Charles,

Yes, I'm still reading! :)

Thanks, that was helpful. I think that's exactly what's happening, my camera trying to close down more than it can, but still blowing out the whites. I've tried the ND filter setting on my GL2, and that helps, but sometimes I still have to go to the shade. I didn't think of manually stopping down the camera. I usually have it on auto or shutter priority. I suppose full manual would be better, but I'm still learning this stuff.

Trying to shoot around f8 makes sense to me. I'll have to keep that in mind.

Thanks again!

Tim Buege
tjbuege@visi.com

the problem with "white" is that the human eye can't easily distinguish polar white from eggshell white. Ergo, a white balance calibration error occurs. An 18% gray card is "calibrated" so there can be no mistake.

I use RAW image software processing program called Capture One. C1 has a tool that allows sampling part of the image to determine white balance. The software will give feedback concerning the "quality" of the white being sampled. It's incredible how much "white" really isn't white. I think there's a lesson in that observation.

Okay, here's another revision--

1. You can balance with a grey card. A grey card is really white with equal RGB values (reduced luminance). This may even be desirable if lighting is very intense.

2. Using white for white balance is very handy since any white object in the shot, can be used to rebalance the camera. White balance in the shade, if possible. Use ND, aperture, and shutter to bring the exposure down before white balancing.

3. For sunrise or sunset use a daylight or cloud setting.

-----------------------------------------------
Skipping the sweet spot discussion, how critical is the color of white for balancing?

Charles, besides logistics what are the downsides of using a gray card? Would there be noticable differences between video that had been balanced on a properly exposed gray/white card?

Bill, from a theoretical standpoint I can certainly understand that concept, and that an 18% card will eliminate that uncertainty.

I only wonder (and this on a practical level) if the difference between shades of white is as relevant to the vast majority of DV users. Given that different brands of camera have a vastly different color rendition, let alone different models within each brand, there's already a vast range of what is considered "calibrated" video.

Attending my first true tape-to-tape color correction session years ago, I was stunned to learn just how green the Sony standard is (this was using a Betacam). The camera was properly calibrated and white/black balanced, even with "cheated" white balance to improve skin tones, but it wasn't until I saw the before and after versions that the colorist dialed in that I came to realize how far off the "standard" is. I've since heard various theories over the years why Sony cameras tend to the green.

So, playing devil's advocate a bit, is not the color correction process every bit as or more important than assuring a perfectly neutral target; or is it more relevant to select a target that will "cheat" the white balance to a more desirable tone (something like the warm cards, although I would want to add some green into the mix to overcome the stated problem above)? Certainly agreed that a consistent target is desirable.

I agree with you, completely, Charles. It seems a lot of newbie's are hung up on trying to define a "standard" of calibration that doesn't exist in prosumer or consumer level equipment. It's akin to buying $5000 stereo speakers for a Radio Shack stereo system.

At any rate, my own process is that i've found some "colored" white balance cards that biases my white balance in the way you sugested. Works great, and I'm very pleased with my results.

Bill,

Are you saying it's impossible to calibrate the white balance/color on a Canon GL2? I'm not sure what "standard" you're saying newbies are trying to define.

I consider myself a newbie to DV, but I don't consider myself a part of the vast majority of DV users who just want to record the event and put it on DVD. I'm too much of a perfectionist for that. I may not be a professional, but that shouldn't mean I can't learn and shoot stuff just as good if not better.

Personally, I can see the difference between the effects various shades of white have on the video. I've tried normal writing paper, teeshirts, the car, the side of the house. The only thing so far that I've been satisfied with is a sheet of epson heavy weight matte photo paper. To me, is the closest to a balanced RGB white as I've found.

Tim...


Sorry if you took my reference to newbie to heart...I didn't mean it in an insulting way. We were all in the position of learning, I still am. My experience is just that cameras like the GL2, xl1s, anything less than the multi 10,000 dollar DV cams, really don't distinguish between the finer shades of white. For all of the good intentioned new filmmakers, the accuracy of these lesser cameras just doesn't justify too much technical perfection.

The bottom line....experiment with different setups, including white balancing to different shades and colors. Find one "reference" that a-gives you pleasing results and b- that you can duplicate...then stick with it. It's the "b" part that's critical. Can you duplicate your own standard wherever you go? Otherwise, the whole point of calibrating white balance is an effort in futility.

Ok, no insult taken. :)

I can surely understand that a $40,000 camera is going to be more accurate than a $2800 GL2, but on the same note the $2800 GL2 is going to be more accurate than a $600 cam. That's why I spent the money.

As for duplicating white balance, time will tell. Even if I can't perfectly reproduce white balance in every situation, my results should be better than not white balancing at all.

I'm still in the learning phase, realizing that sun and shade are colored different, for example. I'm not trying to get perfect balance. Just closer than I'm at. I've got some shots where the white balance is great, in my opinion. So I think that's still doable.

Most of my white balance problems now are due to my not understanding the nature of the current lighting situation when shooting. That will only come with experience, and help from this forum, of course.

Thanks.

Especially in daylight, when the sun shines, I like to use the preset daylight WB on the XL-1. Scenes in the sun come out a little warmer of tone, scenes in shadows are a little colder of tone. That is perfectly OK & natural and at least the WB is consistent with the ambient light available. Of course this does not work indoors as there are way too many lightsources with different characteristics to use one preset. It would be nice for the XL-1 to have one or two WB memories.

I'm new, but I'll take a stab. If the light exceeds the upper limit of the dynamic range of the sensor, the white balance will be inaccurate. For example, if the RGB components of the reflected light are 125%, 150%, and 200% of the upper limit of the CCD, they will read as 100%, 100%, 100%, respectively.

The auto-exposure corrects that.

I go with 18% gray, works awesome especially in different types of artificial light such as shooting video at night under halogen lights, where you would normally have trouble getting perfect white balance. I shoot a lot of indoor skate parks and the lighting varies all over the place, I would be lost without my 18% gray, makes life simple, also I notice my shots have much sharper focus when I have the correct white balance.

I just had to get some paint for 18% gray, makes it easy to paint objects such as a dolly or a piece of wood to have the correct white balance readily available.

I took my Kodak gray card to Lowe's and had them scan the color and make me a quart of paint, I have seen 18% paint online at outrageous prices, $100 up. This as a lot more durable and cheaper than Kodak Gray cards which can cost up to $65 a set.

Here is the formula - if I recall it was around $8 to $10 a quart

Valspar Ultra Premium
Interior Eggshell finish
Base 4 - Quart size
101-32 107-3.5 109-3.5 113-2Y10

I am pretty sure if you get a gallon it changes the formula, so be sure to tell them the formula is for Quart size, they can convert it to a gallon, if you need more.

Sorry for bringing up an old topic (old wounds)
I figured some people would want the formula
but I'm a newbie, so what do i know

Thanks for the formula, Ralph.

As an aside: it amazes me how many people I work with think that 'white balancing' refers to setting the exposure. I'm about to start referring to the process as 'colour balancing' instead.

Interesting to see a discussion from 2002 pop up! Now that videos can placed into a post, I hope that some find this example of the warmcards to be useful.