What is a Cine Lens and Why must it be different from a Photo Lens?

A lens is a lens, right? Of course not. To compare lenses on the basis of superficial features like focal length, T-stop, weight, price, brand, etc., has its place, but it doesn’t tell you the whole story. It’s almost like judging how good a doctor or a lawyer is by looking at the design on the business card and the location of the office.

This means, there are some features of lenses that are beyond the obvious. You’ve probably seen a cine lens and know what it looks like (if not, don’t worry, I’ll explain it soon). But very few people know that just because a lens ‘looks’ like a cine lens it doesn’t mean it is a cine lens.

Let’s see how and why a cine lens must be different from a photo lens or a ‘pseudo-cine’ lens.

Exclusive Bonus: Download my free guide (with examples) on how to find the best camera angles for dialogue scenes when your mind goes blank.

Cooke S5i

What is a cine lens?

Image quality is a given. Whether you’re working with cine lenses or photo lenses or telescopes or microscopes or eyeglasses, the quality of the images produced must be excellent, or at least good enough. In fact, you’ll see many reviews of cine lenses being compared to photo lenses, and the image qualities are similar. Very often, you’ll find a ‘photo lens’ version and a ‘cine lens’ version of the same lens, so which one do you pick?

Let’s get the definition out of the way first. A cine lens is a lens designed specifically for the demands of cinema production.

So, what are these ‘demands’ that cinema production forces on a lens that photo lenses don’t have to worry about? We’ll get to that next, but first, another definition.

What is a pseudo cine lens?

This is not a fair term. I intend no negative connotation to the term ‘pseudo’. What I simply mean is: a pseudo lens is a lens that appears to have some of the characteristics of a cine lens but not all of them. Of course, this also means all cine lenses are pseudo lenses, because hardly any of them share the exact same features!

So, don’t get too hung up on this term. I use it simply because there are manufacturers who slap on a few ‘easy’ features to make a lens look like a cine lens, but neglect quite a bit of important features. Pseudo cine lenses are to cine lenses as decaf is to coffee. It’s what they don’t do that makes the difference.

Whether these features are important to your production, only you can judge. After all, in video production, people use all three types – photo lenses, cine lenses and pseudo cine lenses. They all have their place.

Now to the features.

Why must a cine lens be different from a photo lens?

The cine lens, in addition to image quality, have a lot of additional responsibilities to fulfill. Let’s divide these responsibilities to three main categories:

  • Construction
  • Usage
  • Optical abilities

Construction

There is a good reason why cine lenses are large and heavy. Here are the comparisons:

Feature Low-end photo lens Professional Photo Lens Cine lens
Weather sealing Maybe Most of the time Always
Solid, rugged construction to ensure performance across demanding situations, including rental knocks Unlikely Always Always
Protruding front or back element/barrel when focusing or zooming Almost always Sometimes Never
Distinctive outer design and standard housing Hardly Most of the time Always
Consistent physical lengths Hardly Hardly Always
Easy to service? No, especially due to image stabilization and ‘silent’ motors, AF, etc. Yes
An effort to keep lenses around the same weight No No Always
Made for extreme weather Never Sometimes Always

A professional photo lens is owned by one person (most of the time), but a cine lens is usually rented. They are like spoons and forks, and they must be standard sizes so everyone can use them in the same way.

Usage

A cheap consumer-grade still lens is a donkey. A professional photo lens is a horse. A cine lens is an elephant. All perfectly respectable animals. Here’s how that works:

Feature Low-end photo lens Professional Photo Lens Cine lens
Totally reliable markings Unlikely Most of the time Always
Uniform filter threads and front diameters Almost never Sometimes Always
Solid PL mount that exchanges electronic lens data, including those required for VFX work N/A N/A Sometimes
Focus throw Jerky Smooth, but mostly short throw for quick focus Long throw
Breathing (not parfocal) Almost always Most of the time Sometimes
Aperture Ring These have mostly vanished Always
Smooth (de-clicked) aperture ring Hardly Always
Extremely smooth zoom movement Never Hardly Always
Focus gears/teeth Yeah, like baby teeth Always
Designed to focus using… AF Your hand, AF Follow focus system

A cine lens is designed to record continuous motion. If you want to change the aperture, focal length or focus while the shot is being recorded, without drawing attention to the fact, then you need certain features. Still lenses don’t need these features.

Optical abilities

Even though you will find image quality comparisons on the Internet, they’ll miss out on these critical factors:

Feature Low-end photo lens Professional Photo Lens Cine lens
A full range of focal lengths – from wide to telephoto – all available as a single purchase Yes Yes Limited to cine requirements
Uniform and calibrated T-stop performance so you can match lighting Never Never Always
Matching image characteristics so you can match shots without worrying Never Hardly Always
Uncompromising optical performance Maybe Most of the time Most of the time
Anamorphic choices? No No Yes

How many photo primes share the exact same f-stop or T-stop? Let’s say you shot a 50mm and then changed to a 35mm and then an 85mm with a photo lens. Will all three lenses have similar optical qualities? Never. Cine lenses are designed keeping in mind that shots taken days or weeks apart must match, regardless of the focal length, exposure, weather, etc. In fact, you could say that, except for the focal length, a cine lens prime kit must be identical twins in every respect.

Imagine how challenging it must be for a lens designer to not only make an optically perfect lens, but also ensure the design fits in the same sized box? Now you know why a top of the line Arri Master Prime or Cooke S5i costs about $20,000 per lens.

You can see quite clearly why cine lenses have to be as they are. Next time you’re thinking of using a photo lens or a pseudo cine lens or even a cine-modded (still lens converted to cine lens) lens, make sure you look for these features and know exactly what you’re getting into.

I hope this article has highlighted the important features one must consider when opting for a cine lens. For a comparison of prime cine lens kits costing less than $10,000 per lens, click here.

What do you think? What features of a cine lens are important to you and what aren’t?

Exclusive Bonus: Download my free guide (with examples) on how to find the best camera angles for dialogue scenes when your mind goes blank.

8 replies on “What is a Cine Lens and Why must it be different from a Photo Lens?”

  1. I would like to see more information regarding the following

    “If you want to change the aperture, focal length or focus while the shot is being recorded, without drawing attention to the fact, then you need certain features. Still lenses don’t need these features”

    I’m thinking follow focus systems, so I shall check out more of your articles

  2. If you’re a film producer studying a film script, you should know what this article teaches. So you can control the cost of design of viewer’s experience, targeting the narrative. Within a prescribed budget!

  3. Wow! Thank you for useful explanation. I left the webpage after reading intro lines.. When I came back to check it again I found your compare tables most useful.

Comments are closed.