Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
09-28-2011, 10:20 PM   #31
Junior Member




Join Date: Sep 2011
Photos: Gallery | Albums
Posts: 40
QuoteOriginally posted by jimH Quote
I have the same problem with "reds" blowing out with my K10.... If I reduce exposure to eliminate it the whole picture is underexposed.
Another reason to shoot raw files. You can raise the blue and green curves.

Also, many raw converters have a control to raise the midtones, separate from a control to raise the exposure across the entire range. In the free raw converter Raw Therapee, for example, there are two such controls: the Brightness slider and the LAB color space Brightness slider. I often reduce the exposure in RT while raising the midtones this way.

09-29-2011, 07:31 AM   #32
Inactive Account




Join Date: Aug 2008
Location: Michigan, USA
Photos: Gallery | Albums
Posts: 7,485
QuoteOriginally posted by Rupert Quote
I failed to mention it, but that is a nice red bloom Jeff. The color and exposure are very well done. I think that may be the key ingredient in shooting reds? Backing off the exposure...and then correct in processing?
Regards!
Thanks, Rupert.

I've found that it's typically better to under expose and post processes for the photo you want later. Especially with bright colors. With the K5 shooting RAW particularly, it's very easy to avoid the blowouts. I think anyway.

09-29-2011, 11:03 AM   #33
Pentaxian
Designosophy's Avatar

Join Date: Sep 2010
Location: Northeast Philadelphia
Photos: Gallery | Albums
Posts: 1,095
I had this problem more with my K-7 than I do with my K-5. I can see JPEG artifacts in this, as well as some sort of noise reduction, either from the in-camera JPEG conversion or from NR applied by the camera. I think this may be contributing to your loss of texture in the reds. I think shooting in RAW will help with this problem. Furthermore, the detail in solid, primary colors relies largely on that one channel, so you have only 1/3 of your CCD providing information. This would seem to make it easier to lose detail in objects that are intensely red, blue or green.

I also wonder if the texture of the red shirt is really identical to that of the white shirt. Maybe the red just has a more subtle texture. Without any sharpening, I can see a little texture in the red shirt. If I sharpen like crazy, I can see a diagonal pattern in the red, but the white seems to be cross-hatched.

On a side note, I'd be interested to see a comparison of identical, brightly colored Red, Green and Blue objects to see if there is less dynamic range in the red channel.

Another thought: sRGB has a smaller color gamut than Adobe RGB or Pro Photo RGB. I see the largest visible difference in reds. Sometimes I have to work really hard to maintain the hue of a red object (such as a flower) without losing its detail & contrast when converting to sRGB.
09-29-2011, 11:26 AM   #34
Pentaxian
RonHendriks1966's Avatar

Join Date: Jan 2009
Photos: Gallery
Posts: 8,674
Original Poster
QuoteOriginally posted by Designosophy Quote
I also wonder if the texture of the red shirt is really identical to that of the white shirt. Maybe the red just has a more subtle texture. Without any sharpening, I can see a little texture in the red shirt. If I sharpen like crazy, I can see a diagonal pattern in the red, but the white seems to be cross-hatched.

Another thought: sRGB has a smaller color gamut than Adobe RGB or Pro Photo RGB. I see the largest visible difference in reds. Sometimes I have to work really hard to maintain the hue of a red object (such as a flower) without losing its detail & contrast when converting to sRGB.
Wel the texture is different and the red shirt is more smooth from texture, just looked into some pictures. But then again, it is the colour that is going overboard.

I looked at some tests on DxO and indeed the red channel is the smallest of the three.

DxOMark - Pentax K-5 look into color response and maybe some-one can give some insights on this matter?

Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
camera, channel, dslr, k-5, k-5 ii, k-5 iis, k5, pentax k-5
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
K7, Kx, Kr, Information overload jerryleejr Pentax DSLR Discussion 14 09-07-2011 04:29 PM
blue/red channel diffraction test Nass Digital Processing, Software, and Printing 5 09-01-2011 07:48 AM
People christmas stupor / overload.... dcmsox2004 Post Your Photos! 2 12-31-2010 03:33 PM
What's with the red channel at high ISOs? robgo2 Pentax K-5 9 11-24-2010 03:00 AM
How to reduce red channel saturation? jms698 Photographic Technique 8 12-01-2008 09:09 PM



All times are GMT -7. The time now is 12:17 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top