Either one better?

I bought an 18% grey card. Perhaps I did it wrong, but I didn't like the look at all. They say white, however, can saturate the luminance in the camera.

Someone on here (I'd credit them but I don't know who it was) had this tip for creating "warm balance cards" that give a warmer look to footage. If you don't have these programs, you can always go to the local Kinko's and get it done.



"To make the cards I used CorelDraw and printed in "best quality" on 8 1/2 X 11 card stock, but
Photoshop should do the trick, too. The color saturation values (C-Cyan, M-Magenta, Y-Yellow, K-Black)in percentages I used were:

Warm 1 -- C/15 M/2 K/5
Warm 2 -- C/20 M10 K10
1/2 Warm: C/7 M/1 K/2
Minus Green: C/10 Y/10 K/2
1/2 Minus Green: C/5 Y/5 K/1"

Be aware that the white balance setting on any DV camera is very sensitive to color in the reference card. This includes the effect of the light being used to illuminate your "white card" during calibration. For example, if you white balance early or late in the day, under sunlight, the yellow tint of the light during that time of the day will affect the overall white balance as somewhat blue and cold. I've found the best white balance lighting to use is noontime on an overcast day, with diffuse light...no shadows....and use that 18% gray.

Good luck.

Well, I have been using a gray card and it seems to work well. I wanted to see what the group was using, plus I think this is an excellent topic for newbie shooters.

BTW, is there some place to get those white balance cards that are different colors? I know that some shooters like them because it can enhance certain colors during production.

Thanks

I don't understand why anyone would use a grey card for white balance. The grey card is for exposure, pure and simple. I can see using a colour for effects but grey?

Which is better for white balance, I'd say white. I have a 3x3 swatch book for creative WB, the most used gels are 1/4 to 1/2 CTB, Straw and CTO

As long as there is enough light, white balancing will work with 18% reflectance cards too. White balancing is a matter of ratio's between RGB (mainly RB) ratio's in a scene, not the absolute light levels.

I picked up a set of white balance cards from warmcards.com

They have a white balance card system that is very portable and comes in different gradations depending on what the available lighting is like.

"Be aware that the white balance setting on any DV camera is very sensitive to color in the reference card. This includes the effect of the light being used to illuminate your "white card" during calibration. For example, if you white balance early or late in the day, under sunlight, the yellow tint of the light during that time of the day will affect the overall white balance as somewhat blue and cold. I've found the best white balance lighting to use is noontime on an overcast day, with diffuse light...no shadows....and use that 18% gray.
"

In general, I have found that white balancing in the shadows rather than in direct sunlight gives the most pleasing results...warmer skin tones and neutral shadows. When the late afternoon sun becomes noticeably warmer, this will preserve that look rather than neutralize it. It's important to keep white balancing through this period before the sun goes down to maintain some consistency.

I have always used a white card, just make sure that you expose for it which may be different than the scene you are shooting. I don't see why a grey card will work also, but if you are moving fast and packing light, there's plenty of white objects around (paper, clean t-shirt) but the card is one extra thing to haul.

So Charles if I understand you right there really is no difference in using a gray card vs. a white card? [b]HOWEVER[B], since most scene likely have white objects than gray ones to white balance the cam on, white is probably a better choice?

I guess the question now would be is how important is it for the white balance target to be really, really white? Could you mix gray card and white cards without much (or noticable) difference?

An 18%gray card is smack dab in the middle of the luma range of black to white. 18% grey, while reflecting only 18% of the light striking it, is, nevertheless 50% black and 50% white. The advantage to using this to calibrate a still camera lightmeter is obvious. Movie cameras are a little different because of the issues of white balance. The camera lightmeter can't tell the difference when it comes to white, between 7.5, 18, 50, 70, 90 or 100 %. I contend that a white card, if the illumination is too bright, will saturate your light meter and hose up the white balance. An 18% grey card is less likely to do this and since white balance only measures luma, the camera doesn't give a rat's axx whether it's 18% or 100%.

I suggest you check out this website: http://www.geocities.com/hollywood/location/5272/expose01.htm

It's got some extremely interesting and useful info about white balancing.

An interesting site, Bill. Two remarks however:
- On yr post: whitebalancing is based on RGB ratio's measurements and not on luma. Saturated luma outputs (about)equal amounts of RGB and like you mention BW corrections aren't possible anymore.
On the article: an incident lightmeter doesn't measure 18%, it just caculates out of the 100% incident light, what the exposure setting need tol be at 18% scene content.

DRE...

Yep....I learned the Zone Sytem on 35mm still photography. It has a use in video, IMHO. Indeed, if I go into photoshop and set up three "cards" at:
1-16, 16, 16
2-120, 120, 120
3-255,255,255
I will get three cards at 7.5 IRE, 50IRE and 100IRE

RGB indeed maps to IRE. Note that most image editting programs will map an RGB of 16x16x16 to the setup value.

you can use almost anything to white balance off of as long as the color components are identical to pure white. one trick that I learned years ago...rather than spending money on "warm cards"...get free "Jungle swatch book" from Roscoe or Lee...they are big (about 3" square) swatches of gel, including all of the Blue Correction and CTO orange gels....just pic the amount of warm or cold you want to add or detract, stick the swatch in front of the lens when you white balance, and tweak as needed.....great if you are in a pinch....the ORTHODOX way to adjust color is to white balance, then add correction with gel over the fixtures..the swatch book is the quick and dirty way too do it.

Steve:

I've never used the warm cards, but I can see a certain advantage in that it can be physically awkward to wield the swatchbook in front of the lens, particularly when shooting handheld. Imagine that late afternoon run-and-gun mode, having to fish the Jungle book out of a pocket and select the gels, all with camera on the shoulder.

And incidentally, great minds do think alike (or in my case, substitute "fair to middlin'" for "great"):

http://www.dvinfo.net/conf/showthread.php?s=&threadid=1356&highlight=jungle+book

Just remember that it is not always desireable to white balance. For instance, if you white balance in the late afternoon light, you eliminate the lovely warm color that is available at that time of day.

Additionally, if you "cheat" the white balance using warm cards or balancing through a blue gel, you are making global corrections to your picture. That means that the blue suit the executive is wearing will become brown. Not a good thing.

The best time to improve the look of the picture is in post, where you have more control over the corrections. This is one of the reasons every foot of film that is shot goes through color timing.

Remember that all whites are not created equal. There will be subtle color differences that the camera will discern, giving you slightly different color balance, from scene to scene as your white source changes. You can buy a Kodak gray card at any photo store, which has 18% gray on one side and white on the other. This will give you a good white standard to use. There is also a new card coming from Kodak, called the "Gray Card Plus." It contains white, black, and gray chips on one side. Besides using it to white balance, shoot a bit of footage under your scene lighting, then correct the footage in post to the proper levels. Then adjust the levels to create your "look."

Wayne

I cant agree about the fix / tweak it in post idea...
I have a LOT of clients who like to alter or tweak color during the lighting process....the feeling of a lot of corporate producers seems to be that the shoot is the time to create the look, not in post. Certainly , having to color correct all the footage in post to get that warm look when you could have gotten it by adding some no-color gold to your fixtures during the shoot just wont make sense to a producer who is spending $400 an hour to edit in a muti-format room. I hate to sound like a fogey, but after shooting for about 20 years in corporate and broadcast video, the notion of "fix it in post " is a worn out and hackneyed cliche, that was always said in sarcasm...people dont even say it anymore, because most production people just assume that its not a smart thing to do. Color correcting in post has traditionally been a process that is done only when you have to because of the time and expense. In addition, there is always a quality hit....so I must politely differ...just because you CAN do it, doesnt mean you should...the job of the cinematographer and the lighting director is to create the look, first and foremost...that should include creating a look, nite or day or late afternoon, happy , sad, whatever the client needs, thru creative use of lighting fixtures, expentables , etc....post is a good time to enhance or fix if YOU HAVE TO...thats being said, I have had to color correct bad footage on occasion, and while I am glad I had the capability to do it, I feel that it should have been shot the right way in the first place....post is no time to be bailing out poor photography.

I think we are talking about different situations, Steve. I was responding to questions regarding white balance in run and gun, or situations where total control of the image is not possible. You are mentioning full blown productions with grip and lighting control at your disposal, with a producer checking a professional monitor, and maybe an art director at your side. Sure, in that situation, trying to get as close as possible to everyone's understanding of what the final "look" is to be, is desirable.

But if you have half a dozen interviews to do, at as many different locations in a day, you may not have the time or the support to make everything look perfect. This is where knowing you have the ability to fine tune the finished product in post is a godsend.

I have at least as much experience as you, and I know that "fixing it in post" is not always a cop-out. I wonder how many times some "creative" white balance that was done in the field, has turned into a nightmare when it was seen in the cold light of post production?

But of course, there are times (think news) when it is not possible to "fix it in post" and you better have gotten it right in the field.

Wayne

Exactly, Wayne. Changes you make and put on tape are permanent. Fixes in post you can change your mind about. Real time color correction (or most any other video or audio change) make this type of work easy, not expensive.

I always go for a neutral setup if I can and change it afterward if I wish.

fair enuf Wayne, there are at leaste as many kinds of shoots as there are people......

I am curious to know what kind of paper you use to print those cards?

Previously, someone posted these CMYK settings:

Warm 1 -- C/15 M/2 K/5
Warm 2 -- C/20 M10 K10
1/2 Warm: C/7 M/1 K/2
Minus Green: C/10 Y/10 K/2
1/2 Minus Green: C/5 Y/5 K/1

Are these in the 0-100 range, or 0-255 range?

I'm quite sure they are percentages (0-100).

Russell

Hi,

I Googled for Roscoe gel books, but was unable to find a source.
Would you please point me in the direction of a place that sells
the Jungle swatch book?

Thanks !

I found the web site, but there is no direct link to the Roscoe Swatch book.

From http://www.rosco-ca.com/,

Click on Products -> Film/Video Products
-> Cinegel -> scroll to bottom for link to
"Would you like to receive our Cinegel Swatchbook? "

Also, there's a SuperGel book:

Click on Products -> Film/Video Products
-> Supergel -> scroll to bottom for link to
"Would you like to receive our Roscolux-Supergel Swatchbook?? "

Hi all,

The topic of warm cards has come up several times in this and other forums and I thought I would offer some real examples of white-balancing through a swatch book. It's simpler, can be done by one person, and is free.

I've posted a page showing the various effects achieved by white balancing through CTB, CTO, and +green (for flouro effects.)

The samples are of a Kodak color patch chart.

http://www.michael-morlan.net/projects/dv500/dv500_color_balancing_with_gels.htm

Enjoy.

They're sitting on the counter at the grip outlet in my town.

M

Responding to the original question in this thread, as noted by Steve Leone, you can use anything to balance with. I've balanced off a grip's t-shirt before. The camera is not using the exposure info to establish balance but, merely, the balance between red, blue, and green components of the target. Balancing off a grey card at one f-stop is identical to balancing off white with the iris shut down. The only thing you need worry about is overexposing the target -- but the camera will tell you if it couldn't get a balance from the overlit source.

M

You must use a white card for white balance. A grey card is for exposure and not for white balance.
Strength and honor
R

I disagree. Anything can be used for white balance, so long as the RGB values are equal. The luminosity level is irrelevant.

Ok, if any shade of grey (equal rgb values) can be used to white balance, then why do people white balance in the shade as opposed to in the sun? I've had trouble white balancing in full direct sun. My GL2 doesn't want to lock in the white balance unless I put the card in less intense light.

And I can't imagine being able to white balance a card with rgb values of, say, (5, 5, 5). Ok, I know, that's a bit extreme. :)

Tim
tjbuege@visi.com

as , I'm sure you're aware, white balancing is about setting the color temperature calibration of your CCD or CMOS. Everything is relative, eh? When you white balance in the sun, the color temp is for bright sunlight, yes? About 5200 deg K? When you white balance in the shade the color temp is about 7200 deg K. Also, shade provides a lot more diffuse light, as opposed to sunlight where you get a lot of sprectral reflection which can mislead your calibration.

But if the subject you want to shoot is in full sun, shouldn't you calibrate in full sun? How do I get around the problem of my GL2 not locking in the white balance when the white balance card is too bright?

Tim Buege
tjbuege@visi.com

that's the reason i suggest using a gray card. the gray card won't give you a luminance value that blows out the sensor in full sunlight. I think you'll find, if you experiment a little, that there is a slight shift in the color balance of the recorded video if record in sunlight vs shade. Sunlight has a high RED component, which drives the overall color balance too blue for my taste.

I stand corrected then..
I don't really think so but...
I apologize if my info was incorrect.
I just don't see how your camera can get to a balance of white unless the object it balances on is white..
Strength and honor
R

With my DP friends and see what they say about it.
Thanks for the info.
Strength and honor
r

Richard...

gray *is* white...only the luminance has been reduced. the color sensing part of the sensor can't distinguish between white and shades of gray.....it shows up simply as luminance with no color info

Yes.. I understand what you are saying.
I guess I never had a problem with white and since I come from film background I just.. you know put grey with exposure..
<My profound apology for any misinfo I gave.
I did not mean to
Strength and honor
R

LOL...
not to worry.....

These last posts were pretty good ones. While everyone is still reading this thread:

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.

If anyone is STILL reading:

I've always used white for the white balance, simply because there's always something white nearby (usually a sheet of paper). I agree that in theory there's no reason why a grey card won't work, it's just another thing to hump around with you.

If you are in a situation where the camera cannot iris down to a white surface i.e. it "blows out", my feeling is that you are shooting at too high a stop to begin with. If, say, the maximum aperture of the lens is f22 and your proper exposure is f16 on the subject, a white card may well overexpose if you zoom in and hit "auto iris" as it bangs to a stop at 22 while wanting to continue on to 32 (which would be next if the lens had it).

What's the problem with shooting a tiny aperture? Similar to shooting wide open, you are not at the "sweet spot" of the lens, and chromatic abberations can occur as a result (color fringes). Also, you've got no-where else to go in case you have to stop down more--what if that subject suddenly dons a white sheet, for instance? It's a ghost movie, I guess...

Anyway, the ideal is to add some ND or go to a faster shutter speed (less ideal) so that the lens perches at no more than an f8--this gives you plenty of room for opening up or stopping down the iris due to clouds, shade etc.

And another thing: I too white balance in the shade so that the overall image tone is warmer, it almost always looks better unless you are going for an effect. Under these circumstances you are likely to be at a more comfortable f-stop and the white won't blow out anyway. The exception would be at sunrise or sunset, when the shade is exceptionally blue and the sun is exceptionally orange, in which case you may be best off using a preset daylight or cloud setting, or using one of your pre-existing midday white balances if they are still available in memory.

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.