Fine Tune White Balance?

L

lawrenceingram

Active member
I know there is an easy answer for this, but I just can't figure it out. I've got an expodisc for white balance, and when I use it with the AWB, it works great for a neutral color. The vectorscope shows it as a perfect dot in the center box. However, I'm wondering if there's a way to take that WB, and just warm it up a notch (very slight adjustment). Tuning it with the Preset, and the function knob (while the expodisc is attached and facing the same light source), I can't seem to get it to start exactly in the center box of the vectorscope as it is with the AWB. It's always above it, moving left or right as I adjust.

What am I doing wrong?

Thanks,

Lawrence
 
The vectorscope is going to show any adjustment away from a balanced neutral white as shifting the reference white value along the color vector you are adjusting. This is normal.
 
The AF 100 has the function to adjust color temp in 100 degree increments.

Its in the user manual how to do this , its easy and very effective.

Great function.
 
Shooter said:
The AF 100 has the function to adjust color temp in 100 degree increments.

Its in the user manual how to do this , its easy and very effective.

Great function.
Click to expand...

Thanks! I see that it's in the Scene File as "Color Temp Bch." I guess that +1 is 100 degrees warmer than the current setting. I'll have to do some testing with it later, but I think that is going to be perfect!

Lawrence
 
I've been thinking about this some also. I want to use a custom white balance so my color's are accurate in the shot and multiple camera's / angles match each other, but I don't want to remove all the "warmth" of my lighting, if I am including 5600 kelvin lights in the shot.

Is is preferable to use a warm card and make a custom WB for all cameras off of that or better to set the color temperature to 4800 kelvin (or whatever) on all of them so they match and look warm?

My concern with using a manual color temperature is that this will not counter-act lighting in an environment with more lights then just color-calibrated 5600 bulbs, I often film in mixed lighting.


I assume with traditional film cameras this can only be done one way right? Using film stock of a certain white balance? No other options?
 
I have often found that 2 of the same cameras (like my EXcams) will give slightly different numeric values for any given scene. So I always balance each camera to the exact same card in the same position as part of getting ready to shoot, whenever possible. This always nails the WB for me.

Sometimes like an indoor live event. I will just preset all the cams to 3200K.
 
Nityananda_SCSMath said:
I've been thinking about this some also. I want to use a custom white balance so my color's are accurate in the shot and multiple camera's / angles match each other, but I don't want to remove all the "warmth" of my lighting, if I am including 5600 kelvin lights in the shot.

Is is preferable to use a warm card and make a custom WB for all cameras off of that or better to set the color temperature to 4800 kelvin (or whatever) on all of them so they match and look warm?

My concern with using a manual color temperature is that this will not counter-act lighting in an environment with more lights then just color-calibrated 5600 bulbs, I often film in mixed lighting.


I assume with traditional film cameras this can only be done one way right? Using film stock of a certain white balance? No other options?
Click to expand...

Color temp for a film response (or a digital image) can be changed by using filters on the lens or on the lights.
 
lawrenceingram said:
Thanks! I see that it's in the Scene File as "Color Temp Bch." I guess that +1 is 100 degrees warmer than the current setting. I'll have to do some testing with it later, but I think that is going to be perfect!
Click to expand...
Hey Lawrence. You are looking in the wrong place. On the outside of the camera, put the white balance switch in the pst position. Push the White/Black balance button on the front of the camera until you get to the VAR position, it will start at 3200K then 5600K then VAR. Once there the function knob will bump you through the increments 100 degrees at a time.

I trust this helps,

Jan
 
Jan_Crittenden said:
Hey Lawrence. You are looking in the wrong place. On the outside of the camera, put the white balance switch in the pst position. Push the White/Black balance button on the front of the camera until you get to the VAR position, it will start at 3200K then 5600K then VAR. Once there the function knob will bump you through the increments 100 degrees at a time.

I trust this helps,

Jan
Click to expand...

Thanks Jan. When I use the expodisc and the vectorscope together, I get a single point which is placed inside the center box when I use AWB. I know I'm really ignorant in the proper use of the vectorscope, but what I couldn't figure out is why I was using the VAR function, and the point was always above the center box and moving diagonally across as I adjusted the temp (but never getting inside the center box). But this morning, it seems to work just right.

I'm not sure what could have caused that. I did go back into the menu and set both Ach and Bch back to 0 before trying this. That shouldn't have any input into the Prst position. I guess it might have been an exposure issue. I believe I want the exposure right at 50 IRE? Maybe I'm not doing that right. Anyway, it's working great today. Thanks for the help!

Lawrence
 
I have a GF1 still camera which has the color temp adjustment like the AF does and it has one other thing.... an X-Y matrix for fine tuning plus and minus green in addition to plus an minus blue- yellow. If the AF had this feature it would be really sweet.
 
Jan_Crittenden said:
Hey Lawrence. You are looking in the wrong place. On the outside of the camera, put the white balance switch in the pst position. Push the White/Black balance button on the front of the camera until you get to the VAR position, it will start at 3200K then 5600K then VAR. Once there the function knob will bump you through the increments 100 degrees at a time.

I trust this helps,

Jan
Click to expand...

Thanks, Jan for bringing this up. The VAR position is a great feature on the AF100. I've cut 8x12" light blue Savage Matte boards for years to warm white balance but with VAR, I just set my outside temp to 6300 degrees and get a perfect warm image. On my 7D I set the white balance to the 'open shade' position and easily warm up the image for both stills or video. What I like about VAR is that you can thumb thru the settings and pick the color you want, indoors or outside.
 
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