October 25th, 2005, 10:43 PM
this is a stupid question. but for a someone to pull focus other than the operator would they use a focus rod?.... anyone have any info on them.. ie: what i'd be looking for purchasing one that would fit etc..
October 25th, 2005, 10:58 PM
Check this out. I believe Dan may be offering something.
October 26th, 2005, 02:40 PM
The guy pulling focus for the operator is a camera assistant, aka focus puller. The most important job he has is to adjust the focus on the lens as the action progresses. He uses a "follow focus" device that engages the gear on the lens and enables him to perform repeatable and accurate focus changes.
Why doesn't the operator pull focus as he is the only one seeing the image?
Because is hard to judge focus on a flickering screen (motion picture) while his both hands were full of pan/tilt wheels of the geared head.
The camera operator has aesthetical (and practical things) to look after:
Nice framing, correct eye line, reflections, cables, boom mic edging the frame (to name a few) to worry about focus (which is a purely technical job- but non the less could be used for artistic FX) and nearly impossible to him to do.
A camera assistant uses his both eyes and practical marks (on the floor) to judge a few inches distance change between camera and talent and adjust focus on the lens accordingly, while the camera operator could not even detect the change (with one eye in the viewfinder) till the film would have been processed and projected on a large screen (and that'd be an expensive test)
A camera mounts on a "base plate" which has a "rods support system". The follow focus mounts on the rods. The rods will support:
a heavier lens (usually zoom lenses)
a matte box
a follow focus
and will ensure they all remain lined up relative to the camera and maintain the true optical axes of the lens. Sorry for the "long lecture" but I hope it helps.
October 26th, 2005, 04:34 PM
And aren't there flexible axes as extra feature on the follow focus so the focus puller doesn't have to touch the camera and can take a position where he has a better view?
October 26th, 2005, 04:57 PM
Yes Oscar, those would be the "whips" (in different lengths) and yes, they allow focus pulls when the camera is moving (dolly, "rocker", etc) without interfering too much with the operator's moves and/or allowing access in tight corners to focus changes without "boning" everyone for the matter (when a wireless focus is out of the que... hmmm... budget).