Let alone the physics of a camera lens, these light gathering devices can be confusing because of their many types, shapes, sizes, mounts and applications. For the beginners and the curious, I’ve put up a guide of generic lens categories to help you understand their intended purpose, and point you in the right direction, say if you were looking to rent/buy or just want to know for your own benefit. Categories will be sorted in the following manner:
- By “Capture Ratio”: Spherical Lenses vs Anamorphic Lenses
- By “Application”
- By “Focal” type/range
- By “Mount” type
It’s important to assume that these categories are not necessarily dependent from each other (e.g. a lens can be spherical, designed for ENG style productions, and be 24-70mm focal length zoom, all at once). Now let’s put this into perspective…
By “Capture Ratio”: Spherical Lenses vs Anamorphic Lenses
They are the most commonly used type of lenses. They do not distort the aspect ratio of an image, so what you see through the lens is what you get.
Shooting with these toys will get you to get the widescreen cinematographic look you’re used to when watching movies. Look at the centre of the lens, it looks like a cat’s pupil. The image is distorted or “squeezed” to capture additional horizontal information, increasing the resolution of the captured scene. This process also has an effect on the Bokeh and depth of field of an image. The image will then have to be restored or “de-squeezed”, by applying the correct ratio.
(Recommended read: Understanding Anamorphic Lenses)
(Source: Storm and Shelter)
Why filmmakers love the anamorphic look – take a look at this (and check out their awesome anamorphic lens test): What is Anamorphic?
EFP (Electronic Field Production) Lens
It’s a heavy lens designed for ‘studio’ and ‘OB’ (aka ‘Outside Broadcast’) type of cameras (e.g. TV sets, stadiums, concerts). It usually offers powerful zoom factors over 100x, including a 2x extender, resulting in focal length ranging approximately within 3.3mm-2200mm.
ENG (Electronic News Gathering) Lens
It’s a lightweight lens conventionally used for standard video productions. The focus ring and iris are accessible, which allows comfortable control to the operator, for example on a shoulder-mounted setup. The focus ring is designed to turn across ⅓ of its rotation range. Note that some brands will have their focus rings rotate clockwise and others anticlockwise.
Cine Style Lens
Likewise, it’s a lightweight lens but it’s built essentially for film productions. It’s designed to enable a Focus Puller to control the iris, zoom and focus ring. Also, the focus ring can travel on a larger range (a bit less than a full turn) than ENG lenses, to increased focusing precision. These are usually high-end lenses, which offer outstanding optical performances, but are limited in zoom ratios (inferior to 12x).
It is a fixed focal length lens only. Compared to a zoom, it’s usually a faster lens (allows more light to come into your camera, usually one additional stop) and presents less optical defects than a zoom lens (e.g. chromatic aberrations, distortion, ramping, etc..) – essentially because it has fewer glass elements fitted in the object. The depth of field is shallower. The absence of a zoom feature means that you’ll have to change your lens each time that you want to change the focal length.
|Broadcast EFP Lens
Reference: Fujinon XA101x8.9BESM 2/3″ HDTV Field Style Lens
|Broadcast ENG/EFP Lens
Reference: Canon CJ12EX4.3B IASE Lens
|Standard ENG Lens
Reference: Canon EF 24-70mm f/2.8L II USM
|Cine Style Prime Lens
Reference: Canon CN-E 50mm T1.3 L F Cine Lens
|Standard Prime Lens
Reference: Canon EF 50mm f/1.8 STM
By “Focal” type/range
We’ll treat the physics behind this subject in a separate article, but in simple words, the shorter your lens’s focal length is, the larger is the visual field, and the smaller the framed elements will be on your image. On the other hand, the longer your focal length is, the narrower is your visual field, therefore the larger are the framed elements of your image.
|FOCAL LENGTH||TYPE OF LENS||TYPE OF PHOTOGRAPHY|
|8-24mm||Fisheye (Ultra-wide)||Panoramic shots, cityscapes, landscape, real estate, abstract.|
|24-35mm||Wide Angle||Interiors, landscapes, architecture, forest photography.|
|35, 50, 85, 135mm||Standard Prime||Portraits, weddings, street/documentary photography.|
|55-200mm||Zoom||Portraits, weddings, wildlife photography.|
|50-200mm||Macro||Ultra-detailed photography (rings, nature).|
|100-600mm||Telephoto||Sports, wildlife, astronomy.|
(Source: Cole’s Classroom)
By “Mount” type
The lens mount is the mechanical interface allowing a lens to be attached to a camera body. Modern lenses may include electrical connections at the rim of the rear element which can allow control of the image stabilisation, autofocus, electronic aperture, zoom, features which are not available on vintage lenses.
There is a wide range of lens mounts available. Some of the most common standards used by professional videographer/photographers are the Canon EF, Nikon F, Sony A and E mounts. In film, can also be found Arri PL, Sony FZ and Panavision PV mounts. You can find out more about the difference here: Wikipedia.
There are lens adaptors which can allow you to use a variety of alternative lenses on your camera, opening up an entirely new realm of possibilities for filmmakers and photographers. There may be a few downsides to using these depending on the types of adaptors:
- there may be no communication bridge to allow modern lenses to send data to the camera (e.g. autofocus, image stabilisation) when the lens is mounted, due to their mechanical nature.
- Adapting a lens intended for a smaller sensor than the one of the camera may have an effect (positive/negative) on certain optical elements of your final image depending on the conversion and the lense’s properties, and vice versa.
Side note: More recent lenses like the Zeiss Supreme Prime models have been designed to record the metadata of a lens in a frame accurate manner which means that any information of the focal length, aperture, focus distance and depth of field is captured alongside with the image. That can be quite useful when editing and for VFX.
That should set the baseline to building up knowledge on lenses for the production field. Yet, there’s a fair amount to unpack (general physics, optical artefacts, accessories and filters, stabilisation, etc…), so if you’d like us to touch on a particular topic, drop us a line in the comments.