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View Full Version : lens not usable with followfocus - help



earlybird
06-24-2010, 08:17 AM
Hi, I am using a 7D with different lenses. I also have a redrock micro v2 followfocus. My problem is that I can't pull the focus without moving the image. Due to the focus pressing against the lens, the whole camera is moving a bit, but you can see it in the video. When I have a scenario, where I have to change directions of the focus wheel, it moves everywhere.

How do you guys handle that? I thought about fixing the lens to the rails, but I don't know how and I am not sure if that gets annoying again when changing lenses.

Please help,
Axel

Betacam2
06-24-2010, 12:00 PM
Hi Axel,

Do you have a pic of your setup that you could post to understand what's going on a little better?

What lens are you having trouble with?

Do you have the DSLR mount from redrock? If not, you may have to come up with a mount solution to lift the camera and lens up about 2 centimeters. to allow enough room for the follow focus to engage properly. Just throwing this out there, not sure if it is your problem exactly.

Hope that helps a little bit.

Yoyodyne
06-24-2010, 12:40 PM
Hmmm, I've got a Redrock V2 follow focus as well and the thing is solid as a rock. I've used it with a ton of lenses and have never had any movement of the lens/camera. I'm wondering if your camera is mounted solidly to the rails? The torque of the gear could be moving the camera body.

earlybird
06-25-2010, 12:10 AM
Hi,

I will try to attach photos of our setup.
@betacam2: You got me wrong. I can use the followfocus, there is enough room. I have the vocas lifting thing - so far thats fine. But as soon as I pull the focus, the camera is moving in the opposite direction.

@yoyodyne: As the 7D only has one screw hole I'd say it is as mounted solid as it can get. Do you also use a rod support with only one screw?

http://www.dvxuser6.com/uploaded/44652/1277449478.jpg
http://www.dvxuser6.com/uploaded/44652/1277449816.jpg

peti1212
06-25-2010, 12:26 AM
I think what you are talking about is that when you focus, the follow focus causes those micro shakes that make it look like you have a cheap tripod. The solution for that would be to get something called a Whip. It connects to the follow focus and allows you to control it from further away, getting rid of the shake that might be transferred from your hands.

http://store.zacuto.com/zwhip.html

earlybird
06-25-2010, 12:34 AM
I never used a Whip, but know it and how it works. I guess it will not solve my problem. I already tried different technics of focusing, but as soon as I change direction there is something that causes shakes. Or could it be the tiny play I have with the redrockmicro?

Yoyodyne
06-25-2010, 12:52 PM
Hmmm, how solid is that Vocas camera mount?

I'm using the Redrock DSLR baseplate and it's very solid. It has the single screw (of course) and a little pin that sticks into the camera body that keeps it from twisting. I cannot move the camera at all when this mount is tightened down.

Can you wiggle your camera at all when it's mounted?

Another thing to check for is how hard you have the follow focus gear pressed up against the focus ring gear. You don't want to mash it super tight to the focus ring gear, it should be just tight enough that there is no play. Everything should move real smooth.

Also changing focus direction should be smooth, their should be no play. Do you get play in the follow focus gearbox itself? You should be able to hold the follow focus in your hand and check for play. Try holding the gear with your fingers and turn the follow focus back and forth, any play or slop?

earlybird
06-27-2010, 11:16 PM
@yoyodyne
The vocas doesn't have a pin and when I try to move the camera on the mounted plate I can. But how can I solve that with only one screw whole?

jonE5
06-30-2010, 06:25 AM
maybe take the FF off and rack focus by hand? Should be pretty smooth as long as your hands arent to shakey.