Split-image focusing

[Arnie]

Hello!
Has anybody here ever worked a lot with split-image focusing? I'm shooting a lot of animation on a Bauer 709XL. When I get the film back usually about 90% of my shots are fine but about 10% look quite soft. My last roll was worse, probably about 70/30. I've noticed that sometimes when I focus, the image will line up exactly but the image will seem softer. But if the alignment is just a little off, then it looks really sharp. Which would you say is more accurate? Is this the cause of my problems? I guess since the aperture is almost fully open, and I'm in macro mode, I have almost no room for error with my depth of field?
Any tips/suggestions would be great!
Thanks so much.
Arnie.

[StopMoWorks]

I got a couple of Super8 Sankyo EM-60xl's for stop motion work. Split image focusing generally reliable for regular live action filming but when you deal with animation puppets and miniature sets where your camera must be close-up, I go by the depth of field tables that came with the cameras. With split imaging focusing, you are not able to see the actual depth of field in the camera viewfinder. As we all know, one becomes familiar with the camera through trial & error / practice.

So, this is how I do it: Using manual exposure setting, the puppet and/or miniature is lit to stop-down aperature as much as possible (smallest opening) .... once f-stop is set, I look at D of F Table and see where I should set the focus distance to get the necessary depth of field. So essentially, I do not use the split image focusing and go by depth of field tables and the tape measure .... physically measuring film plane to subject distance. Also, I only use the macro-mode sometimes. On my cams, the built-in macro mode, even when it's really stopped down, the depth of field is very narrow .... so I guess there is less room for error. My cams also came with depth of field tables for macro-mode (probably specific to my Sankyo model).

For maximum depth of field, use the lens at it's widest, you then light puppets/sets to get smallest fstop, and set distance at infinity .... everything will be in very-very sharp focus, from in front of lens to infinity. Of course, disadvantage to this, is your camera will be really close to puppets/sets and may be inconvenient to reach in and animate. Again, I refer to d of f table when doing above. Also, another way to get close to animation puppet is by using screw-on plus diopter lens but you do get more of a flat look and much narrower depth of field.

If you really want to be scientific about it, you can do "wedge tests" of your macro mode ....slate each shot, then on separate sheet write everything down, camera settings, lighting notes and especially how you focused with the split-image. This way, you will find out exactly how to adjust or compensate for that softness. In general, do wedge tests for many things. You might think it's a waste of film but in the long term, you will be saving $$$ in costly re-shoots (not only film but your time/labor).

P.S. I think online, one can find general depth of field tables for Super8mm. They may not be specific to your camera models, but they are based on standard photography, lens formulas.

LIO

[Lucas Lightfeat]

Hi there

I would suggest that your diopter (eyepiece) is not focussed properly. This is the first thing do - get it perfectly tuned to the camera operative's eye. You do this by...

...focussing the split image with the diopter on a line over 100metres away at full zoom, infinity focus. Focus the image with a relaxed eye by using the diopter.

I think this should resolve your problem, though if you've already done this, it could get a lot more tricky.

You should also use a depth of feld table. The table in the archives of this forum - see "Articles" will help you a lot. Download and print it.

Good luck

Lucas

[Arnie]

Cool-
Thanks guys!

[Old Uncle Barry]

8O
Also,once you have sorted out the advice above (particularly the eyepiece diopter setting) you might like to consider purchasing a close-up attachment for your camera.This,in my experience gives you a little more flexibility than macro.If you are that close that is!