Focus Stacking

Yesterday, with 15 minutes to spare before my little boy woke from his nap, I attempted to take some images to use for focus stacking. For those of you that don’t know, Wikipedia says the process….

…combines multiple images taken at different focus distances to give a resulting image with a greater depth of field (DOF) than any of the individual source images…

Source Wikipedia

We’d just picked some lovely fresh strawberries from our garden and I wanted to try and capture their red juiciness! For all the images taken, I used a 50mm standard lens and a 21mm extension tube. For the set up below, I also had a mini tripod, an automatic trigger and the focus stacking rail. None of these things are expensive, as I’m on the amateur spectrum, but they’re a good a starting point as any.

As I now have Affinity Photo, I used this to process all the images taken. The images, before processed together, look something like those shown below. I’ve picked a random 3 photos from the 40+ taken. In every picture, the focus point is slightly different.

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With Affinity open, I selected New Focus Merge, added all the photos and pressed OK. Then the computer chugs away and does some magic before your eyes. Below I’ve shown the results of the focus stacking. The first image uses over 40 photos. The second image uses 29 photos. Try and spot the difference!

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Just in case you didn’t spot the difference, Image 2 used less photos. As a result, if you look at the strawberry in the far left, you can see it’s now not in focus. I guess it’s all down to personal taste and what you want from your overall image.

But just for the sake of comparison, I also took some images without the use of the stacking rail. These were just with the 50mm lens and extension tube mentioned before. What do you think? Any preference? I quite like image 3 that doesn’t use focus stacking.

Lessons learned:

• Don’t put focus rail on wobbly grass.
• Don’t over extend the rail, as that increase the wobble risk and image blur.
• Remember to allow room for the final image to be cropped and tidied up, so think of the composition before starting.
• Don’t try to do this in a time constraint, to avoid tense words with your husband!