Am I getting bad information or ...

[Andrew Patterson]

Do still lenses record motion differently that cinema lenses? I've read that still glass isn't made for motion and, I know I'm showing my ignorance here, but this makes no sense to me. What happens in a still lens that doesn't happen in a cinema lens? What goes in within it that makes it react to action differently? What makes them vastly inferior? Or even just slightly inferior or annoying?
And with lenses like the Zeiss Ultra Primes -- which I've read are actually re-housed still lenses -- is it obvious that they are generated from still glass? If so, how can they be marketed and sold as cinema glass? This case in particular confuses me, since in this case it's clear that still lenses are passing as cinema lenes.
Understand that I am coming at this from a layman's perspective. I have spent years shooting HD Cameras with built in lenses and I look forward to having many options. But right now they all look REALLY good -- which is why I would like to know what the professionals are seeing that I currently cannot.
As always, thank you in advance for any advice, opinions or points to other threads!

[Matt W.]

It's more complicated than this, but these are the basics:

Some still lenses (particularly zooms) will shift slightly in focal length while being focused ("lens breathing"), like a tiny zoom in or zoom out. This isn't an issue with still images, obviously, as the focus is in one place when you take a given picture, but it's a problem with motion--so cinema lenses are specially designed to mitigate lens breathing. If you pull a rack focus or a follow focus with a still lens, you may notice a subtle but potentially distracting shift in perspective. (This is nothing compared with the breathing on old anamorphic cinema lenses, though--which was genuinely bad.)

Other issues are just that vignetting, fall-off, flares, ugly bokeh, etc. are all more apparent in motion than in a still image, so cinema lenses are designed for more consistent highlight rendition and more even illumination than still lenses. And they have larger lens barrels for easier focus pulling and they're color matched so each focal length doesn't give you a different tint.

This said, if you're using decent primes (like the zeiss ones you mention) none of these problems are that bad. It's not like still lenses change how motion is rendered, it's just that problems some lenses have are okay for still photography but may show up when used in motion. Generally, with decent glass, it's not a big deal.

[David Rasberry]

For top of the line premium grade optics, there is probably little difference in optical quality between still and cinema lenses. But the mechanics of cine lenses are typically of much better quality than mass market still lenses. They are more ruggedly built, have tighter mechanical tolerances, finer more precise focus adjustments over a wider rotational angle, greater thermal stability, etc.
Optically, issues like breathing (change in image size or geometry with change in focus), constant aperture and constant focus through the full range for zoom lenses are much more critical for motion shooting and more tightly controlled with cine lenses.
These are a few of the major differences.

[Stephen Pruitt]

But there are advantages which go the other way, as well. Still lenses are VASTLY less expensive for the quality offered, are generally much faster for the same price (great still lenses of 1.2, 1.4, etc. are about $1000 to $1500 brand new!), and are generally much, much smaller and lighter in weight and, therefore, easier to use in tight spaces or in hand-held or stabilizer situations. It's a two-way street.

Full-disclosure: We used Nikon primes for our first film and are now using Canon primes (and a few zooms) on our system.

Stephen

[Jochen Schmidt-Hambrock]

The small focus travel (and its "wrong" direction) can make a shot impossible:
Lens wide open, actor and camera moving will be difficult on cine-glass, will be sheer luck on still-lenses.

Jochen

[hans de vries]

I wanted to buy a leica 35 mm f1.4 from ebay so i googled the lens for info, and one of the entries was from Dalsa, which had the same lens, and a number of others, to be adapted for PL mounts. Apparently the glass itself was definitely to their standards.
I'm absolutely not denying any of the objections mentioned above, but I haven't had any trouble yet with my Leica's

[Alexander Ibrahim]

Do still lenses record motion differently that cinema lenses? I've read that still glass isn't made for motion and, I know I'm showing my ignorance here, but this makes no sense to me. What happens in a still lens that doesn't happen in a cinema lens? What goes in within it that makes it react to action differently? What makes them vastly inferior? Or even just slightly inferior or annoying?

No, there is no magic to cinema lenses- just better optical and mechanical engineering.


And with lenses like the Zeiss Ultra Primes -- which I've read are actually re-housed still lenses -- is it obvious that they are generated from still glass? If so, how can they be marketed and sold as cinema glass? This case in particular confuses me, since in this case it's clear that still lenses are passing as cinema lenes.

Zeiss makes a series of lenses called "Compact Primes" which are the same glass as the Zeiss ZF glass for nikon mount cameras. (its also the same glass in the Zeiss ZE mount for EOS cameras and the Zeiss ZF.2 mount, also for Nikon, but which passes lens data.)

Basically this is Zeiss making a list of the things that are seriously wrong with their still lenses when used in a cinema application. Examining what they've changed is instructive.

http://www.zeiss.com/c125756900453232/Contents-Frame/b984d96f381f07fbc12575820044c5d7

As someone else said, the lenses are in a different housing. This housing has proper film pitch gears machined into it, for both focus and aperture. Compared to the attachable rings popular in indy film, the machined rings are much more rigid and reliable in focus operation.

The film housing also provides a much greater rotation. As noted elsewhere a longer focus rotation (or "throw") makes it far easier for the 1AC (or focus puller) to follow focus.

Also, the focus mechanism is improved to minimize breathing. (the apparent change in focal length of a lens as focus is adjusted.) The design of the glass elements is such that you can not eliminate it, but some of the more egregious offenders (I'm looking at the 35mm ZF as I type this) are much improved.

Finally the focus marks are both more numerous and more precise.

The front elements are a standard size. That makes it a bit easier to swap lenses with a matte box and other accessories. A bit easier translates into a lot of saved time on a film set where a DP might call for several dozen lens changes a day.

The focus and iris rings are in a standard position, so you don't have to spend as much time mucking about adjusting the follow focus when you change lenses. Again a bit easier.

The iris ring doesn't have "clicks" in to various positions, so you can pull the aperture smoothly when needed.

Also the iris has 14 blades in stead of 9 in the still lens versions. This improves the bokeh of the lens. For the record I think the bokeh of the still lens is already very pleasing in both still and motion. (That isn't to say the compact primes are not an improvement- because they are.)

The iris is marked in T-stops instead of f-stops, and once again there are more and more accurate markings.

All this said, the still versions of these lenses produce spectacular pictures. I typically set things up so that I do not have to pull aperture, and so that a human can accomplish the focus pulls needed, so Zeiss ZF (nikon mount) lenses have served me very well on my RED and now on my Canon 7D.

That said, my next lens series is likely to be the Zeiss compact prime set. Individually they are approximately 2-3 times the price of their still lens counterparts. So they are expensive, but they are definitely worth the price difference.

Looking up at Zeiss's Master Prime collection of lenses, its harder to see the difference. The actual glass is different. So is the entire machining of the lens housing. Color matching is far better between lenses, and all the lenses open up to a uniform t-stop.

OK, so notice that none of this addresses the actual glass. The glass can be perfectly fine, and you can still have a deficient lens for motion picture photography.

Ultimately seeing is believing, and I suggest you go to the local rental house and see for yourself.

[Andrew Patterson]

I wish I could go to a rental house, but there is no such thing in Oklahoma City. So most of my purchases are happening "blind", so to speak.

This was all very helpful and has convinced me that I could reasonably use still lenses and work with their mechanical deficiencies. I will be using a few RED ZOOMs for now.

Thank you for the detailed and thorough explanations.