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Hello all,

Due to the rain and clouds I reprocessed the Sculptor and Helix Nebulae. A mate came over and  found a astrophotography processing method in photoshop using the "high pass" filter... I gave it a go and it seems like I got a bit more detail out of the Sculptor Galaxy and Helix Nebula data...

What do you astronomers think... improvement or too much?

Thanks for looking,

MG

post-43662-0-26568400-1441368082_thumb.j

post-43662-0-69535200-1441368090_thumb.j

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Very nice. I especially like the Galaxy. Lots of detail and natural looking colours. Thanks for posting.

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very nice nice indeed on both the helix looks just a little bit soft but great images no the less  :smiley:

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I'd say the processing was in good accord with the data. The Helix would benefit from a lot more time but so much of the outer part is terribly faint.

Olly

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very nice nice indeed on both the helix looks just a little bit soft but great images no the less  :smiley:

I thought it came out a bit soft too, then I figured that its a gas cloud, and the seeing was not good enough to get the fine cometary shock waves. There is a hint of them but no cigar... 

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I'd say the processing was in good accord with the data. The Helix would benefit from a lot more time but so much of the outer part is terribly faint.

Olly

Thats just it with astrophotography... there is never enough time spend on exposures.... I had to limit the number of nights I spent of the Helix due to the uncertainty of weather. I could give it a few more nights for gathering Halpha.... might do it too if seeing:time:weather ratio line up.

I do see a couple of problems or reasons why I didn't get the faint nebulosity around the "eye".. firstly it might be the QE of a modded 40D... which brings me to the second problem. I was already exposing for 1800s per sub... I think I did a couple that were 40-45 mins... so just how long subs would I need, and when does it become so long that the time vs useful photons becomes diminishing results.

I do want to give it another night with say 1 hour subs and see what I get, but it is really going to make tat much difference?  or do I just wait till I got a cooled CCD with a much greater QE before I give this object another go at 2000mm.

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I think they look good, especially from a DSLR! My guess is that subs as long as 1 hour would be too noisy. I'd stick with no longer than 1800 seconds. Then again, I haven't tried subs that long myself :)

Sent from my phone using Tapatalk

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I don't know about max sub length in DSLR. I regularly do 30 minutes in CCD and might try longer, I dare say, on ultra faint targets.

I think bigger pixels would help at your FL.

But this is a darned good result, let's not forget.

Olly

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very nice nice indeed on both the helix looks just a little bit soft but great images no the less   :smiley:

I thought it came out a bit soft too, then I figured that its a gas cloud, and the seeing was not good enough to get the fine cometary shock waves. There is a hint of them but no cigar... 

 sorry if this came out wrong it wasnt a dig or any thing like. it is a great image mars and i would be proud of that image well done indeed.

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I think they look good, especially from a DSLR! My guess is that subs as long as 1 hour would be too noisy. I'd stick with no longer than 1800 seconds. Then again, I haven't tried subs that long myself :)

Sent from my phone using Tapatalk

I found that subs that I've done for 45 minutes were no more noisy than the 30 min long ones. Don't misunderstand me when I'm saying that I'm not too concerned about the noise. Basically the noise level on the RAW file is quite high, but the photoshop raw filter does an amazing job on the noise removal, so I'm not worried from the noise side of going to a 3600s sub... How good the PS noise reduction is has to be seen to be believed..... That's why I'm attaching a standard raw to tiff with no noise reduction and next to it the exactly same frame opened in Photoshop with the default setting at 1:1 pixel crop. Helix ISO800 on top and the eagle nebula ISO400 bottom... Halpha 7nm filter used.

I don't know about max sub length in DSLR. I regularly do 30 minutes in CCD and might try longer, I dare say, on ultra faint targets.

I think bigger pixels would help at your FL.

But this is a darned good result, let's not forget.

Olly

Of course doing the exposures on a cooled CCD, which most likely has a much better QE than a DSLR would result in much less noise, would capture fainter details and I imagine that the noise reduction would remove some fine detail in the objects due to either the detail that would have been obliterated by the noise and the nature of noise reduction being to soften a image, very slightly but nonetheless soften it by replacing the noise pixel with a average of the shades surrounding it.

post-43662-0-78079100-1441555151_thumb.j

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very nice nice indeed on both the helix looks just a little bit soft but great images no the less :smiley:

sorry if this came out wrong it wasnt a dig or any thing like. it is a great image mars and i would be proud of that image well done indeed.

Nothing came out wrong at all... I appreciate all comments, and I do agree that's it's a bit soft... I prefer honest opinions to just praise if it's not due, and there is no such thing as a prefect image... It is the critical judgements that help everyone to improve their astrophotography.

I'm happy with my current version since it is a improvement over the last one I imaged... I'm wondering if this is one of the objects that would really benefit from a cooled CCD.

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Nothing came out wrong at all... I appreciate all comments, and I do agree that's it's a bit soft... I prefer honest opinions to just praise if it's not due, and there is no such thing as a prefect image... It is the critical judgements that help everyone to improve their astrophotography.

I'm happy with my current version since it is a improvement over the last one I imaged... I'm wondering if this is one of the objects that would really benefit from a cooled CCD.

In my view all objects benefit from cooled CCD - at the moment. In the next few years that may change but one thing that won't is that, for serious imaging of the full range of DSOs with a single camera, mono will win. You need full control over which wavelengths you record and for how long.

Olly

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In my view all objects benefit from cooled CCD - at the moment. In the next few years that may change but one thing that won't is that, for serious imaging of the full range of DSOs with a single camera, mono will win. You need full control over which wavelengths you record and for how long.

Olly

Soon I will find out, Olly... I just hope it's not going to be a $6000 spend for none or minimal improvement... I'm going for the QSI683.

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