White Balance

[jchooper12]

Can someone explain the proper method for white balanceing your camera.

Say you are using a 17-55mm lens, when setting the WB does the entire Gray Card have to fill the view finder or does the camera only use a small portion of the frame for WB. If you have to fill the frame does that mean that when using the 17-55, you can only be a few feet from the card to fill the frame, so if I want proper WB from somthing that is 20' away, does that mean that I have to walk up to the actually location I am shooting to set the WB or can I focus on somthing Gray from the 20' away mark and take a reading even though the frame is not filled in with all gray?

I hope this question makes sense.

[PeteQ]

Originally Posted by jchooper12

Say you are using a 17-55mm lens, when setting the WB does the entire Gray Card have to fill the view finder or does the camera only use a small portion of the frame for WB.

Yes, you need to fill the frame. Small portion won't work correctly.

Originally Posted by jchooper12

If you have to fill the frame does that mean that when using the 17-55, you can only be a few feet from the card to fill the frame, so if I want proper WB from somthing that is 20' away, does that mean that I have to walk up to the actually location I am shooting to set the WB

Taking a white balance reading of where the subject is located is best.

Originally Posted by jchooper12

or can I focus on somthing Gray from the 20' away mark and take a reading even though the frame is not filled in with all gray?

No, see above comments.

Getting an accurate WB goes a long way toward image quality. Especially in mixed lighting situations. Once you get the hang of it the process only takes a few seconds and will easily save you that much time later.

I hope this helps a bit....

[jchooper12]

Thank you very much, that answers my question. I do have one more though, I was talking to a guy yesterday at a Camera Shop and he showed me this WB system, basicaly one side is white and the other is gray, he said he WB to the White side and then takes a sample shot of the gray in from of the subject, what does this accomplish verses WB to the gray side?

Also, I take it what when you fill the screen with the Gray (or white) it does not matter if you are at 17mm vs 55mm, the WB would be the same right? That is probably a dumb question but just asking anyways :O)

[CaptainTom]

Your question makes a lot of sense. I hope my answer makes sense.

when setting the white balance you are telling the camera what the average color temperature is of the light that is falling on your subject. To get the most accurate reading, you should have the reference card, placed at the exact location of your subject. Fill the viewfinder with the card. The light reflected from the card will now give you a reading of the light falling on your subject. This assumes a steady light source.
If you are in an area that is lit by only one light source, or type of light source, you can get a reading anywhere and know that you will be very accurate. I.E. the sun is a steady light source and the white balance shouldn't change unless the clouds move in, or the declination (the angle of the sun on the horizon) changes. A reading at the camera should be the same as one on the subject some distance away. What may seem like a steady light source can also be influenced by reflected light... another variant.

Generally speaking. Unless you are shooting for a catalog or publication that requires very precise color rendition (and this can be replicated in PS anyway), if you set your WB and the general lighting remains the same, you will end up with a very accurate photo.

Pete types faster and is not as long winded ( the hell he isn't !) as I am.

The white side for WB, the grey side for exposure. Plus, when you pull the photo up in your program you can select the white and the grey and use them for reference of color balance and exposure.

[Wes]

I hope that this doesn't hijack the thread too terribly much, but I've always wondered what purpose the cards serve and how you use them to set WB. This is going to sound stupid, but my D70 has several WB settings available. What's wrong with using them? Or, for that matter, just switching the WB to "Auto"?

[PeteQ]

Wes, the presets are a good general place to start and in place of a custom white balance they will get you in the ballpark. If you know the lighting is full sunlight, then set the balance to sunllight. Likewise for shade, flourescent, etc. The AUTO on the D70 (IMO) isn't too bad, but it's not very good at all for any mixed lighting conditions. For them it is essential to set a custom WB (IMO).

The D2X and D200 does very well on MOST situation that I have found, but still has trouble occasionally. For that, I have a couple of methods, one is the Fong dome cap, the other is the collapsible white balance/gray card.

Yes, in RAW you can move things around at will. But again, if I can get it right in the camera, I am way ahead of the game when it comes post time.....

[CaptainTom]

nothing wrong with using the WB on the camera if it is a Canon ( always have to take a shot at Nikonians). Really. If you are shooting in regular daylight the daylight setting will be great. Tungsten (bulbs) and flourescent lamps can vary in the actual color they emit. We can't usually see the difference because our brain (except Pete's) makes it all look normal to us. You can use the other settings, and will get satisfactory results if you are not anal about the WB. Using auto WB gives the camera the option to read the color temp and set accordingly. This is OK, but can lead to different color casts throughout a shoot, depending on the cameras decisions about temperature. I.E. a bridal photog would be crazy to shoot all the shots with auto WB because the white dress would end up with differing variances of white depending on the lighting. Unless he/she was using a Canon and then the photos would be perfect at all times without having to think at all ( like me).

[Wes]

Pete and Tom:
I understand the importance of getting the correct WB, but how does a card help you do that? In other words, how do you actually use a card to help you achieve the right WB? I mean, okay... I hold a card up next to my subject. Now what? I'd love to understand this one better. I spent Tuesday evening shooting some friends on and around Lake Arlington between 7 and 9 p.m. While the setting sun over the lake made for some awesome shots I found that I was constantly having to adjust the WB on almost every shot because of how the sun had affected the lighting. The post got kinda tedious.

(BTW - huge thanks to Pete for showing me how to use Curves and then the white eye-dropper tool!)

[Duffy Pratt]

The idea is that you take a picture of the white card, with the card filling the entire frame.

Then, there is a funtion in your camera that allows you to set custom white balance. You select that function, and then select the picture of the white card as the reference that the camera will use for the color white. From there, the camera will use that picture to figure the color temperature.

Since you have a Nikon, I can't tell you the exact controls, but it should be in your manual.

Hope this helps,

Duffy

[Duffy Pratt]

One more thing: if the lighting is changing very rapidly, and white balance is still critically important to you, then its probably a good idea to just set the camera to auto white balance and shoot in RAW. That way, you get the camera's best guesstimate and you also get to adjust the white balance to your taste for every single shot.

Duffy

[PeteQ]

Actually, you can do it either the way Duffy mentions, by choosing a picture, or you can just tell the camera (via the Custom WB procedure in the book) that you will be doing a custom WB. After setting it up, when the shutter clicks, it captures the WB info and stores it but no reference picture is taken. For continually changing lighting (brides that move) this is a good way to do it. On the D70's you only get one preset but on the D2X and D200 you get four. You could then use the card method and quickly store and recall four seperate custom white balance references. This is handy for sports shooters who may work three or four arenas. They can store the WB of an arena and easily recall it for the next time they shoot there.

[PeteQ]

Originally Posted by Duffy Pratt

One more thing: if the lighting is changing very rapidly, and white balance is still critically important to you, then its probably a good idea to just set the camera to auto white balance and shoot in RAW. That way, you get the camera's best guesstimate and you also get to adjust the white balance to your taste for every single shot.

Duffy

The only thing about adjusting to taste for every single shot is that especially when doing bridal work you will see slight color variations from picture to picture and this just looks unprofessional. If it is sunlight that is changing because it's going down IMO it's better to set a single white balance and let the lighting do what it may. If it is critical maybe rebalance every 15 minutes or so. But, if you are moving from outdoors to inside I would recommend a custom white balance after the change of venue. It only takes about 5 seconds and you get much better consistancy. When you are dealing with weddings remember you are pushing that sensor to it's limits. White whites and black blacks...the whole lattitude and you will need to decide what has to give because the sensor may not be able to cover that latitude. Sometimes adjusting WB after the fact will cause you to lose dress details. Then you will wish you would have taken that extra five seconds. Is this a bit anal, yes. But consistant results are worth it.

[sbp]

I have question regarding this too.

say I have constant light two 3200K bulb that I use. Now do I have to put WB card at nose level or hip level to do WB?
Can I just use regular auto WB and convert all in post processing using 3200K.

[CaptainTom]

In theory this would work. But, we have all had shots show up in PS and had to adjust the white balance to something that probably didn't match what the true color temperature of the scene was. I am not sure what the reason is but this is what occasionally happens.

Most photofloods are pretty close to the indicated color temerature, but I can attest that they can also be all over the dial. We had to get the color temp as close to "standard" as possible because we didn't have PS to correct the color when shooting transperancies. We had to add filters to adjust for complex or unusual lighting temps.

[bfphoto]

John,
I'm not sure you are serious or not. I just looked at your portfolio and your images don't look like they need any color adjstment. They look great Now back to your first question. If you are 20 feet away and have the gray card in the picture, you need to be shooting in raw. In the conversion, just use the eye dropper and click on the gray card. This will give you the correct color temperture. If you are not shooting raw, then fill the frame with the card.

It should also be noted that not all "white" is white, because some whites may have a color cast to them. If you use a white card, be sure it is pure white. A brides dress is not a good source for white balance. Also note, you you use a white card the exposure must be correct, not over or underexposed. Either one will throw off the reading.

Now, my Canon manual talks about using the white card and how to use it. Then at the very end of the section in very small print it states "Instead of a white object, an 18% gray card can produce a more accurate white balance."

Go figure. Anyway, I use a 18% gray card for my white balance and if the spike is in the middle of the histogram, then I know the exposure is also correct.