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Custom White balance


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<p>This question has a lighting base, but a Nikon point so I hope I'm posting it correctly.<br>

I recently purchased a Nikon D60 digital SLR, but was told in order to do table top product photography with CF bulbs, I would need to first do a custom White Balance on my camera so that the CF bulbs would not cause the wrong colors to show up. I did the white balance as instructed but the purple flowers still came out blue. Also the grid I used was a panal with black, gray and white stripes on it. When I did the white balance, the picture came out different shades of brown.</p>

<p>To credit the person who instructed me, they were showing me how on a different model Nikon. Can someone explain to me how to set the custom white balance on a Nikon D60 specifically?</p>

 

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<p>All fluorescent lights present difficult challenges for white balancing. Doesn't matter whether they're Compact Fluorescent Lamps (CLFs) or tubes. They all present unique challenges for various technical reasons. If you want to read one perspective on why from a cinematographer's point of view, see this article: <a href="http://www.cameraguild.com/technology/kelvin.htm">Fluorescents and the Kelvin Myth: Changing the Calibration for Color</a></p>

<p>There are other reasons not covered explicitly by that article, more relevant to digital still photography. The main problem is the continual fluctuation in color temperature. You can try to fight it by bracketing the white balance or shutter speed, or simply taking lots of shots hoping a fixed shutter speed and WB will coincide with the illumination at a given split-second. But the better solution might be to use continuous lights more suited to still photography.</p>

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<p>I'm not sure about how much heat photo light gels can tolerate but Rosco theatrical lighting gels can withstand quite a bit of heat for extended times (many theatrical productions last two hours, and some gelled flood and spot lights on are continuously). The manufacturers of gels should be able to supply accurate specs and recommended uses.</p>

<p>Like most lights, halogen lights designed for household or industrial use will vary with age and warmup times. They'll also vary more from nominal specifications than those designed for photographic use. But in my experience even halogen garage lights vary less in color temperature than any CFLs or low priced daylight balanced fluorescent lamps I've tried. Household or industrial halogens or tungsten floods or spots will vary less in color temp and output from moment to moment compared with fluorescents or metal halide lamps (while the latter wasn't a specific topic of this thread, metal halide illumination typically found in school gyms and auditoriums present another source of frustration for digital photographers for similar reasons).</p>

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<p>Frederick you got good advice to do the white balance using the exact place of your shooting, at least in principle^^.<br>

With a tabletop setup this is easy to do. (BTW: You need no fancy card to do so as long as you always use the same gray card for the same situation to measure WB. You will need to fine tune WB in post processing anyway. OK for those who will complain now about high "standards" I agree a high quality card might be better but then what really counts is a complete color workflow and that includes more important steps than just how accurate the gray card is. You may want to use a color checker card in this case and an individual camera profile etc.. But all this is useless if you do not have the right light source.</p>

<p>Lex gave you the important detail about that the light source is not constant with time. So every time you change your exposure time you may end up getting a color change in the light. If you get the exposure time "right" you will actually see a stripe of changing color in an image of a grey card. Get your lights from a professional reliable company selling table top systems. They know the problem and took care of this for two generations of photographers :-)</p>

<p>Alternatively you could get say 4 flashes. Some of the older manual Nikon flashes (any other good brand will do) are really cheap only because these are manual. Low power is no problem at the small distance. And for your setup manual exposure is no problem at all. Set a small halogen light next to each flash for adjustment (switch of for exposure).</p>

<p> </p>

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<p>Fluorescent tubes will never give accurate colour. They have great gaps in the spectrum of light they put out, and certain colours, especially saturated colours such as those of flowers, can "fall between the gaps" in the fluorescent light spectrum. The technical term for this effect is metamerism, where colours look different depending on the source of illumination.</p><p>You're better off with simple tungsten or tungsten-halogen light bulbs. Use a Nikon B2 (or any other blue A to D) colour balancing filter on the camera lens to bring the colour of the lamps closer to daylight, then the white-balance of the camera doesn't have to stretch its blue sensitivity quite so far.</p><p>For macro work you might want to experiment with the high-brightness white Light-Emitting Diodes that are becoming common these days. Their spectrum is extremely close to daylight and you can get potholing and camping lamps with a very high light output.</p><p>By the way, you don't need any fancy white-balance aids, just a sheet or two of plain white office copying paper. Set the paper in front of the subject and take a picture of it - job done!</p>
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