I've seen lots of movies where they dolly-in to the character, and the focus is perfectly sharp. how do they focus? keep rotating the focus-ring while moving?

I would like to try it with my XL1s.

Watch the credits of a movie closely, and you will often see the credit "Focus puller".

This is the guy who stands next to the camera, and rotates the focus knob to keep the shot in focus as the camera or actor moves.

It helps if you have a focus puller adapter for your lens. This is a large knob that attaches at a right angle to the lens and gears into the knurls cut on the barrel. It also has a white pencil slate around the knob, so you can mark it with starting and stoping points in the movement.

It works best with a manual lens.

Basically, yes. There's someone called a focus puller whose job it is to keep the subject in focus at all times.

On some cameras, though, there's a "Push Auto" button which may accomplish the same thing, and stay focused while you zoom/pan/etc. In fact, the BBC has recommended you do that when moving a VX2000 around since they say the focus ring is annoyingly touchy. So as the dolly moved in, the cameraman would just hold the Push Auto button and not worry about the focus ring.

This is nearly impossible to do with the standard lens that comes
with the XL1S because it is server controlled and has no fixed
end and start points (ie, you can rotate it forever). If you put a
mark on the ring you'll see that setting the point at 12 o clock,
rotating it around a bit and then put it back at 12 o clock the
setting won't be the same. Therefor you can't do this very well.

You can however set sharpness at one point and learn by enough
trial and error how fast (and how hard) you need to rotate the
ring to have the focus shift correctly while moving. You'll probably
will need a bigger monitor then your viewfinder to correctly spot
the moving focus though.

Ofcourse you only have this problem when the distance from the
subject to the camera is varying. If you stay at the same distance
you won't need to adjust your focus at all.

If your subject does move then you'll only need to focus if you
are running with a very shallow depth of field (lowest f-stop
when zoomed in). If you have a large depth of field your subject
won't go out of focus unless it is moving at great distances.

This is sometimes called a "Hitchcock dolly" maneuver because Alfred Hitchcock popularized it in some of his films.

Basically, it's not an easy maneuver for anyone. It requires extreme precision with manual focus and camera movement.

Here's a thread (http://www.dvinfo.net/conf/showthread.php?s=&threadid=8927) that discusses it in more detail.

Ken, are you sure he is talking about that? That is when zooming
and dollying...

Ah, indeed, Nawaf only mentioned focus, not simultaneous zoom. Sorry.

Yeah, I think Nawaf was just referring to the process of following focus.

Because digital, DV in particular, is much more forgiving in terms of focus (because of its extensive depth of field), it can seem to some extravagant to have an individual who's job it is to keep the image focused. But while performing a shot as described on 35mm if the actor chooses to lean a certain way on a whim, the focus puller must take that into account or the shot will be soft. It's a very skilled and demanding position.

thanx everyone. yeah, you guys answered my question. I guess i need lots of practise with focus.

Couldn't you just stay completely zoomed out (widest angle of view), regardless of what type of lens (auto 16x, manual 16x) you use? Unless that gives you undesireable framing, of course. Otherwise, that's how I'd do it. You get pretty much infinite depth of field, with miniDV. Unless your subject's like two inches from the lens.

Josh,
actually, i'm using shallow DOF most of the time, to give it film look. so I'm zoomed-in most of the times, which needs lots of precise focusing.

But even then you have quite large depth of field, it might be
shallow enough to use it nicely for DOF effects, but if you practice
you should be able to keep your camera the same distance
from your character all the time and thus avoiding the need to
adjust the focus.

Nawaf, if you are using the stock 16xIS II lens with the XL1, you have your work cut out for you! It's much harder to follow focus with that lens. If you are shooting at telephoto a lot and interested in narrative-type filmmaking vs run-and-gun shooting, you might want to look at the manual lenses if you haven't already done so. Either the 16x or the older 14x give a much more tactile response to focusing. I like the 14x myself, and they can be found pretty cheap these days, even new.

I always wondered why people use the old manual focus lenses. now I know.

so, with the 16x AF lens I have, I won't be able to do very sallow DOF? for example: if I want to close-up on someone's mouth, and I want the ears to be out of focus. would I be able to do that ?

Off-hand I'd have to say that you won't be able to get -that- shallow of dof with the the 16x Auto (standard) lens.

You may be able to use the macro settings of either the 14x manual lens that Charles mentioned or the 16x manual servo lens to approximate that. (See this article (http://www.dvinfo.net/canon/articles/article82.php) for more information on these lenses.) But the lens would have to be extremely close to the subject.

BTW, there's certainly nothing "old" about manual lenses. Since the consumer camera market, and indeed much of the prosumer market, demands auto everything auto-focus lenses have become standard issue on these products. Manual lenses are generally found on professional cameras designed for more skilled operators.

Nawaf,

As an ex-focus puller I can tell you that no matter what you try with the standard auto XL-1 or XL-1S lens, it is not going to be pretty, it cannot be calibrated to hit the same focus marks time and time again no matter what you do no matter how hard you try.

If you want to be serious about follow focus, you need to first, shelve your auto lens and pick up a manual lens. This will enable you to set actual "hard marks" that will be consistent regardless of what you do.

A First Camera Assistant or "focus puller is probably one of the most overlooked and mis-understood positions on any camera crew...except by the Camera Operator or the Director of Photography, who by the way is the one that pretty much hires the rest of the camera crew.

The focus puller, after getting his initial measurements and marks during the blocking and rehearsal of the scene, has to, on the fly, judge the distance from the camera's focal plane to the actor and "dial it in" accordingly while everything is in motion. This is generally done by eye and "feel" with no outside assistance, at least that is how I did it.

This may seem pretty straightforward but when you introduce simultaneous camera / talent movement, always at varying rates of speed, what you have is a dynamic which is different every time you roll on a scene. This is is never more evident than when pulling focus on a SteadiCam with a longer than usual lens.

I'll never forget chasing and leading Richard Dreyfuss through Hialeah racetrack while SteadiCam operator Randy Nolen kept up with Richard's frenetic pace during the scene. The only drawback was that we had a 50mm Zeiss superspeed lens mounted and we were shooting at about a T2.8! Of course, Dreyfuss's speeds and marks were always different which didn't make life any easier for the camera crew.

When I was doing it for a living, Panavision came up with a device called "PanaTape". In essence, it was a transmitter / receiver that gave you an approximete distance reading in feet and inches which you could use to adjust your focus. I found it innacurate, cumbersome and very distracting, especially when working a long lens with a small T-Stop. Too much to look at in very little time!

Focus pulling is a fine art, it has to be practiced and ultimatley done as second nature.

One very important point on following focus on a dolly shot is that you MUST have a competent dolly grip. He is the one who can make you or break you during a very slow push in with a very long lens while shooting wide open. This was especially true while on an episode of Miami Vice, we were given a shot to do that was to be the show's tag.

Fifteen feet of dolly track inside a dark Miami Beach Hotel lounge. Straight push in to the actor's eyes, full frame. The begining of the shot was a medium c/u using a 150mm Panavison Super Speed Prime, nicknamed the "crispy critter" due to its extreme shrapness and lack of compassion for focus pullers.

The length of the shot was approximately 2 minutes, using a very "creepy" dolly push as the focus continued throughout the shot until we filled the frame whith just his eyes.

I can tell you from experience that half the credit for the shot being successful belongs to my dolly grip, Jimmy Greene who expertly timed his move with my focus needs every time.

The bottom line when it comes to follow focus is that you not only need to know what you are doing but you need the proper people supporting you and, without a doubt you need to go with a manual lens in order to properly control your focus.

Keep it sharp!

RB

See, and in my mind it takes a far more skilled operator to work manual focus on the auto lens! It's a weird skill foisted on us by the folks who design prosumer cameras these days...

With the 16x noticable selective DOF only occurs starting at a distance between subjects of about 20 cm at closest focus (camera distance about one meter) zoomed all the way in. Of course the relative aperture becomes smaller when zooming in, increasing DOF, but zooming out even increases DOF further. Mouth & ear are just a bit too close.

Charles,

With all due respect I have to disagree.

Focusing on the Canon auto lens has absolutely nothing to do with skill. It is an inherent flaw of the lens design that makes it almost impossible to follow focus smoothly and consistently.

As I stated in my previous post, the lens has no calibration marks so you cannot set focus marks prior to rolling the camera. The fact that the focus ring will continue to rotate through 360 degrees is a clear indication that any focus mark made on the lens will be useless as the actual focus will never come back to your original mark.

The weakest link in the XL-1s system has to be the auto lens. We are about to acquire two more XL-1s packages bringing the total to six. ALL of the auto lenses are strictly emergency lenses in case one of the manual lenses goes down. Furthermore, I would canibalize another package's manual lens as an interim fix while the damaged lens is being repaired or replaced before resorting to using the auto.

I understand that the target users are closer to the consumer/prosumer market than the true "motion picture professional" but if your pictures are constantly out of focus you, no matter what category of filmaker you fall under, you might as well go into radio.

The manual lens makes a world of difference in the finished product when using the XL-1. It actually validates it as a production camera. The manual lens takes all of the guesswork out of focusing, allowing you to actually pull with the action. If you do go soft, then it is an issue of you either getting ahead of the action or lagging behind it.

Regards, RB.

I could be very wrong, but I think Charles was being facetious in response to my "...professional" remark. I know he uses a 14x manual lens with his XL1.

I apologize if I misunderstood Charles' post, my reply was not meant to be adversarial. I take my camera work very seriously, particularly when it comes to focus, and when I cannot meet my own standards due to inadequate equipment, I guess it kind of rankles my feathers a bit.

Maybe it is just my frustration with a product that has so many positive attributes but fails in the most fundamental feature that can make or break a production.

I don't quite understand how a company, any company, not just Canon, tries to reach out to the professional filmaker but at the same time ignores the shortcomings of that same product.

I felt that it was necessary to make sure that Nawaf's question was answered in detail and to his satisfaction as focus is one of the fundamental elements of good filmaking.

Again, my apologies if I have offended anyone.

RB

No Rick, on the contrary! I think everyone greatly appreciated your detailed front-line comments concerning the job of the focus puller in professional filmmaking. So many discussions here, and elsewhere, devote their energy to frame rates, depth of field and other technical issues. Precise and persistent focus throughout a motion shot is a matter generally overlooked in such discussions. But it's fundamental to a professional look, yet so deceptively difficult to accomplish on most prosumer cameras. It still baffles me how someone can pull focus often without looking through the lens in some way. But I guess it's an acquired skill that, as you say, can just become second nature with practice and knowledge of lenses.

Thanx everone for the replies, that was really helpfull. I never thought focus-puller's job was that tough!
I've just started getting into short-film. It's nice to know these details, so I know what to invest for the future.

Sorry guys, of course Ken is right and I was being facetious. It's my fault really; I find emoticons annoying and I'm not much interested in writing "hehehe" when I'm being sarcastic either, it reminds me of Beavis and Butthead or something.

I just sold my 16x IS II stock lens because I never use it. I'll bet that somewhere out there folks have spent hours using it and thus improved their skills with it, as alien as that seems to those used to rotating a barrel and landing on a mark predictably. As with Rick, the manual lens is what makes the camera functional for me.

Never been a Panatape fan either, Rick. I did a feature this summer with a Panatape fanatic AC--can't say I saw anything impressive in dailies, and I had to deal with the added gear on the Steadicam all day, every day. Annoying.

I've actually been the voice of caution for anyone considering using the Mini35 on the XL1, pointing out that a skilled focus puller is absolutely mandatory. Most users are so hungry for the shallow depth of field that they want to shoot wide open on the fastest lenses possible, without considering just how demanding that is focus-wise (and more than a few are just focusing themselves by eye--not generally successful on a 50mm or more unless you are an NFL Films cameraman!)