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Strange red tint in image when photographing ice hockey games.


david_a._wong

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<p>Hello folks,<br>

I've been shooting some ice hockey games. These are the settings I was using at the last game:<br>

Canon 70D<br>

Canon 75-200mm 2.8L lens<br>

Manual setting. 2.4f at 1/500<br>

7 frames per second setting.</p>

<p>For some reason I'm getting some strange pools of red tint in my images. While shooting at 7 frames per second, one image will be fine while the next one will have this strange red tint in the image. Please see the attached images.</p>

<p>Question, please. Anyone know what's causing it and how I get it to stop?</p>

<p>Thanks in advance.</p>

<p>David.<br>

<img src="/photo/18287120&size=lg" alt="" /><br>

<img src="/photo/18287119" alt="" /></p>

<div>00e91C-565429984.thumb.jpg.12ce09621194d97dd489f88ded71aed8.jpg</div>

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<p>The lights in the arena are flickering at 60 cycles per second (the frequency at which the alternating current electricity is delivered from the power provider ... 50 cycles/second in some countries). As the power ebbs and flows to the overhead lights, the lights vary in brightness and sometimes in color temperature - and your shutter is open sometimes at the peak of that cycle, and sometimes at the trough. So you're recording your images in variable light. If you were to keep your shutter open for 1/60th of a second, you'd never see the variation - but because you're using a higher shutter speed, you're catching glimpses of the lights in different phases.</p>
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<p>There aren't any easy options here. You can:</p>

<ul>

<li>Go to another arena with better lights</li>

<li>Shoot at 1/60th -- maybe tolerable for player introductions, but no good for action.</li>

<li>Use a flash (if the venue allows).</li>

<li>Shoot lots of bursts and pick the frames that are OK.</li>

</ul>

<p>Nobody else shooting at this arena will be able to avoid the problem. </p>

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<p>David,<br>

hi. You don't say what WB you were using. As the other posters have already said, this is a feature of the stadium lighting - other frames might show a different tint (I often get green->purple->green in a venue I regularly shoot at).<br>

You could try shooting RAW and then post-process everything (applying WB changes to batches depending on the tint). Or you could set a manual WB based on an area of white (though this will still be affected by the lighting changes, it might reduce the variance. Or you could post-process each JPG to set the white point.<br>

Regards<br>

andyc</p>

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  • 1 month later...
<p>Flicker is a problem, but i think this is Variation in the color temp of the lights. When as the lights age and are replaced the color of the new lights may not match the color of the older lights. I think that is what you see here. the fixes they said will work. Also NIK Color Effects pro has a white neutralizer. Flicker is usually worse than this. It can look like a shutter not in sync with flash.</p>
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  • 1 month later...

<p>Lamps will flicker at twice the line frequency, as they are not polarity sensitive.</p>

<p>Incandescent lamps aren't fast enough, but arc lamps can follow the AC frequency. </p>

<p>It is usual to design the lighting to minimize the flicker in sports arenas, where it might make it harder on the sport. With three phase power, if you spread the lamps across the phases, that is usually enough. There are also lead/lag ballasts that can run two lamps phase shifted such that there is much less flicker between the pair. </p>

<p>There are some different arc lamp systems in use, and it isn't so easy to say what the color of each will do. An older one is mercury with a red phosphor, where the red makes up for the red deficiency in red in the mercury spectrum. The timing of the phosphor and the arc are likely different. That might also be true for some fluorescent lamps.</p>

<p>Another lamp is metal halide, which uses ions of other metals, along with mercury, to whiten the spectrum. I would expect all the colors to follow the lamp current, but maybe not.</p>

<p>Note that the background in the image seems to have the right color. </p>

-- glen

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  • 11 months later...

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