1st DSO Andromeda...I'm off the blocks!

[Notty]

Thanks again to Knight for putting me right on the DSS version I needed, but here's my first attempt, admittedly with the only post stacking processing being "Auto levels" set in Paint.net (for some reason the stacked image in DSS looked beautiful but when I opened the tif in Paint.net it was nearly completely black.  I have no clue what to do with levels etc; it seems I'm going to have to surrender to Photoshop as pretty much every tutorial uses it  .

So putting aside my presentation being awful, there seems to be a decent amount of data there.  It's 24 mins as 6mx4 at ISO 400 (too low maybe?) guided.

Any tips appreciated.  I can see my starts look misshapen more towards the fringes, I take it this is because I need a field flattener?  Most around the middle look ok to me suggesting my mount is behaving itself with guidance?  I guess the dark fringes/vignetting are because I didn't take any flats?

Couple of teething issues.  I did find locating it a pain in live view; actually harder on the PC screen in fact through APT with all the exp and ISO set to max I had no idea if I was in the right area despite aligning on a few adjacent stars before via Stellarium.  Had to take a few test shots and manually slew till it came right.  Is this normal?  Must be even harder with a smaller target.  Also my first time at bahtinov focussing... initially using the bahtinov tool in APT, but either I didn't understand it as it left me with golf balls instead of stars so I used live view directly on the back of the camera, but did not appreciate how tiny the pattern was.  I've seen lots of videos of people with huge patterns on their laptop so that left me wondering a bit.

Anyway here's my first attempt.  Oh- I used a Neodynium filter too.

[Notty]

Sorry posted the wrong pic...

[Leveye]

You'll find after imaging this one a few times that layer masking a few different exposures is the best way to go. I did 4 different ones for this image. 5 seconds,30 seconds at ISO 400 for the core and 120 seconds and 300 seconds for the outer disc at ISO 800

[iksose7]

Looks good for your first DSO!

The stacked images always appear very dark when you first open them up for processing. Getting your hand on a copy of photoshop will help a lot, if you look hard enough they can be found online. You may have 'clipped' your black point during processing this which is why it appears so black. 

Once you have a copy of PS, everything you need to know can be found through Youtube, Google and of course, the primers here on SGL are full of goodness also.

EDIT: Yup layer masking is very usefull for objects with a high dynamic range like M31 and M42.

[barkis]

Not a bad start for you, and you will improve as you go on.

Get good data, and master the processing, and your images will soon be

seen in the popular Astronomy Magazines :smiley: .

You'll get there for sure.

Well done on your first.

Ron

[Stargazer33]

Well done! Much better than my first M31. As leveye says take subs at different lengths to avoid 'burning' out bright areas like the centre of galaxies or bright stars such as the Trapezium stars in Orion when it comes round in October. Use the short exposures for the bright areas and the longer ones for the dimmer parts of your target.

Layering your subs is a bit like the old arts project that those of us who are old enough will remember. You coloured in a piece of paper with stripes of different coloured pencils and then coloured over that with black wax crayon. You then used a stylus to do a drawing. Where you removed the back wax your multi-coloured background showed through from below.

So if you put your core/star layer at the bottom and then cover it with your outer galaxy/nebula you can then 'paint' out the centre of your top layer to show the correctly exposed core layer from beneith, but keeping your correctly exposed outer region from the top layer; if you see what I mean!      You use the feather tool so that you get a gradual transition from one layer to the other. I did it last year for the Orion nebula picture in my gallery and if I can do it then anyone can.

[Knight of Clear Skies]

Nice first effort. M31 is quite a tricky target, it may be big but the arms have a low surface brightness while the core is much brighter, making it difficult to get the balance right.

[Notty]

Leveye: Wow.  Well I WAS feeling quite pleased with mine!  So regarding the combination of different exposures, I assume you would take a few of each e.g. 5x5s, 5x30s etc then stack like with like then merge in PS is that the gist?

I must admit I did not think about the issues with the dynamic range, I guess this was not a good target for a beginner in that sense, but last night was all about checking I could focus my DSLR, get PHD to guide etc so this was a bit of a shock tbh!  What is a good target for a numptee this time of year?  I was thinking of M13 next time but I do love Galaxies it's why I got into this game.

Thank you for all your help and tips.  Turns out PS is on offer on the cloud for £7.50 mnthly so I've taken the plunge, and thus YouTube owns me for the next few weeks.

[Leveye]

I process each exposure group separate in DSS and then take those saved TIF files and combine them in PS using layer masks. Btw your first try here is WAY better than mine from 5 years ago trust me. Your on your way!

[Dubhar]

Thats looking really good for a first shot of it, much better than mine. 

[Pete Presland]

great start, keep up the good work

[szymon]

Very nice image!

Sent from my iPhone using Tapatalk

[Astrosurf]

Excellent first image. As has been said, M31 is tricky due to it's high dynamic range. Try something like the Dumbbell Neb or other object that's more balanced. Remember Leveye is more experienced. You'll get there! Processing is a dark art and you'll always be learning.

Guiding looks spot-on, but do try a higher ISO. I use 1600 but then my canon 600D has quite low noise. With my 1000D I didn't go higher than 800 ISO. I think your 1100D has lower noise than the 1000D.

I'm not that knowledgeable but I think you'd need a field flattener with your scope.

I take test shots to find the object, but then I'm without a red dot or Telrad or Rigel finder. They do make things a lot easier. I can't use a Telrad or Rigel as my varifocal glasses make that difficult, so will be buying a red dot. I'm also looking into Alignmaster to help me find objects more easily. See these:

http://stargazerslounge.com/topic/221188-drift-alignment-vs-alignmaster/#entry2402376

http://www.alignmaster.de/

If you have a kid at school you can buy Photoshop cheaply for a student. I got my daughter's for about £200 a couple of years ago.

Onward and upward!

Alexxx

[choochoo_baloo]

Very nice first image. Excellent.

[Notty]

Thank you very much for the kind words and advice everyone I am really encouraged.  Last night I decided to have another bash at her, and took a series of subs at different exposures and ISOs with a view to combining them as per the suggestions made above.  I have also spent all day giving myself a crash course in PS, but if anyone can point me at a tutorial which would facilitate these layering techniques that would be awesome. In the meantime just having learned how to tease out the details with the curves and levels has been a real revelation!  Here is a go I had at my stacked 300s image.  I know the middle is still over exposed but I still this its a real improvement over my first.

[Astrosurf]

That's lovely! Well done. Is that dark blob some dust on the sensor? If so, take flats which will remove that.

This tutorial will give you an idea.

http://www.astropix.com/HTML/J_DIGIT/LAYMASK.HTM

Do get the GradientXTerminator PS plugin to remove vignetting and gradients. It's superb.

http://www.rc-astro.com/resources/GradientXTerminator/

[Alien 13]

Thats a realy good image the additional work has made a big difference it puts my 1st efforts to shame, the suggestions mentioned by Astrosurf would help too.

Alan

[Notty]

Why thank you for the compliments guys!  Yes the blob threw me a bit; I did use darks albeit only 5 at each exposure (due time) but I did have this weird issue with them being presented at a different orientation to the lights... I'll have to keep an eye on that.

[Knight of Clear Skies]

Very nice, lots of detail in the dust lanes there. One tip for fitting more of the target in - simply loosen the camera and rotate it.

[ollypenrice]

The key lies in stretching the image. This is a good tutorial by RobH on here;

http://www.middlehillobservatory.co.uk/articles-primers/Levels%20and%20curves.htm

Personally I think the need for multiple exposure lengths is greatly exaggerated and I very rarely use them. On Andromeda I did shoot some short subs for the core but almost all the final core detail was, in fact, present in the long subs. (These were 30 minutes each at a fast F5, hence my doubts about burning out the core in a couple of minutes or less.) Multiple stretches of the same data can get you into the core without the need for lots of short subs.  http://ollypenrice.smugmug.com/Other/Best-of-Les-Granges/i-3D2Hw7s/0/X3/M31%20Outer%20Halo-X3.jpg

Setting the black point to a good value is also a key skill. I tend to feel that a value of about 23 for the brightness, measured in Photoshop, is a good starting point.

You have a really good first capture there. Most of us didn't do so well, I don't think, in our first attempts!

Olly

[Notty]

Thanks Olly, your image is quite stunning.  When you say 30 minutes each on the subs, how many did you take out of interest?  Mine here is a total of 25 minutes (5x5 stacked) and I've tried going into the core with the curves but I don't think I have the data there.

By the way thanks for the link to that tutorial on curves, that really helps me.

[alcol620]

Hi Leveye

Just a question. How do you combine individual saved TIF file in photoshop using layer masks? i.e. how do you get the individual files into the layers?

Thanks for feedback.

[kirkster501]

A very commendable effort. There's a lot of plates to spin when imaging!

[Astrosurf]

Open all the files in PS. Drag the title of an image down into the work area and it'll 'float'. Do that for all of them. I find that when I drag down a second image, it combines with the first I've already dragged down! (I'm sure there's a key command to stop this but I don't know.) So if that happens, drag it back out again. Make the images in the working area smaller so they're all sitting beside each other - they can overlap a bit. Then, for each image, hold down the shift key and drag it onto what you choose as your lowest layer image. They'll all layer up. Then just close the unwanted idividual images when done.

Alexxx

[alcol620]

Thanks Alexxx, very helpful.

regards

Alec