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DPChallenge Forums >> Photography Discussion >> Getting the Right White Balance in the Studio...!
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 12/01/2008 05:00:38 PM · #1
Hi All,

Please can anyone help me .

I have a Canon 40D which has the handy function of allowing you to take a snap of something white (A4 Paper) and you can use that as your custom white balance. Which seem to work very very well.

My Questions are....

1) Should I be Shooting White (A4 Paper) or an 18% Gray card - and what's - the difference? Better WB with Gray?

2) Every time the lights change to brighter or lower - do i have to repeat the white balance trick 'again' (I did a little test here at home and it did make a difference - just looking fro conf)

cheers all.........

Tony :)

12/01/2008 07:29:51 PM · #2
Most 18% gray cards are not color balanced. They're just for setting the exposure. You need something like a whibal card to do custom white balance.

If you're doing something like product photography where the white balance needs to be exact every time, then you'll need to set the white balance every time. For most people, however, total exactitude is probably overkill.

Whether or not the color changes when you turn your lights up and down depends on what lights your using. In glittering generalities, this is mostly a factor of the price of the lights.
12/01/2008 07:36:51 PM · #3
I think the simple white piece of paper usually looks good enough.

Shooting in RAW also helps, since it is very forgiving AFTER the fact.

I found I had the biggest problem when I used my very cheap and nasty lighting kit (strobe and softbox) on one side, with natural daylight coming in the window from the other. The artificial light was very yellow compared to the daylight, so I had two different temperatures to deal with. Not a good idea!
 12/01/2008 07:58:49 PM · #4
If you find yourself wanting, or needing, to get custom white balance readings, then may I suggest looking into a white balance filter, such as an ExpoDisc.

I use one almost all the time and it hasn't let me down. If you do plan on going for a filter, get the largest possible size so it will fit on any lens that you might be using. Such as a 77mm or 82mm...

Best,
-AC
 12/01/2008 08:00:35 PM · #5
I shoot a Photovision Digital Target. I took a studio lighting class this summer and was introduced to this thing for getting a good exposure and custom white balance. I am convinced that it is THE GREATEST tool I have now for shooting under any conditions! I have seen them come up in the forums here for sale on occassion. I think I bought a 14" from someone through DPChallenge.

Photovision Digital Target

Here are a few of my most recent sessions...sorry, I don't have the chance right now to upload samples to dpchallenge.

Recent Photo Sessions

Message edited by author 2008-12-01 20:02:13.
 12/01/2008 08:18:42 PM · #6
OK, I used to do this with film for a living and it takes some effort, but there are a couple of ways to go about it depending on how critical your needs.

1. You can use a color meter to find the temp of each light source and gel it accordingly to correct it to whatever WB temp you choose. Color meters are less expensive than they used to be, but they're still in the $7-800 range.

2. Buy some kind of WB target, set your camera to reference that WB under illumination from one light, then shoot it under each lamp and determine what gel each light needs to achieve the same WB. Good strobes from a good manufacturer with matched tubes will be really consistent, others not so much.

3. If you're using mixed light, (i.e. strobes and ambient light (incandescents or window light) you'll need to correct your strobes to match the ambient source and set the WB accordingly.

You can try to set for an average WB using something like an ExpoDisk, but if the difference in sources is significant, you'll never get the WB right since if you correct a strobe illuminated area to neutral, the ambient lit area will have a tint and vice versa. That's something you just can't fix with Photoshop.
 12/01/2008 08:20:31 PM · #7
What strobe system are you using? My AB's have a set WB setting to them. Most decent strobes will tell you the K to set your WB too. Somewhere from 5400-5600. I think 5400 is what my AB's are. I set to 5400 and shoot raw and can make some minor adjustments if needed. But I rarely ever do.

Matt
 12/02/2008 04:48:37 AM · #8
Hi All,

Thanks for all the great info....

I will be using 2 x Bowens 500 geminis - one with soft box on with brolly

Studio is in the back of a shop curtains closed - I can turn off the tungsten strip lights above.

Any tips ?
12/02/2008 08:08:23 AM · #9
Here is a link to a page that gives the Specific K value of Gemini lights. Not sure if these are the exact ones you are using or not.

Linkie

Looks like the specified color is 5600. So I'd set it there and make minor adjustments afterwards. Its always better to set a specific K value and have them consisitant then use AWB, depending on what is filling the frame AWB can be fooled.

Matt
 12/02/2008 08:34:32 AM · #10
You can't go by the 'color temp' of the strobes unless three things are certain - one is that 100% of the light is coming from the strobes and there is in ambient getting in there, and second is that the strobes do not vary on color over their output range or as they age, and thirdly that any modifiers you are using are not affecting the color (some things age and you can get softboxes with white, silver or gold reflectors inside).

Teh photovision taget is fantastic. Put it in the subject's position, fill the frame (or on canon's the area inside the outer focus points) and take a shot. If the exposure is right (three spikes on your LCD) then you can use that image for custom WB. Take one more shot to make sure a)it looks right -gray looks gray, and b) make sure changing WB didn't change the exposure (it indeed can so you must check)

I hear the whibal is great and I like the exposdisc as well, but the target is best in the studio IMO and based on my experience. It's also MUCH easier, more accurate and faster to get the WB right at the time of the shoot than trying to figure it out later.
 12/02/2008 08:57:07 AM · #11
Why not take a custom WB reading with your camera? I do that and the WB is spot on. It's so easy to use too.

Or I just leave it on Auto and correct it later. I never wanted to do it this way but I find it eliminates the hassle and saves lots of time. Of course for customer shoots it's always important to get it absolutely correct.
 12/02/2008 11:43:35 AM · #12
I would never use AWB as you will end up with differences between shots. Makes batch editing impossible.

I usually use flash or sunshine WB and any other adjustments I do in Lightroom on my raw files (Though seldom necessary)

Don't worry about your tungsteon lighting. A flash is so much brithter that you can usually leave it on (Unless doing lowkey or dragging the shutter.

Modern strobes are very colour stable so you wont / shouldn't have to do any re calibrations between shots .
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