View Full Version : Is it possible to pull focus on a lens while crash zooming?
Ryan Elder January 11th, 2019, 06:42 PM Yeah that's true. I mean I could possibly rent a lens that could do the zoom but it was said on here that even if I could that tracking shots still look better, even if slower. So if that's true, maybe I should just track it really fast, and see if I can speed it up in post without the actors looking like they are moving fast. If I can't then just live with it being slower compared to a crash zoom then maybe.
But if I was able to get a crash zoom lens, would tracking it still look better do you think?
Pete Cofrancesco January 11th, 2019, 07:24 PM Not to continue to tell you how to shoot your own movie but another approach
There are really an almost infinite number of ways to approach any filmmaking scenario. Your mind is locked into this one idea. Look stuff up on Youtube.
This.
Reminds me of in art school that teachers would repeatedly try to break students predilection of falling in love with their first idea.
I can see many other approaches that would work. But somethings you need discover it for yourself.
Josh Bass January 11th, 2019, 10:10 PM That is true. I have been that obstinate guy before and probably will be again. But at least take a look at other examples from scenes in movies and shows via youtube/vimeo/etc. just to see if there’s something you hadnt thought of that might work, before you spend money to rent a lens (especially given the long time before the shoot that you have to book the gear and the fact that if you have tp reschedule due to a actor conflicts or whatever you lose that money).
That’s one thing I have learned over the years that I feel strongly about...using references to judge your work against or get ideas...see where others suceeded or didnt and see how you might use a similar (not IDENTICAL, we dont want to be thieves) approach.
Ryan Elder January 11th, 2019, 11:03 PM Okay thanks. I actually saw this type of reveal shot with a crash zoom before in movies like The Wild Bunch, where they did a similar reveal, which is why I thought it would work the best cause you can move so far in such a fast speed. The store is actually selling a Sigma 18mm-300mm for cheap, and if I sold my lens and got that one, I wouldn't be out any money. Unless the notion that Sigma lenses not being better at being parfocal while zooming are not true :).
But I can do the tracking fast if that's better. I could cut it but I feel this type of reveal should be done with a point of view move, rather than a cut perhaps.
John Wiley January 17th, 2019, 05:25 PM Okay thanks, but I didn't have the autofocus on in the video. If I put the autofocus on, then the lens cannot zoom back as fast, and it does it slower.
I'm not familiar with the particular lens you're using, but this statement - along with the sample you posted - makes it sound like your lens is a focus-by-wire type lens (ie everything is controlled electronically by motors). Even when you're using manual focus, turning the ring simply tells the AF motors when and how to engage in order to zoom or focus the lens elements, meaning you never actually have repeatable, fully manual control. So the short answer is you cannot do what you want with this type of lens. Any of the 70-200 variants should be able to do this much better though, as you can preset your zoom and focus marks and they'll be fairly close each time.
Having said that, I agree with others that there are probably better solutions than just sticking to your guns and doing the crash zoom. Solve problems with either story, or blocking, before you try to fix them with camera gear.
eg: You say there is not time for him to stop and peer around the corner? Well, give him some other motivation to pause - he flicks the light switch as he enters the parking lot, but the lights don't come on. Or a cat scampers away knocking over some discarded beer bottles and giving him a fright. These are things that can not only solve your pacing issues, but also add tension to the scene - because by the point we see the other people creeping out of the shadows, our protagonist is totally distracted by something else. (Think of the scene in Aliens, where Ripley and Hicks are rushing to the landing pad and get into the elevator - it's an extremely fast paced race for survival, they get in the elevator, push the button.... and nothing happens! They're vulnerable and distracted and the tension builds)
Or, another solution, is that you don't need to do a camera move or edit at all. Use blocking to put your creepers in the foreground in the shadows. Hide them in plain sight, amongst other foreground objects and barely visible until they start moving (again, another example from Aliens is the first encounter in the hive. We see a low angle shot of one of the Marines with the hive wall behind them. When the alien emerges from the wall we realise we were staring right at it the whole time).
Paul R Johnson January 19th, 2019, 03:33 PM One shot and you're thinking of spending money on a lens you don't need. If that shot is that critical, why not rent a camera with a real zoom lens and just do the shot simply and repeatedly. I suspect that hiring a DSLR sized par focal lens might be more money than a different type of camera.
Josh Bass January 19th, 2019, 08:43 PM One last thing (not necessarily THE last thing) I’ll leave you with is that a great piece of advice I was given is that if you hear a certain criticism from only one or two people, perhaps it can be dismissed and chalked up to “everyone has their opinions”, but if you hear the same thing over and over again from a variety of sources it might be something to stop and consider.
Also we talked earlier about how zooms like this were kinda dated, and you werent going for a retro/vintage vibe, but then you said you saw a zoom like the one youre trying to achieve in “The Wild Bunch”...a movie that appears to be from 1969.
We’re all just trying to keep you from doing something you’ll ultimately be unsatisfied with and regret later, or spend money unnecessarily.
Ryan Elder January 20th, 2019, 12:09 PM Okay thanks.
The character does have time to pause before coming around the corner. What I meant was, is that if I run with a gimbal instead of zoom, and then speed it up later, I was worried that the actors would appear to be moving fast, even if standing still. Like a head turn or an arm gesture could still look fast, if sped up.
As for the lens not being worth the money, there are still other shots I want to use a telephoto lens for, other than zooming.
Some shots I want to have a lot of compression in, which the lens is good for, and I also want to be able to do really wide pans and tilts, for some action shots, and the longer the lens, is the more longer the pans and tilts will be. So the lens is still worth it for those types of shots I feel.
I don't have to do the crash zoom, I just felt that it would be more effective than running with a gimbal to reveal the hiding characters, or just simply cutting to it.
As for the motor working all the time in the lens, what is powering the motor? There was an adapter in between the camera and the lens, so what was powering it? Wouldn't an adapter sever all power between the lens and the camera?
Paul R Johnson January 22nd, 2019, 10:40 AM If the idea is to do a really fast crash zoom, then surely only the two ends need to be in focus if it's for effect? I can't quite visualise what you are doing, to be honest?
Pete Cofrancesco January 22nd, 2019, 06:38 PM At this point we’re really beating a dead horse. Without being overly critical, this really seems to be an up hill battle and the ability to visually story tell doesn’t come natural to everyone. I’ve recently watched The Wild Bunch, the original which is a classic, hard to keep track of all the remakes, and I couldn’t remember any crash zooms. Good film making just like acting should be a seemless part to the story without drawing attention to itself.
Ryan Elder January 24th, 2019, 02:02 PM Oh there is only one Wild Bunch, and there are crash zooms in it. There were not any remakes I am aware of. Even though it's from 1969, there are still modern movies that do crash zooms, such as Rise of the Planet of the Apes for example.
If the idea is to do a really fast crash zoom, then surely only the two ends need to be in focus if it's for effect? I can't quite visualise what you are doing, to be honest?
Well basically I wanted to start out on a closer up shot of an actor's face and then zoom out to reveal the people waiting behind pillars to ambush him, for the shot I had in mind.
If I can't get a lens that is like that, then I can try using a gimbal and ramping the speed in post like it was suggested, hoping that the actors do not move too fast. I just thought if they have a DSLR lens that crash zoom and still be in focus like the film riot video, then it seems possible (shrug).
Josh Bass January 24th, 2019, 07:52 PM We're saying if it's a fast zoom, will you even be able to see that it's soft during the zoom itself? It should only matter that it's in focus when you're close and in focus when you're wide. The in between should be so quick as to be unnoticeable.
Ryan Elder January 25th, 2019, 02:35 AM Oh okay, well what about this example I posted before, is it fast enough that you don't really pick up on it?
zooming test - YouTube
Josh Bass January 25th, 2019, 03:08 AM No, you have a point. That's definitely noticeable and it looks pretty janky. I would also say it takes it a beat after the zoom is over for it to be in focus again which is part of the problem.
Brian Drysdale January 25th, 2019, 06:27 AM You need to hire/buy a cine/video (parfocal) zoom lens if you intend to do this type of crash zoom shot. In the end, it's the right tool for the job, still camera zooms are not intended for this type of stuff.
Ryan Elder January 25th, 2019, 11:41 AM Okay thanks. I didn't think it was possible with a still camera lens either, but in the film riot video I posted before, they actually did crash zooms while keeping focus on a still lens on a DSLR. So what was the trick as to how they pulled it off in this video? It's at 4:30 into the video:
The Difference Between Dolly & Zoom Shots - YouTube
I know people are saying to use a gimbal or dolly instead and move the camera fast, but in the video, they actually pull off a zoom completely in focus with a still DSLR lens, and so it can be done it seems.
Brian Drysdale January 25th, 2019, 05:58 PM Some DSLR lens will hold their focus quite well, although the examples given in the video aren't zooming that much and others involve exteriors, so the lens may be stopped down. You really need to research which DSLR zoom lenses do keep reasonable focus when zooming, then run a test to see if it's acceptable.
Jeff Donald January 25th, 2019, 06:10 PM Your looking for parfocal lens, a lens that stays in focus as you zoom/change focal length. Most lenses today are varifocal and change focus/magnification as you zoom. This can sometimes be related to focus breathing. Focus breathing is the change in magnification as you focus closer or further away. The focal length of a lens is determined when the lens is focused at infinity. As you focus closer and closer the focal length of the lens decreases. In other words a 70~200mm lens may be 200mm at infinity. When focused at 10 feet, the focal length may be 185mm. In poor lens designs the focal length may be as little as 135mm or even less.
Ryan Elder January 26th, 2019, 12:36 AM Okay thanks, that makes sense. It's just the one on film riot seemed to be doing a pretty good job so I thought there must be some DSLR lenses out there that can stay in focus during the zoom, without being parfocal.
However, if I have to, I can just run with the gimbal instead to reveal the ambush. It's just I feel it will look like a slow reveal as a result and will have to speed it up in post, like I was told to on here. It's just whenever I do that to footage, it looks sped up, and looks cheesy. I was told that crash zooms can look cheesy, but how do make sped up footage not look just as cheesy by comparison...
But I think the only reason why people associate zooms with looking cheesy is because we are use to seeing them in cheesy shows, such as reality shows and The Office. When they do it in a movie like Rise of the Planet of the Apes, during the action scene on the bridge, which they did, then it looks good. So it pretty much looks cheesy if you use it in a cheesy show, compared to a non-cheesy movie. Unless I am wrong?
Josh Bass January 26th, 2019, 12:41 AM Something you may have missed though someone earlier said it is that your lens has the appearance from that test clip of being servo-controlled or fly-by-wire focus, meaning that you are not directly moving the lens elements back and forth when you zoom; there’s another...something (I dont know the tech side of this) in the middle of the process that tells the lens to move as you turn the ring. A DSLR lens that has an actual finite focus ring would work better...where turning the ring directly moves the elements.
Does your focus ring turn in either direction forever? That’s probably not a true manual focus (maybe using wrong terms here). The kind of focus you want will have a hard stop where you simply cant turn any farther once you get to either the wide or telephoto end of the focus range.
Ryan Elder January 26th, 2019, 12:56 AM Okay thanks. Yes the lens has a focus ring that turns forever in each direction. I can set focus marks, it's just I cannot turn the lens fast enough to focus during the zoom, since the crash zoom is so fast.
When you say fly-by-wire, and that I am not directly moving the elements, what do you mean by that exactly? I am moving the lens with hand to zoom, so wouldn't that be directly moving it, or do you mean something else?
Brian Drysdale January 26th, 2019, 03:07 AM I wouldn't say all zooms look cheesy, only those that are done without thought or motivation can be cheesy. You can bury zooms inside tracking and crab moves, so that they're not as obvious.
Like all shots, zooms have had a period of over use because they're fashionable, the same will probably happen with drone shots that are done because you can do them, rather than being done for a purpose. Although, currently the UK TV fashion of focusing on a meaningless object (grass or a painted doorframe) in the foreground while the two shot of the interview is defocused in the background, has gone well past it's sell by date.
Josh Bass January 26th, 2019, 03:57 AM I'm simply saying when you turn the ring on a fly by wire focus lens, it's not directly turning gears that move the lens elements, the way a purely mechanical focus lens does; there's another step in between where turning the ring causes electronics to control a motor that moves the lens elements. It causes a lack of precision that's probably responsible for your lens behaving the way it does during a zoom, and the way it takes it a fraction of second to snap back to focus after the zoom stops. Search for "fly by wire focus lens" or similar to learn more. If you can get your hand on a lens with purely mechanical focus ring (even just to play with it at a local store), you'll feel the difference in how it responds.
You keep asking how film riot guy could do zoom with a still lens and have it work out well...more than likely they were using a mechanical focus ring lens.
Pete Cofrancesco January 26th, 2019, 10:08 AM My god how many times can you circle around to the same question despite it being answered repeatedly by a number of people.
Your lens can’t do that technique. Either rent/buy a lens that will or don’t do a crash zoom for that scene! Crash Zooms are rarely used and not essential to film making and is generally frowned upon as cheesy technique.
Ryan Elder January 26th, 2019, 12:25 PM Okay thanks, sorry just trying to establish all the possibilities, since the focus ring thing was pointed out now.
As it for it being cheesy, I mean it is used in big budget Hollywood movies like Rise of the Planet of the Apes being the most recent I can think of where I saw it, so I figured if it's good enough for that, than it must not be so bad.
But if I have to, I can just run with the camera on a gimbal and speed it up, like it was suggested to. How do you make it look like it's not obviously sped up though, when it is?
Brian Drysdale January 26th, 2019, 12:36 PM If the actors are moving slowly or not at all during the speed ramp section of the shot, you won't get comedy type movement in their actions,
Ryan Elder January 26th, 2019, 01:14 PM Okay thanks, I'm just worried that the movements are going to look unrealistic if they are too slow or too still. However, if I am going to speed ramp it, should I use timewarp to add additional motion blur to the frames, since there would naturally be more motion blur if moving the camera really fast?
Also it was said that the zooms are regarded as cheesy, but the recommendation instead was to do speed it up with heavy post VFX manipulation. Wouldn't VFX also run the risk of looking cheesy, since it's VFX and not captured naturally in camera?
Josh Bass January 26th, 2019, 04:31 PM At this point I would start doing tests of all the ideas you have of different ways to do it. Rope family or friends in for an hour or whatever it takes, find a suitable stand in location, something where you could block the actors the way you imagine they would be on the real shoot day, and record tests where you try the gimabl thing, try the speed up thing, try the speed up thing with them moving normally and without moving at all, borrow the right kind of lens or rent it for the test day, basically every variation of each of the many ideas tossed around here. I think thats the only way to know if x will look to cheesy/stupid.
Brian Drysdale January 26th, 2019, 04:40 PM Test. test, test is the way to go.
Speed ramps have been used on quite a few films.
Here's an example that has both slow and a fast speed ramp. Usually they're used for slow motion, so doing the reverse, by going faster, is different.
Fast Forward Speed Ramp Effect - Adobe Premiere Pro Tutorial - YouTube
Lying and cheating is all part of filmmaking.
Ryan Elder January 26th, 2019, 04:59 PM Okay thanks. It's just that when speed ramps were done before, the directors intended for the actors to look like they were moving faster, where as I am not, so I didn't think it would work for mine. But I can try it. If I were able to get my hands on a parfocal lens do you still think that a speed ramped gimbal move for the shot, would look better than a crash zoom?
I mean it was said before that crash zooms do not look cinematic cause they are done often in documentary TV shows. But fast speed ramps are also done in documentary TV shows, so wouldn't also look TV-ish, as a result?
Brian Drysdale January 26th, 2019, 05:42 PM Speed ramps are used in action films.
Doing a test is the best way to find out. No one here knows the build up or what happens afterwards, so any decision up to you. However, unless whole crash zoom shot is quick and doesn't linger I would tend not to use it.
Ryan Elder January 26th, 2019, 06:13 PM Okay thanks. I should watch more action films :).
Well I did a test here. One advantage over the speed ramp compared to my zoom lens is that I can cover a lot more ground.
Here are two speed ramp tests I did with some footage where I ran with a gimbal. The second speed ramp, I added additional motion blur to it:
https://www.youtube.com/watch?v=8yOAtp43Ko0&feature=youtu.be
Do these speed ramps look like I did it properly, and does the added motion blur help?
Pete Cofrancesco January 26th, 2019, 07:01 PM Okay thanks, sorry just trying to establish all the possibilities, since the focus ring thing was pointed out now.
As it for it being cheesy, I mean it is used in big budget Hollywood movies like Rise of the Planet of the Apes being the most recent I can think of where I saw it, so I figured if it's good enough for that, than it must not be so bad.
But if I have to, I can just run with the camera on a gimbal and speed it up, like it was suggested to. How do you make it look like it's not obviously sped up though, when it is?
None of us has vested interest in you doing it in a particular way. We are saying if you have your heart set on that type of zoom then get the proper lens. That is purely a technical point. Whether you should do it in the first place is a subjective question. Generally speaking a technique is not intrinsically good or bad it’s the application. It be like asking if you should use a wide angle lens.
Ryan Elder January 26th, 2019, 07:04 PM Okay thanks I see what you mean.
Well I could do the speed ramp way if it means saving on trying to rent such a lens. I mean it was said that crash zooms look cheesy so if the speed ramp way is better than I could do that if it will work.
What about the speed ramp, did it look better than a crash zoom possibly?
Josh Bass January 27th, 2019, 01:40 AM For me (remember this is only guy's opinion) the answer would be no. When it speeds up the composition goes completely to hell. If that trash can was your subject you would want it to stay fairly centered during the fast part and it does everything but. Plus your planned move, that we've been discussing for 6 pages, is the opposite of that anyway, right? start close, quickly go wide?
Anyway, the idea was for the move to look fairly smooth and not janky...that test definitely does not.
Brian Drysdale January 27th, 2019, 03:18 AM I suspect you don't have the resources to have the camera steady enough for a good fast speed ramp. When making films sometimes you (more than you'd want) have to bite the bullet and spend money to create what you want.
Ryan Elder January 27th, 2019, 03:46 AM Okay thanks. Well normally someone else operates the gimbal where as for this test, I just borrowed it from a film school and ran as fast as I could down the street. However the wind kept turning it and keeping it from having a dead on frontal POV.
But again, in the past I have gotten a separate gimbal operator with more experience, where as this was just a practice test I did myself to see how it would look speed ramped.
I would get a gimbal operator to do it for the actual movie when we shoot it, it's just I don't know any would be interested in operating the gimbal for me, for a day, just for a speed ramp test.
If I had a professional gimbal operator who could move it more smoothly without wind problems, would that make the speed ramp look better?
Plus it was said on here that zooms look cheesy and unnatural but don't speed ramps look unnatural as well, since the footage looks obviously sped up, at least to me it does.
Brian Drysdale January 27th, 2019, 05:23 AM Wind and lack of skill will work against you. It has to be fast, but smooth.
Crash zooms need to be either part of a cutting rhythm combined with fast moving action or a punch effect.
Tarantino // Crash-Zoom on Vimeo
Zooms don't need to be cheesy, they can be very effective,
The Kubrick Zoom - YouTube
Ryan Elder January 27th, 2019, 11:55 AM Okay thanks. It was said before that speed ramps are used in action movies, what are some that have them so I can see how they are done right?
Also, if I were to zoom it instead, I would cut it with movement like I've seen in other movies...
And if I need a lens that has a focus ring that is a mechanical one, and not a fly by wire, are there any lenses that have mechanical rings that go up to 300mm that I could get for no more than say 550 USD? I asked at the store for any DSLR lenses that do that but they were not sure cause it was an unusual request. But are there any?
Brian Drysdale January 27th, 2019, 12:32 PM What size sensor are you using and what is the wide end focal length required for your shot?
Ryan Elder January 27th, 2019, 12:47 PM 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 January 27th, 2019, 01:52 PM 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 January 27th, 2019, 02:08 PM 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 January 27th, 2019, 02:19 PM 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 January 27th, 2019, 02:21 PM 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 January 27th, 2019, 04:01 PM 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 January 27th, 2019, 04:07 PM 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 January 27th, 2019, 04:10 PM 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 January 27th, 2019, 05:08 PM 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 January 27th, 2019, 06:28 PM 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?
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