View Full Version : What Does This Mean?
wxwax
Mar-11-2005, 09:06 AM
I wandered through photo.net the other day, stumbled across a thread about shooting shows in poorly lit clubs/bars. As you may know, I also do that from time to time.
Here's the thread (http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00BQ2F) for those of you who might be interested - there's good info in it.
But some of the advice is over my Photoshop head. Could someone interpret the following paragraph for me?
I do gamma 3.5 to get a roughly normal tif (even on a normal exposure a linear tif has way too low a gamma), do a 1-pixel median, then dupe the layer and run Grain Surgery on it. I then load the green channel as a selection, invert it, and apply it as a mask, so the shadows are being denoised much harder than the highlights. I apply fairly agressive levels to the mask so that there are larger areas that have full denoise and zero denoise. I then dupe this layer, kill the mask, fill the red and green channels to black (only to save storage space), set the layer options to only use blue, and then run Grain Surgery at max settings on the blue channel. All this gets batched in an action in my absence, and takes about 45 minutes per image on a dual 1ghz G4.
I wandered through photo.net the other day, stumbled across a thread about shooting shows in poorly lit clubs/bars. As you may know, I also do that from time to time.
Here's the thread (http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00BQ2F) for those of you who might be interested - there's good info in it.
But some of the advice is over my Photoshop head. Could someone interpret the following paragraph for me?
It's way over my head too! But I'm just learning curves and how to denoise! I think that person needs to go into a little greater detail. :):
wxwax
Mar-11-2005, 09:30 AM
It's way over my head too! But I'm just learning curves and how to denoise! I think that person needs to go into a little greater detail. :):
I hate to push my luck - he wrote a lot of great stuff and I'm grateful he took the time to do so. Now I'm hoping someone here has the expertise to decipher the gamma stuff!
cletus
Mar-11-2005, 10:49 AM
I hate to push my luck - he wrote a lot of great stuff and I'm grateful he took the time to do so. Now I'm hoping someone here has the expertise to decipher the gamma stuff!
I did some googling on photoshop, gamma, and tiff. Found some info. Take a look here (http://www.siggraph.org/education/materials/HyperGraph/color/gamma_correction/palette.html). It would seem that gamma is an adjustment that shifts the midtones realative to the white and black point. Raising the gamma would tend to darken them while lowering gamma would brighten the midtones - I could be way off on this.
When he says "...a linear tif has way too low a gamma..." that would mean that in a non-gamma corrected tiff the midtones are too bright.
The part that doesn't make sense is " I do gamma 3.5 to get a roughly normal tif" According to the info I was able to find, a 3.5 gamma adjustment would be huge!
I'm not sure how he's implementing the gamma change either. It might be in levels (the midpoint slider in the levels dialog is called "gamma") :dunno
lynnma
Mar-11-2005, 11:21 AM
I wandered through photo.net the other day, stumbled across a thread about shooting shows in poorly lit clubs/bars. As you may know, I also do that from time to time.
Here's the thread (http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00BQ2F) for those of you who might be interested - there's good info in it.
But some of the advice is over my Photoshop head. Could someone interpret the following paragraph for me?Has something to do with colonoscopy I think.....:1drink
wxwax
Mar-11-2005, 11:44 AM
I did some googling on photoshop, gamma, and tiff. Found some info. Take a look here (http://www.siggraph.org/education/materials/HyperGraph/color/gamma_correction/palette.html). It would seem that gamma is an adjustment that shifts the midtones realative to the white and black point. Raising the gamma would tend to darken them while lowering gamma would brighten the midtones - I could be way off on this.
When he says "...a linear tif has way too low a gamma..." that would mean that in a non-gamma corrected tiff the midtones are too bright.
The part that doesn't make sense is " I do gamma 3.5 to get a roughly normal tif" According to the info I was able to find, a 3.5 gamma adjustment would be huge!
I'm not sure how he's implementing the gamma change either. It might be in levels (the midpoint slider in the levels dialog is called "gamma") :dunno
Thanks Cletus. I think is he referring to Levels.
digismile
Mar-12-2005, 09:41 AM
I wandered through photo.net the other day, stumbled across a thread about shooting shows in poorly lit clubs/bars. As you may know, I also do that from time to time.
Here's the thread (http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00BQ2F) for those of you who might be interested - there's good info in it.
But some of the advice is over my Photoshop head. Could someone interpret the following paragraph for me?
Wasn't this the dialog in a Clarica TV ad? The Clarica advisor steps in and translates (Photoshopgeek guy speaking to Photoshopgeek girl) "Hi. I think you're cute. Wanna hookup on Friday?" :rofl
wholenewlight
Mar-14-2005, 10:15 AM
I wandered through photo.net the other day, stumbled across a thread about shooting shows in poorly lit clubs/bars. As you may know, I also do that from time to time.
Here's the thread (http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00BQ2F) for those of you who might be interested - there's good info in it.
But some of the advice is over my Photoshop head. Could someone interpret the following paragraph for me?
Also, maybe you already know this one but "Grain Surgery" is a photoshop plug in.
link:
http://www.visinf.com/gs/ps/
review:
http://www.retouchpro.com/reviews/grainsurgery/
wxwax
Mar-14-2005, 10:46 AM
Also, maybe you already know this one but "Grain Surgery" is a photoshop plug in.
link:
http://www.visinf.com/gs/ps/
review:
http://www.retouchpro.com/reviews/grainsurgery/
Thanks, that one I kinda had figured. But the rest... :scratch
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