Is it possible to pull focus on a lens while crash zooming?

[Ryan Elder]

We haven't quite decided on a camera yet, but we will most likely be using one with an APC-S size sensor, since I might not want full frame, cause full frame might be too much shallow depth of field for what I want.

As for the wide end, it's hard to say but I was overall satisfied with my 70-300mm so far, but if I can zoom from 300mm to even wider, without having to pay too much more for a mechanical focus ring lens, than that would be good too. I am not sure what equipment I need until I figure out what I need to get the shots I want first.

[Josh Bass]

Unless I’m missing something, APS-C is about 1.5x cropped compared to full frame and 70-300 would be well into telephoto, not wide at all and not even medium. Seems like the opposite of what what you would want for either your zoom or gimbal ideas (gimbals like to be on wider lenses usually for shot stability and a. better sense of movement in the shot). For a zoom I would think you’d be looking at a “superzoom” lens that goes from very wide (or at least medium) to very tight...sounds great but the compromise is theyre usually not great quality image-wise and dont open up that wide (f4 or 3.5 many times, and fully telephoto can only open to 5.6 or 6.7 or something so you have to stay as closed down as required for your tighest focal length to keep the exposure from changing in the shot.

That’s with still lenses. Cine lenses will behave differently bt now we’re talking about spending money and they’re usually pretty long and heavy if they’re zooms of significant range.

[Ryan Elder]

Oh okay. Well the reason why I wanted an APS-C sensor was for other factors. I wanted actors to be able to move around more in wide master shots, without going out of focus as much compared to a full frame. I also like APS-C sensors in the past cause if I wanted to use a telephoto, they allow me to zoom in further compared to a full frame, which you cannot zoom in as much compared to an APS-C, and get higher compression for some shots.

So that was my reason for wanting an APS-C sensor. However, for a zoom shot, I still think that the sensor will be able to be wide enough for when zooming back, won't it?

As for other shots where I want to use the gimbal, I haven't heard of other people with APS-C sensor cameras, having issues with the gimbal, as long as the lenses are not too long, unless I'm wrong If I were to use a gimbal instead of zooming for that shot, I would throw on probably a 50mm lens or something, so the gimbal would be more smooth. But I don't like going too wide because then I would have to get really close to the actors face before running away with the gimbal, and then there would be some barrel distortion in the face.

[Brian Drysdale]

You should be able to get away with a 35mm lens without much barrel distortion.

A few directors use a 32mm lens as their main lens.

[Ryan Elder]

Oh okay, but where does a 32mm lens come in? Or do you mean 35?

And yep I could probably use a 35mm as well. But as for doing possible crash zooms, are there any lenses that are around 70mm-300mm that you can get for a similar price to the Canon 70mm-300mm, that do not have a fly-by-wire focus ring? I am looking online, but a lot of the stores and ebay, do not say whether or not the lens is fly-by-wire or not in the specs.

[Josh Bass]

You might join a photography message board and ask them for recommendations or about any specific lens you might be interested in. Those nerds’ll know all about that stuff.

[Brian Drysdale]

The 32mm is a cine lens, Cooke make them..

There are 14mm lenses that don't have much barrel distortion, but you wouldn't want to use the for a close up, unless you were after a certain look.

[Ryan Elder]

Okay thanks. Yeah 14mm wouldn't look good for the look I want for a close up. I could ask on a photography forum, it's just that I thought they were more into still photography, and weren't use to doing crash zooms or pulling focus while zooming in video. But I could ask there as well.

It's just that cine lenses cost a lot more and I wanted a lens I could own instead of rent, since shoot days keep changing in past experience, and I can then have it for whatever days I need.

[Josh Bass]

No no no. Im saying since we’re probably talking about still lenses for your purposes the stills guys would know more details about them like if theyre mechanical focus or fly by wire. Not the stuff about crash zooms. You’d ask them about the type of focus ring on various lenses.

[Ryan Elder]

Oh okay, sorry, thanks. Actually something just occurred to me. I'm going to be using this zoom lens for other shots other than the zoom shot. I'm going to use it for shots where we're doing long pans and tilts.
If I hook this lens on to a different camera for those shots, the lens is not going to be able to focus at all, right? If it's a fly-by-wire focus that means that no camera it is hooked up to will be able to power the system to focus it if there's an adapter between the camera and the lens, right?

[Derek Heeps]

Originally Posted by Ryan Wray

Okay thanks, but is how is the technique a fad now though? I haven't seen it done in a movie in so long that I thought it would be a newer technique for today, compared to 30 years ago.

Mostly I just wanted to do a couple of crash zooms, to show reveals, like when an actor runs into a room then we quickly zoom back to reveal that their are men waiting to ambush him. That is what I wanted to use it for, things like that.

I was told to dolly back instead, but I can't move the dolly fast enough, and it then becomes a much slower reveal, instead of a fast reveal. The actors then have to wait for the camera to play catch up to their ambush, if I am dollying much slower, if that makes sense.

This is why I was told to pull focus faster, when doing the crash zoom. But is focus pulling during a crash zoom absolutely impossible then?

Why not just use a separate shot of the baddies lying in wait ?

Much simpler and more effective, and after the cutaway you can always come back to a wider shot showing the ambush from another angle ...

[Ryan Elder]

Well I thought of that. It's just I thought that a fast zoom would be more suspenseful to the situation rather than just simply cutting a lot of the time.

However, I think we have a much much bigger problem now though. It seems that the lens will not focus at all if we turn the focus ring. Not just for zooms but for anything it won't. Is it because we have an adapter in between the lens and the camera, and we need electric power going to the lens for the focus ring to work?

[Pete Cofrancesco]

Once you understand the limitations of using dslr with non cinematic lenses you’ll be able storyboard approaches to avoid these limitations. While it’s fine to be inspired by Hollywood movies you’ll find replicating them problematic. Much of film making is creative problem solving. Rarely what you envision in your mind will survive the real world.

Generally speaking photo lenses found on these cameras aren’t designed to zoom or focus manually smoothly. They’re made to be used with auto focus. As a result it’s best to avoid zooms and while it’s easier pull focus it’s better to avoid it.

We can’t answer your specific questions without knowing what your exact setup is. Sounds like your camera and or lens is highly reliant on automatic settings. It might be one thing to turn off auto and another to be able to control things manually.

In the past zoom/focus ring on a lens directly changed the internal elements but now theses rings are no more than buttons that communicate with servo motors in the lens and/or camera that in turn move the lens elements.

[Josh Bass]

Which cirlcles us back around yet again...I think it’s worth completely rethinking the shooting approach to this sequence. There are nearly infinite ways to cover it and you lasered in on this one. shoot...probably every marvel/netflix show has many examples of scenes just like yours. How did THEY shoot it? Did their decision lack tension and suspense etc. etc.? Probably not.

I think if you watch other films/shows youll get a ton of new alternative ideas on how to stage and cover this. That’s one of things it took me years to figure out...researching what other have done and letting their ideas inspire you instead of just trying to figure everything out in your mind.

[Brian Drysdale]

Basically, if you don't have the tools to do a shot one way, you have to come up with another method that will work with the tools you have available. Sometimes you can come up with a more imaginative way of doing it. limitations often spur creativity.