Getting ISO Right in the Digital Camera II
I know that I’m in trouble when I insist at the beginning of a blog that “This will be a short one”. It usually means that it will go on for pages, but this time, I am committed. I have a talk to prepare for the Worcester Camera Club and I have much more to do. I could always dust off one of my old talks, but my plan has been to do a new presentation covering a lot of the “Getting It Right in the Digital Camera” articles that I have been publishing of late. So, HONESTLY, this will be a brief extension of my recent “ISO Control” article.
|ISO 100 Moving Foliage|
In my landscape photography, I am often faced with trying to get broad depth of field in situations where the wind is moving the foliage.When I stop down to expand the depth of field the resulting long exposure usually leaves the foliage a blurry mess, especially in the foreground.
|Stacked Image with Foliage Motion|
For my example I am using the same image that illustrated my first ISO Control article. The picture taken at ISO 100 and 1.3 seconds had the best image quality, but with blurred foliage, both on the foreground tree and in the background. ISO 1600 gave me a shutter speed of 1/8 second which was sufficiently fast to freeze the movement and had good DOF at f20. I simply stacked the ISO 1600 above the ISO 100, aligned the two with Auto-Align and then painted a mask to reveal the sharp foliage over the areas of blur. With the use of noise reduction and the application of the high ISO image only where needed the final picture retained high image quality.
That’s IT. I told you this would be short. In this case the "best image from the camera" was actually two images at different ISOs. Give it a try and let me know how it comes out.
OK, I can’t resist. Just one more point while we are talking about moving foliage. Another technique I use occasionally to freeze motion is based on the fact moving foliage does not all move at the same time. If you take a number of images at the same focal length you can often combine parts of each to isolate times when each region is relatively still. This is inevitably a tedious process of selective masking, but the results can be quite effective.
That’s it, I promise. Now off to Powerpoint.