Grey Cards

I recently moved up in the digital world from a basic point and shoot camera to a DSLR and have been reading about grey cards.

Are they really useful?

Thank you,
Pat

In my opinion they are very useful for metering in the film world. With digital cameras the histogram gives you a much better way of determining proper exposure.

Guy

I think Guy gave you good advice there Pat. Getting familiar with the histogram is really important in digital.

I agree with using histograms to evaluate metering.
Does anyone shot grey cards to provide a reference for color balancing?

Guy & Bill--

One of the magazines I shoot for, TRAINS, likes me to shoot a gray card to submit with my images. Their stated optimums for digital capture is to shoot RAW with a 10+mp camera, and include a gray card if possible. I think this helps them to set exposure AND color balance, perhaps? Both of the magazines I shoot for prefer to do their own PS work. They request either: (1) RAW file (2) a slide (3) raw scan of a slide. Since you do your own PS work, know what you want the image to look like, and obviously know your way around your software, it might be less important for you to use a gray card, perhaps? Magazine art directors are constantly complaining about images they received that were done on uncalibrated monitors, oversharpened, and so on. This is a problem you completely avoid, of course.


Kent in SD

Hi Pat,

I use a gray card for color balance in tricky conditions, but as Guy mentioned, rely on the histogram (and blinking "blown highlights") for exposure.

I have to say I'm not very confident of the card I have, however (one of those cheap off-the-shelf camera store ones) -- seems like my images are often really warm when I use it to set the white balance. I'll probably get a gray card from Kodak or Gretag to boost my confidence level, but will continue to use one to set the white balance when necessary.

I have two methods for getting precise white balance. I have a Whibal grey card, and a Expodisk. They both work very well. The grey card is less expensive, but is a little more of a pain to use. The expodisk is used to set a custom white balance on my D2x. It is very accurate. I always use one of the other if at all possible.

I'm with Martin. The gray card is virtually superfluous for exposure measures on digital cameras, but invaluable for doing custom white balances- better than white cards in my experience. There's a good writeup on gray cards for custom white balances over at Luminous Landscape. It's a couple of years old, so you'll have to search in the articles section for it. BTW- custom WB is only necessary if you get into artifical lighting situations, or especially with product shots featuring artificial colors such as modern fabrics. It's tough enough to get a sensor to register some of those colors without introducing the added variable of light color.

Thank you all for your responses, they were very helpful.

Pat

In addition to artificial lighting, I find the need for custom white balance even in the shade -- depending on the type of shade. For example -- at least with the Nikon D70 -- the "shade" setting may work okay for the shade of a building, but not for dappled shade coming through trees (and even then it depends on if their redwoods or autumn aspens!). But it's only critical when you really want/need to get the color right. You can always change the color later in Photoshop, of course, but I'm of the mind of getting things as close as possible to start with, and tweaking from there.