Jump to content

Pulling Focus Tips


Recommended Posts

Hi all,

 

just like to find out if any of u more experienced ACs' have any tips or guidelines as to pull focus successfully.

 

recently tried to pull focus on a P+S mini35 / XL2 with an 85mm, aperture wide open, and it was damn hard to get the subject sharp. the shot was a MCU of a person sitting down talking, and she was moving her head back and forth as she spoke.

 

other than using a smaller aperture, are there any other tips which i can follow?

 

thank u : )

Link to comment
Share on other sites

  • Replies 51
  • Created
  • Last Reply

Top Posters In This Topic

Practice at home with a tape measure. Place something next to you to represent the camera then start guessing distances. On the set measure other items in the room that are fixed close to you actor, edge of table for instance. This helps give you a reference. Run your tape right before the take. If it is a tough shot ask the actor to freeze, they won?t but they might learn, and run a tape to where they were. Try to do this with confidence rather then insecurity. More like a gunslinger then Barney Feif.

Link to comment
Share on other sites

  • Premium Member
Practice at home with a tape measure. Place something next to you to represent the camera then start guessing distances. On the set measure other items in the room that are fixed close to you actor, edge of table for instance. This helps give you a reference. Run your tape right before the take. If it is a tough shot ask the actor to freeze, they won?t but they might learn, and run a tape to where they were. Try to do this with confidence rather then insecurity. More like a gunslinger then Barney Feif.

 

 

One of the best things I have found that you can do is to get very, very good at eyeballing distances accurately. That will let you take those tape measurements and from those know the distance to any point on the set. Also, get in the habit of being very close to the camera when ou do it so you can see the lens barrel and the subject without turning your head. This makes it much easier to watch both things at once and not be late to your marks because of head-turning and reaction time.

Link to comment
Share on other sites

Hi all,

 

just like to find out if any of u more experienced ACs' have any tips or guidelines as to pull focus successfully.

 

recently tried to pull focus on a P+S mini35 / XL2 with an 85mm, aperture wide open, and it was damn hard to get the subject sharp. the shot was a MCU of a person sitting down talking, and she was moving her head back and forth as she spoke.

 

other than using a smaller aperture, are there any other tips which i can follow?

 

thank u : )

 

 

Let the subject go in and out of acceptable focus??

 

Remember the 1/3 2/3rd's rule, use that 2/3's behind the focus point you set to bring it a little forward, giving the actor some more room to move. If they are moving tons, switch lenses or close down.

Edited by Jmetzger
Link to comment
Share on other sites

  • Premium Member
Let the subject go in and out of acceptable focus??

 

Remember the 1/3 2/3rd's rule, use that 2/3's behind the focus point you set to bring it a little forward, giving the actor some more room to move. If they are moving tons, switch lenses or close down.

 

Hi,

 

It's actually more of a misconception than a rule.

 

In Macro photography the DOF is distributed 1:1.

 

Shooting a landscape at the hyperfocus the DOF will be distributed 1: infinity.

 

Stephen

Link to comment
Share on other sites

  • Premium Member
Hi all,

 

just like to find out if any of u more experienced ACs' have any tips or guidelines as to pull focus successfully.

 

recently tried to pull focus on a P+S mini35 / XL2 with an 85mm, aperture wide open, and it was damn hard to get the subject sharp. the shot was a MCU of a person sitting down talking, and she was moving her head back and forth as she spoke.

 

other than using a smaller aperture, are there any other tips which i can follow?

 

thank u : )

 

I forgot a useful trick that Doug Hart taught me: at a given stop and focus distance, if you mark the limits of the depth of field on the barrel of the lens (as in, a mark on either side of the witness mark for focus), it will tell you the depth of field at all other focus distances at that same stop. It will help you know your DoF so you can tell whether or not you nailed the shot.

Link to comment
Share on other sites

Practice the pull until you have physically "memorized" the motion of your hand. If you want you can even point your thumb at a certain orientation (12 o' clock, 3 o' clock, etc) on the follow focus wheel to help give yourself a reference point. Many times if your body knows something well enough, your mind will hardly have to consider it. It sounds like a stupid hippie trick and next I'm gonna tell you to do yoga, but it does help!

Link to comment
Share on other sites

  • Premium Member
Practice the pull until you have physically "memorized" the motion of your hand. If you want you can even point your thumb at a certain orientation (12 o' clock, 3 o' clock, etc) on the follow focus wheel to help give yourself a reference point. Many times if your body knows something well enough, your mind will hardly have to consider it. It sounds like a stupid hippie trick and next I'm gonna tell you to do yoga, but it does help!

 

 

Annie has a very good point. Take advantage of muscle memory. It's your friend.

 

Annie, wanna go do yoga now? ;) :P

Link to comment
Share on other sites

These are all great tips, but no amount of muscle memory or barrel markings are going to help you in the situation described above. The depth of field on a wide open 80mm lens on a 35 adapter with its 1/2000th inch CofC is just not a reasonable amount to work with when shooting a moving human being. Even after taping out, there is no way to judge when an actor has leaned forward as little as 1". In this case it is best to inform the DP of this logistical nightmare rather than sit quietly and hope to get lucky. A professional DP will often plan ahead for these types of situations by lighting to a better stop. Unfortunately with the 35 lens adapters DP's feel they have free reign to stay wide open all the time. The best advice in this situation, is to make sure you have a really good view of the monitor and a 2nd AC who will listen to your complaints afterwords.

JANDY

Link to comment
Share on other sites

  • Premium Member
These are all great tips, but no amount of muscle memory or barrel markings are going to help you in the situation described above. The depth of field on a wide open 80mm lens on a 35 adapter with its 1/2000th inch CofC is just not a reasonable amount to work with when shooting a moving human being. Even after taping out, there is no way to judge when an actor has leaned forward as little as 1". In this case it is best to inform the DP of this logistical nightmare rather than sit quietly and hope to get lucky. A professional DP will often plan ahead for these types of situations by lighting to a better stop. Unfortunately with the 35 lens adapters DP's feel they have free reign to stay wide open all the time. The best advice in this situation, is to make sure you have a really good view of the monitor and a 2nd AC who will listen to your complaints afterwords.

JANDY

 

 

Why the 1/2000th inch circle of confusion? The XL2 is a standard def camera, surely it doesn't need finer focus than 16mm film meant for projection...?

Link to comment
Share on other sites

I forgot a useful trick that Doug Hart taught me: at a given stop and focus distance, if you mark the limits of the depth of field on the barrel of the lens (as in, a mark on either side of the witness mark for focus), it will tell you the depth of field at all other focus distances at that same stop. It will help you know your DoF so you can tell whether or not you nailed the shot.

 

This is a cool trick. But doesn't the depth of field grow with distance to subject?

Link to comment
Share on other sites

  • Premium Member
Yes, but remember that the focus marks are spaced logarithmically, not linearly.

 

 

Exactly. It works exactly the same as the DoF markings on a still camera lens.

 

 

Does anyone know the answer to my question above? Why would the XL2, a standard def camera, require a 1/2000th inch circle of confusion? True, the sensor size is comparable to other formats that require such fine focusing but it can't resolve such fine detail anyway....right? :huh:

Edited by Christopher D. Keth
Link to comment
Share on other sites

  • Premium Member
Exactly. It works exactly the same as the DoF markings on a still camera lens.

Does anyone know the answer to my question above? Why would the XL2, a standard def camera, require a 1/2000th inch circle of confusion? True, the sensor size is comparable to other formats that require such fine focusing but it can't resolve such fine detail anyway....right? :huh:

 

Hi,

 

I would have thought 1/700 would be a good starting point, in reality maybe 1/500

 

Stephen

Link to comment
Share on other sites

  • Premium Member
Hi,

 

I would have thought 1/700 would be a good starting point, in reality maybe 1/500

 

Stephen

 

Exactly. To have resolution to make a 1/2000th CoC matter, you would have to be in the pixel realm of 1080 HD.

Link to comment
Share on other sites

"These are all great tips, but no amount of muscle memory or barrel markings are going to help you in the situation described above. The depth of field on a wide open 80mm lens on a 35 adapter with its 1/2000th inch CofC is just not a reasonable amount to work with when shooting a moving human being. Even after taping out, there is no way to judge when an actor has leaned forward as little as 1". In this case it is best to inform the DP of this logistical nightmare rather than sit quietly and hope to get lucky. A professional DP will often plan ahead for these types of situations by lighting to a better stop. Unfortunately with the 35 lens adapters DP's feel they have free reign to stay wide open all the time. The best advice in this situation, is to make sure you have a really good view of the monitor and a 2nd AC who will listen to your complaints afterwords."

 

Not sure I agree with all of this. I DO agree that the DP is also responsible for focus by lighting to a stop that the focus puller stands a chance with. This stop is on a shot by shot basis and in part depends on the abilities of the 1st AC. I'll assume the stop in question here is a 1.3 because the original poster mentioned an 85 on the PRO 35 adapter and this is what the Zeiss Super speeds open to (I'm ruling out Cook S-4s, Primos, etc. since they are expensive and usually seem to end up on film jobs - big difference, in my book though, between a 1.3 and a 2 though). Was the camera moving or just the actor? It sounded to me like it was just the actor. If so, the 85 is a common lens for CUs and one needs to be prepared to get MOST of it in focus - I say most because it is indeed hard. More experienced film actors tone it down a tad for CUs, but not all, making it hard on the operator and AC alike. When faced with shots like this, you need to figure out a percentage of acceptability, which in a nutshell means how much do I need to nail?

 

As for it being impossible, I recently shot a bunch of Steadicam footage at a T2 on a 135mm in a boxing ring roaming about between the two boxers. Killer stuff, but I was keenly aware that only moments would be useable.

Link to comment
Share on other sites

When you have this difficult shots , 85mm, T2, close to the camera , one thing you can do , is to ask for a little help . If you can , do a mechanic rehearsal with te actor. Tell the cameraman to tell you when you miss the focus. Do this with full aperture for 2 reasons : best definition for the cameraman and less DoF for you, to practice . Sometimes, that little out of focus, that generally happens when the actor moves forward or backward's , is compensated when you put the right T-stop ( unless you are working with full aperture!!!) . I always try this when I can. Also you will see the actor's movements , so when ready to shoot , you are more prepared cause you know when did you miss the focus.

Another thing you can do, is to put marks on the floor or the table , and ask your 2 assistant to follow the actor's eye with his finger.

And the most important thing, if you missed the focus, ask for another one !!!!! it's cheaper !!!!

Link to comment
Share on other sites

Christopher,

Regarding your question:

I do think Mini-35 adapters have a CofC of 1/2000 in. because of all the additional glass elements added behind the lens. Remember that there is a depth-of-field (in front of the lens) and a depth-of-focus (behind the lens). Once the image is projected onto a spinning ground glass, then bounced of three mirrors and then magnified by a diopter which is crudely attached to the front of a video lens, that focus tolerance is going to be greatly reduced, regardless of the definition of the CCD.

http://en.wikipedia.org/wiki/Depth_of_focus

JANDY

Link to comment
Share on other sites

  • Premium Member
Christopher,

Regarding your question:

I do think Mini-35 adapters have a CofC of 1/2000 in. because of all the additional glass elements added behind the lens. Remember that there is a depth-of-field (in front of the lens) and a depth-of-focus (behind the lens). Once the image is projected onto a spinning ground glass, then bounced of three mirrors and then magnified by a diopter which is crudely attached to the front of a video lens, that focus tolerance is going to be greatly reduced, regardless of the definition of the CCD.

http://en.wikipedia.org/wiki/Depth_of_focus

JANDY

 

 

OK, so it's more to make up for the mechanics of the adapter, not so much that it can actually resolve a 1/2000th inch CoC?

Link to comment
Share on other sites

  • Premium Member
Christopher,

Regarding your question:

I do think Mini-35 adapters have a CofC of 1/2000 in. because of all the additional glass elements added behind the lens. Remember that there is a depth-of-field (in front of the lens) and a depth-of-focus (behind the lens). Once the image is projected onto a spinning ground glass, then bounced of three mirrors and then magnified by a diopter which is crudely attached to the front of a video lens, that focus tolerance is going to be greatly reduced, regardless of the definition of the CCD.

http://en.wikipedia.org/wiki/Depth_of_focus

JANDY

 

 

Hi,

 

I don't understand why you are connectiong depth of focus and depth of field as they are inversely proportional.

With a macro shot the depth of field is tiny but the depth of focus is huge. If you don't believe me try a bellows on a 35mm still camera and see what I mean.

 

Stephen

Link to comment
Share on other sites

Dude, Don't even complain. I just got off a show on the HVX200 with the "RedRock cinema adapter" and Nikon prime lenses. Let me put it this was, after this show I could do anything.

 

The red rock adapter was not Attatched to the camera's front filter threading, it was guided by the support rods and we had to just keep checking its allignment, that was the first issue. That lasted for the first 2 weeks then I said we needed to do it right and we got the adapter to make it solid.

 

My lenses were Nikon primes and the marks were 100% useless, I had no real Follow focus!, and because of all this crap on the camera we were always WFO indoors, and usually at 55 mil, and 135mm to 200mils for the punch ins, It was tough. But I was introduced to Zen-Focusing.

 

Here is my suggestion to you, and what worked for me.

 

On the MCU this should be easy, but on the CU and ECU's it's tricky. It requires a lot of concentration.

 

Focus the static* subject, then roll the focus back and forth and get a feel for the lens. Find out the furthest you'd need to go and the closest. (I was pulling from the berrel as I had no FF and maybe on the CU a good thing) Do this while looking into the monitor if available, otherwise the viewfinder works, but not as good for obvious reasons.

 

Then watch the action of the subject and compensate with the mental lens marks you should have in your head, by feel of your wrist rotation. I zen'd Half of the movie and I didnt get one complaint of a soft shot, all the dailies were sharp. I actually got rewarded with a bonus for how much was sharp, as the DP expected pulling focus on the rig would be nearly impossible.

 

I did it, I have complete faith in you.

 

Good luck,

Allen

 

If anyone else is interested, I have many many stories about the rig, as well as pictures and advice.

 

 

 

 

One last tip, If it's possible share the monitor with the DP, if available that is. And isntead of eyeballing distances in front of the camera, Use the subject SIZE in the frame be a good reference...

Link to comment
Share on other sites

  • 1 year later...

I wouldn't mind advice or pictures about that rig. I just finished pulling with it and have a couple of things coming up with it so any more tips im sure would be useful. We had the follow focus attachment though...

 

Dude, Don't even complain. I just got off a show on the HVX200 with the "RedRock cinema adapter" and Nikon prime lenses. Let me put it this was, after this show I could do anything.

 

The red rock adapter was not Attatched to the camera's front filter threading, it was guided by the support rods and we had to just keep checking its allignment, that was the first issue. That lasted for the first 2 weeks then I said we needed to do it right and we got the adapter to make it solid.

 

My lenses were Nikon primes and the marks were 100% useless, I had no real Follow focus!, and because of all this crap on the camera we were always WFO indoors, and usually at 55 mil, and 135mm to 200mils for the punch ins, It was tough. But I was introduced to Zen-Focusing.

 

Here is my suggestion to you, and what worked for me.

 

On the MCU this should be easy, but on the CU and ECU's it's tricky. It requires a lot of concentration.

 

Focus the static* subject, then roll the focus back and forth and get a feel for the lens. Find out the furthest you'd need to go and the closest. (I was pulling from the berrel as I had no FF and maybe on the CU a good thing) Do this while looking into the monitor if available, otherwise the viewfinder works, but not as good for obvious reasons.

 

Then watch the action of the subject and compensate with the mental lens marks you should have in your head, by feel of your wrist rotation. I zen'd Half of the movie and I didnt get one complaint of a soft shot, all the dailies were sharp. I actually got rewarded with a bonus for how much was sharp, as the DP expected pulling focus on the rig would be nearly impossible.

 

I did it, I have complete faith in you.

 

Good luck,

Allen

 

If anyone else is interested, I have many many stories about the rig, as well as pictures and advice.

 

 

 

 

One last tip, If it's possible share the monitor with the DP, if available that is. And isntead of eyeballing distances in front of the camera, Use the subject SIZE in the frame be a good reference...

Link to comment
Share on other sites

  • Premium Member
Does anyone know the answer to my question above? Why would the XL2, a standard def camera, require a 1/2000th inch circle of confusion? True, the sensor size is comparable to other formats that require such fine focusing but it can't resolve such fine detail anyway....right? :huh:

 

 

Because it's a 35mm sensor when you have the adaptor on ? That is the target size that you're focussing on. That is why you use 35mm lenses with the adaptor. It's then reduced through the adaptor. It's not about the resolution. it's about the target size of the projected image from the lens. The lower resolution will still capture something out of focus or in focus or whatever it is in between.

 

Most of the great focus puller's I have worked with have just been guns as FEELING the actors movement. In as much as the actor is in a space when acting, it's up to them to follow. Most of the good ones will run the tape for references and environmental distances, but then they are usually looking intensely at the performance. Not the onboard monitor. Hardly at the lens and hardly at the marks. It just comes from experience and doing it lots.

 

I worked with a guy earlier this year on a 35mm anamorphic shoot. There was only one take that was soft after 8 days of shooting. A 100mm shooting T2.8 at 4' from the camera. Even then it was only soft part of the time. The second take was perfect. He had no marks. just ran the tape just before slating for a start point and went from there. And he knew it was soft.

 

That was on the first day (and my first anamorphic shoot) and he politely asked me later for a bit of help.

 

jb

Link to comment
Share on other sites

Allen, I feel ya about the RR with Nikon lenses. The barrel markings are close to useless. I pulled on a commercial recently with this setup, and after that I am a strong believer in the "zen" art of pulling, like you mentioned.

 

135mm at F/2 of a girl walking down a runway, while dollying...talk about mental witness marks!

Edited by Andrew Brinkhaus
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Forum Sponsors

Broadcast Solutions Inc

CINELEASE

CineLab

Metropolis Post

New Pro Video - New and Used Equipment

Gamma Ray Digital Inc

Film Gears

Visual Products

BOKEH RENTALS

Cinematography Books and Gear



×
×
  • Create New...