Using a Tilt/Shift Lens on a Steadicam

[thisisapocalypse]

Hi guys - have a question I thought I'd run by a few of you.

I'm going to be shooting a scene of a film using the GH1 (still waiting on it to finally arrive) but I've started picking up lenses for it already.

I'm going to be doing a low-light, exterior steadicam shot where the camera will be about 6 feet in front of the two people walking down the street, and talking.

As I want to get the best image I possibly can, I want to crank the ISO as little as I absolutely have to do, so the kit lens is not something I want to use (and besides, I won't have the kit lens as I bought a japanese body-only).

I picked up a Canon FD 35mm Tilt Shift lens in FD mount and it has a maximum aperture of f2.8, which is as fast as I've found any tilt shift/perspective control lens.

I picked it up, after reading about tilt/shifts and looking at quite a few images, and it seems, with tweaking, that it is possible to get a very deep depth of field, and certainly more than would be needed, it appears, for the slight changes in distance from the camera and the subject.

I *think* that if the camera is kept very level, while on the steadicam, and we stay pretty consistently close to the subject, that if dialed-in, the tilt/shift lens will allow us to create a depth of field deep enough to keep the subjects in focus during the steadicam shot without using a focus puller, etc. (and from what I've read, this doesn't even necessarily work very well when using a steadicam, unless you've got a much more expensive rig and very experienced people running it, which is much more than I will have for this project).

So, anyways, I guess this post is just about a single question: Do you guys think something like this has the potential to work, and work reasonably well? As soon as the body arrives, I'm going to start testing, but I thought I'd just throw this out there as a question, and also to see if anyone else has tried something similar, and/or whether or not anyone else has thought of using a rig like this for steadicam work. It's certainly not a perfect solution, by any means, but well, I'm mostly curious for your thoughts while I await the ability to test this out myself!

Thanks guys!

 

[Martti Ekstrand]

I don't get this. You want a deep DOF from a camera on a steadycam and instead of using a small sensor light camcorder with a inherently deep DOF you opt for a big sensor camera and then instead of stepping down the aperture with a normal lens for a deep DOF you want to use a tilt-shift lens that basically splits the image in two focus areas which will force you not to move the camera during takes to get both planes in focus? Why?

 

[thisisapocalypse]

Well, I think I should give you more background:

This project I'm about to shoot is a feature-length narrative, and I chose the GH1 because of its ability to use lots of different lenses. I have a great deal of Canon FD lenses, some Zeiss glass in Contax mount, some EOS glass, etc. that I wanted to be able to use.

I also like that the GH1 makes it relatively easy to obtain shallow depth of field, and some shots will take advantage of this, while others will have a deeper depth of field, so it's not as if I went out and picked the absolute wrong camera for the job here - if this were the *only* scene I were shooting, I'd probably use something else for ease, but it's not.

The GH1 will work very well for all of the other scenes that I need to do, hence me trying to finagle a way to make this scene work in, an admittedly, unorthodox manner. This TS lens will also find other uses in scenes where I'd like to use it's perspective correction capabilities.

As I noted in my previous post, the scene in question is an exterior in low-light tracking/steadicam shot. It will be dark outside and I want to shoot it in available city light, which means that taking a normal lens, and stopping it down is not an option. A T/S lens is just a tool like any other.

I believe I can get just enough light at f2.8, and a deep enough DOF with the TS lens to shoot the scene in a way that looks good. My question was about whether or not this could potentially work, whether or not I'm using the ideal camera for this shot is another question entirely (and one I did not ask) - few of us ever have the "ideal" camera/lens for every shot we have to shoot, there's usually some compromise of some type, or using equipment in a way that is unique in order to deliver our projects.

Just because the GH1 offers up "easy" shallow-DOF that doesn't mean that every scene you shoot has to have it.

 

[thisisapocalypse]

I'm also not trying to get both planes in focus. I just need to keep the talent in focus on the "in focus" range of the focal plane during the shot here, I don't need the entirety of the frame in focus, just the range where the talent is.

 

[Martti Ekstrand]

Well, it doesn't work that way with tilt-shift lenses. What they do is slant the focus plane through the depth but it's still as shallow as 2.8, no way around that. So the only way your plan would work is if the subject crosses the FOV diagonally. If you add that the camera is in motion you got some serious blocking rehearsals before nailing it, if it's even possible.

 

[Ken Steadman]

I wouldn't go for the T/S personally that seems like a nightmare, your steadicam is going to move while it wont be perceptible with a wide lens I woudl think it would be very ntoicible with a T/S might even give the audience motion sickness. I'm doing a similar shot for what it's worth, I'm using a nikon 20mm f2.8 down to f4 which will give me just enough room to keep them in focus while running the steadicam.

I feel your low light pain.

 

[thisisapocalypse]

Hey Martti - The TS lens I have has been converted to allow full rotation of the lens and it can tilt/shift on the same plane, and any plane.

I do understand that tilt-shifts slant the plane, no question about that, but if I am slanting it forward, from the camera, essentially laying the plane over my subject, then they shouldn't need to cross the FOV diagonally, right?

If I'm looking at the shot (and I have tested the lens on a Canon film camera so I can see how it moves things in and out of focus), I am able to lay the focus plane forward, i.e., tilt forward, so that I have both near and far subjects in focus, essentially the entire frame is in focus - I just haven't tried this with moving subjects and a moving camera yet.

That said, I would think that any subject that is within the plane (the 2.8, in this case, affects how "thick" or "tall" the focus plane is, as its laying forward from the camera, essentially "laying" over whats in front of me - and tilted the right way, it can cover quite a bit of the frame, almost all of it, with quite sharp focus, and since it's shooting on a crop sensor, the it might even be possible to adjust the lens so tha the part of the frame that isn't in focus (through the lens) doesn't even appear on the sensor.

I also find that when I move the camera up and down with the TS lens on it (again looking through the viewfinder on my film camera, having laid the plane frontward, that things do stay sharp, so we'd have to be very careful in keeping the camera aimed straight, but if that were possible, I think the image may stay steady. That said, in all honesty, I guess there's just no way to know if it's doable, or rather, if it's doable by *me* until I try it, but I do think it's an interesting subject, which is why I've brought this up.

Just so you know, I really appreciate your input, I just want to make sure I get all the information out there on this, I certainly don't contend that it will be easy. I should also note that this scene won't be terribly long, 10-15 seconds, when it comes down to it, I've only really got to get it right once for it to work, it's moreover a question of whether or not it will be possible to get it right at all, using this method, which again, I'm sure is going to be a pain in the ass, but I just don't know what my other options are if I want to use the GH1.

I will have a Tokina 11-16mm f2.8, would I be better off just hyperfocusing this lens and keep the subjects at infinity?

At absolute worst case, I could shoot this scene with say, a Canon HV20/30/40 or HFS10, and call it a day, but I'd rather not, as buying another camera just for this one scene isn't *really* what I want to do, and I'd like the footage to be consistent.

Does that make sense?

Put another way, what technique would you guys use, knowing that it's low light, exterior, figure we need 2.8 or faster, 35mm focal length (or less), on a steadicam, subjects facing the camera, walking towards the camera, camera to stay appx. 6 feet away consistently, and the shots will be about 10-15 seconds long.

 

[thisisapocalypse]

Hey Martti - Just looked at some of your stuff on Vimeo - curious, how do you like the FD 35mm f2 on the GH1? That's the one lens I haven't yet decided on, but all the film users I know love that lens! Do you have the one with a concave front element or the newer one?

 

[Martti Ekstrand]

I love it - it's my base lens. Just as I always preferred a 40 mm on 35 mm movie cameras. It's the older FD with silver locking ring, not the newer FDn with bajonett lock. No concave front element though.

I think the Tokina at 4.0-5.6 / 16mm would be a better choice for steadycam work than a T/S lens at 2.8. The problem is that even if you can make the slant in vertical angle you'll end up with the close subject's head in focus and the back subjects stomach but not face in focus. It's hard to make a T/S lens work even when just panning on a tripod. On a steadicam I think you'll end up with something looking weird enough to throw the audience out of the narrative, much more than using a small sensor camera for the one take. Look at some movies with steadicam work and you'll see it's seldom done in low light situations and that DOF is fairly deep on the shots and FOV is pretty wide. But hey, you already got the lens, do some experimenting and tell us what you find.

 

[thisisapocalypse]

The problem is that even if you can make the slant in vertical angle you'll end up with the close subject's head in focus and the back subjects stomach but not face in focus. It's hard to make a T/S lens work even when just panning on a tripod. On a steadicam I think you'll end up with something looking weird enough to throw the audience out of the narrative, much more than using a small sensor camera for the one take. Look at some movies with steadicam work and you'll see it's seldom done in low light situations and that DOF is fairly deep on the shots and FOV is pretty wide. But hey, you already got the lens, do some experimenting and tell us what you find.

And yet again something I should have mentioned before, is that I'll be having the subjects walk side by side at the same pace (well, as closely as they can manage), that might have been a helpful thing to put out there, so there won't be one close subject, and one distant subject, they should be equally distant, or at least, very closely so.

But yeah, I think you're right, up until I get a chance to actually experiment, it's really unknown how well it may work - at best, however, it seems like if it can indeed work, it can really only work in a very, very limited number of scenarios!

 

[sunporchmedia]

You can and definitely should, test the lenses in advance. Nothing beats testing.

Greater depth of field on the wider lens (the Tokina). But does the Tokina offer the field of view that you want? It's substantially wider than the other lens, which may be more important than other factors. As are as focus, I'd set the focus to make sure they are in focus, even if the background is out of focus. If you want to, you can cheat the focus toward the hyperfocal, but you stand a better chance of keeping your actors solidly in focus if you put them square in the middle of the DOF.

Do you have experience with the Steadicam? Is it an actual Steadicam or another brand/model of stabilizer? The T/S will probably "announce" itself more readily if your shot is bouncy (which it will be unless you've been practicing for months at least).

I understand that you don't want to buy another camera for one shot. But maybe you can borrow one....? Above all, you must decide how you want the shot to look first, then test it to see if you can achieve the look. If not, redesign the shot or find the equipment that will do the job. Only you can say what you are willing to accept.

 

[thisisapocalypse]

Greater depth of field on the wider lens (the Tokina). But does the Tokina offer the field of view that you want? It's substantially wider than the other lens, which may be more important than other factors. As are as focus, I'd set the focus to make sure they are in focus, even if the background is out of focus. If you want to, you can cheat the focus toward the hyperfocal, but you stand a better chance of keeping your actors solidly in focus if you put them square in the middle of the DOF.

Well, I don't yet know. My gut would be that the Tokina, at that wide, is not what I was initially going for...now, if I could stand track the shot from say, 6" in front of them, that FOV might work, but I've never tried doing a shot like that, and the DOF at that distance will be incredibly unforgiving.

This is definitely a tricky shot, but it's also, for this project, a very important one, and one that really does have to be right.

I'd love for the background to be out of focus for this shot, it will make the rest of the scene cut together much more nicely and consistently. The reason I'm looking for depth of field, of course, number 1, the talent must be in focus, that's critical. Since it's going to be a nighttime exterior, and I want to maintain image quality, I want to crank the ISO/gain as little as possible, so shooting at stopped down apertures just isn't possible.

Hyperfocusing is another thought, but then of course I may have to keep the subject much further away from the camera than I want them to be, and I am just concerned that it may not look right, at least at f2.8

If the lens "announces itself" - then it's a non-starter and I'm going to have to find another option. I just don't know yet whether or not it will.

I have not decided on which model of "steadycam" (using this term generically, sorry!) that I will be using. I am not an experienced steadycam user, and this film doesn't have many steadycam shots (this one may be it!), so I plan on doing a lot of testing and rehearsing before shooting it for real.

Another thought I have is the Panasonic 20mm f1.7 pancacke lens, which sounds like it does continuously AF with video (although I'm still not sure whether it does in 1080p mode).

Even if I had to shoot it in 720p, that might be a better solution than using a different camera entirely - the FOV with the 20mm can be made to work and 1.7 is much closer to the ideal light gathering capability of a lens that I'd like to use in this scenario.

 

[sunporchmedia]

A wider angle lens is usually prefered for steadicam shots for many reasons.

A wider angle lens will give you more depth of field. That is good for keeping your actors in focus, especially at low light.

It will also give you a wider field of view, so you will need to be physically closer to the actors in order to have them fill the frame as much as a longer lens--or to put it another way, at a given distance from the actors, a wider angle lens will show more of their bodies. The advantage of the wider field of view is that it minimizes camera shake and weave, just like if it were a handheld shot.

If you want the background to be out of focus, then you definitely do NOT want to set the lens to it's hyperfocal distance..."hyperfocal" by definition means that everything from a certain point to infinity is in focus. If you don't want that, you should set the focus for the actual average distance from you that your actors will be.

Finally, if you have no experience with a steadicam or other stabilizer, you are much better off to do the shot with another technique. Though a stabilizer can give great results in experienced hands, they take a LOT of practice to get good at. Consider handheld (with a shoulder brace), a dolly shot, or even a makeshift wheelchair dolly. You may find these to give better results than trying to operate a stablilizer.

You will answer a lot of your own questions by simply testing out the options beforehand. Good luck.

 

[thisisapocalypse]

If you want the background to be out of focus, then you definitely do NOT want to set the lens to it's hyperfocal distance..."hyperfocal" by definition means that everything from a certain point to infinity is in focus. If you don't want that, you should set the focus for the actual average distance from you that your actors will be.

Thanks again for your input. This is actually why I came up with the idea of T/S.

I thought hyperfocal on a super-wide could be a workable option, but I didn't want to have the foreground out of focus, and all of the background in focus. If it were the only way for me to accomplish the shot, then I could live with it, but it's not ideal and will be strange since I have other shots in this scene that will definitely have shallow DOF with the background out of focus. I'd like them to match as much as possible so that the shot changes are as seamless as possible.

Now, If *everything* were in focus (which is what I will attempt with the T/S lens, although I don't know how well its going to work - but I will try it) that would be okay, I think, but I think having foreground objects out of focus, and everything else in focus would be strange for this scene.

It's just gonna be a tough scene and I think I'm going to have to come up with a different way of accomplishing it.

I think you are right about not going the stabilizer route - this isn't the best time for me to be learning an entirely new art! I think a shoulder rig (have also looked at fig-rigs) would be better for me. Doing this as a dolly shot is something else I've been considering and that might also work.

Thanks again.