Tuesday, September 9, 2014

This Stage Shot is a RawTherapee Challange

At first look there is not much to see. I found the low res jpg while poking around in a Lorde fan site. Lorde is, if you are not up on your pop music, a New Zealand teenage who at 16 played her first show in a 140 seat Auckland pub half filled with relatives and school friends. Last month at 17 she up her audience to an estimated 70,000 to 80,000 at Lollapalooza  in Chicago. And on September 26 she will be playing to a maybe sellout crowd of 5000 in Milwaukee. I will be sitting a few rows back from the stage with Charlotte and her BFF, Jessica. It's Charlotte's going-into-the-7th-grade-with-an-A-report-card birthday gift.

Naturally I will be there with a camera. Unfortunately it won't be my D7000. Only pocket cameras allowed. So I'm resurrecting my Canon S3IS, a 6mp oldie that hasn't seen a photo electron in years. It takes a moderately decent movie and can be updated with CHDK to output RAW files, Then I can handle some over exposure.

Unfortunately I expect a lot of overexposure. Lorde's new tour features a wild light show. A photographer's nightmare, the light show demands much under exposure (see above) or it will wash out a good hunk of everything on the stage. So I'll be depending on RT to drag details out of thick mud.

The fan site didn't lie. This is Lorde singing her double grammy winning super hit Royals. Auto exposure added 2.36 stops of exposure,

It's an obvious candidate for tone mapping.

 CIECAM  adjusted colors. contrast. and brightness.

Noise reductions did its thing. Since I started  with a 464 x 750 pixel jpg there wasn't much detail to worry about. Another adjustment is needed to move the histogram to the left and darken the blacks.

A Kodachrome 64 film simulation both darkened the blacks and enhanced the red. I now had the dramatic look I was hoping to see

Finally I resized the photo.  Because of the low res jpg don't look for fine details, but except for that problem this image is now a reasonable addition to a Lorde fan's twitter page . And I have a better idea of the photographic conditions I'll face at the concert.

After a few hours relearning how to use both the camera and CHDK I discovered the camera is less noisy than I feared. At ISO800 and exposures similar to the original jpg, RT gives me midtone  to highlight S/N of 20 to 40.  Not bad if it holds up at the concert. Plus if I go the CHDK raw route the camera has a stop of headroom for highlight reconstruction. So watch this spot after Sept26. I'll be posting a few examples on how things worked out.

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