One of the challenges I faced yesterday when taking bird photos at the Lab of Ornithology was to capture birds (in this case, mostly ducks) in flight without their wings being blurry from flapping too fast. In order to do that, I needed to make the shutter speed nice and fast… which means that the camera had that much less time to capture light. Other things I could change, to re-capture some light, were aperture (how wide the lens opens up – the maximum was dictated by the lens), ISO, and exposure compensation. After I set the set the aperture and exposure to compensate for the shutter speed, the pictures were still coming out dark. (Spending upwards of $1000 for a new lens would have helped, but wasn’t an option.) That meant I had to push the ISO up to 800.
Added to that, the birds were pretty far away — which meant I had to zoom in as much as possible, and then crop the resulting photos when I got home.
The high ISO value does allow that extra light, but also means that there’s lots of noise (graininess) on the photo. Cropping the photo, and then enlarging the result, makes that noise seem even worse.
I went ahead and submitted one of the photos for the challenge, after upping the contrast and blurring it a little bit (to reduce the noise) , but I was still unhappy with the noise. Enter Photoshop. This morning I found this nice video tutorial that demonstrates how to use the Photoshop “surface blur” filter in each of the channels (red, green, blue) to only blur each channel as much as is needed.
Here’s part of the image before the surface blur was applied:
… and then after contrast and color level changes were applied:
… and finally, the resulting photo.