First Light Modded 1100D - M51

[Gina]

Here is my first go at M51 with the modded 1100D captured last night and processed in DSS today with further tweaking in GIMP. 75 subs of 45 secs at ISO 1600 of which DSS chose 56. I'm not entirely satisfied with the processing on this - I think I've over cooked it.

[Quatermass]

Have you got the .tiff file Gina I would like to have a go at processing that in photoshop and see what we can pull out of the hat for you.

[Gina]

Yes, I do have the TIFF - I'll upload it and link to it. thank you

[Quatermass]

Cheers Gina

[Gina]

Here's last night's capture - 75 subs of 60s at ISO 1600 of which DSS selected 58 to stack. Adjusted in DSS and further tweaked in GIMP. Hmmm... Doesn't look so good on here

BTW - I'm going to upload the TIFFs to "filehosting" and provide links shortly.

[Zakalwe]

You can stack 2 nights worth of data in DSS (load them into different Groups at the bottom of the page).

The polar alignment looks to be a bit out (looks like star trailing) and/or the focus looks a wee bit out. If you can crack these two, then you could go for some longer subs, which will help to drag more detail out.

Do you take darks? If not, try dropping the ISO a bit as there is a lot of noise in the image.

Good progress though!

[Gina]

You can stack 2 nights worth of data in DSS (load them into different Groups at the bottom of the page).

That's useful - thanks

The polar alignment looks to be a bit out (looks like star trailing) and/or the focus looks a wee bit out. If you can crack these two, then you could go for some longer subs, which will help to drag more detail out.

Yes, the PA is a bit out - I'ms hoping to do a drift alignment soon. I think the focus was alright - I set it with a Bahtimov mask. But that is cropped a lot as the galaxy is quite small in the frame. I plan to add a x2 Barlow next time I get a chance.

Do you take darks? If not, try dropping the ISO a bit as there is a lot of noise in the image.

I have 15 darks from each night - taken directly after the lights but haven't used them. Do you just add in the darks after the lights and before Registering images?

Good progress though!

Thank you

BTW - I must say, I love your avatar - makes me laugh every time I see it

[Gina]

Here's a link to uploaded TIFF from DSS of last night's M51 :-

filehosting.org - download page for M51-2012-04-11-1.TIF

[Zakalwe]

That's useful - thanks

Yes, the PA is a bit out - I'ms hoping to do a drift alignment soon. I think the focus was alright - I set it with a Bahtimov mask. But that is cropped a lot as the galaxy is quite small in the frame. I plan to add a x2 Barlow next time I get a chance.

I have 15 darks from each night - taken directly after the lights but haven't used them. Do you just add in the darks after the lights and before Registering images?

Thank you

BTW - I must say, I love your avatar - makes me laugh every time I see it

A 1.25" Barlow will cause a lot of vignetting with a DSLR.

As for darks, yes, just click on the Darks in DSS, then chuck them in. If you are stacking different nights worth of data, then add the darks into each separate group. AFAIK, anything (darks/bias/flats) in the main group is applied to all other groups.

My avatar? You should see me in real life!

[Zakalwe]

Here's a link to uploaded TIFF from DSS of last night's M51 :-

filehosting.org - download page for M51-2012-04-11-1.TIF

I can't open that TIIF? Irfanview, PS or DSS wont recognise it. Are you sure that this is in TIFF format?

[Gina]

A 1.25" Barlow will cause a lot of vignetting with a DSLR.

It's a 2" ED Barlow (Skywatcher).

As for darks, yes, just click on the Darks in DSS, then chuck them in. If you are stacking different nights worth of data, then add the darks into each separate group. AFAIK, anything (darks/bias/flats) in the main group is applied to all other groups.

OK thanks - I'll give that a go

My avatar? You should see me in real life!

[Glen]

Thats a good image Gina, I think the thing 'letting it down' if there was one, is the ISO at 1600 if I'm brutally honest.

Try for longer subs and/or more at say 800 ISO and see how the output is then?

Good to see you out there after all the hard graft though and getting use of the obsy

Clear skies,

Glen

[Zakalwe]

I can't open that TIIF? Irfanview, PS or DSS wont recognise it. Are you sure that this is in TIFF format?

My mistake...downloading it now.

[Zakalwe]

There's some very weird blocks of colour on this image....was the framing per sub wildly off in comparison to each other?

In fact, looking at the trailing hot pixel, I'd say that the framing varies wildly from sub to sub???

[Zakalwe]

Awful quick and dirty attempt.

[Gina]

There's some very weird blocks of colour on this image....was the framing per sub wildly off in comparison to each other?

In fact, looking at the trailing hot pixel, I'd say that the framing varies wildly from sub to sub???

That's very strange, the TIFF file converts to 8 bit when imported into Gimp without any of that.

[Zakalwe]

That's very strange, the TIFF file converts to 8 bit when imported into Gimp without any of that.

AFAIK, you should always do your processing in 16bit.

I loaded the file straight into PS, and that's what I got without touching it.

[Quatermass]

Had a good old go at this for you Gina the stacked images had lots of overlaps in it which makes it impossible to deal with unless your seperate everthing out so when your stacking your images make sure there as well framed up as you can get them. You can use backyard EOS to line up your last image when your out there taking more subs that way you get a nice clean stack with out any overlaps.

Heres a before and after.. your focus was a tiny little bit out on the main sub but its all there and looking good. Hope you like it.

[badgers]

Best I can manage here

QM has managed to keep better colours though and more signal.

[Gina]

Had a good old go at this for you Gina the stacked images had lots of overlaps in it which makes it impossible to deal with unless your seperate everthing out so when your stacking your images make sure there as well framed up as you can get them. You can use backyard EOS to line up your last image when your out there taking more subs that way you get a nice clean stack with out any overlaps.

Heres a before and after.. your focus was a tiny little bit out on the main sub but its all there and looking good. Hope you like it.

That's brilliant! Thank you:) I think I'll run DSS on that lot again. I'm seeing that strange "framing" sort of effect when I open the TIFF directly. All lights were taken one after the other so I don't know where it's come from.

[Gina]

Best I can manage here

QM has managed to keep better colours though and more signal.

That's amazing - thank you

[Quatermass]

When your going through your subs if they look very different try just stacking the very best one and try not to get any ones that are ovelapping or you get that framing effect. It does the same to me if I am not very picky over which ones I am going to put through the final stack. Sometimes you can get better results by stacking 20 good ones as opposed to 60 not so good ones.

[Gina]

I'll try that - thanks

[Zakalwe]

Ive had another bash over lunch. Not anywhere near as good as Quartermass (sigh...so much to learn in this hobby!), but better than my previous

[ArmyAirForce]

What's the cause of all the stars looking like they are illuminated from the bottom left of the image and appearing as a 'phase'? Is that a collimation issue because it's something I've noticed on some of my pictures.