Luminous Landscape Forum

Raw & Post Processing, Printing => Colour Management => Topic started by: itopia on April 30, 2009, 02:38:26 am

Title: Xrite colorchecker vs. Whibal card for white balance
Post by: itopia on April 30, 2009, 02:38:26 am
I am looking to balance incandescent/mixed lighting and have not been particularly happy with the Whibal card for white balance
using D700 and Lightroom for processing the RAW files.  The Whi-balanced shots are too much on the blue side and I have to
compensate by raising the color temp.  

How do you white balance using LR and Xrite colorchecker?  Is this method overkill for a majority of incandescent scenes?

Thanks.
Title: Xrite colorchecker vs. Whibal card for white balance
Post by: digitaldog on April 30, 2009, 09:30:00 am
Quote from: itopia
How do you white balance using LR and Xrite colorchecker?  Is this method overkill for a majority of incandescent scenes?

You'd use the 2nd white for WB on the MacBeth. That said, it often that after WB, I tweak the tint/temp slider to a tad warmer as an absolute neutral numerically isn't always pleasing.
Title: Xrite colorchecker vs. Whibal card for white balance
Post by: Eyeball on April 30, 2009, 11:11:18 am
Some additional thoughts, some of which you may have already considered:

- Mixed lighting can always be tricky since positioning of the card and then the subject can be critical.  If the highlights are coming from one light source and the shadows are being illuminated by another, for example, then just about anything you do is going to be a compromise - at least as far as global white balance is concerned.

- There are white balance cards and filters available that are a little bluish.  These will result in a warming balance.  If you consistently like a warmer shot and prefer to not have to adjust the color temp controls in LR, you might want to add one of these to your toolkit.

- Some of what you are seeing may be a result of the camera profile you are using in LR.  If you are using LR2, you might want to invest in a Colorchecker chart  if you haven't already and use Adobe's DNG Profile Editor to create a custom profile for your camera.  You can shoot a primary profile using dual-luminants (daylight and incandescent).  You can also shoot specialized profiles under mixed or fluorescent lighting if you like.  The Profile Editor is pretty easy to use.  Some people complain it doesn't use enough sample points but it helped improve the color accuracy on my camera quite a bit.
Title: Xrite colorchecker vs. Whibal card for white balance
Post by: jackbingham on April 30, 2009, 07:54:07 pm
Mixed lighting is just that. You can't get a "good" gray balance or a "good" profile that handles two contradictory things. If you are looking for neutral grays, then unmix the lighting. If you want grays that favor one source or the other balance under that source and live with the cast created by the other source. But don't spend much time trying to make two sources look like one, can't be done. The problem is not the type of gray card, it's the expectation of what's possible.
Title: Xrite colorchecker vs. Whibal card for white balance
Post by: Gellman on May 04, 2009, 01:29:56 pm
The mixed lighting problem depends upon how the lighting is mixed. If you have two different (color temp) light sources lighting the same spot, then you should be able to use either of the color balancing tools you mentioned to get you close. However, if one light source is lighting one part of your subject, and another area of your subject is lit from the different light source, and you want to optimize the entire composition to a single color temp look, then get a reading from each light source and balance the raw file to the primary source. Then open the file again and balance for the secondary source. Then blend the two versions of your raw exposure with layer masks.