Jump to content


Photo

Little help


  • Please log in to reply
21 replies to this topic

#1 Fuad zulkifli

Fuad zulkifli
  • Basic Members
  • PipPip
  • 18 posts
  • Grip
  • singapore

Posted 19 October 2009 - 08:42 AM

My apologies if i create another thread about this.

Any advice/tip on how to do a fast pull focus. Cause i doing a short film soon for my school project and there's some scene that i need to do a fast pull focus. So is there any tips on how should i start on doing a pull focus. Any advice would be much appreciate
  • 0

#2 Chris Keth

Chris Keth
  • Sustaining Members
  • 4427 posts
  • 1st Assistant Camera
  • Los Angeles

Posted 19 October 2009 - 04:41 PM

My apologies if i create another thread about this.

Any advice/tip on how to do a fast pull focus. Cause i doing a short film soon for my school project and there's some scene that i need to do a fast pull focus. So is there any tips on how should i start on doing a pull focus. Any advice would be much appreciate


What's the shot?

Generally, there are lots of ways to do it. Probably easiest is to use a speed crank. Sometimes I'll use a whip and kind of twist my arm up so I can do the move in one big fast smooth motion and still not disturb the camera for the operator. If you have a remote ff available, that sometimes makes really fast pulls easier because you can hold the unit in one hand, the wheel in the other and twist with both hands and get a larger range of motion.
  • 0

#3 Edgar Dubrovskiy

Edgar Dubrovskiy
  • Basic Members
  • PipPipPipPip
  • 348 posts
  • Cinematographer
  • London

Posted 19 October 2009 - 06:13 PM

Make sure you start with UNCOMFORTABLE hand position and go to the COMFORTABLE one, as you pull.
Will help arriving in the focus in a smoother manner (if that makes sense).
  • 0

#4 Fuad zulkifli

Fuad zulkifli
  • Basic Members
  • PipPip
  • 18 posts
  • Grip
  • singapore

Posted 19 October 2009 - 09:12 PM

Thanks for the advice. But how to do you measure the focal length to the subject?

As in take example a car racing scene, i wanna to pull focus on the car but the car moves in a very fast speed. any advice on this?
  • 0

#5 Chris Keth

Chris Keth
  • Sustaining Members
  • 4427 posts
  • 1st Assistant Camera
  • Los Angeles

Posted 19 October 2009 - 09:37 PM

Thanks for the advice. But how to do you measure the focal length to the subject?

As in take example a car racing scene, i wanna to pull focus on the car but the car moves in a very fast speed. any advice on this?


While it's moving, you have to estimate the car's relationship to points in space you have already measured. For example, if you're on a racetrack with a long lens, you might have to set up cones on the side of the track that correspond to marked distances on your lens.

Also, you're not measuring focal length. You're measuring focus distance.

Edited by Chris Keth, 19 October 2009 - 09:38 PM.

  • 0

#6 Ryan Thomas

Ryan Thomas
  • Basic Members
  • PipPip
  • 85 posts
  • Grip
  • San Francisco

Posted 20 October 2009 - 01:19 AM

Another thing you can do is have a few people sit out where they can see things better. Like, if you're looking straight on, have them positioned on the side with walkie talkies. Then you have them call it out as they get to the 1st, 2nd, 3rd, and so on marks.
  • 0

#7 Fuad zulkifli

Fuad zulkifli
  • Basic Members
  • PipPip
  • 18 posts
  • Grip
  • singapore

Posted 20 October 2009 - 06:31 AM

While it's moving, you have to estimate the car's relationship to points in space you have already measured. For example, if you're on a racetrack with a long lens, you might have to set up cones on the side of the track that correspond to marked distances on your lens.

Also, you're not measuring focal length. You're measuring focus distance.


Oh, now i get it. Thanks for the advice. But how to do i measure focus distance?


Another thing you can do is have a few people sit out where they can see things better. Like, if you're looking straight on, have them positioned on the side with walkie talkies. Then you have them call it out as they get to the 1st, 2nd, 3rd, and so on marks.


oh, okay. Thanks for the tips.
  • 0

#8 Chris Keth

Chris Keth
  • Sustaining Members
  • 4427 posts
  • 1st Assistant Camera
  • Los Angeles

Posted 20 October 2009 - 09:19 AM

Oh, now i get it. Thanks for the advice. But how to do i measure focus distance?


With a tape measure.
  • 0

#9 Fuad zulkifli

Fuad zulkifli
  • Basic Members
  • PipPip
  • 18 posts
  • Grip
  • singapore

Posted 21 October 2009 - 09:32 AM

With a tape measure.


But how to do your calculate them? Pardon me for being such a bother.
  • 0

#10 Chris Keth

Chris Keth
  • Sustaining Members
  • 4427 posts
  • 1st Assistant Camera
  • Los Angeles

Posted 21 October 2009 - 10:56 AM

But how to do your calculate them? Pardon me for being such a bother.


There is no calculation. When you want to focus on a point in space, you measure the distance from the film plane (marked on the body with a circle with a vertical line through it) to that point and set the focus ring to that distance. This all assumes that the lens and camera are set up properly.
  • 0

#11 Brian Dzyak

Brian Dzyak
  • Basic Members
  • PipPipPipPip
  • 1517 posts
  • Cinematographer
  • Encino, California USA

Posted 21 October 2009 - 02:06 PM

But how to do your calculate them? Pardon me for being such a bother.



When the distance is too far for a tape measure, simply ask the Camera Operator for some time with the camera. YOU look through the viewfinder, zoom in (if you have a zoom on), and find specific landmarks, focus on them, then make marks ON THE LENS for each landmark that YOU choose in the distance. Use a "China Marker" for this (it's like a colored pencil, use white on a black lens).

For very fast objects, don't make too many marks because if you're trying to hit each one, you'll almost certainly be BEHIND the object (with focus) as it speeds off into the distance. If anything, you want your focus to be ahead of the object, not behind it.

When dealing with very fast things (like cars), generally, you'll have a starting focus mark and an end and maybe a middle point for reference. When the car takes off, you'll start your focus pull, slowly at first, but ramping up in speed as it heads off to infinity (on your focus ring). The middle point reference mark(s) will help you gauge just how fast to pull, but generally, you'll just start rotating the focus ring and keep moving it faster until you reach infinity. Trying to "hit" exact marks with a very fast moving object isn't likely and you're more likely to miss.
  • 0

#12 Chris Keth

Chris Keth
  • Sustaining Members
  • 4427 posts
  • 1st Assistant Camera
  • Los Angeles

Posted 21 October 2009 - 07:14 PM

When the car takes off, you'll start your focus pull, slowly at first, but ramping up in speed as it heads off to infinity (on your focus ring).


I'm sure this was a typo but it's the other way around. You have to pull slower at the infinity end and faster as something gets close to the camera.
  • 0

#13 Fuad zulkifli

Fuad zulkifli
  • Basic Members
  • PipPip
  • 18 posts
  • Grip
  • singapore

Posted 21 October 2009 - 07:56 PM

Thanks for the advice. But what does the measuring tape are for? Is it for to measure the focal length from camera to subject or?
  • 0

#14 Chris Keth

Chris Keth
  • Sustaining Members
  • 4427 posts
  • 1st Assistant Camera
  • Los Angeles

Posted 21 October 2009 - 09:38 PM

Thanks for the advice. But what does the measuring tape are for? Is it for to measure the focal length from camera to subject or?


Yes, the tape is for measuring the distance from camera to subject. This distance is what you would set on the lens to have the spot you measured to in focus. This is not the focal length. It's called subject distance.
  • 0

#15 Fuad zulkifli

Fuad zulkifli
  • Basic Members
  • PipPip
  • 18 posts
  • Grip
  • singapore

Posted 21 October 2009 - 10:52 PM

Yes, the tape is for measuring the distance from camera to subject. This distance is what you would set on the lens to have the spot you measured to in focus. This is not the focal length. It's called subject distance.


I'm quite confused. Okay, take example if i take out the measuring tape and measure the the subject from the camera and it's 5 meter away. What do i have to do next?
  • 0

#16 Chris Keth

Chris Keth
  • Sustaining Members
  • 4427 posts
  • 1st Assistant Camera
  • Los Angeles

Posted 21 October 2009 - 10:54 PM

I'm quite confused. Okay, take example if i take out the measuring tape and measure the the subject from the camera and it's 5 meter away. What do i have to do next?


Set the focus ring on the lens to 5 meters.
  • 0

#17 Fuad zulkifli

Fuad zulkifli
  • Basic Members
  • PipPip
  • 18 posts
  • Grip
  • singapore

Posted 24 October 2009 - 06:31 AM

Set the focus ring on the lens to 5 meters.


I tried to do what you told me to do. But it seems like the lens didn't show something like 5 meter and stuff. It only show like "MF 96.3" and if you turn the focus ring it the number of the MF would either go up or go down. And some goes to the lens. As the camera lens it's a zoom lens. But i'm not really sure what the stats of the lens. but i'm pretty sure its a build in lens.
  • 0

#18 Chris Keth

Chris Keth
  • Sustaining Members
  • 4427 posts
  • 1st Assistant Camera
  • Los Angeles

Posted 24 October 2009 - 06:09 PM

I tried to do what you told me to do. But it seems like the lens didn't show something like 5 meter and stuff. It only show like "MF 96.3" and if you turn the focus ring it the number of the MF would either go up or go down. And some goes to the lens. As the camera lens it's a zoom lens. But i'm not really sure what the stats of the lens. but i'm pretty sure its a build in lens.


OK, I guess you have a DVX or an HVX. I was assuming otherwise, I suppose.

You can set the display to show you the focus distance in feet+inches or meters. I don't know how accurate it is, though. Your best bet is to just pull focus by eye. Focus pulls are not at all repeatable on those cameras so any kind of marks are pointless. If you want, you could zoom in on the furthest point on the track and on the closest point and remember those distances or arbitrary focus numbers. That would let you ballpark focus for any point on the track without really thinking or breaking the shot.

Edited by Chris Keth, 24 October 2009 - 06:09 PM.

  • 0

#19 Denny Lajeunesse

Denny Lajeunesse

    New

  • Basic Members
  • Pip
  • 6 posts
  • Other

Posted 02 December 2009 - 11:36 PM

Focus pulls are not at all repeatable on those cameras so any kind of marks are pointless.



That's not entirely true. The feet/inches marker in the lcd is pretty accurate. Focal plane is from the end of the lens (odd I know) and is not marked to say so.

You really do need an electronic focus remote for those cameras. They are markable (and repeatable) with a china marker. You really want one of the brands that has a large diameter focus wheel, otherwise they can be touchy. (The smaller the diameter of the focus ring then the easier it is to miss your mark as you only need to turn a short distance to blow past it, especially if you are pulling based on the numbers in the display. I highly suggest using a maker.) I have a varizoom and I find it too small for display based pulls. (I use the one with focus/iris and zoom).

If you are pulling with the on camera focus ring then you can only repeat the focus based on the numbers in the LCD or viewfinder.

The above of course is for using the built in lens. If you are using one of those film lens adapters then you do not use the on camera focus other than to focus onto the spun glass when setting the unit up. You then use the attached lens system for focus.

Edited by Denny Lajeunesse, 02 December 2009 - 11:40 PM.

  • 0

#20 Chris Keth

Chris Keth
  • Sustaining Members
  • 4427 posts
  • 1st Assistant Camera
  • Los Angeles

Posted 03 December 2009 - 12:54 AM

That's not entirely true. The feet/inches marker in the lcd is pretty accurate. Focal plane is from the end of the lens (odd I know) and is not marked to say so.

You really do need an electronic focus remote for those cameras. They are markable (and repeatable) with a china marker. You really want one of the brands that has a large diameter focus wheel, otherwise they can be touchy. (The smaller the diameter of the focus ring then the easier it is to miss your mark as you only need to turn a short distance to blow past it, especially if you are pulling based on the numbers in the display. I highly suggest using a maker.) I have a varizoom and I find it too small for display based pulls. (I use the one with focus/iris and zoom).

If you are pulling with the on camera focus ring then you can only repeat the focus based on the numbers in the LCD or viewfinder.

The above of course is for using the built in lens. If you are using one of those film lens adapters then you do not use the on camera focus other than to focus onto the spun glass when setting the unit up. You then use the attached lens system for focus.


I've witnessed DVXs feet+inches reading off by FEET. That combined with the fact that you can't do anything in the way of calibration or backfocus adjustment led to me making that statement.
  • 0


FJS International, LLC

Paralinx LLC

Ritter Battery

Technodolly

Rig Wheels Passport

CineLab

Willys Widgets

Opal

Abel Cine

Media Blackout - Custom Cables and AKS

Visual Products

Tai Audio

CineTape

Aerial Filmworks

Broadcast Solutions Inc

Wooden Camera

Metropolis Post

rebotnix Technologies

The Slider

Gamma Ray Digital Inc

Glidecam

Ritter Battery

Gamma Ray Digital Inc

CineTape

Metropolis Post

Broadcast Solutions Inc

Glidecam

The Slider

Tai Audio

Paralinx LLC

Willys Widgets

FJS International, LLC

Media Blackout - Custom Cables and AKS

Aerial Filmworks

Opal

Abel Cine

Visual Products

CineLab

Technodolly

Wooden Camera

rebotnix Technologies

Rig Wheels Passport