Author Topic: New Harry Page Video : MUST SEE FOR ALL NEWBIES  (Read 12826 times)

Offline sleshin

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Re: New Harry Page Video : MUST SEE FOR ALL NEWBIES
« Reply #15 on: 2011 May 02 15:07:00 »
Hi Harry,

I find your tutorials to be very well done and informative. I never fail to learn something so I must not be "past your little old video's" yet. :D

BTW, I didn't mean to suggest that doing BN before DBE was incorrect. Just wanted to detail how I approach that step in processing. I have also done it both ways and can't clearly see a difference. Nonetheless, on the chance that faint background "real" data might be altered if BN is done before removing gradients with DBE, I skip the BN step.

Steve
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Sedona, Arizona

Offline RBA

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Re: New Harry Page Video : MUST SEE FOR ALL NEWBIES
« Reply #16 on: 2011 May 03 02:34:53 »
This is for jlake...

You deal with gradients first (DBE) because they're there polluting the real data.
Once the gradients have been dealt with, the (background) data is much more reliable for a BN operation, or anything else for that matter.





Offline Josh Lake

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Re: New Harry Page Video : MUST SEE FOR ALL NEWBIES
« Reply #17 on: 2011 May 03 06:05:46 »
Thanks, RBA, that does make sense. In my mind, the BN was always getting rid of the massive color wash (often red or yellow in my case), then letting DBE get rid of the more complex gradient from the chip and cooling deficiencies.

Offline harist

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Re: New Harry Page Video : MUST SEE FOR ALL NEWBIES
« Reply #18 on: 2011 May 03 08:16:01 »
Quote
In my mind, the BN was always getting rid of the massive color wash (often red or yellow in my case), then letting DBE get rid of the more complex gradient from the chip and cooling deficiencies.

That's the approach I had, but the other skinning method  ;D sounds quite convincing as well.

Tasos

Offline RBA

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Re: New Harry Page Video : MUST SEE FOR ALL NEWBIES
« Reply #19 on: 2011 May 03 11:43:21 »
Actually, if you asked me, I'd say that the best way to work with DBE is by working each channel separately, for a bunch of reasons I've said several times in this forum already.

First, each channel is going to have different gradients, even when using an OSC camera, and each may respond better to different DBE applications (samples placed at different places, etc).
While DBE applied to a RGB image processes each channel separately, it builds its background model responding to the very same set of samples and parameters.
Sometimes this may not matter much, depending on your goals and your data, but other times it may. Foe me it matters every time.

Also, I like to "read" the background model, as it often helps me "guess" whether I'm removing JUST the gradient or something else/less, then go back to rework the samples and/or parameters if I don't like what I see. RGB composite background models often look rather psychedelic and are very hard to "read".

Someone may say that this could be solved by breaking the RGB background model into its RGB components, but then, when you go back to make adjustments, you're fighting three different channels all at once. Personally, that sounds like a much more difficult task than just applying DBE to each channel separately!!

Now, when you apply DBE separately on each channel - and that's how I do it all the time - the workflow seems quite simple and intuitive:
A slight crop on each master comes first, then DBE on each channel (where I spend as much time as necessary), then star alignment, some more cropping, RGB integration, and then finally BN followed by CC.

My opinion. Skin your goats as you like  :angel:

Offline mmirot

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Re: New Harry Page Video : MUST SEE FOR ALL NEWBIES
« Reply #20 on: 2011 May 03 12:24:22 »
I told everyone said the same thing do DBE in each channel seperately along time ago.
In theory, it should be OK on RGB.
It is much better with each filter in practice. The tolerances don't have to so wide for the good filters too.

Max

Offline sleshin

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Re: New Harry Page Video : MUST SEE FOR ALL NEWBIES
« Reply #21 on: 2011 May 03 14:33:14 »
RBA,

I know you've mentioned doing DBE on each channel separately in the past but this more detailed explanation is very useful and makes a lot of sense. Going to give it a try.

Steve
Steve Leshin

Stargazer Observatory
Sedona, Arizona

Offline Nocturnal

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Re: New Harry Page Video : MUST SEE FOR ALL NEWBIES
« Reply #22 on: 2011 May 14 10:57:53 »
I'd like to hear Juan's take on this. My sense is that as long as all samples are on the background (ie. have no stars, nebulosity etc) it doesn't help to do each channel separately. The reason is that DBE already processes each channel separately. It could be that there are disadvantages to applying the same tolerance and other parameters on all 3 planes. Clearly if you process each channel separately you can tweak the settings for each channel. If your samples are well placed you can re-use the sample set assuming registered layers.
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Offline Harry page

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Re: New Harry Page Video : MUST SEE FOR ALL NEWBIES
« Reply #23 on: 2011 May 14 11:01:18 »
Hi

I have tried separate channels and combined and can not find any difference so i stick to the simple way  >:D

Harry
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