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|| SportsShooter.com: Member Message Board
Color Shift under stadium lighting
Jeff Stanton, Photographer
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Princeton | IN | USA | Posted: 2:20 PM on 10.11.09 |
->> I shot boys soccer under the usual football field lighting on Saturday night. As usual, very poor lights and unable to use a strobe. Parts of the field are better lit than others. I set my white balance near the areas I would be shooting from most, which is behind the goal areas at each end.
Is it possible that it's impossible to set a decent white balance under these conditions? With the lights recycling, my colors, well, they weren't colors. They were more like hues. Green, yellow, bronze, burnt orange, you get the idea.
Besides wishing, is there anything that can be done on the front end to keep the Photoshop work to a minimum on the back end? |
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Samuel Lewis, Photographer
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Miami | FL | USA | Posted: 2:38 PM on 10.11.09 |
| ->> The best results I've found when shooting under non-continuous spectrum lighting is to switch the white balance setting to Automatic, and then open the images in photoshop using ACR (if you use the photoshop file open dialog window, you can select a JPG but tell photoshop to open the image in camera raw). Once in ACR, you can correct the cast using sliders, or might even be able to get away with simply adjusting the color balance (I've even found auto color balance in ACR sometimes gets the color as close to being correct as any number of manual adjustments). |
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Danny Munson, Photographer
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San Dimas | Ca | United States | Posted: 2:43 PM on 10.11.09 |
| ->> Not much you can do as far as custom WB is concerned. The only thing I can add to what Samuel posted is to shoot RAW. |
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Cecil Copeland, Photographer
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Marietta | Ga | USA | Posted: 2:44 PM on 10.11.09 |
->> Jeff ....
I have always maintained that you cannot get consistent, accurate white balance under stadium lights .... due, as you said, to the recycling of those lights. And I say that because I've tried to set custom white balances for conditions as you've described them - only to have a wild range of colored images afterward. White balance is all over the spectrum with those stadium lights ....
The only thing that's given me consistent white balance under stadum lights has been to use a flash while shooting football or soccer .... |
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Jeff Stanton, Photographer
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Princeton | IN | USA | Posted: 3:59 PM on 10.11.09 |
| ->> I went into the hue/saturation adjustments and was able to help the images quite a bit that way and even set up an action to expedite the work. |
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Guy Rhodes, Photographer
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East Chicago | IN | USA | Posted: 5:47 PM on 10.11.09 |
->> Here's a thread I wrote on this topic a few years ago:
http://www.sportsshooter.com/message_display.html?tid=20873
Fixing the problem in post by adjusting raw images' white balance may help, but is not really a solution to the problem as a whole. When discharge lamps pulse, certain parts of the spectrum (sometimes large chunks) are missing. It's hard to get good color on your subject's skin when the parts of the spectrum necessary to render a person's skin the correct color weren't being emitted by the lights at that moment in the first place.
An exaggerated way of thinking of this would be lighting your subject with a flash through a blue gel, then expecting to color correct the skin tone back to normal in post. While you might be able to get things close, the light is never going to look correct because you were missing a lot of the red / yellow wavelengths in the light (absorbed by the gel) necessary to render a person's usually warm skin tones.
I suspect we're seeing more of this problem lately with cameras like the D3 / Mark III / 5D where 6400 ISO and higher are becoming the norm. As shutter speeds increase with higher ISO sensitivity, the light cycling becomes more pronounced. |
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Dave Doonan, Photographer
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Kingston | TN | USA | Posted: 6:23 PM on 10.11.09 |
| ->> part of the problem I learned through my images is that sodium vapor lights are wired at 220 and they pulse very fast and sometimes the camera picks this up as a color shift. This is very prevalent in high school stadiums. the lights are cheaper and theres less of them. |
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David Manning, Photographer
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Athens | GA | | Posted: 7:15 PM on 10.11.09 |
->> Sometimes you have to either stick with AUTO or aim for the slowest shutter speed you can get away with.
Either that or strobe it. |
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David Harpe, Photographer
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Louisville | KY | USA | Posted: 7:33 PM on 10.11.09 |
| ->> It helps if you have some white in the frame. Then in ACR you can eyedropper the white balance by holding down the shift key and clicking on something white in the frame. Works great if one of the teams has white jerseys/helmets. |
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David Harpe, Photographer
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Louisville | KY | USA | Posted: 7:34 PM on 10.11.09 |
| ->> Forgot to mention that black and grey also work the same way (all the eyedropper is looking for is something neutral - not necessarily something white). |
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Paul Alesse, Photographer
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Centereach | NY | USA | Posted: 8:04 PM on 10.11.09 |
| ->> Jeff... Just shoot everything at 1/60 of a second or less and you'll be fine |
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Jeff Stanton, Photographer
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Princeton | IN | USA | Posted: 10:52 PM on 10.11.09 |
| ->> Thanks, Paul. I'll try that. |
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Guy Rhodes, Photographer
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East Chicago | IN | USA | Posted: 10:54 PM on 10.11.09 |
->> Dave,
I pity you if you're actually shooting football under sodium vapor (typical streetlight orange color). I assume you meant mercury vapor, which is the most common flavor of metal halide lamps used on football fields / basketball gyms.
Regardless of the power the lights are wired to (120, 208, 480, etc.), the lights will always cycle at the line frequency, which in the U.S., is 60Hz. The only time this is different is with fixtures that use special ballasts, like in a Kino Flo fluorescent fixture, where the ballast does indeed drive the lamps at a very high frequency to stop this pulsing issue from showing up on video - where it causes problems too, believe it or not.
Power to most industrial and commercial buildings in the US is delivered in three phases of 120 volts at 60Hz. Each of these phases is 1/3 out of step with the next, meaning each phase reaches its "peak" on it's own, away from the other two. This is important when we start talking about lights where this cycling shows up, like on football fields.
On larger fields with many lights per pole, each pole is usually wired with all three phases of power. This means that, on each pole, at least 1/3rd of the lights will be at their peak at the same time. This usually means most areas on the field will remain pretty even despite the cycling, especially if groups of lights on the same phase are focused out over the entire field.
With older schools with less lights (I speak of one locally where I've experienced this myself), you'll often see entire poles being fed with only one phase of power. This causes all lights on the pole to cycle at the same time, often resulting in huge areas of the playing field shifting color radically through a motor-driven set of images.
While I'm sure Paul was being sarcastic with his reply about shooting at 1/60th or slower, this is really the only sure way to not catch this issue in your photos. I've found you can get up to 1/125th before you start noticing the color shifts. |
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Jeff Stanton, Photographer
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Princeton | IN | USA | Posted: 11:41 PM on 10.11.09 |
->> Guy, thank you for the education regarding the lights. As you know, shooting at a 1/60th or 1/125th is not an option. The only silver lining in this is the images I shot are running in black and white. So that fixes that, but if it's necessary to publish any in color, then it presents a real problem.
Our high schools around here, for whatever reason, will allow strobe at football games, but frown on it at soccer matches and prohibit it at basketball and volleyball.
One gym I shoot at has fairly new lights, but still have some color cast issues, but not as severe as other places. The issue becomes yellow. Yellow jerseys, yellow floor, yellow bleachers and setting a white balance becomes another issue again. It seems I can't win. |
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Dave Prelosky, Photographer
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Lower Burrell | Pa | US | Posted: 11:52 PM on 10.11.09 |
| ->> Something I try to do do consistently is use the color temperature settings rather than generic cloudy sky-shade-strobe presets. Even when dealing with three phase wired lighting, the camera is set to record color consistelntly frame to frame. I'm getting best results at about 4000K |
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David Harpe, Photographer
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Louisville | KY | USA | Posted: 12:11 AM on 10.12.09 |
| ->> You know, this seems like a really good opportunity for one of the camera manufacturers to "step up" with something. Nikon used to have an external ambient light sensor on the prism housing to assist in auto white balance. Would be cool if they could come up with something that would sample ambient light at the precise moment the shutter is open and make adjustments accordingly. |
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Guy Rhodes, Photographer
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East Chicago | IN | USA | Posted: 6:11 AM on 10.12.09 |
->> As I pointed out with my experiment I posted in the other thread, white balance (be it custom Kelvin or one of the presets, or even auto) almost never helps solve this problem, especially in the more extreme cases.
Even if there were some sensor to sample the color of the light the moment the shutter opened, if that sensor is sampling garbage colored light at a trough in the power cycle missing 80% of the color spectrum, your results are still going to be poor.
When strobes aren't an option, and when fast shutter speeds are necessary, the variable of the light cycling sometimes has to be dealt with like all the other factors that have to fall into place (focus, framing, etc.) that can make or break any action photo. |
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Hal Smith, Photographer
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Sedalia | MO | USA | Posted: 11:35 AM on 10.12.09 |
->> I find that slowing down from 9 to 4 frames a second will usually allow the entire sequence to be within the same color balance, it will vary from sequence to sequence. The faster the frame rate the more variation.
Auto can not compensate quick rate cycle of the stadium lights.
Using strobes is the best bet for keeping a consistent white balance, but like most people I use a camera that works well at high ISOs and I have little time for prep before a game. |
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David Harpe, Photographer
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Louisville | KY | USA | Posted: 12:42 PM on 10.12.09 |
->> Even if there were some sensor to sample the color of the light the moment the shutter opened, if that sensor is sampling garbage colored light at a trough in the power cycle missing 80% of the color spectrum, your results are still going to be poor.
True. In those situations you won't have any improvement because there's really not a lot of light to sample, so it's not a color temperature problem as much as it is an overall illumination issue. But in the frames where there is some light but not of a uniform color, an exposure-time sample would be helpful. |
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Jeff Blake, Photographer
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Columbia | SC | USA | Posted: 2:31 PM on 10.12.09 |
| ->> I haven't shot football at NC State in a few years, but the last time I was there, I had a similar problem with the cycling lights. When shooting motor-drive, one frame would be dead-on exposure/WB, the next would be red and underexposed, and the next would be several stops under and unusable. |
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Kyle Harvey, Photographer
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San Jose | CA | USA | Posted: 2:19 PM on 11.03.10 |
->> A suggestion from shooting a lot of prep games...I now shoot with a d700. It was very tempting to pump up the ISO to 3200 or 6400 and shoot available light. The problem, as you stated, is that the available light cycles and you get bad color cast even in different parts of the same image. What I have found that works for me is to set the camera below ambient light and fill the difference with a strobe set to TTL about half way down my monopod. I rarely get any red eye with the strobe 2-3 feet below the lense and the light turns out pretty darn good. I used to use a super clamp, but now use a Manfrotto 175 clamp with my SB-800 and a battery pack. Let the flash be the majority of the light and fight the urge to use the ISO to compensate. A typical poorly lit HS field may be 1/30 at f/2.8 at ISO 800 or less. I set my camera to manual exposure, 1/250 at f/2.8 or f/4 at ISO 800 or sometimes 1600, and set my flash to maybe +.3 or +.7. As long as you don't use the high sync settings and keep the shutter at the actual rated sync speed, the flash should take care of the color cast issues. (If you push the shutter speed to higher than the sync ratings, you may get too much ambient light and have half the frame with color cast issues)
Just my 2 cents... |
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Jim Colburn, Photo Editor, Photographer
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McAllen | TX | USA | Posted: 3:46 PM on 11.03.10 |
| ->> Since shooting sports as Raw images is sometimes tough fps-wise could you fix the JPEGs by opening them in Camera Raw using Abobe Bridge? |
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