White Balance test in Fluorescent Lighting

[tara_ratliff]

<p>Recently, a group of students were doing custom white balance tests with a gray card in fluorescent lighting. All the Nikon Cameras came out normal and the Canon cameras everything turning green with their custom white balance test. Does anyone know why? </p>

[howard_m]

<p>were the shutter speeds the same ? I'm guessing the answer is no.</p>

[sarah_fox]

<p>Tara, I think what Howard is suggesting is that at a high enough shutter speed (maybe 1/100 or faster), you could get a different color balance and even exposure, depending on when the shutter trips with respect to the phase of the electric cycle. Fluorescent lighting is evil, particularly at the wrong shutter speed. I would suggest only shooting at 1/60 and 1/30 in the US, 1/50 and 1/25 in the UK, etc. That will give you more consistent WB.</p>

[William Michael]

<p>^<br>

My experience is the slower two shutter speeds (1/30s and 1/25s) will yield more evenly consistent results.<br>

The reason is, when shooting with a shutter speed exactly the same as the electricity cycle rate (i.e. 1/60s or 1/50s) we get a full (electricity) cycle of exposure but the shutter might be released at the 1/2 way to the end or 1/2 way to the beginning of the (electricity) cycle and if so there will be minor colour and exposure differences to when the shutter is released at the beginning of the (electricity) cycle.<br>

A more even Exposure and Colour Balance throughout a set of Photos is achieved by using TWO FULL (electricity) cycles (i.e. 1/30s or 1/25s) because the ‘averaging of the light’ (for want of a better phrase) is more consistent.<br>

Similar techniques apply to shooting under lighting powered by three phase electricity.<br>

Obviously if you wish to address Subject Motion – you will have you work cut out for you . . . usually one lives with the WB and exposure being erratic – or use Flash and Gel.<br>

<br>

WW </p>

<p>"Fluorescent lighting is evil" - I like that.</p>

[Marcus Ian]

<p>Were the lights on 3phase power, or were they on one phase (typical)? I find that I encounter banding (light and dark bands) more often w/ 1 phase, and color shifts (to green) w/ 3 phase fluorescent (when I forget to slow down the shutter speed of course ;-) ), though both are possible w/ either (depending on the specifics).</p>

[tara_ratliff]

<p>I am not sure what the fluorescent lighting was, it was whatever was in the room we were in. I believe they had their settings on 1/60 f1.4 and a High ISO. I just don't understand by the Nikon camera's came out normal and the Canon's did not. </p>

[William Michael]

<p>OK . . .<br>

Then ‘what are the other variables’ needs to be investigated:<br>

can you be sure the (Canon) students were following correct procedure?;<br>

how many Canon cameras? (a small number?); - etc.</p>

<p>I don't know of any particular issue with Canon and Fluro' lights – my cameras work OK (given the above comments) - but that doesn't mean there isn't an issue . . .</p>

<p>WW</p>

 

[sarah_fox]

<p>Also what models of Canon cameras, and how did you determine the pictures were green. I ask this, because an earlier production Canon 5D (original), for instance, is known for having a yellowish/greenish LCD playback. This has nothing to do with the actual color of the picture, however. If you were to upload the pic to the computer, it would look perfectly fine.</p>

<p>FAIW, I'm a Canon shooter and have used a few models of Canon dSLR professionally. I've never had a problem with WB under fluorescent lighting since I went digital in 2004. That said, fluorescent light is almost universally evil with regard to color rendering, as it is not very spectrally rich.</p>

[peter_mckone]

<p>More than any other single factor, florescent light separates the serious photographers from the point-and-shooters. Does anyone use the in-camera custom white balance? Why not teach the students to shoot raw, and then correct the white balance when they get home? In a perverted way, I like florescent light, because it lets me demonstrate that I know how to do post processing.</p>

[hjoseph7]

<p>Lets's face it the Canon White balance whether presets or custom, leaves allot to be desired, Case Closed !</p>

[keith reeder]

<blockquote>

<p>Let's face it the Canon White balance whether presets or custom, leaves a lot to be desired, case closed !</p>

 

</blockquote>

<p>Nothing that can be fixed - if necessary - with one click during conversion, is an issue.</p>

<p>I've never had a problem in any light with Canon WB. I've had problems with <em>some converters'</em> WB efforts (AfterShot Pro, for example), but never anything that could be blamed on the cameras themselves...</p>

[tara_ratliff]

<p>Okay, maybe they just did the test wrong. There were only two of them. </p>