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

[Brian Drysdale]

I haven't used a remote focus control on a fly by wire stills lens, only on cine lenses, but I suspect the principle is the same. The higher end controls have hard stops that you set on on the focus knob, you can also adjust the scale length, but you have to put your own focus marking on the focus knob. You have to do this every time you change the lens.

You should use google to research this and the different brands and models available tother with their specification. Also check if they'll interface with your camera/lens combination.

[Ryan Elder]

Okay thanks, that's what I was told before. I was told that a fly-by-wire is perfectly usable as long as I mark the marks.

However, when if I mark, say mark A on the lens, and then try to rack focus to mark A, mark A is not in the same place all of a sudden.

I think the fly-by-wire does not have the same places every time, the way their rings focus, unless I'm doing it wrong...

[Brian Drysdale]

We're going over old ground here, seemingly the speed that you pull focus is a factor with fly by wire, this introduces inconsistencies. I suspect it's designed for a feedback loop, which is supplied by a camera's auto focus system and corrects for this. The remote focus control used by the camera assist you mentioned may also work this way.

This thread is going in circles, for precise manual focus by directly pulling on the lens focus ring using marks, the answer is to get manual focus lenses, forget fly by wire. It's a waste of time for this type of stuff,

[Paul R Johnson]

That's the problem Brian - the focus ring is useless for marking because all it does is increase or decrease feedback, through, I think, an opto-isolator and gapped cog. Marking the ring doesn't work. Move away from the mark, and return, and it's out of focus.

[Pete Cofrancesco]

1. I can’t follow focus with a fly by wire lens what should I do?
2. You need a manual focus lens.
3. Yeah but someone told me it’s possible to follow focus with a fly by wire lens.
4. Go to line 1

[Ryan Elder]

Okay thanks. Just making sure he wasn't pointing out something I was missing or anything. As long as selling the fly-by-wire lens, and taking hit in money is absolutely needed then to pull focus. I could also get a camera with a really good ISO and just shoot at a really deep DOF so I won't have to pull focus, but could this also cause other problems though?

[Brian Drysdale]

You will get increased noise if you increase the ISO and this may become objectionable after a certain point, especially if you want deep focus and don't have the budget to light to the required levels.

Getting the right kit always works out better in the long term.

[Josh Bass]

How much shallow focus (typical narrative depth of field) do you want in the rest of the film? If you dont care then you could just rent/borrow a fixed lens cam with a proper video zoom. solves your problem.

[Ryan Elder]

Well I was thinking I would have shallow DOF mostly for the scenes where characters talk and are very still, but then open up deep for action/chase scenes, which is what I was going to use A telephoto for anyway mostly. Would that be too inconsistent of a style, if I had shallow DOF in the talking and close up shots, but deep DOF for action?

[Brian Drysdale]

There's no reason/rule why you can't do that.

[Paul R Johnson]

When you plan each shot, DoF is a choice you make. When people paid attention to what their shots looked like - they'd consider what the audience was looking at? Is the background supportive or intrusive - as in if you see mountains with snow on them, the viewer knows where you are, or if you need the viewer to concentrate just on the faces, then an interesting background is counter productive. Backgrounds can often pull focus (acting term) from the subject. Simple stuff, like maybe a notice on a wall encourages people to try to read it rather than listening to what's being said. Equally, if the background 'might' be interesting because it's not quite out of focus enough, then people start to figure out what the blob on the right actually is, instead of listening and looking at what is intended. DoF is a tool. Those people that use it like a fashion item when it's not needed do movie making a disservice - and make the cameraman job 10 times harder. Look at TVC programmes. Do you ever see something like 'How does it work' showing you images that are anything other than sharp? Sharpness everywhere in the frame is critical. News tends too be sharp, but occasionally you see inserts shot by people who think they're shooting art - some of those hotel room celebrity interviews for example. all soft backgrounds and clever shadows - and it really grinds against the rest of the programme.

Shallow DoF is fine when it's needed, but it is NOT a slap it on everything technique.

[Pete Cofrancesco]

So we finally agree on a plan that makes sense! What a relief! I feel like we should do something to celebrate.

I’m curious why you’re making this movie? Are you doing it for the fun of it or are you trying to build a reel in hopes of landing a job as a director?

[Ryan Elder]

Well I was going to use the telephoto lens for action/chase/fight shots, since I can pan for a long time on a telephoto and follow the actors as the run and all. So does the background need to be out of focus, during a running chase scene do you think?

[Brian Drysdale]

The decision is yours.

[Ryan Elder]

Yep for sure, I am just asking for an opinion on what is better for action scenes do you think? Will deep focus background be too distracting during chases and fights?