DPChallenge: A Digital Photography Contest You are not logged in. (log in or register) 
 

DPChallenge Forums >> Hardware and Software >> A few PS questions
Pages:  
Showing posts 1 - 10 of 10, (reverse)
AuthorThread
 05/09/2006 01:18:28 PM · #1
On another forum, I read about a techinique called "defogging". This is done with the USM with settings that are along the lines of 30-30-0 or someting like that. Do any of you use that techinique or even heard about it? If so, what are you feelings on it? What it is supposed to do is boost the contrast but the specifics escape me at the moment.

Second, how do you add contrast to your pictures? Any special techniques you'd like to share?

And last but not least, I shoot raw and of couse I have no in camera noise reduction. I have tried to smooth the image out with Adobe PS CS raw converter but I just can't quite get it right. It is the sky most of the time which I have to end up smoothing out with a filter called Dynamic Skin Softner in the nik ColorEffex series. Is there a better way?

Thanks in advance!

June
 05/09/2006 01:23:34 PM · #2
De-fogging usually refers to methods to increase overall contrast. In addition to the PS "brightness/contrast" adjustment (which I never use), there are two others that I use:

1. Curves - developing the "s" curve to boost contrast
2. "Over sharpening" which was what I call the USM with settings of about 35/85/4 (or thereabouts).

Both these methods will work for getting rid of a fog. Be careful though, because both can also result in an image that is overly contrasty and both can blow highlights easily.
 05/09/2006 01:24:28 PM · #3
Originally posted by Chiqui:


And last but not least, I shoot raw and of couse I have no in camera noise reduction.


What do you mean by this? The 20D does have in-camera noise reduction. That's one of the reasons I'd love to upgrade to a 20D or 30D.
 05/09/2006 01:28:26 PM · #4
Originally posted by strangeghost:
Originally posted by Chiqui:


And last but not least, I shoot raw and of couse I have no in camera noise reduction.


What do you mean by this? The 20D does have in-camera noise reduction. That's one of the reasons I'd love to upgrade to a 20D or 30D.


I have it turned off, besides, if you shoot raw the camera won't do noise reduction.

June
 05/09/2006 01:30:19 PM · #5
Originally posted by Chiqui:


I have it turned off, besides, if you shoot raw the camera won't do noise reduction.

June


Ah, I didn't know that, but it makes sense.
 05/11/2006 07:11:24 AM · #6
bump
 05/11/2006 07:14:34 AM · #7
Originally posted by Chiqui:
bump

Bump? - You're in the wrong timezone now, you need to give people another 2 hours to wake up. :p
 05/11/2006 07:35:15 AM · #8
I just tried the USM sharpening on the image I was working on and holy crap, cool! It looks like it could be a little tricky to use, and it did blow a highlight but used on a second layer it was easy to just erase it from the highlight and problem solved. I'm not sure I'd use that all the time but it actually worked really well on that image. It definatly removed the 'grey fog' of non-contrastyness. Hows that for technical jargon?

Anyway my usual contrast is a combination of Curves and Levels, helped out sometimes by the 'contrast' slider in Capture One. A really cool trick using curves is to CTRL+Click (option+click for Mac) on a point on the image which will add that point to the curves dialogue. You can get a lot of control over the tones in your image that way.

For noise reduction I don't have a ton of experience with it, but Neat Image has always worked really well for me using the 'auto' mode. If necessary, I go back afterwards with the history brush and 'erase' the NI from areas of really fine detail. Or NI a seperate layer and use a regular eraser, both work pretty well.

And in two hours, I'll probably be going to bed :P
 05/11/2006 07:39:38 AM · #9
Originally posted by Chiqui:
I have it turned off, besides, if you shoot raw the camera won't do noise reduction.


I'm pretty sure it does. But it only does it on exposures that are 1 second or longer. You'll know it when it does it - because it doubles the amount of time to take the picture (i.e. for a 10 second exposure, the shutter will be open for 10 seconds, then it will be closed for 10 seconds while the camera does noise reduction).

HOWEVER< I suspect that is not what you're talking about at all. From your description, I'm guessing that you are seeing jpeg artifacting up in the sky as the gradients are hard to represent properly in an 8-bit jpeg. Try converting to a 16-bit tiff instead, and do all of your editing in 16-bit mode. Then flatten the image at the end and save it to jpeg.
05/11/2006 08:39:43 AM · #10
Originally posted by Chiqui:
On another forum, I read about a techinique called "defogging". This is done with the USM with settings that are along the lines of 30-30-0 or someting like that. Do any of you use that techinique or even heard about it?

The "trick" to this technique is to use a low "Amount" setting with a high radius. For amount I use between 12-16%, diameter is 48-64 pixels, TH = 0.
Pages:  
Current Server Time: 09/24/2025 12:08:42 PM

Please log in or register to post to the forums.


Home - Challenges - Community - League - Photos - Cameras - Lenses - Learn - Help - Terms of Use - Privacy - Top ^
DPChallenge, and website content and design, Copyright © 2001-2025 Challenging Technologies, LLC.
All digital photo copyrights belong to the photographers and may not be used without permission.
Current Server Time: 09/24/2025 12:08:42 PM EDT.