Help with Glowing Red's

Tutorials, questions, demos, questionable images ,,,

Moderator: Moderators

Forum rules
Please ensure that you have a meaningful location included in your profile. Please refer to the FAQ for details of what "meaningful" is.

Help with Glowing Red's

Postby Wocka on Thu Nov 29, 2007 12:00 pm

Gidday,

I seem to have real trouble processing RAW files when my daughter is wearing red. Once I PP them in RAWShooter the pants are absolutely glowing.

But in order to have the other colours / exposure nice it seems this is what has to be.
This has happened to me before with my daughter wearing red pants outside in the sun.

The shot below was taken on the weekend, the flash was pointed at the ceiling. I'm in the process of reading "Understanding Exposure" by Bryan Peterson. So I set the camera to Manual, F2.0 to blur the background and then set the shutter to 1/160 as that indicated correct exposure.

As shot in camera, before PP
Image

Once I have processed the RAW file.
I have added +20 for saturation, but if I take that off it makes no difference in RAWShooter.
Image

RAWShooter Clipped Pixels
This is actually showing the top and pants as being dark ( shadows? ) and not over exposed as per the window in the background and the white patches on the t-shirt. From what I can see, I don't think the red on the pants is over exposed pixels, just red.
Image

I don't have any in camera settings turned on, although I don't beleive they effect RAW files anyway. What am I doing wrong or missing?

cheers
Warwick
=======
Canon 40D : 350D
Canon 18-55mm : Canon 75-300mm IS USM : Sigma 30mm EX HSM DC 1.4 : Sigma 10-20mm
User avatar
Wocka
Member
 
Posts: 472
Joined: Mon Jul 04, 2005 6:05 pm
Location: Northern Beaches

Postby Killakoala on Thu Nov 29, 2007 10:00 pm

You could try using a different colourspace either in camera or in Rawshooter. That may help tone down the colours to a more manageable level.
Steve.
|D700| D2H | F5 | 70-200VR | 85 1.4 | 50 1.4 | 28-70 | 10.5 | 12-24 | SB800 |
Website-> http://www.stevekilburn.com
Leeds United for promotion in 2014 - Hurrah!!!
User avatar
Killakoala
Senior Member
 
Posts: 5398
Joined: Fri Aug 13, 2004 3:31 pm
Location: Southland NZ

Postby sirhc55 on Thu Nov 29, 2007 10:21 pm

Sensors are notorious for not handling red very well - can’t remember why, but Google is your friend. BTW - the first image looks fine before the manipulation.
Chris
--------------------------------
I started my life with nothing and I’ve still got most of it left
User avatar
sirhc55
Key Member
 
Posts: 12929
Joined: Fri Sep 17, 2004 6:57 pm
Location: Port Macquarie - Olympus EM-10

Postby DaveB on Thu Nov 29, 2007 11:30 pm

Definitely looks like an overexposure problem.
As Steve suggested, using a bigger colourspace (profile) in the RAW converter may give you a bit more headroom on the saturated colours. But it probably won't solve the problem.

I don't think RAWShooter is indicating underexposure with those purple areas...
The initial image even LOOKS overexposed. And with the 350D's luminance(green)-only histogram that's hard for you to see when chimping.
This is why the cameras with larger LCDs have R/G/B histograms. Without that you just have to be aware and try an underexposed shot also.

Try taking a photo of a red rose amongst green leaves in bright sun: same issue. Not unique to the 350D either. Welcome to the wonderful world of the in-camera meter! It doesn't see things the same way you do...
User avatar
DaveB
Senior Member
 
Posts: 1850
Joined: Wed Aug 31, 2005 10:57 pm
Location: Box Hill, Vic

Postby jammy2 on Fri Nov 30, 2007 12:54 am

Had a quick look at both original and processed photos in photoshop.

Some of the purple areas in RAWshooter may indicate out-of-gamut colours rather than underexposure/overexposure ie the colours rendered at outside the colour-space used. So choosing a wider colour space may well help though as mentioned saturated reds/purples are difficult to capture faithfully. Choosing a different, less contrasty tone curve may also help
jammy2
Member
 
Posts: 158
Joined: Thu Oct 12, 2006 4:46 pm
Location: Booragoon Perth

Postby Wocka on Fri Nov 30, 2007 11:36 am

Thanks for the response guys.

I changed my colour space from SRGB to AdobeRGB (1998) and the underexposed ( well what I thought it was telling me ) oixels disappeared.

I have re editied the images under the new colour space and while the red isn't fantastic, it's a lot better than it was.

Cheers
Warwick
=======
Canon 40D : 350D
Canon 18-55mm : Canon 75-300mm IS USM : Sigma 30mm EX HSM DC 1.4 : Sigma 10-20mm
User avatar
Wocka
Member
 
Posts: 472
Joined: Mon Jul 04, 2005 6:05 pm
Location: Northern Beaches

Postby macka on Fri Nov 30, 2007 11:45 am

Why don't you mask out the reds when doing your processing?
Cheers,

macka
a.k.a. Kris
User avatar
macka
Senior Member
 
Posts: 1092
Joined: Sat Dec 31, 2005 4:18 pm
Location: North Rocks, Sydney


Return to Post Processing

Who is online

Users browsing this forum: No registered users and 1 guest

cron