Tuesday, April 8, 2008

HDR Photography

I started using Flickr last year and while cruising photographs of my home town Newcastle Upon Tyne came across some startling pictures of the quayside. The detail in the pictures was amazing; rich blue sky with tendrilled vapor clouds, and yet the details in the shadows of buildings was just as rich, giving the impression you could see every individual brick.

It turned out they'd been shot using high dynamic range imaging, something that's been around for a few years but somehow I'd missed. There's a bunch of different groups on Flickr: the main HDR group has over 20,000 members and more than 120,000 pictures. There's many others, and this group has a collection of winning pictures voted on by Flickr members. Some landscapes can we startling, like this picture taken in Germany, others looks entirely unreal.

Pete Carr has a great beginners guide on HDR that uses Photomatix software to create the HDR image and do the tonemapping. Ryan McGinnis has a nice post too. There's other software you can use - Panotools has a nice wiki summary. I downloaded the free trial of Photomatix and have produced a couple of images - terrible, but you can see the potential. I've set my Nikon D50 to bracket at +/-2EV and used the three images to generate the HDR. I also had to lock the ISO rating at 200 (the lowest setting), and now realise I'll have to work in apeture priority mode to get around depth-of-field issues. Even at ISO 200 I can see noise artifacts, and Photomatix can quickly generate its own artifacts as you adjust settings. But even at default settings the resulting image has amazing tonal depth.

If anyone has advice on software, techniques or how to get the best results with HDR let me know.

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