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Photo Lenses for Video: There is no Free Lunch.

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SLR video cameras and the newer large sensor video camcorders, are often used with photography lenses — which provide outstanding optics at amazing cost savings compared to lenses specifically designed for film/video. A superb photography lens may cost $2,000; about 1/10 of what a good cinema lens or servo zoom ENG style lens costs.

However, if you think you’re going to get  $20,000 worth of function for $2,000 I have some bridges and swampland I’d like to sell you. Every time a new camcorder is released we have 30 people who want to rent the lens Famous Video Guy used when he made the demo videos for the manufacturer because his footage was incredible. They forget that Famous Video Guy also had 8 techs, 6 manufacturer’s reps, and a sound crew on the set and spent two weeks shooting multiple takes, making sure all the weaknesses were minimized and the strengths emphasized.

When someone tries to reproduce that look on a real world budget with a limited crew they’re disappointed that the lenses they chose didn’t work like they assumed they would. Photo lenses aren’t video lenses, don’t behave like video lenses, do things differently than video lenses. Like any good tool, they can be extremely effective when used properly. But if you don’t take the differences into account when planning equipment for a shoot they’ll be just as effective as using a sledgehammer for computer repair. So in an effort to prevent assumptions (because we all know what assume means) we put together a little reality checklist.

You’ll notice that the word photo(graphy) is underlined every time it precedes the word lens. We added extra emphasis here. Photo lenses are not video lenses. They can be used for video if you work around their limitations.

Zooms

  • There are no wide aperture 10x photo zooms. If you need one lens and wide aperture, you need a $20-40k video zoom.
  • Less expensive photo zooms are variable aperture. That is they may be f/3.5 at the wide end, but maximum aperture may be f6.3 at the long end.
  • Photo zooms are NOT parfocal. If you zoom, you will have to refocus when you get where you are going. If you plan to zoom AND maintain focus, you will need an amazingly gifted assistant. (There are a very few exceptions listed in “This article“.)
  • Many photo zooms telescope when zooming. As in the lens can get 3 times as long zoomed in as it was when zoomed out. Support equipment must take this into account.

Aperture

  • Most photo lenses have electronic aperture control. You will need to select a lens or adapter that allows manual control if you want it.
  • If your camera supports electronic aperture control, realize this is noisy. You do not want to use a camera’s internal microphone if you are using electronic apertures.
  • If your camera has electronic aperture control, realize this does what it wants, not always what you want. If you change from f2.0 to f/2.8 it may do go to f/16 or f/1.4 on the way there. Yelling at the camera doesn’t help. Yelling at us doesn’t help. Yelling at the lens doesn’t help. It’s like the changing of the tides: you have no influence on it.
  • On those lenses that have mechanical aperture rings, they will click at given stops. They are not smooth and continuous like video lenses.

Focusing

  • Photo lenses breathe. If you change focus you will usually change image size slightly.
  • Focusing throw on photo lenses is very abrupt. A video lens may turn 360 degrees during focusing. Photo lenses generally turn 120 degrees at most.
  • Critical focusing is less accurate on photo lenses. And don’t ever try to use the distance scale. They are wildly inaccurate.
  • Autofocus is not critically accurate. When shooting SLR video autofocus microadjustment must be set up before the shoot if you want critically sharp focus. But if you really want accurate focus you’d best pull it manually. Not an issue at f/5.6 usually, but usually an issue at f/2.0
  • When autofocus is available with an adapter (certain Panasonic and Sony cameras) it will be very slow and often inaccurate. There is often a tendency for the lens to “hunt” for focus.

Other

  • Electronic photo lenses are noisy. Electronic aperture control, focus motors, and image stabilization systems all make interesting buzzy sounds. If you use an in-camera mic they will ruin your audio (on-camera shotguns are often, but not always, OK).
  • f/stop is not T/stop. An f/2.0 lens is probably close to a T3.0 lens, maybe a bit faster. Depending on the manufacturer the f/stop rating is either a rough estimate or a boldfaced lie.

Some General Recommendations

If you’ve read this and are thinking “well now I don’t know what to do” good! We may have prevented you from wasting an entire shoot. We’ll give a few quick, general suggestions:

  • Don’t plan on using in-camera audio if you’re using any of the lens electronics (stabilization, autofocus, electronic aperture). A camera mounted shotgun mic may be enough isolation, but not always.
  • If you can use prime lenses, that’s best. If you must have a zoom realize you’ll need to repull focus after zooming. Staying in focus during a slow zoom with a photo lens requires amazing skill and practice.
  • Use only f/2.8 fixed aperture zooms. Variable aperture zooms are extremely difficult and usually of lesser image quality.
  • Manual aperture control is usually best (Older Zeiss and Nikon lenses have manual apertures). Adapters with manual aperture control are available even for some electronic aperture lenses (Zeiss, Nikon, and Sony).
  • Unless you’ve shot the specific lens and camera combination before, allow yourself at least a full day of practice. I guarantee you Famous Video Guy (or his staff) did.

If you have questions about lens selection, please send us an email at support@lensrentals.com We’d much rather figure out what’s best on the front end than hear about how the lens didn’t do what you assumed it would after your shoot.

Roger Cicala
Erik Morrison
Kris Steward
Lensrentals.com

11 Responses to “Photo Lenses for Video: There is no Free Lunch.”

Samuel Hurtado said:

* whenever possible, nobody should use on-camera audio, or mount a mic on the camera (the mic is poor, the filters are poor, the mic should be closer to the subject, everything in the camera is noisy)

* declicking a lens with a manual iris ring is often quite simple; there’s a risk that you may ruin the lens, but it’s not any more difficult than dissassembling the lens to clean it on the inside; I’ve done it myself on most of my vintage primes; I’m pretty sure you could declick some lenses and rent them specifically to video users

* f/2 to T/3? really? that much? the f/ number is supposed to be a mathematical thing, easy to calculate with a disassembled lens, so manufacturers shouldn’t be able to lie about it; and light absortion in the glass itself doesn’t seem to be so high even on my cheapest zooms; f/2 to T/2.1 is common on high quality lenses (read: zeiss ZE/ZF to CP.2), and I wouldn’t expect any decent lens to absorb more than f/2 to T/2.2, maybe T/2.3 if it’s not a prime but a relatively complex zoom; of course, my knowledge about lenses is dwarfed in this agora, so please just take my comment as an excuse to elaborate, if you will…

* amazing blog; I discovered it through canonrumors a few months back, and have since read most of the old articles; really, really great, thanks a lot

Bob Howland said:

Or you can just buy a dedicated camcorder and give up on the idea of using all your photo lenses for video. Last year, I purchased a Panasonic HDC-TM700 consumer camcorder as a learning tool and it has been a painful and humbling education. Which brings up the question: have you folks ever considered renting video cameras in the Canon XF100/105/300/305 class?

Samuel Hurtado said:

asking me to shoot with “a dedicated camcorder” with a 1/3″ sensor is like asking you to take your stills with a point-and-shoot (best case, if it is a $4K small sensor videocamera, you can compare it to a canon G11, but that’s it)

LensRentals Employee

Roger Cicala said:

Samuel,
It varies a lot, not just depending on number of elements. Zeiss lenses tend to be pretty close (perhaps because they make video lenses also?) but even the Zeiss 50 f1.4 and 85 f1.4 photo lenses are T2.1 in cp.2 form, despite being optically identical. The Canon 24-70 f2.8 is actually T3.4. It rarely is a whole stop but a half stop isn’t unusual.

Roger Cicala

Derrick M. Reyes said:

Thanks for the insight fellas. Some of this has been covered, but it’s well worth saying again in ONE spot as apposed to digging for it through countless pages of forums.

Sharp shooting!

Derrick Michael Reyes
http://www.no2ndtakes.com

Edwin Herdman said:

Famous Video Guy’s 1D Mark IV video was shot entirely in one evening after scrounging up help from some pals (all serious video people, of course) and was working with a camera on day one. Keeping all the above in mind, it’s just that extra bit more making Guy’s video yet more amazing, and the trouble they must have gone through for what was really just a short web clip should give pause to anybody thinking of guerilla-filming even an indie band’s first music video (though I’ve seen it done with my own camera, and not too badly at that).

I went ahead and read the Photo Lenses for Video link, great stuff. Amazingly complete, though even that article doesn’t emphasize enough (to my mind) that focus breathing is a show-stopping problem. For video, the term “focus breathing” doesn’t seem severe enough…more like a focus heave-until-seasickness-induced. Variable angle of view is perhaps a nuisance for wildlife shooters (who discover sometimes that their camera lenses aren’t exactly good as far out as they’d think, as their 400mm end often ends up closer to 370mm) but when you notice the whole picture pulsing in and out when simply focusing you have a whole new species of problem.

Shorter lenses have these problems too – the 50mm f/1.4, have it, and the TS-E 90mm is even more extreme (I would expect the old-fashioned extending-barrel macro lenses to also be extreme). You’ll notice that Famous Video Guy’s video (if I remember right) barely changed focus, mainly allowing stuff onscreen to move through the plane of focus. It was still unqualifiedly a movie, instead of a slideshow, but it is obvious that the amount of motion they could cope with was limited. If anything, the effect should be only magnified on the APS-C crop cameras an amateur is more likely to be able to afford.

Of course, the gritty manual focus wheel on the classic Nifty Fifty (Canon f/1.4) isn’t helping either.

So instead of a nice smooth quarter turn (or however far it is on video lenses) of a lever, just to yank that camera prime from near focus to far you have to grab and twist the ring – a few times. To go from minimum focus (about .45 meters) to beyond infinity (oh…that’s another drawback of photo lenses – focus past infinity for the autofocus system, which could only be useful on manual video focusing, perhaps, for focusing tilt lenses – when’s the last time you saw that in a movie?) is more than 180 degrees around. What’s more, from 1 to 3 meters is about a fifth of the distance around. And even through that relatively normal focus range, focus breathing is significant.

By the by, isn’t the TS-E 17mm a pretty good (as it goes) substitute video lens? I see you guys put the 24mm sibling up there. Nice manual focus ring (in terms of smoothness and precision, don’t remember how far a complete pull is in degrees, but still too far of course) and it also doesn’t change length, and if I remember right has no to very little focus breathing.

Thanks Roger!

LensRentals Employee

Roger Cicala said:

Edwin,

Thank you for chiming in: very excellent comments. I was actually referring to Panasonic Famous Video Guy, though :-)
I especially appreciate your replacement terminology for focus breathing: I totally agree, that term just doesn’t give the proper gravity to the situation. And I agree about the 17 TS-E (one of my favorite photo lenses) except that the bulging front element can play havoc with filters and matte boxes for some shooters.

Roger

Arnaud said:

Just discovered your blog through CR. Being in France, I may not be a customer of yours any day, but I just wanted to say that your blog is amazing. Go on that way !

matt said:

I think its worth mentioning that focus breathing can be eliminated automatically in post with many software programs. While not ideal it is a solution that works and can salvage footage when shot with photo lenses. Works quite well on lenses that don’t breath much.

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