M16 Ha- Reprocessed

[PRejto]

More experimenting with the Astrophysics barlow and my TEC140. I think I get a flatter field and better star shape with the barlow at 1.8X rather than 2X. Unfortunately seeing wasn't particularly good over the two nights I imaged this, but I think it looks dramatic. Comments always appreciated. Thanks for looking!

TEC140 + Astrophysics Barlow at 1.8X = .63 arcsec resolution = 1746 mm or f12.6
ONAG Guider + St-i
12 mm Astronomiks Ha filter 126 min (9 min sub frames)
Processed in CCDStack and Photoshop CS-5

75% full frame: http://www.pbase.com/prejto/image/152670115 removed

50% full frame: http://www.pbase.com/prejto/image/152670116

Center Crop: http://www.pbase.com/prejto/image/152670117 removed

Reprocessed 75% http://www.pbase.com/prejto/image/152773146

Reprocessed 50%: http://www.pbase.com/prejto/image/152773039

Reprocessed Center Crop: http://www.pbase.com/prejto/image/152773147

Hoping these are better!!


Peter

[pluto]

Super smooth and great detail! Gotta be happy with that :)

[RickS]

Very nice, Peter!

[batema]

That looks fantastic.

[Larryp]

Marvelous, Peter!

[multiweb]

Truly super data Peter but you've gone a bit heavy handed on the contrast during processing and burnt a lot of the details. There's a lot more to be had. Due for a repro and straight to the pool room. :thumbsup::thumbsup::thumbsup:

[gregbradley]

Great image Peter. As per Marc its a tad overcontrasted and to my taste overly smoothed (noise reduction done?). Ha images usually have a slight grain to them.

But I agree, its very dramatic and the barlow is transforming your TEC nicely.

Greg.

[PRejto]

Thanks for the comments all!

I agree that it is probably over cooked and needs a reprocess. I'm off to New Zealand tomorrow so it will be a while. I've only processed one other Ha image so I'm just trying to find my way with this data. Just so I understand..... Greg, you think the blacks are too black, and the whites too bright, and Marc your issue is the white is too white and burned, but the black may be ok?

This may be a monitor thing. I originally processed the image on my laptop which has a particularly bright screen and shows heaps of detail. I've learned to dial the screen brightness back to 50% doing RGB and the results have been pretty good viewing on other monitors. However, no matter what I've done on the laptop this time the images look quite dark with the blacks showing almost no detail at all no matter which other monitor I view with (except the laptop!), so I used a friends beautiful MAC monitor to do a final levels push. What I presented looks OK to me on that machine. So to be honest I'm confused about how to decide about these matters when the image looks so very different no matter what I do. Anyway, I can certainly cook up a less contrasty version.

Thanks,
Peter

[gregbradley]

Yes plus I was agreeing with Marc the highlights look a tad blown and the image overall seems (at least to my style of processing - not necessarily correct) overly smooth.

But that's picking at it. Its overall a splendid image and I can see why you like it. Its detailed, sharp, has a lot of depth to it. So the criticism is a minor point really of a splendid image.

Greg.

[PRejto]

Thanks Greg! I appreciate your advice. I actually did smooth, but used an inverted mask of the image so that it would only smooth in the dark areas. I didn't detect it smoothing in the highlighted areas (I used noise Ninja). And I sharpened (unsharp mask) doing the reverse. Ie, with a straight mask of the image so that only the highlights would sharpen.

Anyway, perhaps one of you experts would care to have a quick go with my data? I'm uploading the raw image from CCDStack in case someone might want to see how they would present it. I certainly would be curious and I'm sure I would learn a great deal!!

Peter

[PRejto]

Here are two stacked images coming out of CCDStack in case anyone would care to try processing these. I'd love to see some other results!

1. DDP/stretched in CCDStack: http://www.pbase.com/prejto/image/152675016

2. Unstretched out of CCDStack: http://www.pbase.com/prejto/image/152675141

Images are around 16 mb.

Peter

[nebulosity.]

I have no idea what I'm doing and probably wrecked it :lol: Anyway it was fun to play around with :D

Jo

[jase]

Heed the advice of others related to stretching data. Helps to research what your are shooting too - 'know thy subject'. There is nothing wrong with pitch black shadows if there is indeed no information to show but often such contrast doesn't work against strong mid tones and highlights. Too much for the eye to comprehend.

Get rid of the white borders on the pbase images. They do nothing for your images. For web display, if you want to use borders, make them black or dark grey. Disregard the above for a monochrome fine arts project, then eek every pixel for detail and present with a white border as it visually emphasise the detail. An example of this is the work I produced with Chris Soos a few years ago on a ten panel mosaic of the horse head region using a 24" RC- http://cs.astronomy.com/cfs-file.ashx/__key/telligent-evolution-components-attachments/13-73-00-00-00-46-62-95/LB-_2D00_-IC-434-_2D00_-Chris-Soos.jpg
An extreme example, but give you an idea. White borders and colour images certainly don't match. Anyway, keep them coming. Good to see the great progress you are making.

[PRejto]

Jase,

Thanks for your input! I will get rid of the borders for sure. The interface at Pbase isn't the easiest to figure out so I have not invested any time with that.

Re your comments about black I do agree for sure. As mentioned earlier I do seem to have a particularly bright screen that does show detail in sections that may look black to others. I'm not sure how to deal with that without replacing the screen I work with. Hence, my request to look at a "properly" processed image using my data. I could then compare how it looks on my screen and probably make some progress. Thanks again!

I'm traveling so cannot access the image you pointed to in your post. But, I will over the next few days.

Peter

[Paul Haese]

Detail looks good to me, contrast not as dire as what I have read above. I don't think the contrast is that bad, but highlights could be controlled a little better. Stars are nice and round and you seem to have sorted some of the issues we talked about at the conference. I look forward to the finished result.

[Ross G]

Great looking monochrome photo Peter.

I like the contrast.


Ross.

[PRejto]

Many thanks Paul and Ross!

I've just posted an attempt at a reprocess. Not sure if it's better or not!

Peter