Another M83

[scagman (John)]

Hi all,

Here is my attempt at M83.

Taken thru my NG127mm with a 2xPowermate and a Qhy8l OSC riding on my G11 G2 and guided with the orion SSAG and ST80.

A combination of 5x5min,10x10min and 5x15min subs stacked in MaximDL and processed in PixInSight which I'm slowly coming to grips with. Just waiting on the link to download the new DVD tutorial so hopefully I'll learn how to use this software and make use of the features it has.

It got very windy half way thru the night which played havoc with guiding so some of the subs didn't make the cut.

Attached is a cropped copy and here is a link to the full size image.
Full size image http://astrob.in/39322/

Any and all feedback welcome.

Cheers

[rustigsmed (Russell)]

Great job! Core not too blown out, excellent image

[Gem (Grant)]

Nice! Its a great object to target and you've done it well.

[Larryp (Laurie)]

Looks good, John!

[scagman (John)]

Thanks guys for the comments. It is a good looking galaxy.

Cheers

[stevous67 (Steve M)]

Hello John,

This is a very good attempt, with detail throughout the image. It appears that differential flexure may be causing that star elongation which translates to loss of clarity/sharpness.

It's a very nice image, well done.

Steve

[scagman (John)]

H Steve, Thanks for the comments. How/why do you think its diff. flex. and not alignment or the wind causing the elongation? I have been wondering if I have much flex in the setup but always thought that my pa and guiding have been the main cause of elongation. I have pempro but havn't run it yet. Due to the lack of time I spend out with my setup I have been putting running pempro off as I want to image instead.

Again thanks all for the feedback.

Cheers

[stevous67 (Steve M)]

Hello John,

Wind causes a different effect, where this is a clear elongation in one direction. It could be another issue, but when a separate guide scope is used, the issue will often be flexure.

At this focal length, even a fraction of flex in one element will have this effect on your image. Your polar alignment and guiding can be perfect, the result will be the same.

Wider fields of view suffer less from this issue. Resolving the problem is not easy, but there are many sources on the net on how to proceed, but, it’s up to you what to do and it just depends on how much it bothers you.

Like I felt, your image is very good.

Cheers,

Steve

[scagman (John)]

Hi Steve,

Thanks for the explaination. I probable have flex in the guidescope like you say. It is something I havnt looked into yet but will one of these days.

Normally I dont image at that FL only when I use the powermate.
Just another thing to sort out

Cheers

[ving (David)]

well done! i like it

[carlstronomy (Carl)]

John, nice image looking really good.

[scagman (John)]

Thanks guys.

Your all to kind.

Cheers

[MGTechDVP (Mariusz)]

Great looking galaxy... I'm impressed that you were able to get 15 minute subs... the most I ever got was 5 mins and that wasnt even perfect.

[scagman (John)]

Thanks Mariusz, Yes I'm happy to be able to get 15mins subs. I do spend a lot of time drift aligning using my ccd. I find a star start imaging it then move the mount with the arrow keys 15sec left then 15secs west, have a look at the image. If the star trail forms a "v" I then adjust the ALT or AZ. depending on where the star I'm using is. Then I will do this again until I get a straight line then I increase the exposure time and do it all again. I do this working my way up to 10min exposures. This is the easiest method I have found, but probably the slowest.

Cheers.