What A Focus Puller Does On Set: Crew Breakdown
INTRODUCTION
In this series I go behind the scenes and look at some of the different crew positions on movie sets and what each of these jobs entails.
Since, the camera department is what I’m most familiar with, having worked as a camera assistant in the film industry myself for years, I’ll break down the role of the 1st AC or Focus Puller, to uncover what they do, their average day on set and some tips which they use to elevate their game.
ROLE
A Focus Puller or a 1st Assistant Camera are responsible for maintaining the camera lens’ optical focus by manipulating the focus gear on the barrel of the lens. Cinema lenses come with distance markings, which are usually displayed in feet and inches, but sometimes also in metric units depending on the country.
Pulling focus is the act of using these distance measurements to manipulate the focus distance on a lens so that they align with the distance between the subject and the camera's focal plane or sensor. For example, if an actor is 6 feet away from the focal plane and the 1st AC sets the lens to 6 feet then the actor will be sharp and in focus.
Focus can also be determined by referring to sharpness on a monitor using the eye.
Usually the focus will shift during a shot, for example when an actor moves closer towards the camera or if the camera moves closer towards its subject. It is the job of the 1st to time the focus pull so that the distance of the focus is always correct throughout the movement.
In most cases cinematographers will hand pick their 1st AC, based on their track record, prior relationship, or a recommendation from a trusted source. The technical act of capturing the image lies largely in their hands, so DPs are careful about their selection.
Contrary to what the name may suggest, pulling focus is far from being the only job that the focus puller performs. Some other responsibilities include: building the camera and configuring it depending on how it will be rigged, troubleshooting any technical camera glitches, setting the exposure which is dictated by the cinematographer, changing lenses, providing technical advice about camera gear to the DP and being responsible for the overall running of the camera.
Although focus pulling is largely a technical pursuit, it does require an artistic eye or emotional sensitivity to the story. They choose, literally, where to direct the focus of the audience’s eye, anchoring their attention to a particular part of the frame. Often the focus is on the actor, but not always.
Who should be focused on in a two shot featuring two cast members? Should the focus change, or rack, between them? Do we stay on one of them the whole time? When should the focus shift? These are all decisions usually made instinctively by the 1st, sometimes with feedback or suggestions from the DP between takes.
The first thing that many non-film people ask when the role of the focus puller is explained is: Why not just use autofocus? My smartphone can do it. Why can’t a tremendously expensive cinema camera do it?
There are several reasons.
First, autofocus can’t read human emotion or nuance. An autofocus motor will set focus based on what it’s told by software. ‘This thing is in the middle, focus on that!’ However, as mentioned, sometimes the language of cinema will require focus to drift or sharpen or defocus unconventional parts of the image for artistic effect. People can make reactive, creative decisions about focus better than software can.
Second, autofocus is not always smooth. Over the years audience’s have become familiar with the more organic way that focus pullers change the focus using a human touch. Autofocus can sometimes feel overly jerky, too quick and precise, or laggy. Although new technology in this field, like the Preston Light Ranger 2, is rapidly advancing the capabilities of autofocus.
Third, it’s faster. Rather than having to programme a specific area in the frame for the focus to hit, or struggle with any technical glitches, 1sts can do it instantly.
And finally, this way of working has been established as the industry standard over decades. High end cinema cameras, accessories and even how shoots are managed and structured (such as having a rehearsal before shooting) is with focus pullers in mind.
AVERAGE DAY ON SET
Before the day of the shoot, a focus puller does a gear check. They will get a list of camera gear which the cinematographer has requested including lenses, the camera and accessories.
During the gear check they will assemble the camera, shoot lens tests using a chart and determine that all the gear that they have is functioning normally. If there are any issues with the gear they will consult with members of the rental house to fix it or source a replacement. During the gear check they will consult with other crew members on the shoot such as the DIT, VT, sound recordist, and grip to ensure that their gear works properly together with the camera build. For example if there’s a crane shot that the grip has planned then the 1st may need to source an extended power cable or build the camera with an extra iris motor to alter exposure remotely.
Once this is done they will mark up the lenses. This is a process where the distance markings on the lens are synced by either programming or manually transcribing the distances onto the focus rings which they’ll be using.
There are two kinds of follow focus systems which can be used. A traditional follow focus or a wireless follow focus. Both use similar principles but a wireless follow focus has become the standard preference nowadays.
The focus puller mounts the follow focus or wireless motors onto camera rods positioned under or above the lens. The follow focus gears or motor gears are aligned with the gear teeth on the cinema lens. The follow focus is then turned, either physically or using wireless motors and a handset, to change the focus distance on the lens. For each lens, the distance markings should match the markings on the focus ring. So that as the 1st turns the ring, the distance on the ring matches the focus distance on the lens. If you’re really working with no budget, have a super old school cinema lens or a stills lens without a focus gear, or don’t have time to attach and calibrate a follow focus, the focus can also be adjusted by directly turning the barrel of the lens.
The two industry standard wireless follow focus brands are Preston and Arri. But other brands such as RT Motion or Tilta can also be used.
On the day of shooting the focus puller will chat with the DP about what configuration the camera is needed in for the first setup and what focal length they would like to start on. They’ll then assemble the camera, put on a lens, a mattebox and any necessary filters.
If working wirelessly they’ll build their focus setup which will include a wireless handset, a monitor and a receiver which will get fed a live wireless image transmitted from the camera.
The camera will then be placed on a rig, such as a dolly, or handed over to the grips for more complex rigging or handheld work. The first shot is lined up.
The cinematographer will then work out what exposure they want and communicate that to the 1st. There are different ways of doing this. For example the DP may ask for a shooting stop, such as T/2, and then expect the focus puller to add or subtract the adequate ND filtration to achieve that stop throughout. The cinematographer may ask them to change exposure by adjusting digital camera settings such as EI. Or, if working on film, the DP may use their light meter to measure the amount of light, such as T/11 at 250ASA, and then expect the focus puller to calculate the correct amount of ND filters to add so that the lens may be shot wide open.
Once a shot has been lined up and everything is in place, the 1st assistant director will call for a rehearsal. The focus puller will use this time to practice and make any marks that they need to, usually coordinating with the actor’s marks that the 2nd AC will put down.
For example, they may see that the actor starts the shot at 10 feet from the camera and ends the shot at 5 feet. They then know what distance to start at and what distance to end on and can concentrate on getting the timing in the middle right as they roll the focus from 10 feet to 5 feet in time with the actor’s movement.
This is the traditional way of preparing for a focus pull. It was very necessary to work off distance marks when ACs were working on 35mm film, before the assistance of an HD monitor feed, as they had no optical reference to see if they were sharp and had to judge focus distance purely by eye.
As you can imagine this is an extremely difficult skill that took years of training and practice to master.
Now, with HD, and even 4K digital video feeds, focus pullers have the option to either: judge focus purely from looking at an image on a monitor, use a combination of judging distance, using marks and going off a monitor, or, rarely, pull focus completely old school without a monitor.
Film tended to also be slightly more forgiving than digital. This is because DPs working on film would usually give focus pullers a workable stop, for example T/4 instead of shooting wide open at T/1.3. The focus rolloff on film is also more organic and forgiving. There was more of a graduated roll off between the sharpest point of focus and what was out of focus. So, for example, if you are out by 6 inches on the focus on 35mm it may still look sharp enough.
However, because of the high resolution of digital cameras and the precise, modern optics they are paired with, if the focus is not completely on point it will probably look soft.
This makes using a monitor to judge or check, focus an important tool in the digital AC’s arsenal.
Nowadays, because of digital cameras not requiring expensive film stock for each take, rehearsals are becoming increasingly rare and the 1st AD may ask ‘to just shoot one and see what happens’ without a rehearsal.
When ‘roll camera’ is announced the 1st AC will roll, if there’s sync sound they will pull focus to the clapper board and then rack back to the actor or subject once it has been clapped, ready to pull focus for the scene. As they play out the scene the blocking may change or the actor may miss their mark or improvise. It’s the 1st AC’s duty to be able to adjust their pulling accordingly.
After completing a shot the focus puller may be asked to change the lens, filter or rebuild the camera, for a different configuration such as a Steadicam shot.
When shooting on film the focus puller is also required to change and lace the new magazine. They’ll check the film gate before moving onto a new shot to check that there isn’t any dirt or dust which would ruin the take.
TIPS
The cliche of the grumpy focus puller may have a grain of truth to it. This comes from it being a very stressful job on set.
If a high enough percentage of their pulling is out of focus, their performance isn’t up to scratch - or if the film negative in fact gets scratched - they stand the risk of getting fired.
So let’s go over some tips to avoid that from happening.
Every focus puller should know how to use marks and judge distance. An old trick is to carry a tape measure around with you, continually calculate distances in your head, then take out the tape to measure and see if you are correct.
Taking marks is a great way of laying a foundation so that you know where you stand. One way is to use start and end marks as mentioned, another is to use physical marks on the set for in-between distances. For example, if an actor walks up to a table halfway through a shot, the focus puller will measure the distance from the camera to the edge of the table so that they have an in between point.
These marks can either be mentally noted, physically marked on the focus ring with a marker or with what are known as arrows - pointed markers cut out of gaffer tape - or marked using different finger positions on the focus ring.
The only time focus pullers might set the lens to a different distance mark is when they split the focus. This is when they are required to keep two objects sharp which are different distances from the lens. In this case the focus is set to the distance in between the two objects until a middle ground is found where they are both sharp.
Always test to make sure everything is working properly and you are happy with your camera build before lining up a shot. No offence to the assistant directors out there but when they say “Just bring out the camera so we can have a look and you can build it later”...they rarely mean it.
Since camera technicians are dealing with electronics and software, which have a tendency to bug out from time to time, they need to be good at solving technical issues very quickly. When troubleshooting, always be methodical. For example if a monitor isn’t working first check the battery, then try a new SDI cable, then go to the menu to make sure the camera is outputting a feed or recycle the transmitter. Following steps logically and calmly will solve the problem as quickly as possible.
The job is largely psychological. You have to always be confident and calm. The more you begin to panic the worse and less accurate your pulling will get.
It also helps to know what variables will make your job more difficult or easier and what tools you need to assist you. Longer focal lengths, shooting the lens wide open, focusing on objects very close to the lens or using large format cameras will make the depth of field more shallow.
So if the DP decides to use a 150mm lens at T/2 with the actor running straight at the camera you need to control the situation because getting pin sharp focus will be extremely difficult. For example: you could ask the AD for a moment to take marks, you could use a focus bug for a distance indication or you could kindly ask the DP if they could stop down a bit to increase the depth of field.
A final way to make life easier is to be surrounded by a strong team.
Having a competent 2nd AC that ensures the camera is always running, gear is well organised, reloads happen smoothly, actors are always marked and the clapperboard is always put in the correct place, will decrease your workload and allow you to focus on the most important part of the job - the focus.