependant on temperature as well as exposure. The ampglow in Paul's 30 sec shots is actually very small. You really have to overstretch the image to see it. That said, amp glow is a problem for me all the time with my 300D, It becomes obvious in 1 min exposures during summer. However, it is usually effectively dealt with by dark subtraction.

Cheers

[beren]

Impressive ....top work