First attempt - M42

[kkara4 (Krishan)]

Well here is my first attempt at M42, please give me your feedback on what i can improve!

http://i1186.photobucket.com/albums/...ps31fc1f2c.jpg

EdgeHD 9.25 @ f/10, Canon 5D MKIII, Hutech IDAS LPS-P2 filter,
Orion ST80 w/ QHY5L-II.

Autoguiding with PHD2, rough polar alignment only.

8 x 180sec @ ISO 1000, 3 x 180sec darks, 9 bias frames

Stacked with DSS with default settings, all processing in photoshop CS6.

I know I should probably drop the ISO, increase exposure time, but i havent figured out how to use PHD2 to polar align yet, the graphs are all over the place and no idea what to make of them yet!

pretty stoked nonetheless!

i also have 8 x 120sec but cant figure out why DSS isnt stacking them just yet, will have a play over next few hours.

EDIT: Thanks to Steve for the walkthrough you posted! Here is the composite, and i do actually like it more than the core being blown out!

http://i1186.photobucket.com/albums/...psf88ac963.jpg

[Stevec35 (Steve)]

Nothing wrong with that! Colour and guiding all look good. Of course it's burnt out in the centre which tends to happen with M42. People often combine a short exposure and a long exposure of M42 to get the full dynamic range. Here's one way of doing it:

http://starizona.com/acb/ccd/software/ps_dynmask.aspx

I would also recommend giving Eta Carinae a try. I've always found it very forgiving.

In any case I think you've started out really well!

Cheers

Steve

[kkara4 (Krishan)]

THanks a lot for your feedback steve! I took some 120 sec and 90sec exposures with the aim of doing a HDR composite, but I found that I really like the look of the core blown out a touch.

In any case i finally got the 120 sec to stack in DSS, so ill attempt a HDR composite i think!

I will wait for autumn for eta carinae Steve, light pollution is highly unfavourable here with carina's current position!

[Camelopardalis (Dunk)]

Nice round stars there mate

With that scope you could no doubt resolve a lot of detail in the core, but you'd need much shorter exposures to show it. For example, my shot here used 120 second subs for the main (crap polar alignment) and 2 *second* subs so as not to blow out the core.

[kkara4 (Krishan)]

Originally Posted by Camelopardalis

Nice round stars there mate

With that scope you could no doubt resolve a lot of detail in the core, but you'd need much shorter exposures to show it. For example, my shot here used 120 second subs for the main (crap polar alignment) and 2 *second* subs so as not to blow out the core.

Cheers Dunk! What ISO were you running at for your 120 and 2 second subs?

30 second subs were starting to reveal some of the nebulosity around the core so with my scope ill start there I think and work to see what works best

THere is no way i would get all that dust in the light pollution! it looks amazing from a dark sky!

[Rex]

Not bad for a first attempt kkara. As has been said, you will need very short subs for the core. Nice colours and detail starting to show, well done mate.

[kkara4 (Krishan)]

Originally Posted by Rex

Not bad for a first attempt kkara. As has been said, you will need very short subs for the core. Nice colours and detail starting to show, well done mate.

Thanks Rex! When i get my PA sorted Ill really crank up to the light pollution limit, she had more to give I reckon, but field rotation was giving me problems

I really need someone to come and show me how to use PHD2 for PA haha.

I will also try and squeeze out detail using shorter subs. Ill stack my 30 second subs later on and see what detail was captured there.

[Camelopardalis (Dunk)]

Originally Posted by kkara4

Cheers Dunk! What ISO were you running at for your 120 and 2 second subs?

30 second subs were starting to reveal some of the nebulosity around the core so with my scope ill start there I think and work to see what works best

THere is no way i would get all that dust in the light pollution! it looks amazing from a dark sky!

I was using ISO1600 as that is reputed to be the signal to noise sweet spot for that sensor. Anything more than 2 seconds and I couldnt separate the trapezium stars, which are already a challenge with the little scope and chunky pixels

Given you're using the LP filter, if your image is brightening it there could well be a good signal component to it. Longer exposures do tend to look quite bright on the camera screen, but it all gets dialled back during stacking.

[kkara4 (Krishan)]

Originally Posted by Camelopardalis

I was using ISO1600 as that is reputed to be the signal to noise sweet spot for that sensor. Anything more than 2 seconds and I couldnt separate the trapezium stars, which are already a challenge with the little scope and chunky pixels

Given you're using the LP filter, if your image is brightening it there could well be a good signal component to it. Longer exposures do tend to look quite bright on the camera screen, but it all gets dialled back during stacking.

I had a look at the 30 second subs and the trapezium stars are clearly separated, but still bloated from over exposure. The detail in the core is a touch more, but not much more. I used live view to focus the stars, perhaps i should use FWHM to get it dialled in precisely using backyard EOS or some other software. Or perhaps ensure the minimal exposure on live view and visually get the smallest star possible. And then of course field rotation was probably giving me an issue due to bad PA.

so many possibilities!

[Camelopardalis (Dunk)]

Yup, welcome to the world of astrophotography

[Ryderscope (Rodney)]

Originally Posted by kkara4

I had a look at the 30 second subs and the trapezium stars are clearly separated, but still bloated from over exposure. The detail in the core is a touch more, but not much more. I used live view to focus the stars, perhaps i should use FWHM to get it dialled in precisely using backyard EOS or some other software. Or perhaps ensure the minimal exposure on live view and visually get the smallest star possible. And then of course field rotation was probably giving me an issue due to bad PA.

so many possibilities!

From a focusing perspective it is worth looking at the use of a Bahtinov mask. I have used one quite successfully with my Canon 60Da, 100mm refractor and Backyard EOS. Not that there were any issues with the image that you posted as the stars looked pretty good.

RW

[kkara4 (Krishan)]

Originally Posted by Ryderscope

From a focusing perspective it is worth looking at the use of a Bahtinov mask. I have used one quite successfully with my Canon 60Da, 100mm refractor and Backyard EOS. Not that there were any issues with the image that you posted as the stars looked pretty good.

RW

Thanks Rodney, I have thought about getting a Bahtinov mask made up i really like the idea of them. Initially i was reluctant because i would have to keep taking the dew shield on and off, but then I thought, what about getting one custom laser cut out of acrylic to fit firmly inside the end of the dew shield? Might be difficult to do that though. I suppose a non-issue realistically taking the dew shield on and off occasionally. I have yet to try FWHM methods as well.