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Yawn! Yet another M31!

DeanWatson

By DeanWatson
in Imaging - Deep Sky

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DeanWatson

DeanWatson

Posted
Posted

Hi all, kept myself busy form 9 last night until 3 in the morning- Heres my first this year of M31 and the Pleiades. Quite pleased with the M31, it really is a holy grail getting an image you're reasonably pleased with. I used a 4" F5 ST on its six inch big duplicate as a guide (with the Orion starshoot guider), a Canon EOS300D with cls clip filter on a HEQ5 skyscan. M£! was about 3 hours of data at varying exposure lengths, M45 about 2 hoursish.

Hope you like them.

8807_normal.jpeg

(click to enlarge)

8808_normal.jpeg

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Psychobilly

Psychobilly

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Hi Dean,

How pics look so different on different monitors is a real PITA :smiley: I hope you dont mind these comments as I am only trying to be constructive...

On my calibrated (with Pantone Huey) monitor the M45 image is way to cyan and there are are wierd coloured stars in the M31 image.

Its natural to push data to hard and far to try and get the last bit of info out of it I know I do it quite often as well.

One think I'm learning is when applying changes its better to do a few incremental changes rather than do it in one hit.

Billy...

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glennbech

glennbech

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(Sorry Glenbech, didn't mean to sound like I'd copped an attitude! - They look much better in tiff)

My point is only that I think you've got some real good data that doesn't come out in it's full right. I can see faint details in the outer dust lanes, but the core of the galaxy is burned out and all white. There is also some artifacts that I think might come from Jpeg compression (or local contrast enhancement) see my side by side image for a comparison (the left side is my very recent M31 image). My opinion is that it disturbes the image a bit; but I guess it's also a matter of taste.

Please don't take this the wrong way; I'm only trying to give honest feedback :-) Maybe you could post your original data so that others could play with it?

8816_normal.jpeg

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Cloudwatcher

Cloudwatcher

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High,Dean. I had a look at your image at increased res and I can't be sure but it has the look of having been a tad over sharpened in the centre giving rise to the dark artifacts.I had a quick play in Photoshop,reducing the saturation of the background and using the Hue/Saturation tool on the galaxy,pulled back the green and increased the blue levels. A yellow filter was used on the centre and the dodge and burn tools used to bring out the contrast.The result may not be entirely satisfactory but I think it does begin to show that your image does contain quite a bit of usable data. Cheers CW

Click as usual.

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DeanWatson

DeanWatson

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Thanks guys, all useful comments - Hope I didn't sound prissy! Its not often I subject myself to my peers, I'm entirely self taught and work more or less in isolation.

I was holding off on using a mouse on the picture Cloudwatcher (I may as well paint a picture as do that) but it is an improvement regardless so I think I'll give that a try myself - I'm a big one for doing it myself as then its still 'your' work, however faulted it may be. As to sharpening, I'd not applied any, just used Carbonis local contrast enhancement which I guess uses some of that.

You're right Glenbach, its the dark artifacts that cause a problem - I'll have a look at removing them somehow or smoothing them out. Hope again I didn't sound prissy (When I know full well I did! - Well, you know what its like working for 5 hours with 10 minutes sleep!- Its a wonder the crime rate among amateur astronomers isn't higher than the national average isn't it! A simple offer of a cup of tea in the morning can be met with 'Tea? You offer me tea?!! Damn you, Don't you know that I only drink coffee after a night session? COFFEE dammit! I want a divorce!)

Pig of an object to get just right isn't it? I think God put it next door thinking (Ah! In 3 million years amateur astrophotographers will come along having evolved from the primordial ooze wanting to have a crack at a nice bright galaxy right on their doorstep! I'll show them! Wahhahaha....)

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Psychobilly

Psychobilly

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Hi Dean,

Your doing a great job and as long as you treat your original data as "digital negatives" and never do any work on the "originals" then you have absolutely nothing to lose and loads to gain by trying things out in the processing...regular saving to different files at key points is also recommended as is staying at least 16 bit lossless and full res until the last possible moment.

I'm the same I like to try things out like my layer stacking approach to HDR images there are other ways to do it but as the great man said.... " I did it myyyyyy way..." Ijust I hope "the end" isn't near at least for a good few years yet...

Billy...

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MartinB

MartinB

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Dean, I think you have done all you can with the amount of data you have. M31 is an absolute pig to image, in fact it''s the hardest DSO I know. those outer areas are really dim and need a lot of exposure whereas the core takes no time at all. You've managed to capture the dust lanes which is an achievement in it's own right. You're quite right in wanting to display them even at the cost of the image being noisy. You could have stretched it hard to do this but it you had held back the overall shape and detail would have been lost. It's a toss up really. You've attempted to smooth out the noise on the last one but I much prefer the first version.

The issue isn't the processing it's the the S/N ratio which is down to exposure times and sensitivity of the set up. Yours is certainly one of the better M31s and shows lots pretty much the whole of the galaxy

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DeanWatson

DeanWatson

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Thank you ever so mch for your kind comments martin (and everyone else as well of course - I'm always nervous about posting online to the big wide world, I might think I'm getting reasonable myself but god alone knows what everyone else thinks!), It really means alot!

Its a sod of a thing isn't it?! I'm preferring my final 'cleaner' version now myself and am pleased that I brought out all the pertinent detail without (I think...) overdoing it. I've been doing this all on my own for 3-4 years now 'seriously' and am entirely self taught but stil learning. Thats why its helpful to come on here and hear other peoples thoughts and advice. Whats interesting about astroP i that no one ever seems to agree on processing (other than that the images are pretty!). Its so much a matter of personal taste isn't it.

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