DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   Sony VX2100 / PD170 / PDX10 Companion (https://www.dvinfo.net/forum/sony-vx2100-pd170-pdx10-companion/)
-   -   How the @#$^$ do you pull focus on a VX2000? (https://www.dvinfo.net/forum/sony-vx2100-pd170-pdx10-companion/17536-how-do-you-pull-focus-vx2000.html)

Paul Tauger November 24th, 2003 03:27 PM

How the @#$^$ do you pull focus on a VX2000?
 
Okay, I'm in Europe, shooting a new travelogue, and I've got my nice new carbon-fiber tripod with me. I've got a shot I want to do in Firenze -- low level, shooting over a long row of parked bicycles. I want to start focused on the front bicycle, with the background out of focus, then snap focus to the background (a majestic square). I'm shooting at night, so the lens is wide open and I have enough depth of field to do this.

The only problem -- I can't set the focus point. When I try to snap the focus (is this called "rack focus"?) to the background, I always undershoot or overshoot. It's not practical to mark the focus points on the lens barrel, I'll wind up with a bunch of magic marker blotches. There must be some way to do this.

How do you guys manage a shot like this?

Rob Lohman November 24th, 2003 03:37 PM

Basically we don't. As you point out correctly marking and pulling
focus with our DV cameras is just not possible. With enough
training I have been able to do some little focus pulls with my
XL1S lens, but only after a lot of practice and steady hand.

Rob Wilson November 24th, 2003 03:59 PM

Paul,

Just a thought, not familiar with the shot you're trying to get but... In post, you could freeze the video for what ever duration you're looking for at just the instant it's in focus.

Robbie Smolinsky November 24th, 2003 04:52 PM

Hey,
This is just a thought, but maybe you could set the camera to manual focus, and focus on the bikes in the foreground, then hit the auto focus button (while staying in manual focus mode) and hope that it will jump to infinity- to capture the square. I figure if you are shooting just high enough over the bikes, or do a pan up, you can set the focus where you like in the foreground (and then if the bikes are not entirely obstructing the view) the autofocus button might cause it to jump focus to the distant backround.

Otherwise, Iwould say to try to keep your hand on the focus ring, set it for the distance and remmeber what position your hand is in and then just twist the focus to the bikes without moving your fingers from where they are placed. That way when you want to pull out your finger and hand position will be the reference for the long focus. I don't know if this is possible based on how far you will have to rotate the focus, but I think if you were able to repeat it a bunch of times it might work.

Either way, good luck! I hope you get it to work!

Robbie

Boyd Ostroff November 24th, 2003 05:18 PM

Yeah, it is next to impossible (based on my experience with the VX-2000). I think Robbie has a pretty good idea though. Try setting for manual focus and focus on the foreground object. Pushing the autofocus button should do this. On the VX-2000 you can momentarily push down on the manual focus switch and it will shift to infinity which may accomplish what you want.

As you said, marking the focus ring won't help, it's just a servo that spins endlessly. When I used my VX-2000 a lot I got pretty good at using the manual zoom ring though, so I imagine with enough practice you might become proficient with the focus ring as well.

But none of these prosumer cameras are much good for that type of thing...

Bill Ravens November 24th, 2003 07:33 PM

it can be done, but, you've gotta attach something like a chrosziel follow focus with a calibrated knob.

Bryan Beasleigh November 24th, 2003 10:45 PM

Cavision makes one as well.

www.cavision.com

Rob Lohman November 25th, 2003 04:13 AM

You will need a manual lens with such a follow focus system as
well, right? Otherwise the markings will still not line up after you
rotated the knob.

Boyd Ostroff November 25th, 2003 07:10 AM

Yes, any form of calibration will be worthless on the VX-2000 focus ring. There are no absolute marks on it because it just spins round and round continuously. And it's sensitive to how fast you spin it as well. If you rotate it very slowly then nothing will happen at all. Very difficult to get any sort of consistent results with this sort of system.

Paul Tauger November 25th, 2003 02:44 PM

Rob, thanks for the freeze frame idea -- it's not exactly the effect I want, because there's a lot of movement in the shot, but it should be interesting.

Robbie, you're brilliant! I didn't get a chance to try it, as we've already moved on, but I'm almost certain that it will work.

Bill and Bryan, I'm not sure what a chrosziel follow focus with a calibrated knob is, but I'll check it out.

One thing is clear, though: as good as the VX2000 may be, it's not quite professional gear, or this wouldn't be an issue.

Mike Rehmus November 25th, 2003 06:39 PM

Yea, whenever I need that kind of shot, it's DSR-300 time.

A slick way to do a focus shift from near to far is to focus the lens on the far target in the normal manner, then shift the macro ring to focus on the near target. Then to shift the focus, just click the macro ring back to the normal position. Works every time and you don't need a Camera Assistant.

John Jay November 25th, 2003 07:15 PM

this is a job for the postman?


lock down on your tripod, get the two shots focussed

then using a time lined gaussian blur in post , xfade between them

try easy in out for the blur profile

Bryan Beasleigh November 26th, 2003 12:08 PM

Rob and Boyd are correct. the VX2K will not work with the follow focus.


All times are GMT -6. The time now is 03:11 PM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network