Light Cycling

Manual exposure and WB. Only difference between shots is the park lights cycling.

Gas discharge lighting changes intensity and color at twice the rate of the power line frequency. This is because the voltage is cycling from 0 volts to maximum 120 times per second in the US and at 100 times per second in places using 50Hz power. This is an often-seen thing with fluorescent lighting.

When using gas discharge lighting and a shutter speed faster than 1/120 second (or 1/100 second where the power line frequency is 100Hz), the images can easily look different from one to the next, both in intensity and color.

SkipD wrote in post #10233593
Gas discharge lighting changes intensity and color at twice the rate of the power line frequency. This is because the voltage is cycling from 0 volts to maximum 120 times per second in the US and at 100 times per second in places using 50Hz power. This is an often-seen thing with fluorescent lighting.

When using gas discharge lighting and a shutter speed faster than 1/120 second (or 1/100 second where the power line frequency is 100Hz), the images can easily look different from one to the next, both in intensity and color.

Thanks SkipD. I knew that, but I was just sharing this graphic I made so that others could be aware about it. Thank you for the description.

JoePhotoOnline wrote in post #10233617
Thanks SkipD. I knew that, but I was just sharing this graphic I made so that others could be aware about it. Thank you for the description.

Can you slow down the cycling of the images so folks can see the differences better? Five to ten times the delay would be good in my opinion.

Sure. I'll see if I have another example that would also be a longer shot sequence

A very good example of how the cycling of lighting can affect the images.

And also a good example of where RAW comes to the rescue - all the shots can be recovered to the "correct" WB with a few simple clicks with no IQ loss at all.

neilwood32 wrote in post #10235548
And also a good example of where RAW comes to the rescue - all the shots can be recovered to the "correct" WB with a few simple clicks with no IQ loss at all.

This is not quite true, at least with the photos presented in the demo.

If you look carefully, the background is lit and colored the same way for all of the shots in the series while the foreground changes from shot to shot. This is because the entire image is not lit with the same source. The background is natural lighting and the foreground is lit with the stadium's lights. This makes for a very difficult job of correcting the images to have them all look the same.

I see what you mean - the deep background outside the fence is "lit" by ambient light or the lack of it. However within the fence, it appears to be lit evenly (hard to tell at the rate of the frames).

I did a quick try within PSP (only package I have at work) and altering WB did not affect the background by any noticable amount (due to the darkness of the areas).