Use of gray card or reflector for proper WB?

<p>Hey all. Let me start by thanking all of you in advance for reading my question and hopefully helping me out a little. I am getting deeper into my photography and one of the things I am realizing I could really use help on is white balance. I have seen a photographer on site who used a gray reflector that was 18% gray and they stated they used it to set their white balance in Lightroom. I am assuming they used it in some way in conjunction with lightroom to set the proper color temp for all of the photo's in that series. Does anybody have a workflow or product they use that they could recommned? I am clueless as to how the procedure is done from start to finish so any detailed explanation would be greatly appreciated. <br>

Also if it's not too much to add on. If I am shooting with my 580EXII in a tungsten or flouroscent lit room is it possible to get the photo completely accurate color wise without putting a gel on my flash? Also, will each shot vary if I don't get the flash depending on how much of my subject is lit by my flash vs. the light in the room. Again thanks for any help. If this "beginner" question would have been better suited for lighting I apologize but I felt it shows my "beginnerness". :)</p>

<p>I'll give you an example of my workflow, Douglas. Provided I am working under controlled lighting I will set the gray card up near where my subject will be or, if they're mobile, under the same lighting conditions and take a shot of it. Then I go about my business, provided the lighting doesn't change. If it does, I'll re-shoot the gray card, taking care to avoid glare on the card as that will ruin my reference. If you're using a flash, shoot the card using your flash. Again, know the family of angles. You want the card to be lit by the diffuse or indirect light of the flash, not directly as that will create glare.</p>

<p>In post processing, I use the white balance eyedropper in Digital Photo Professional (Canon) to register a white balance recipe based on the gray card from my reference shot and apply it to all shots taken under the same lighting conditions as my reference.</p>

<p>Regarding your flash not firing... yes, that will completely change your white balance when shooting under either tungsten or fluorescent lights. It's not a good idea to mix lighting because it makes balancing the color cast near impossible. If you don't have a choice then you'll have to try and salvage the shot in post using one of your other shots as a reference. When the flash fires, your subject will be influenced by the light from your flash while the balance of the scene will be cast in the color of the ambient lighting, you'll have to balance the shot for your subject and let the rest fall where it may.</p>

<p>Douglas,</p>

 

<p>Simple, short version: get yourself a $10 Kodak gray card. Put it in the same light as your subject.

Spot meter off the card. Take a picture with the card filling the frame. Either select that picture for the

custom white balance on the card (if shooting JPEGs) or click on it with the eyedropper tool in your

RAW processing software.</p>

 

<p>Almost all the time that process will produce excellent exposure and color balance.</p>

 

<p>There’s all sorts of improvements to be had — including tools that cost dozens or hundreds of times as much as the Kodak gray card — but I would strongly recommend forgetting all about them until you get to the point that you find your results with this procedure inadequate.</p>

 

<p>I <em>would</em> most emphatically recommend the Kodak gray card, though, and not a piece of “white” paper or a wall or a shirt or some other artifice. The Kodak gray card is very spectrally neutral, indeed better than many other much more expensive gray balance tools (though there are some which are marginally better). “White” paper simply isn’t, and you’ll introduce a significant color cast to your pictures if you use that instead.</p>

 

<p>Cheers,</p>

 

<p>b&</p>

<p>If you are going to get serious about color, you are probably going to want an X-rite chicklet card, "color checker", "Macbeth card". One example here: http://www.adorama.com/DKMCC.html?searchinfo=x+rite+color+checker</p>

<p>I just use a gray card or figure it up in my head; but, that type of color checker has been in use for many years.</p>

<p>Flash & ambient, color temp' question: if you use two kinds of light, and they each have a different temperature, they will each yield a different temperature in the recording. </p>

<p>I suppose it might be possible to use postprocess to mask and adjust temperature of one section of a photo; but, I do not do this myself, so I don't know the full answer. However, in the initial recording, it is most likely that an unfiltered photo would yield both temps. </p>

<p>Instead of gelling the light as it strikes the subject, another option is to gel the light as it enters the camera. Color correction and color compensating filters do this. Keep in mind, there's no end-all answer for that one; there's no good substitute for careful attention to filter selection; really, there's no substitute for careful attention to color temperature all around. </p>

<p>Meanwhile, I use almost a complete disregard for color temp; in that, I accept the observed temperature, and will sometimes exaggerate it: strong gels, strong CC filters, that sort of thing. </p>

<p>P.S. I concur about the paper; it can be used in a pinch, but it helps to know about the properties of the paper and the light hitting it to begin with; stroll into an art store sometime; you may easily see 25 kinds of white or natural papers. </p>

<p>In theory, I think , the only way to get color just right would be to use a source gel. A filter on the camera would not alter the fact that you are mixing two different types of light. However, in practice, shooting flash without a gel in tungsten light and adjusting white balance in post (e.g., Lightroom) is generally fine for my purposes. I don't even own gels. I don't shoot much in florescent lighting, so I can't speak to that.</p>

<p>You can shoot one shot with a neutral gray card (I agree with Ben--don't use paper, because it comes in all different tones), use that shot to set white balance in post, and then copy that setting (or adjust it manually) on all shots in the series with similar lighting.</p>

<p>When I shoot with mixed flash and tungsten, I usually end up going slightly warmer in post than the gray card indicates. If you shoot RAW, this is no big deal--you can change it however you like.</p>

<p>I suggest you start by learning how to deal with gray cards and adjusting in postprocessing, and move on to gels if you need it.</p>

<p>Great post - it will help me. I have used the eye dropper on a white or neutral area of my photos (like say a white t-shirt) - and sometimes that hits it "spot on" - but many times not so much. I have not tried the gray card method - should to an extent standardize the process hopefully to give more consistency. Thanks everyone for the great info - have a merry christmas!</p>

<blockquote>

<p>"If I am shooting with my 580EXII in a tungsten or flouroscent lit room is it possible to get the photo completely accurate color wise without putting a gel on my flash?"</p>

 

</blockquote>

<p>No. The flash is color-balanced for daylight.</p>

<p>I usually include a gray card (from my antique Kodak Color Data Guide) in most images, and use the CS4 gray dropper to correct color balance. It is far more objective than my eye, especially when it comes to skin tones. Although I am not familiar with any other program besides PS, and many moons ago, MS PhotoDraw, I am sure others have a similar feature. I would recommend you become familiar with it. You can get an 18% gray card in most photo stores for less than $10. Kodak's is 18% gray on one side and pure white on the other.</p>

<p>Whenever I shoot color film, especially portraiture, the first frame is always the subject holding a gray card. With my color analyzer properly calibrated for the batch of paper I am using, all I need to do is project the image with the gray card on the baseboard, and using the sensor on my analyzer, any changes in filtration and exposure for that particular film batch or lighting become very easy and very repeatable to make. The key to printing consistent color prints with a color analyzer is to keep as many variables as you can constant. Long before the days of digital post-processing, this was the only way you could do it!</p>

<p>Want a neutral color for the RAW eyedropper, move it around and watch the RGB numbers til they are nearly equal, eg 212, 210, 211, then click.</p>

<p>Wow guys...thanks for all of the information. I have so much to learn as it relates to WB obviously. Sorry I didn't respond sooner to thank all of you but as you can imagine the holidays are making things crazy. Never thought about using the Raw eyedropper that way Bob, that's a great idea. Thanks again everybody so very much for your time and knowledge.</p>