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M31 Andromeda (Yes, I know!)


Tim

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I am starting to think I may be a closet masochist.

We've just had a couple of clearISH nights. However, conditions have been far from ideal for getting decent piccies, you may have noticed the following;

1) Nearly full moon splurging all over the place.

2) Gusty winds, that come right in the last few seconds of an exposure and ruin the shot. (C9.25 with dewshield in place gathers lots of wind as well as light)

3) Wispy high clouds. Not enough to hide the guide star (although 2nd night they did a bit), but lit up enough by the moon to smudge the sky.

4) Sky not really dark anyways.

5) Light Pollution (I'm in Coventry, surrounded by cities on all sides)

We all had those conditions to deal with, no problem then. But I have had this constant nagging constructive advice from the Mrs about getting a decent shot of M31. My previous attempts have been met with scorn and derision, to the point where getting a reasonable image of the damned thing has become almost a rite of passage in our household, so you can imagine how impatient I have been for it to come back out of the murky depths. Anyways, M31 is just about visible at around 22:30 now, and I was determined to get SOMETHING at least of M31.

The kit used consisted of a WO72 Megrez for imaging, (I dont have a field flattener yet as you will see), a C9.25 for guiding (M31's core fills the whole field if I use this for imaging, gonna have a go at a composite in the autumn maybe). Actually taking the snaps was a Canon 400D. This camera isn't modified, and I used it in conjunction with a clip in CLS filter. This combo REALLY filtered out the red light, and sadly this shows big time in the results. Checking the red channel in PS showed it gathered only about 40% of the data gathered by Green. Maybe it would have been better without the CLS filter, but then the sky/moon glow would have overtaken???

I tried shorter exposures, but they didnt make any difference to the background lightness, but the fainter detail on M31 didn't show through.

I have learnt LOADS through this imaging process, and for that reason the ride has been worth it, but honestly, the lengths you have to go to, just to keep the Mrs happy! :whip2:

Wanna know the best bit? When I showed her the pic, she said "That's not one of yours." Heheh, why do I bother!

Here's the small version (big one on UKA) with a single original for comparison.

Cheers

TJ

7206_large.jpeg

And the original;

7207_large.jpeg

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Hey mate, I think you are a ringer. You've got to be too good too quick. :mrgreen:

Your progress has been pretty phenomenal.

I think you will be rivalling Mr Parker in a year maybe.

Great Image by the way. :shocked:

Ron.

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Here is a much less processed version, which I prefer, although it really shows the tint of the CLS filter. The detail in the dust lanes is much clearer I think.

(Thanks Ron, I'll take that as a compliment, although in a year I fully expect to have moved on hobby wise, after all, I've been at this astronomy caper for 7 or 8 months already. Besides, at kelling in spring I locked Rob Hodgkinson in my caravan and wouldn't release him till he revealed everything he knew about photoshop, it's SO much easier when somebody actually SHOWS you how to do stuff.)

7210_large.jpeg

Which do you guys prefer?

Cheers

TJ

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Quote:

(Thanks Ron, I'll take that as a compliment, although in a year I fully expect to have moved on hobby wise, after all, I've been at this astronomy caper for 7 or 8 months already. Besides, at kelling in spring I locked Rob Hodgkinson in my caravan and wouldn't release him till he revealed everything he knew about photoshop, it's SO much easier when somebody actually SHOWS you how to do stuff.)

:laughing3: :laughing3:

there will be loads of good and cheap equipment up for sale then. :lol:

The second image seems to have added something, and the dust lanes do stand out pretty well.

:shocked:

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M31 - is it that time of the year again already!!!

Well done TJ - you've nailed the processing side of this imaging thing extremely well. It's a very nice image. :shocked:

Sam

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Great capture TJ, I personally like your second image - I think it looks the more "natural" of the two.

You might like to try doing a "select colour" in PS on the second image and try reducing the cyan some more. This should give a whiter look to structure which may improve the contrast without pushing the levels and causing the cores to blow out - worth a try.

cheers

RB

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oops yes, forgot to include the exposures etc.

Canon 400D

4 x 1/4000 bias frames

4 x 1sec iso 100 Flats (Didnt use these though, gave the whole thing a wierd look)

20 x 360 sec iso 1600 (first night)

20 x 420 sec iso 1600 (second night)

Stacked in DSS, processed in CS3, little bit of Noels Tools used.

Probably spent 6-8 hours processing though, trying things, deleting etc etc. The second image on the other hand was processed in about 5 mins.

When I can get some decent RED data, I will add that into the mix, which should hopefully bring out a bit of that nice brown in the dust lanes.

Cheers

TJ

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TJ,

I was just about to ask the same question re the processing steps. I have tried from you light blue image but can't bring out the nebula.

Could you provide a step by step of the processing?

John

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That's fantastic TJ- If that's what you can produce on a bad night :shock: I prefer your 2nd offering :lol: Of course you do realise that someone's likely to lock you up in their caravan next time - until you reveal all you know :shocked:

Well done mate :salute:

Karlo

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Processing steps (what I can remember)

1) Open TIFF file saved by DSS. These are typically 98mb 32bit Tiffs. (Using 2xdrizzle makes them 350-495mb!!!!!)

2) in 32 bit mode, do an initial LEVELS. I do these per channel.

3) convert to 16 Bit, and redo levels.

At this point, I suppose about 70% of what you want is right there. The next steps involve CURVES to stretch and brighten the histogram, and lots of actions applied to different layers. For instance, I usually take one layer and guassian blur it to say 3-5 pixels, then brighten it a little, then using layer blend mode, and LIGHTEN, use it to help bring out some of the fainter areas.

I have to say, everything I have learnt so far (think i'm about 1/4 of the way up the learning curve) has been learnt right here. I dont use or visit or forums apart from UKA as an image store. Martin B's primers and Rob Hodgkinson and Kevin beyondvision showed me a few tricks, and the rest you just pick up as you go along. Noels tools are useful, but I find myself using them less and less, as I learn more about how to get the results they give myself.

It is mostly about the quality and quantity of the data I think, just as everyone said at the start. For instance the light blue jpeg original posted above weighs in at 418kb. The original RAW file (always use RAWS) are 11.4mb.

I will post below this post a comparison using single images, firstly the jpeg above processed as best as I can, then the same file from RAW.

Here is the light blue jpeg posted above this one, this is about the best I can do with it:

7225_large.jpeg

In a couple of mins I'll post the same pic done from RAW and not from jpeg.

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Of course you do realise that someone's likely to lock you up in their caravan next time - until you reveal all you know :shocked:

Karlo

If that is the case Karlo, then I need as many as possible to start recruiting green eyed busty long legged redheads/brunettes/blondes etc etc.

Locked up eh? You mean with handcuffs and everything?

:lol:

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