why did custom WB produce poor results outside?

[wolfestone]

I've recently tried using custom white balance on my eos 350D. My method for setting the custom WB was to photograph a sheet of regular white copier paper, using manual focus so that it filled the entire area. At the beach, I did this holding the paper out in front of the camera, not in the shadow, and facing out toward the ocean. Essentially I lined up the shot I wanted, then held the paper up in front of the camera.

Here's the outcome:

I know I should probably be using neutral gray instead of white, but I'm really interested to learn why the results were so terrible at the beach. Should I be using custom WB outside like this, and if so what would be the correct method for setting it? Custom WB definitely improved the indoor photos, it removed the orangish tint and gave a very accurate reproduction.

 

[Robin Usagani]

so you are 100% sure you defined which photo to use for white balance? Personally I never use custom when Im outside. I just change it to the sun preset. ONly time I use custom is when I am inside.

 

[ababysean]

I've recently tried using custom white balance on my eos 350D. My method for setting the custom WB was to photograph a sheet of regular white copier paper, using manual focus so that it filled the entire area. At the beach, I did this holding the paper out in front of the camera, not in the shadow, and facing out toward the ocean. Essentially I lined up the shot I wanted, then held the paper up in front of the camera.

Here's the outcome:

I know I should probably be using neutral gray instead of white, but I'm really interested to learn why the results were so terrible at the beach. Should I be using custom WB outside like this, and if so what would be the correct method for setting it? Custom WB definitely improved the indoor photos, it removed the orangish tint and gave a very accurate reproduction.

Looking at the two beach photos it looks like you moved a bit?
The thing is with cwb is that you have to be in the same spot, same settings, and save light, which we all know changed every second outdoors, if just by cloud cover.
CWB outside is almost pointless. Just shoot auto and change it in RAW.

 

[wolfestone]

Sorry, I should have mentioned - those beach photos aren't identical (but that might explain a lot right there).

I definitely used the right picture to set the white balance, but I set it once at the start then moved around to take pictures.

I didn't realize CWB was sensitive enough to be used on a per-shot basis, that's great to know. Thank you.

Sounds like I should steer clear of using it outside during the daytime.

 

[KmH]

White copy paper isn't always actually white and often does not reflect all colors equally, which is what is needed for an accurate white balance.

That's why using a quality gray card produces more reliable results.

Here is some info on a top quality grey card: Michael Tapes Design - LensAlign - WhiBal - IJFR - WhiBal Certified Gray Card for White Balance

 

[table1349]

Ahhh....The tricks of the human mind. That was not a custom white balance. You mind sees the paper as white, when it is not. The Whibal is a good option as are some of the other products such as the Lastolite Ezybalance. You may want to even consider one of the newer 12% gray targets that are starting to be used. They are geared more towards capturing the proper mid-tone range.

 

[wolfestone]

Thanks again all, the advice is invaluable.

 

[JenR]

White copy paper isn't always actually white and often does not reflect all colors equally, which is what is needed for an accurate white balance.

That's why using a quality gray card produces more reliable results.

THIS

Your paper probably is not true white. Invest in a good digital gray card, they are generally cheap and well worth the money.