I'm stuck on White Balance Technique

Steve_Goldenberg · #1 03-02-2004, 11:07 AM

I have recently noticed that I'm not particularly happy with the white balance settings coming off my 10D. I don't think anything is wrong with the camera, just that my eye is growing more sophisticated in judging pictures. I was shooting one morning a few weeks ago and I took a picture of an old door. It was about 5 PM and a bit overcast. The first picture was far too cool:

I changed the WB to "cloudy" and it came out better, but a bit too warm:

The second picture was close to what my eye saw, but I believe it could have been more accurate. As you may have gathered from previous posts of mine, I'd rather not have to fix photos in PS if possible - but I really don't yet feel comfortable manipulating the WB yet. I have a gray/white card but I always feel like I'm going to do a worse job using it that the auto-system will do selecting a white balance. I also shoot in JPG because the RAW workflow is too burdensome for my tastes.

So, what techniques do you all use for your white balance settings? What are the best ways to make sure you "got it" in the field if you set a WB setting manually or through a gray/white card? Also, should I use the white side or the gray side of the card for WB? I've always been confused with that one...

-Steve Goldenberg

Noel_Carboni · #2 03-02-2004, 12:05 PM

If you want shot-time perfection, you're going to have to shoot a card and set up a custom WB on site.

Me, I always shoot in Auto WB and fix the images to look the way I want in Photoshop. I've really never come across one I couldn't turn into what I wanted after the fact. I use Image-Adjust-Color Balance mostly. People tell me this tool is not the "pro" way to do it, but hey, it works for me. I also use my actions for a few specific things, like getting rid of an overly orange cast in incandescent illumination.

There is a quick Photoshop technique that sometimes jumps right to the answer, depending on your image: Go into Image-Adjust Curves, select the gray (center) eye dropper, and click on something that's supposed to be neutral gray in the image. I did that with your first door image, sampling the area circled and came up with this:

Sometimes this works even better with the white dropper and choosing something that's supposed to be white. That also has the advantage of normalizing the levels. Doing that on the same spot as above yielded this:

-Noel

Dave_Sauder · #3 03-02-2004, 02:22 PM

You might also consider using the ExpoDisc (www.expodisc.com). Very easy to use and provides very good results with the 10D. In my opinion, it is much easier to use and provides better results than the gray card.

Paul_Lukinich · #4 03-02-2004, 03:06 PM

Or you could use a coffee filter. I tried this over the weekend before I took some shots of youth basketball and I was amazed at the results. It ain't perfect, but it's close enough imo.

Noel_Carboni · #5 03-02-2004, 03:49 PM

Help me get my mind around the use of an Expodisc (or other transmissive diffuser) over the lens vs. a card...

[*] With a neutral card put right up in front of the subject (difficult with distant subjects, admittedly) you're essentially measuring the color of the light falling on the subject.

[*] With the diffuser you're measuring the color of the light reflected off the subject.

These strike me as completely different things!

One might imagine that measuring the reflected light through an Expodisc could result in a biased reading. A real-world example: Shoot a small subject in front of a large and substantially green background (e.g., grass, trees). The light delivered through the disc can't help but be green! How could this possibly work?

In a sense, isn't shooting through an expodisc - save for being a very wide angle and fully diffused view of the light - similar to doing Auto White Balance?

-Noel

Jim_Larson · #6 03-02-2004, 04:29 PM

I understand the natural reluctance to shoot - and process - raw.

I must admit that I shoot RAW and process with Capture One. In capture one, I take the image and adjust the Kelvin temperatue of the image. Fairly quick and easy.

For me, the "eye dropper" technique never, ever, seems to work.

Usually, "AWB" from the camera is not too bad. I have no problem shooting "AWB", as I find fussing around to figure out correct white balance difficult in the field. I personally don't have a clue if conditions are "cloudy" or "clear" from one shot to the next => Maybe I am just lazy, or I have enough to deal with focusing on composition and exposure.

For what I shoot, setting up a grey card on the subject is a nonstarter.

Unfortunately, I don't really think we the shooters have enough feedback on the camera regarding the capture to judge white balance results like we can judge exposure results. I therefore chose to fuss over whitebalance in front of the computer as opposed to out in the field.

The other reason I shoot raw is so that I more readily perform levels adjustments, if needed.

(note: This is not intended to start a Raw/jpeg debate => as everything i do with RAW can be done to JPEGs as well. What I am debating is the case for doing post processing, vs getting the image perfect on the CF card).

Jonathan_Wienke · #7 03-02-2004, 06:00 PM

[ QUOTE ]
Help me get my mind around the use of an Expodisc (or other transmissive diffuser) over the lens vs. a card...

[*] With a neutral card put right up in front of the subject (difficult with distant subjects, admittedly) you're essentially measuring the color of the light falling on the subject.

[*] With the diffuser you're measuring the color of the light reflected off the subject.

These strike me as completely different things!

[/ QUOTE ]

Nope. The Expodisc is white plastic similar to the AWB colorimeter window in the front of the 1D/1Ds. It collects light from a very wide range of angles, just like a gray card will reflect light that strikes it from a wide range of angles. The only difference is that a gray card will reflect light from a ~180 degree swath in front of the card, and an Expodisc transmits light from a ~180 degree swath in front of it. So a gray card measures the hemisphere behind the camera and the expodisc measures the hemisphere in front of the camera. In most circumstances, there won't be much difference between the two.