Hello... I am trying to get a clear answer on white balance cards. In taking a test shot to set the white balance on my D90 (PRE), I shoot a 18% grey card under the existing lighting conditions. In doing some investigation I find photographers are shooting off a digital white balance card which is pretty much pure white. It seems that the 18% grey is used more for metering not for use as a base to set the white balance. Can anyone clarify this for me. Thanks, Ron
#1. "RE: Digital White Balance Cards or 18% Grey Cards" In response to Reply # 0 Sat 02-Jun-12 12:46 AM by elec164
The target needs to be spectrally neutral. Problem with some gray cards is that lower cost ones might not be spectrally neutral. That's not a problem when setting exposure, but can cause an errant per-WB setting.
For that matter any shade of gray can be used, as long as it is spectrally neutral.
#2. "RE: Digital White Balance Cards or 18% Grey Cards" In response to Reply # 1
Fountain Inn, US
This is a well discussed topic and there are as many opinions about it as there are photographers.
I will here offer mine.
The only time you will need scientifically perfect white balance is when you do that shoot for a paint company or fabric company who will demand EXACT matches to their pride and joy colors. Otherwise it's quite subjective on your part. What looks right to you.
Use anything white at the site. There is always something. I use napkins, a white tee shirt, a table cloth, anything white. Shoot a WB preset of the item then shoot away using that preset. IF you're at a wedding for instance that takes place in more than one room with differing lighting, create a preset in each room and save it, then remember to change it when you move from room to room. You do NOT need a spectrally, scientifically balanced, camera branded (and therefor expensive) product.
Better than that, simply use auto white balance, shoot everything in RAW, making sure to shoot something white in each environment, then in post processing, do a white balance grey-point adjustment on that photo in each group and do a batch process on all the rest. Then you don't have to deal with it at the shoot.
#3. "RE: Digital White Balance Cards or 18% Grey Cards" In response to Reply # 2 Thu 07-Jun-12 04:46 PM by elec164
>Use anything white at the site. There is always something. I >use napkins, a white tee shirt, a table cloth, anything white. > Shoot a WB preset of the item then shoot away using that >preset.
For the most part I would agree with you, except for one point.
Using anything white at hand is OK as long as OB’s (optical brighteners) are not present.
Some soap manufactures use OB’s to make your whites look whiter; and some paper manufactures use OB’s to make cheaper pulp that would normally look yellowish look white, and some white papers with a yellow tinge look even brighter.
OB’s will give you an errant pre-WB setting. If you want something cheap that’s easy to carry around and give relatively good results, white coffee filters work well.
Actually if you wanted a good read on a comparison of different WB setting products, check out this article. The surprise of the group was a Melitta white coffee filter for $.01 compared to much more expensive commercially produced products.
#4. "RE: Digital White Balance Cards or 18% Grey Cards" In response to Reply # 3
Fountain Inn, US
>For the most part I would agree with you, except for one >point. > >Using anything white at hand is OK as long as OB’s (optical >brighteners) are not present.
Pete, just my personal opinion, but I think we have a tendency put WAY too much emphasis on these technical fine points. I think you'd be very hard pressed to find the difference in a photograph that used an "OB" enhancer in the table cloth, and one that was taken off an old well worn tee-shirt.
I would bet that most wedding or event photographers and even fashion photographers will tweak the finished white balance by eye to suit their own artistic tastes considerably more often than they will insist on perfect optical white in a specific photograph.
And you have to remember that a white object in an image is never just one shade of white. If it bends around an object, the shadow is a completely different color than the highlight so it is only the illusion white that we are looking for anyway.
My personal preference, and it is simply that, a preference is NOT to carry a lot of extra stuff in my bag, even if it's a .01 cent coffee filter. There is ALWAYS something white enough in the image to get a white balance reading from. Ive even used the whites of eyes in post to get a greypoint reading, then tweak the final balance to my own taste.