Originally Posted by
William W
It depends on:
> the type of lighting
> the age of the lighting
> the amount of the lighting bank that is powered up
> the amount of windows; what time of day and how much sunlight gets into the pool
Best if you can set a "Custom White Balance" to get the degrees Kelvin for your particular pool. I think you use Nikon, Nikon might reference this procedure slightly differently but it will be words like 'custom' or 'manual white balance'. I don't know the exact menu / buttons to push for Nikon but it will surely be in your user manual. Also check if the Custom White Balance will automatically set the TINT in your camera(s) – or if you have to do that manually too. (See below about what I have found to be the common “TINT”.)
To do a Custom White Balance - use a Standard Photographic GREY CARD or a correct instrument like a ‘WhiBal’ card . If you do not have those devices, you can use a sheet of quality WHITE printing/photocopy paper (not he re-cycled stuff). Make sure the Photographic Card / pieces of paper fills the entire frame and (IMPORTANTLY) the card / paper is under the lighting scene, just as the swimmers would be.
If you can't do that - or can't get the grey card or the sheet of paper under the exact lighting scene as the swimmers would be, then you can do it another way, if you have a little bit of time, but you need to have access to a computer or a device to read raw file data. This is what to do:
1. Make a few test shots (of a swimmer) and capture in raw and use AWB
2. Read the raw data and average the Colour Temperature that the camera automatically set as AWB and then use that the figure as degrees Kelvin for your Manual White Balance
3.One almost constant that I have noticed is that when using AWB, the TINT of most lights used at the pools where I work is heavily GREEN biased – which requires a heavy MAGENTA (automatic) correction. Now the point is, you can get almost the same WB using no TINT correction if you increase the CT by about 100 degrees - so, knowing this, my really simple method is, I often just make a few tests shots with “AWB” have a look at the raw preview; and average the CT value; and add about 200~300 degrees and set that as my manual degrees Kelvin and I do not set any TINT correction.
If it is three phase lighting (and I expect it will be) you’ll very likely get a variation of colour between some shots: but if you 'machine gun' shoot a set of THREE frames for every shot that you want, then you should have very few issues getting one with good colour. I have never have any issues with the simple method I explained above and it has worked for me since 2004~5.
If you can’t do any of that above, then if it is a pool with reasonably modern lighting banks and about half of the bank is powered up and if you set about between 4000 to 4700 degrees Kelvin, I think that you should be very close to the mark. (If it is an older pool with the old type tungsten lighting then set around 3200 degrees.)
Obviously if you can get in for a practice shoot, that would be good.
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One issue with this shooting scenario, when capturing ONLY JPEG, is that the Tv (Shutter Speed) of the camera will be way faster than the 1/2 cycle rate of the three phase lighting - which creates havoc with the AWB in many digital cameras.
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Yes it does. But a lot of the more modern or recently refurbished pools (obviously I reference only where I have worked) use reasonably consistent modern lighting spilling out on average about 4000 ~ 5000 Degrees Kelvin. Obviously that varies around the world and the type/level/use of the pool –but if it is indoor pool and used for some respected level of competition, then I’d expect that the Pool Management would have invested a few quid/bucks in updating the lighting.
WW