Ok, can someone please explain to me what a grey card is for, and what an expodisc would be for?  I'll make myself sound like an idiot and tell you what I THOUGHT.  I thought that I could set the custom white balance by using a grey card.  I've never gotten it to work correctly, thus started asking about the expodisc.  SO, I go in to buy an expodisc today and mention "grey card" and they guy there tells me there is no use for a grey card in digital, and that a grey card is for EXPOSURE.  He said use a white piece of paper to set custom white balance.  Now, I KNOW some of you are toting around that grey card, and since I know you're shooting digital, we can't all be idiots, right?  So, can you please help me understand?  Oh, and I bought the expodisc.  I figured I was there, I've heard good things about it, and whatever it IS for, will probably be helpful.  Plus, I like the little green frog:-)  ok, not really, but I bought it.  LOL

Thanks!

As usual you can pay no attention to the guy at the store... he's clueless.

Gray cards can serve a couple different functions.  One is for white balance and the other is for exposure.  In the days of film (and even now with digital) gray cards were most commonly used to aid in exposure.

Since gray cards are a neutral middle gray (or should be) you can also use them for white balance with digital cameras. You can use an expodisc instead of a gray card, which ever you prefer.  They both have the same function though they work a bit differently. 

The problem with a white piece of paper is that it often is slightly blue which will make your images a little on the warm side.

Jeff's answer is excellent.  You use a referance that you know to be neutral to set white balance.  You use a referance that you know to be middle gray (18%) to set exposure.

Just to clarify: you CAN use a white-whatever for white balance. Yes, it works very well. In fact, the Canon 10d manual says to use it. Subsequent manuals however, do not.

It's just harder to use correctly (I had no problem using it for years) and if you have a 18% grey card, you just don't need both.

Very good answers.

http://www.luminous-landscape.com/tutorials/dig-exp.shtml

 This is a great tutorial about the whole white balance/exposure problems.  I read this on another forum tonight, and thought it might help you.

Jenn

Although it is a bit peripheral to the gray card topic, you do not have to use a custom white balance in camera, even if using a gray card.  Instead, simply take a shot of your gray card in each setting and then back at the computer, adjust the white balance sliders of your post processing program to get your middle gray tone.  Then simply apply that setting to all photos.  Except for when I am trying to do digital IR, I find it less time consuming to just adjust back in the comfort of home/office with coffee or some other beverage in hand.

 

Now for a contentious point of view.  For most situations, getting the white balance "correct" in an absolute sense is really not necessary - or even desired.  What often matters more is being able to create the mood/color shift that is desired.  I rarely use any color calibration approach on scene unless the lighting is really weird or the subject is very saturated (e.g. a redder than red rose).  Instead, I focus on what balance looks good (not necessarily "faithful") on the computer.  This can then be applied to multiple images shot under similar conditions.  For best results, the monitor must be calibrated.  Shooting in RAW is also required.

 

Jim 

Well said Jim.

I certainly fall into the "beverage in hand" crowd when it comes to wb because I find it's a totally subjective adjustment, at least when it comes weddings, portraits and landscapes.

I handle my WB pretty much the same way Jim does.

The WhiBal is an excellent grey card, BTW.

http://www.rawworkflow.com/products/whibal/index.html

Ok,

 You set your white balance for what light source you are shooting at. This will give you accurate colors. When you say I dont set it and let it give me the mood. what? come on.

You shoot this at weddings. So the white wedding dress can come out yellow or what ever else.

You can get photos that are yellow among other things. This is the whole reason you will NOT need to shoot in raw to fix all your mistakes in your color balance and so on.  Shoot it right the first time and you can shoot in jpeg. I use the grey card to get an accurate reading from my light meter. But if you do not set your white balance and take what you get then yes you will definetly need to shoot in raw to fix all your mistakes.

 

I hear of people shooting raw because they say they need to tweak the photos. the print is not going to see the tweaks you need to make if the exposure is right to begin with.

My meter is calabrated with the grey card and my white balance is set on the strobes in the studio when I and in the studio and the exposure is dead on and yes I shoot jpeg.

 

 

Steve,

Can only speak for myself here, but what I wrote is what I do.  I do not shoot weddings, but they are an example where you could want to actually reproduce the absolute real white balance, because people assume that - as you point out - wedding dresses are white.  In other settings where clear color references are absent or subjective, establishing a mood or tweaking the white balance can make a picture more interesting, more flattering, etc.

As long as your exposure is correct, however, correcting white balance on the white dress example that you mention is dead easy in post production.  For that, I would simply click the white point/gray point/black point button (depending on software) and then a white part of the dress or a gray shadow on it.  Voila...instant WB.  In truth, one could click several different places on the white dress and get slightly different answers.  Likewise, if you went pixel peeping on one of your custom white balanced images from your gray card, you would find very few pixels on that dress that were an exact balance of the RGB colors.  I'll bet you a beer on that one.  Therefore, even on what we all know should be a "white" dress, even properly calibrated WB will give a range of colors.  Once you realize that, you also realize that you can subtlely (as much as +/- 200 in some shots) shift the WB value and have almost no perceptible shift on the neutral tones (including white) but pick up a totally different mood on colored tones, like skin.

There is definitely nothing wrong with doing WB on scene, and I do it sometimes myself.  In the end, where my WB values land is likely to be close to where they would if I used a gray card, but they rarely land exactly there.  However, I find that those subtle shifts can really change how a person will react to a picture, both in terms of what mood it sends them and whether they want to buy it.

Cheers,

Jim 

Want something that you can use to set white balance that is next to free, is light weight and takes up no room to speak of?

Buy a can of Pringles, eat the chips and save the white plastic cap. Trust me. It works. Really it does. 

jjhat1:

As usual you can pay no attention to the guy at the store... he's clueless.

The guy at the store might not be as clueless as you think.  He stands to make quite a bit more money if he can convince folks to buy an expodisc instead of a $2.00 gray card. One of my college jobs was a pawnbroker and I still think in a wheel-n-deal mode when it comes to stuff like that.

Ok, snapping back into photographer mode.  A gray card is useful even if you're using an expodisc.  After setting your custom white balance using the 'disc, compose and take a picture with your gray card in the frame.  If you're shooting people, have your assistant or even your subject hold the gray card right below their chin. 

I call this a "control image" because you can use it to check and verify that your custom white balance is good and use it to correct your images if needed.    Here is how it works:

When you get ready to convert your raw images open the control image and check the RGB levels on the gray card.  If your custom white balance is good it should be R=G=B=Gray!   (or within a point or two)    If your color is off, you 'll know because the numbers won't match.  Use your RAW processing software to correct the image and then store your correction and apply it against the other photos without the gray card.  :-)

Steve,

Sure, I have the camera's white balance set for daylight or auto... whichever, but that's not a custom wb.  AutoWB or Daylight gives me reasonable colors most of the time but to get what I want, I always adjust the wb in the raw processor based upon what I see on my calibrated monitor.  If I want the dress white I make it white but I'm often not shooting for accuracy but rather pleasing skin tones.  And lets face it, pleasing isn't always the same as accurate.

If I have time, such as a normal portrait sitting, I'll introduce a gray card into the scene but for weddings I'm not going to take the time to fiddle with a gray card or expo disc every time the light changes.

 

Apple Aperture has both an eyedropper and slider to adjust WB.  With the eyedropper you simply click on a white spot of the photo and WB is perfect.

THANK YOU!!!!  So, I'm not a complete idiot.  Well, maybe-- I DID spend the money for the expodisc, but I was planning to do this anyway.  Simply because of convenience.  It's around my neck, and I USE it.  I thought the grey card was complete neutral so it would work.  And actually, they guy at the store wasn't trying to sell the expodisc either, he told me to use a piece of paper.  I think maybe he was just "old school" and doesn't shoot digital?  Whatever, I feel better now.  Thanks so much for all your help and advice!

rubysphoto:

You set your white balance for what light source you are shooting at. This will give you accurate colors. When you say I dont set it and let it give me the mood. what? come on.

I'm going to say that there ARE times when you want the white balance to be off.  I'm somewhat of a purist, so for me it is rare.  But photography isn't just about making it right, it is also about making it FEEL right.  I'd agree with you 90% of the time though.

You shoot this at weddings. So the white wedding dress can come out yellow or what ever else.

You can get photos that are yellow among other things. This is the whole reason you will NOT need to shoot in raw to fix all your mistakes in your color balance and so on.  Shoot it right the first time and you can shoot in jpeg. I use the grey card to get an accurate reading from my light meter. But if you do not set your white balance and take what you get then yes you will definetly need to shoot in raw to fix all your mistakes.

I hear of people shooting raw because they say they need to tweak the photos. the print is not going to see the tweaks you need to make if the exposure is right to begin with.

My meter is calabrated with the grey card and my white balance is set on the strobes in the studio when I and in the studio and the exposure is dead on and yes I shoot jpeg.

In general I agree with you, especially for a wedding photographer, who I think needs to get it right the first time.  I think wedding photography has been infiltrated with amateurs and it perturbs me.  But that's another subject.  However, for those of us who are shooting as hobbyists, it is often far too much trouble to set a white balance everytime we change situations.  Shooting in RAW lets us correct w/b later if the camera missed it in Auto.

In the studio, you should have everything pretty controlled, so white balance should not be an issue there.

My only disagreement with you about wedding photography (and I don't do it, so I'm just going on logic here) is that if you DID make some weird mistake, shooting in RAW might save a bunch of photos that you wouldn't have been able to salvage from jpg.  I guess my question is, "What is the downside to shooting a wedding in RAW?"  It adds one extra step to your processing, but you can batch them to jpg.  Plus you can do some edits (like cloning out something) BEFORE going to jpg, so you don't have an extra degradation.  You can also crop ahead of time if you like, so you can possibly present "saved only once - ever" jpgs as the final product in many cases. 

The "downside" of RAW... I'm not sure if there is a real downside.  If any, it's a matter of storage space. 

From the discussions on this forum the arguments against shooting raw are a matter of creative philosophy rather than any technical drawbacks.  No one will ever convince me that "RAW is only for correcting mistakes in photography..."  implying that a good photographer has no need for all that extra data and control the raw provides; as if control of the image is a bad thing.  That's like saying whoever shoots negative film, at a wedding for example, is somehow less of a photographer because the film is so much more forgiving than say slide film... or even Polaroids.  I doubt anyone ever accused  (Insert name of famous landscape photographer here_______) of being a lesser photographer for bracketing a shot of the Grand Canyon when shooting color slide film.  Keeping your options open for the greatest amount of creative control is NEVER a bad thing.

I shot film for years before moving on to digital and for the most part I don't miss it much.  However, the one thing I did miss in my first days shooting digital (jpgs) was that there was no longer a latent image on film that responded to processing in a similar way.  Before, the sky was the limit in what you could do with that piece of film in both processing and printing.  In essence, a camera processed image jpgs were, in a creative sense, a big step backward... compared to negative film.  Capturing a RAW unprocessed image brings back all of those possibilities I had with film.

You're right, about the only downside to RAW is storage space, and post processing time. You can't really batch process your RAW files at a wedding as each photo is potentially in a different exposure/color situation. Portraiture is a good place for batch processing with RAW. I shoot about 800-1200 images per wedding and edit every image. Storage space is paramount so I shoot JPEG only for weddings.

I know this is an older post, but I was looking into getting an expodisc disk, but settled on a gray card--this time.  When I got home, a ran across a thread (on another forum) that, when shooting digital, you should NOT use the 18% grey card.  18% should only be used with film shooters.  In fact, digital shooters should be using a 30-37% grey card.  Is this true??

 

http://www.calumetphoto.com/item/IM6700/

If you're using the gray card for exposure, most cameras are set to meter for 18% gray.

If you're using it for WB, any brightness of a neutral tone (no color hue at all) works. White, 18% gray,  37% gray, 99% gray, doesn't matter. The reason white balance cards are usually lighter is because it's easier for the eye to see color shifts in lighter hues.

I got a $10 version of an expodisk (ebay white balance lens cap) and it does a fabulous job of getting accurate colors. Problem is, to my eye, it looks cold (I shoot lots of mixed flash/ambient light). You can batch WB with wedding images (in RAW), you adjust for lighting scenarios, not individual images. (Portraits lit by flash, mixed no flash lighting on the altar, mixed flash/tungsten in a reception, etc). It's easier to do getting them right going IN the camera (as Steve said) but for critical images, I still prefer the extra insurance of RAW, especially when the action is fast.

Just my thoughts!

Shan