Stacking II

Well, intrigued by this focus stacking business, I figured out quite quickly that the big difficulty is actually changing the focus in between shots.

You can do it manually, by twisting the ring, or most likely by shifting the camera, or probably also by shifting the subject. But unless you have some kind of rig that can be shifted precise and by minute amounts - to shift either the camera or the subject - it's not gonna work flawlessly. At least not with me twisting that focus ring and my crappy tripod.

Then I figured out that Canon has a software development kit for their EOS cameras, and I thought: what if you could let the computer drive the focus, small steps at a time and in between take a picture?

Turns out that SDK of Canon had exactly the right functions to do that, so I wrote myself a little application. It shifts the focus by a certain amount and then takes a picture. You can tell the computer how much to focus, in what direction to focus and how many pictures it has to take.

Works pretty well if I say so myself, and the big advantage: I don't have to touch that ring anymore.

The application is a bit rudimentary, and I still need to figure out the focus distances between the different options Canon gives me.

There's basically 3 types of focus drive: minute steps, bigger steps, quite big steps. Either closer up or further away. But I'm pretty sure they relate to one another. Question is: how many minute ones fit into one bigger one, because knowing that allows for more control if the bigger steps are too big and the small steps lead to way too many pictures.

Here's a picture truly not worth the effort (although this stuff goes pretty well with caviar, I assure you), but the proof is in the pudding (or something like that), so I took a crazy 100 photos and stacked those into 1...

Anyone interested in the software: I'll most likely have some kind of version worthy of distributing very soon. It's specifically for EOS cameras with Liveview capabilities (that's essential, else the focus won't drive). Tested on Windows 7 with a 5D Mark II...

Note though for those not grasping this fully or reading it half: it's not stacking software. It's 'automated focusing & picture taking' software. For the actual stacking of the resulting photos you need other software.

First of the 100...

Last of the 100...

All 100 combined...
Click on the photos for the larger version...