I first read about focus stacking a long time ago and I have been meaning to try it for ages. The premise is to take a series of shots with the focus set in different positions throughout the scene and then to use software to blend the images together to create on image with focus all the way through the shot. This seemed like a simple thing to have a try with but I never got around to having a go. Then I came across a situation that looked like it might be a good example to try.
I was visiting a model show at the Museum of Flight. I was taking a few photos of some of the more expertly crafted models on display. I was shooting with a longer lens and using a relatively small aperture to try and minimize the shallow depth of field that you get when shooting small objects close up. I decided to shoot a model of a Fairey Gannet and the shallow depth of field triggered something in the deep recesses of my brain about focus stacking. Of course, I had not planned for this so no tripod and just an effort to get focus on different parts of the model without moving the camera too much.
I took the shots and got on with my visit. When I got home, I almost forgot about the stacking experiment but, fortunately, I did remember. I exported the images to Photoshop as layers of the same shot. Then, since they were hand held, I did an Auto-Align action to get them in place. After that, Auto-Blend was selected. It seemed to realize that they were a blend stack rather than a panorama – quite clever – and the software quickly did its thing. Despite not taking too many shots and do it all hand held, the result came out pretty well. The top shot is the finished product while the lower two show the extremes of the focus range for the original shots. If I had managed a shot focused right on the back of the fin, the result may have been a bit better still.