Follow-focus for zooming?

[Nic van Oudtshoorn]

I am thinking of buying the Red Rock follow focus and am wondering of anyone has used it not only to rotate the focus ring but also the zoom ring? I am used to a smooth motorised zoom from pro lenses and also from the zoom that came with my XL-H1, but find I cannot replicate it by manually turning the lens ring of a Canon lens mounted on the 5D Mk II while filming. Any other suggestions apart from a FF unit would be welcome.

[Ryan Mueller]

I would also like some information about this. I have been thinking about whether or not it's possible and can't for the life of me think of a reason that it wouldn't work.

[Mike Williams]

the zoom via follow focus would be neat. wonder how it would work?

[Evan Donn]

Just saw a rig for this somewhere, maybe Cavisions site? It was basically a dual follow-focus rig, with a right side dial for the zoom and left side for focus.

[Nic van Oudtshoorn]

Thanks for the lead - I checked out Cavision and the answer appears to be here

Basic Mini Single Wheel Follow Focus - Dual Setup

[Nigel Barker]

For a smoother manual zoom you don't need something a elaborate as a follow focus which may not be very useful without a large knob anyway. You simply need a lens ring with a lever attachment that gives you something more substantial to hang on to but also crucially allows your hand to move through a much larger arc. It's easier to create a smooth movement by rotating your hand & wrist through 90 degrees rather than rolling a focus ring between forefinger & thumb.

[Charles Papert]

When zooming, the effect is immediately obvious on the frame and thus to the viewer. Consistency of speed and feathering of starts and stops are both critical to making zooms invisible (if that is the goal), otherwise, a snap zoom is all about speed and accuracy and landing at the exact focal length desired. For a follow-focus type mechanism to work best for a zoom, it has to have just enough drag that one can enact a super-slow zoom and feel a certain amount of resistance; too little, and the hand has nothing to "lean against", too much and you fight against the friction which results in erratic bursts of speed. As Nigel indicates, a larger hand motion is much more effective at simulating a continuous movement. This is the theory behind the geared head, where the big rotation of a generous and weighted handwheel allows the operator to create a super smooth pan or tilt; contrast this to doing the same thing on a fluid head where the operator must train the muscles to perform like a machine, applying a tiny and perfectly linear force to the head (which of course provides an adjustable amount of resistance to make this possible). Old pedestal type studio television cameras had a large zoom crank for this reason.

Zoom levers work OK by the principal of leverage; many years ago I used to take a ballpoint pen, empty out the ink cartridge and stick it on the tiny little lever on my camcorder to increase the leverage and required arc (still not a bad trick)! I'm not particularly convinced about the use of a follow focus to do the same thing. Certainly it's better than just a couple of digits on the barrel of the lens, but I would keep looking for other mechanisms. Maybe it's time to bring back the crank zoom! I just remembered the venerable Angeneuix 12-120 16mm lens that had an integrated crank--here's a pic:

http://xl1solutions.com/i-1_B.jpg

[Olof Ekbergh]

I sometimes just use a zip tie on the focus wheel to get a nice follow focus at a penny price, the truth is follow focus is often best done with a "speed crank" and that is pretty much what a lever does. I also mark focus cues on lens barrel with white tape.

I have not tried it on zoom wheels yet, but it would probably work fine.

There are a lot of different zip tie weights, if you use a long one that is stiff you can have a long lever. The thinner ones flex nicely for smooth stops and starts. I usually cut them so they stick out 1-2", heavy ones can be 6" long.

This may sound silly, but a few people that have seen me do this are blown away with the result. It is certainly worth a try.

[Dylan Couper]

Originally Posted by Charles Papert

When zooming, the effect is immediately obvious on the frame and thus to the viewer. Consistency of speed and feathering of starts and stops are both critical to making zooms invisible (if that is the goal), otherwise, a snap zoom is all about speed and accuracy and landing at the exact focal length desired. For a follow-focus type mechanism to work best for a zoom, it has to have just enough drag that one can enact a super-slow zoom and feel a certain amount of resistance; too little, and the hand has nothing to "lean against", too much and you fight against the friction which results in erratic bursts of speed. As Nigel indicates, a larger hand motion is much more effective at simulating a continuous movement. This is the theory behind the geared head, where the big rotation of a generous and weighted handwheel allows the operator to create a super smooth pan or tilt; contrast this to doing the same thing on a fluid head where the operator must train the muscles to perform like a machine, applying a tiny and perfectly linear force to the head (which of course provides an adjustable amount of resistance to make this possible). Old pedestal type studio television cameras had a large zoom crank for this reason.

Good point! Let me add another challenge to the pile...
Since we're talking about 35mm still lenses, there's also the fact that almost none of these (save the push/pull models) zoom smoothly through the whole range. So on top of the challenge of spinning a wheel consistantly, you've also got to ramp up the force (or limit your zoom range) at the right time to avoid suddenly losing/gaining speed in the zoom. Like you said, a large hand motion would help, but I prefer the following method:

many years ago I used to take a ballpoint pen, empty out the ink cartridge and stick it on the tiny little lever on my camcorder to increase the leverage and required arc (still not a bad trick)!

I've done this with a pen and a heavy elastic band for years from a tip I got off DVinfo, and in retrospect, I'm pretty sure it was from you!

[Alvise Tedesco]

here's a dedicated solution from Chrosziel
http://www.chrosziel.com/data/chrosz...LR_english.pdf

[David A. Fisher]

Many, many years ago a mentor of mine said this, "Living zooming is a sure sign of the amateur. Frame your shots. If you want drama get a dolly." I've stuck to that to this day. Zooming is for soccer mom's, framing is for professionals.

my $.02

[Jon Fairhurst]

Originally Posted by David A. Fisher

Zooming is for soccer mom's, framing is for professionals.

Then again, zooming is also for news and live sports - and when you want a POV amateur shot in your film. :)

[Josh Dahlberg]

Originally Posted by David A. Fisher

Zooming is for soccer mom's, framing is for professionals.

I guess that makes me a soccer mum :-) (although I do try to carefully frame and control both ends of my zoom, which I guess this thread is about). I have a dolly, a glidecam and a jib arm, but I still find plenty of opportunities to zoom, and I do miss the slow, smooth zoom of a camera like the XHA1 when I'm using the 5D.

For intance, I was just shooting a doco on an Island from which you can glimpse a major city. Using the XHA1 I was able to do a tight shot of the city then zoom wide to include the city, the cliffs of the island I was shooting from, and the sea between. It was a way of contextualising the island for viewers that I couldn't have achieved without a zoom.

I often use slow, creeping zooms in nature shoots and corporate vids, although I wouldn't use one for a drama. A lot of times it's impractical to take a dolly along, or it just doesn't achieve the degree of movement required.

Rather ironically, I have a redrock follow focus but I can't test out how well it works with a zoom as I sold the three zooms I had - they weren't getting much use on the 5D as I've been using primes. I never thought of using the follow focus that way, dang.

[Charles Papert]

Originally Posted by David A. Fisher

Many, many years ago a mentor of mine said this, "Living zooming is a sure sign of the amateur. Frame your shots. If you want drama get a dolly." I've stuck to that to this day. Zooming is for soccer mom's, framing is for professionals.

my $.02

The key here is "many, many years ago". For a long time, zooming was considered "dated" following the initial craze in the 70's--you can see tons of them in amazing films (how about that opening shot of "The Conversation"?!) as well as the dreck from that area. Starting about 10 years ago, zooms have crept back into acceptance for features and episodic, and they can be downright cool these days if used with discretion and creativity. The key is to deciding when to use them rather than just substituting them for a dolly move. I work with one particular DP who I introduced to the Radio Microforce, which allows him to sit at the monitor and work the zoom while I do a Steadicam shot. He tweaks my frame around, I respond to that, he responds back--we have a marvelous little dance that keeps things interesting and ever evolving.

Don't be afraid of the groovy zoom, folks! Have fun with it!

[Charles Papert]

Originally Posted by David A. Fisher

Many, many years ago a mentor of mine said this, "Living zooming is a sure sign of the amateur. Frame your shots. If you want drama get a dolly." I've stuck to that to this day. Zooming is for soccer mom's, framing is for professionals.

my $.02

The key here is "many, many years ago". For a long time, zooming was considered a dated concept following the initial craze in the 70's--you can see tons of them in amazing films (how about that opening shot of "The Conversation"?!) as well as the dreck from that area. Starting about 10 years ago, zooms have crept back into acceptance for features and episodic, and they can be downright cool these days if used with discretion and creativity. The key is to deciding when to use them rather than just substituting them for a dolly move. I work with one particular DP who I introduced to the Radio Microforce, which allows him to sit at the monitor and work the zoom while I do a Steadicam shot. He tweaks my frame around, I respond to that, he responds back--we have a marvelous little dance that keeps things interesting and ever evolving.

Don't be afraid of the groovy zoom, folks! Have fun with it!