Friday, August 24, 2007

Contrast (and noise)

Talking about contrast, here is a picture I made as an experiment a couple of years ago. (Note this was done for science, not art! The car is not so fascinating.:)

I took these three pictures and assembled them in photoshop to get the dynamic range.
Now you can do it automatically, but you need to take the pics on a tripod so the camera does not move and particularly don't rotate between images.




Assembled image:

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Oh, and apropos to today's discussion of the new Nikon cameras: the 100% crop (click on it) below shows how huge a leap Nikon has just taken in high-ISO perfermance. The picture was taken at 800 ISO with the Nikon D2x. Look at all that noise! The Canon 5D is noise free at that speed. And the Canon 1D III is better than that. And supposedly the Nikon D3 is even better than that. Imagingresource.com describes big prints from 6400 ISO which look really good. Quite amazing.

2 comments:

Alex said...

See, I found a solution to dynamic range problems in urban areas. I took to using a neutral density grad grey filter. This was particularly effective for cars which were in full sun on one quarter, but in deep shadow of the building for the rest of the body length.

I tried this approach shooting toward the sun on a field trip to Pinnacles, unfortunately I got hit with internal reflections between filter and front of the lens.

I've only really used photoshop to increase contrast on monocrhome images, but for one reason or another I prefer WYWSIWYG.

Alex said...

"The car is not so fascinating"

There were three cars which dramatically changed the British Touring Car Championships in the mid 90's. The Vauxhall Vectra was one of them.

This race was dominated by Vauxhall Cavaliers. In 95 the Volvo V70 made serious in-roads. In 96, the Cavalier was replaced by the Vectra, and all the Vauxhall drivers, except John Cleland, fell into serious difficulties. 96 also saw the replacement of the V70 with S70, and the introduction of the Renault Laguna.

So, this GM world car had a large impact in a small portion of the motor racing world.

That's been bugging me since I first read this post....