M44 - The Beehive Cluster (thirteenth night)

[MikeWilson]

Hello earthlings,

It was a cool and moist evening with a full moon. The moon was rising but wasn't in a direct line of sight with the target. Moisture was reflecting light pollution to the extend that the nearby constellation of Leo was barely visible. However nothing was going to stop me attempting to image something!

Temperature ranged from 17 to 22 degrees centigrade and dark calibration images were taken at the start (~22c) and end (~17c). I stacked the whole lot together in DSS and the darks did a fairly good job of reducing noise, despite the five degree temperature range.

M44 - The Beehive Cluster by MikeWPhotos, on Flickr

14 x 5 minutes lights

19 darks

19 flats

Tonight was also first light for our new garden fence, which effectively blocks out the majority of the streetlight light tresspass (yay!), and for the first time I was unable to see the cables in the grass while I was working - I tripped and landed on my knee. It hurt, but it's worthwhile for the extra bit of light cut!

On the flipside, some of our neighbours down the lane seem to be waging a war on who can have the brightest security lights. In the past fortnight there have been three new security light installs and all of the same type (flat wall mounted, non adjustable, 500watt type annoying B&Q specials....).

Comments, criticism, unfettered praise, it's all welcome :-)

[GrantEb]

Nicely done Mike, I like the star colours.

[MikeWilson]

Nicely done Mike, I like the star colours.

Thanks Grant, I like the star colours too.

When I opened Photoshop to process the stacked .tiff, it was apparent that all of the star colour was retained within the edges of the star and the center of the stars had blown out to white.

The 'Increase star colour' action from Noel's Actions performed perfectly, taking the colour from the edges of the stars and applying it a little deeper. Not all the way to the middle (sadly) - does anyone know a trick to make the star colour effect stronger (apply all the way to the centre) without iterating the action?

Clear skies,

Mike

[AndyUK]

Hi Mike - VERY nice... no particular noise evident at all, and those star colours are superb! I'm afraid I can't answer your query about getting Noel's actions to bring the colour in all the way to the centre though - I've often wondered what parameters they use, but I doubt Noel would let that particular secret out!

[Deneb]

What you can do Mike ! I might be wrong here, but you can download something called StarSpikes Pro from the Noel Carboni Website - a trial for 14days, you would be able to slightly up the star colour with it & maybe change the orientation of the spikes.

Nadeem.

[Deneb]

Hope you don't mind Mike, but I had a fiddle with your M44..

Nadeem.

[MikeWilson]

Hi Mike - VERY nice... no particular noise evident at all, and those star colours are superb! I'm afraid I can't answer your query about getting Noel's actions to bring the colour in all the way to the centre though - I've often wondered what parameters they use, but I doubt Noel would let that particular secret out!

Hi Andy,

Thanks for your comments I'm pleased with the colour (bear in mind the subs were five minutes long) and I suspect that if I used shorter 2-3 minute subs that I wouldn't have had the colour at all.

Hope you don't mind Mike, but I had a fiddle with your M44..

Nadeem.

Hi Nadeem,

Not only do I not mind, but I LOVE what you've done. More precisely, how did you kill that gradient?

Mike

[roundycat]

Some thoughts about star colour. If you expose the stars for too long each channel, whether CCD or DSLR, will saturate and you will not have any star colour. Figure this one out for yourself as it depends on camera, filters, scope and sky transparency.

The main reason you have very little star colour is almost certainly due to over stretching in Photoshop. Don't forget that when you increase saturation or sharpen usually all three channels will increase in value. If you have values approaching 250 levels before you start to sharpen or saturate they will all blow out at the next processing step.

A couple of iterations of Image - Adjust - Saturate in PS will help a lot but do it before you over stretch anything. Then don't overstretch anything!

Dennis

[Deneb]

Gradient Xterminator Mike, you can download a 30 day unlimited trial.

GradientXTerminator

Nadeem.

[rfdesigner]

Not only do I not mind, but I LOVE what you've done. More precisely, how did you kill that gradient?

Mike

I was looking at the same thing..

I used IRIS (free) and got this, I used the subsky command, although I had to snip off the border as it was throwing the alorithum.

Subsky uses a 2D polynomial to match and then remove the sky gradient. I limited it to 1st order (offset + straight slope) using the setsubsky command.

Derek

[Neilius]

One of my favorite d.s.o's. Great image; I never tire of looking at the Beehive!

[MikeWilson]

Thank you for your kind words, Neilius; your advice, Dennis; and both Nadeem and Derek for the excellent gradient removal advice.

Now, GradientXterminator looks very compatible with my workflow but here's a thought... I shall at some point soon be moving to CCD and therefore I'm assuming that I'll need some capture software. Nebulosity has my eye at the moment although I haven't evaluated it and I don't think it has a gradient removal tool.

I'll have a play around with IRIS (since it's free) and also see if I can get my head around PixInsight (LE) to see if I can replicate those clean backgrounds that you've both managed to achieve!

Thanks very much, I thought I'd have to live with that gradient!

[roundycat]

Buy MaxIm. Don't be put off by the price as it will last you a lifetime, more than can be said for your scope, cameras, car etc.

Simple gradients can be removed in PS as part of the post processing. Just use a gradient quick mask and Curves.

Dennis

[MikeWilson]

Buy MaxIm. Don't be put off by the price as it will last you a lifetime, more than can be said for your scope, cameras, car etc.

Simple gradients can be removed in PS as part of the post processing. Just use a gradient quick mask and Curves.

Dennis

Maxim DL (Pro) seems to be the way most people end up going although the license cost seems rather high for me. Heck, I'm only technically at the end of my second week of imaging.

Thanks for the tip about quick masks - I've not used them before. I'll Google for a tutorial.

Best,

Mike

[roundycat]

try this one Gradient Reduction

Dennis

[MikeWilson]

try this one Gradient Reduction

Dennis

Thank you! Much better than the other ones I've found.

Best,

Mike