My son has been getting into stop motion, and we're thinking of taking things a small step upwards. He's currently using an old webcam that has a very small physical focus ring that is awkward to use. We've been reading about the benefits of a camera with the capability of controlling focus through software. So we're thinking of looking out for an old Canon EOS body with live capture. But now we're reading about flicker problems with Canon lenses, and it seems the consensus solution is to use old manual-aperture lenses. (I have some old Pentax K glass that might do the trick.) But wouldn't that eliminate the possibility of focusing the camera remotely? Wouldn't that put us back where we started, i.e. having to focus the camera physically, and more often than not nudging the camera itself and ruining the shot? (We're talking a 12-year-old.)
Any advice would be appreciated.
Generally you need to disable all the auto settings, so the camera isn't trying to change anything to improve the photo from one frame to the next. What you need for animation is consistency. You want to set exposure, focus, white balance yourself and have it stay there where you put it.
Actually changing focus during a shot is tricky, it is hard to move the lens a small enough amount, and an even amount each time. I avoid it as much as possible, and if a puppet is coming closer to the camera during the shot I usually use wide angle lens and stop down to f-16 (or f-32 if the lens has that) for deep focus. I set the focus at the mid point of the move, and start and finish it so it isn't outside the range of acceptable focus. If I have to "pull focus" I put a big 300mm foam core disk on the lens, with increments marked off around the edge and a bit of wire positioned to act as a pointer, so I can do very fine even moves. That includes ramping-up - start with very tiny move, gradually increase over several frames until it is at full speed. (Just like moving puppets, camera moves benefit from accelerating into a move, and decelerating before coming to halt.) Many lenses do a slight zoom effect when they change focus, and that looks bad if it is uneven.
If the software can do fine accurate focus changes like that, sometimes less than 1 degree of rotation, then that could be good. But I suspect it can't.
So, if you have to touch the camera while animating, it needs to be on a tripod, not a super light and flexible one you take in your backpack. A piece of ply or particle board on the floor with a hole for each leg to rest in, and sandbags or other heavy things to stop it moving easily can help keep it steady.
I did a test animating with Stop Motion Studio on an iPad, where I had to touch the screen to take the shot and to scroll back to compare the live view with previous frames, and because the iPad was firmly attached to a tripod, I was able to do it without it moving around. But using a phone as a remote trigger (as I think you can with the paid version) would have made it easier.
Yeah, so I do recommend the Canon EOS with a different brand of manual lens, and setting the focus before you start the shot. I think there are Pentax K mount-to-Canon EOS adapters. I use Nikon lenses with my Canon EOS, and one old Olympus OM lens, and I got the adapters from eBay, around $12 each with free shipping from China, simple ones with no electronics so the camera can't talk to the lens. Here's one for Pentax K lenses on eBay Australia: https://www.ebay.com.au/itm/Pentax-K-Lens-to-Canon-EOS-EF-Mount-PK-...
Thank you for all your advice. I was under the impression that the remote focus would still be under our control, i.e. not be auto-focus, but would be set and only adjusted manually-remotely when necessary.
And thanks for the tip regarding the adapter.
I have a Pentax lens that I use with an adapter on my Canon EOS body, and it works fine.
A tip on focusing... Get a focusing chart, looks like a dartboard in black and white. There are loads of them you can download, just Google Camera focus chart. For stop motion you don't need a particularly large one. Print onto some card if possible, highest resolution you can manage.
Then before each shot plonk this on your set where you want the focus to be sharp, and using Live View activate the 5X/10X focus magnifier on the camera (top right button on the 600D) and get the image nice and sharp. By moving the focusing card closer to the camera and also further away from it, you can establish the depth-of-field.
The card makes it easy, and you can really see the effect of getting the focus just right. It should be nice and practical for a 12 year old!
If you need to change focus during a shot, there are some rubber rips with a little handle sold cheaply on eBay, designed to fit onto a lens focus ring. The handle means you can make small movements, but be careful not to knock it during the shot!
Thanks for both tips! Very practical.