Low-light with action. How often does this situation strike fear? I was shooting my son doing Long Jump in a Pentathlon. It was late and the day was overcast so it got darkish early. The sporting field floodlights had come on, but the long jump was off to a side near trees and didn't get a great amount of artificial light.
I'd been shooting other events at the Pentathlon with the K-3 & DA* 60-250/F4, but since the light was getting weak, I switched to the Sigma 70-200/F2.8 II HSM. I normally shoot long jump close to the ground so I can show the elevation the jumper gets. But at this field there was a fence around the two jumping tracks, so I had to stand on an embankment, with the lens resting on the top of the end fence. In this resting position I was unable to easily turn the zoom ring during the jump, so I had to shoot the whole jumping sequence at a fixed 70mm FL. The high shooting position means that the shot I'm presenting here gives little impression of the jump height achieved, but it's better than trying to shoot through a chain-wire fence.
Camera settings were LL desperation stuff: Matrix metering, TAv, AF.C Extended Area M (25-point), 1/800s, f/2.8, ISO5000.
First off, the original shot with default raw development.
Using ISO5000 & f/2.8 has turned semi-dusk into day. (The bright spot above his head is a lamp, possibly a street light.) The shot was developed in SilkyPix Developer Pro 5. (Only SP development controls used for the 3 versions shown here.) I let SP5 make use of its database of camera models & ISO-specific default parameters. It is cognisant of the sensel size & MP. So the various sub-settings in the Sharpness, NR & Demosaic Sharpness sections are all of SP's choosing. I wanted to see how good a job it did. (The NR is supposed to be better in SP5 than in SP4, supposedly up to LR quality.)
If you look in front of the blue cone on the right, you'll see a slight shadow, being cast by the flood lights. So the front of the jumper was slightly shadowed. (Some of the earlier shots in the sequence in the run-up phase, when his feet are close to the ground, show a more distinct shadow.) In the image version below, cropped the way I like it, I've applied some global dodging and raised the black point slightly. Comparing the position of the green peak on the histogram, this is equiv. to about a +0.3EV boost on the front of the jumper i.e. similar to shooting at ISO6400. Image size of this crop is 13.9MP, so it's approx. the same number of pixels you'd get if you shot with a higher FL on a K-5. (I didn't want to zoom more than 70mm FL as, due to my closeness, the athlete in the landing part of the jumping sequence got very large by the end of the jump.)
Finally, here is a 100% crop from the 2nd image, showing the amount of sharpness vs noise trade-off:
You can see there's still a reasonable amount of detail left at this level of ISO & NR. The noise is now obvious, but you usually don't look at an image with this high a level of zoom-in. I could increase the amount of NR but, for web presentation or A4/11" sized printing, it should be fine.
The light level for the camera settings is 7 LV. However, when you consider lens transmission losses and the use of dodging, the actual light level was probably 6.5 LV or a little less.
Also, the K-3 & Sigma 70-200/F2.8 AF combo did well under this lighting level considering the speed of the subject's approach.
Dan.