What do Lens Adapters do? & Why?
Each camera has a unique blend of style, function, features, and limitations. All of them, though, have a lens. These lenses will be either built-in or removable. Ones with removable lenses are normally called interchangeable lens cameras.
With an interchangeable lens camera, you can remove the lens and replace it with another. Different cameras have different systems to attach lenses, which we call lens mounts. Sometimes they're called systems too, but this means the mechanism by which we attach lenses to a camera.
Manufacturers provide their lens mounts with names so that you can tell which lenses to buy. If you have a Sony E mount camera, you need a Sony E mount lens. Nikon F lenses generally will fit onto any Nikon F body, with a few exceptions.
But what if you want to use a lens from a different system? This is where lens adapters come in. With adapters, you can mount lenses from one system on a camera from another. With modern advances in technology, the possibility for adapting has increased dramatically.
Because of the rise of digital in the 2000s, new lens systems were developed. These systems replaced the older systems which led to lower prices of this older analog gear.
And this is why adapting old lenses is so appealing. You can use any number of lenses on your modern camera at a much lower cost than new lenses.
There are many reasons to use lens adapters, including:
- I found some old lenses in my attic and want to try them on my camera.
- I want to switch to a Sony camera but I already invested in Canon lenses.
- I want a new lens but the ones made for my camera are too expensive.
- I own different systems already, I want to mix and match!
- I need a specific lens for a specific purpose, but it’s not made for my camera.
- I want to use my expensive lenses on my cheaper back-up body.
- I want to get creative and do some weird stuff!
The size of an adapter depends on the model of the camera body and the lens you want to attach to it.
With an adapter, you can use old film camera lenses on a new digital camera. Especially with mirrorless cameras, there are tons of options for adapting. Many of these cameras even have built-in functions to assist with manual focusing and stop-down metering, making it extremely easy. It might even be easier to use these lenses on digital than it was on film!
Older legacy lenses have optical features and characteristics that are impossible to replicate with newer lenses. Advances in technology have made lenses incredibly sharp, fast, and precise, but many people are looking for a vintage look in their photography or cinematography that these lenses (or post-processing) cannot deliver.
In our webstore you can find a wide selection of lens adapters for different purposes.
How Lenses Work
A lens working properly depends on two things: the physical connection and a matching flange distance. This basically means that the lens has to be attached to the camera and it has to be a specific distance away from the sensor/film in order to focus properly.
Flange distance is the distance between the lens mount and the camera sensor/film plane. Lenses are designed with very specific distances in mind, and these distances depend on what system the lens is designed for. If a lens is moved closer or further away from this specific distance, it will not focus properly.
Physical attachment is pretty obvious, but lens systems are designed to only work with the right equipment. A Canon lens will not fit on a Nikon camera and vice versa because the two companies specifically designed their lenses not to. Canon cameras will only work with Canon lenses, or lenses made by third party companies that pay Canon to use their lens mount.
This specificity is what defines a lens mount. Cameras and lenses with matching mounts were designed for each other. You can rest assured knowing that the lens will attach normally and the flange distance will allow for proper focusing.
How Do Lens Adapters Work?
Based on what we just said, it's fair to think that using a lens on a camera from a different system is impossible. The lens won't fit or focus properly! Fortunately, adapters solve both of these problems at once.
Generally, adapters are simple metal rings or short tubes with two different lens mounts. One mount is on the back, designed to attach to a camera. The other is on the front, designed to attach to a lens. This solves the attachment issue.
The adapter will also be a very specific thickness in order to match the flange distance of the lens. By getting the lens the right distance away from the film plane/sensor, your lenses will focus even if they're attached to a camera from a different system!
However, not every adaptation is this simple.
You may already be wondering how a lens with electronic functions can communicate with the camera if there is a metal tube between them? Or “I don’t have a full frame sensor, how will that affect my images if the lens is made for full frame?”
We'll answer that below, but first let’s see some examples of what we've already covered.
The thickness of the camera body will give you an indication of the flange distance of the system. The difference is obvious when comparing an SLR and mirrorless digital camera side by side.
Here we've attached a lens to the SLR and an adapter to the mirrorless camera. Notice how the adapter goes roughly to the same spot as the end of the SLR lens? The adapter compensates for flange distance in this way.
Now we've moved the lens onto the mirrorless camera. Because the adapter is specifically designed to put Nikon F mount lenses on Micro 4/3 bodies, it has the right bayonets and flange distance to allow for proper attachment and focus.
Many film and digital cameras are Single-Lens Reflex (SLR) cameras. These designs have mirrors between the shutter and lens, leading to relatively long flange distances.
Modern mirrorless cameras, on the other hand, do not have a mirror. This means their flange distances are quite short. What does this mean?
It means that adapting to mirrorless cameras is almost always possible. You're only limited by the availability of the adapter and the lens' image circle. Mirrorless camera systems, like Sony E, Micro 4/3, Fuji X, Nikon Z, Canon R, Fuji GFX, and many more are great options if you're looking to adapt vintage lenses.
In the photo above we show some mirrorless cameras with adapted lenses. There's a Sony camera with a Nikon wide-angle lens, an Olympus with a Leica M mount Voigtländer lens, and a Panasonic camera using an Olympus telephoto lens.
What if you don't have a mirrorless camera? What if you want to adapt a film system to another film system? Well, it's not always possible.
One SLR system that is easily adaptable is Canon EF (& EF-S). This system has one of the shortest flange distances of any SLR, so you have a good variety of adapting options. Sony A and Pentax K mount cameras can use M42 mount lenses with the right adapters, too. These SLR-to-SLR adapters generally change the flange distance only a few millimeters, so the adapters look more like rings.
Flange Distances of Popular Lens Mounts
|Sony E / FE
|Leica Thread Mount (LTM / M39)
Even if you have a combination of lenses and cameras where it is possible to adapt, finding an adapter can be difficult, if not impossible. These lens and camera combinations are very uncommon, and adapters are equally uncommon.
Some manufacturers, like Olympus, made lens adapters for their various systems. It is possible to mount Olympus OM lenses on the Olympus PEN F half-frame SLR because of an Olympus-branded adapter. Many manufacturers also sold adapters for using M42 lenses on other camera systems.
If you're looking to adapt film-to-film, your best bet is likely to find a vintage adapter rather than a new one.
What Kinds of Adapters Are There?
These adapters do not communicate with the camera, and your camera may not know there is a lens attached. With some cameras, you may have to enable something like "shoot without lens" in order to adapt lenses properly.
This also means the lenses are fully manual. For some photographers, the lack of autofocus and aperture control might be a hindrance. Others prefer the manual, tactile feel of these lenses. Cinematographers may even prefer the physical focusing rings.
Even though the lenses are manual, most cameras are able to measure the light coming through and meter properly. Even in aperture-priority (A or Av) mode, many cameras can reliably pick the best shutter speed for the situation without issue.
Many mirrorless digital cameras often have focus peaking and other assisting functions which help you to use manual lenses correctly. It’s not nearly as difficult as you may think!
Adapting Autofocus or Electronic Lenses
In the 1980s, Minolta introduced the first autofocus lens mount. It was Canon, though, in 1989, that introduced the fully-electronic EF mount. These lenses did not rely on physical connections with the body for focusing, aperture control, or any other function.
With a dummy adapter, you can adapt electronic lenses to any system with the right flange distance. Unfortunately, you would lose control of focus or aperture or both. That's why adapters with electronic contacts were invented.
While these adapters are more expensive than their dummy cousins, they allow for control of focus and aperture electronically. and breathe life into tons of lenses.
In the photo above, we use ad adapter with electronic contacts to mount a Mamiya 645AF lens to a Sony FE body and a Canon EF lens on a tiny Canon M mirrorless body.
Because features like autofocus, image stabilization, and aperture are able to be controlled by the camera, these adapted lenses behave just like lenses designed for the system! There are even adapters that can turn manual focus lenses into autofocus ones.
This makes switching systems much easier, especially if you're switching to mirrorless. Canon, Nikon, Olympus, and Sony all have official adapters for mounting older SLR lenses on newer digital systems. Canon EF & EF-S lenses in particular can easily be adapted to almost any current mirrorless system.
Generally the lens is mentioned first when describing an adapter. This means a Canon EF - M adapter would be for mounting EF lenses on an M mount camera. Here are some links to official adapters:
Canon EF – Canon M AF (Mount EF lenses on EOS-M cameras)
Canon EF – Canon R AF (Mount EF lenses on EOS-R cameras)
Sony A – Sony E / FE AF (Mount Sony A/Minolta AF lenses on Sony E/FE cameras)
Nikon F – Nikon Z AF (Mount Nikon F lenses on Nikon Z cameras)
Olympus 4/3 – M4/3 (Mount Four Thirds lenses on Micro Four Thirds cameras)
Limits of adapting lenses
Just because you can adapt, doesn't mean you should. Older lenses may not have the resolving power to take advantage of a newer sensor, and they may have optical qualities that are subjectively unpleasant.
It's also possible that the image circle of the lens is too small for your modern camera. That means that the lens was originally designed for a film frame or digital sensor that's smaller than the camera you want to adapt it to. In the worst case scenario, this lens will damage your camera.
There are some lenses that can be adapted but will damage your camera anyway because of how the lens is designed. If a lens has a rear element that sitcks quite far out the back of the lens, there's a chance it hits the mirror, shutter, or something else inside your camera.
This is pretty uncommon, and by now we're well aware of what lenses will cause issues. If you're worried, you can always message us or check the internet. It's likely that someone else has tried the exact combination of camera and lens that you'd like to try.
Often you can tell if a lens will produce a big enough image circle based on the size of the lens itself. C-mount lenses, for example, were designed for movie cameras that used narrow 8mm or 16mm film. If you mount one of these lenses to a full-frame digital camera they will leave a significant portion of the frame black.
This Som Berthiot 25mm f1.4 Cinor Paris is a small C-mount lens designed for 16mm film. You can see the size of the image circle when we mounted this lens to a full-frame digital camera. This lens simply was not designed to cover such a large sensor.
Here we've mounted the same C-mount lens on a Micro 4/3 camera. Because the Micro 4/3 sensor is much smaller than a full-frame sensor, the effect is much less pronounced. This could easily be described as vignetting and fixed with some minor cropping.
Speed boosters / focal reducers – turning crop sensor into a full frame?
Some adapters go even further than adding electronic contacts by adding glass elements to the equation. This can give a variety of features, but the most common adapter with glass is called a speed booster.
These adapters shorten the focal length of a lens and concentrate the light passing through them. This casts more light on the sensor, allowing you to use faster shutter speeds with the same aperture and ISO. That's why we call them speed boosters!
Another reason to use these lenses is that they somewhat undo the crop that happens when you use a camera with a sensor smaller than full-frame.
Because a speed booster concentrates the light coming through a lens, your field of view becomes wider than it would be without the speed booster. It's sort of the opposite of a teleconverter, which magnifies the field of view and loses light.
But wait.. Crop? Small sensors? Concentrated light? Let's take a step back and explain a bit.
What is a Crop Sensor Camera?
Crop sensor cameras have smaller sensors than full-frame. Different crop sensor systems (Micro 4/3, Fuji X, Canon EF-S, etc.) have different sensor sizes, but they're united in being smaller than full frame.
Full frame sensors are the same size as a frame of 35mm film. Many professional cameras have sensors this size because cameras and lenses have been built around this image size for almost 100 years.
When you use a lens designed for a full-frame camera on a crop sensor camera, you only capture the center of the image. The sensor is too small to capture all of the light coming through the lens.
For example, imagine a sign that read "supermarket" that fills the entire frame when you have a full-frame lens on a full-frame body. When you take the photo, the entire word will be visible.
Fit the same full-frame lens on a crop sensor body, though, and you may lose letters on either side. It might say "upermarke" or even "permark" depending on the size of the sensor. You also lose space on the top and bottom of the frame.
So images taken with a crop sensor camera will appear zoomed-in compared to images from a full-frame sensor, even if they're taken with the same lens. This zooming gives a similar effect to cropping the full-frame camera's image, which is why they're called crop sensor cameras.
The most common type of crop sensor is the APS-C sensor, which has a crop factor of 1.6x. This means that your subjects will appear 1.6 times closer on an APS-C camera than with a full-frame camera, even with the same lenses.
Generally, this isn't an issue, but it is important to know when buying a camera or lens. Unfortunately, it's time for us to do some math. I'm so sorry.
50mm full-farme (FF) lens on FF body:
50mm lens x 1.0 = 50mm
Result: The image captured is equal to the field of view the lens captures.
50mm FF lens on example Crop Sensor body:
50mm lens x 1.6 = 81mm
Result: The image captured is not equal to the exact field of view the lens captures. It appears equivalent to using an 81mm lens on a full-frame sensor.
This difference is the crop factor of the body. When you hear about "full frame equivalent" that means that the lens will give a field of view similar to a 50mm lens on a full-frame sensor.
While it may seem simple, this can be quite a confusing concept in practice. This also means it's harder to find wide angle lenses for crop-sensor cameras, since you're always cropping by 1.6x. Now maybe a speed booster makes more sense!
Speed Boosters for Crop Sensor Cameras
As we said before, speed boosters can effectively undo the crop factor we just explained. This means that a 50mm lens will give the same field of view on your crop sensor camera as it would on a full-frame sensor.
In the following photos you can see the effect. In the first one, a full-frame lens is mounted with a standard dummy adapter to a crop sensor camera. In the second, the same lens and camera are used with a speed booster adapter. The subject was the same distance away.
It's only possible to use this kind of adapter when the lens produces an image circle bigger than the sensor area of the camera. There are also some compatibility issues that prevent some lenses from being used.
The most prominent manufacturer of speed boosters is Metabones, but other companies make them as well. Because they offer a completely unique experience, these adapters can range in price from 100 to over 1000€ depending on the manufacturer.
When you combine electronic control and speed boosting, adapters can become quite expensive. Nevertheless, they remain an efficient way to use old lenses on new systems without sacrificing light transmission or your focal length.
Examples of Speed Booster Manufacturers:
This article was originally published on 21.4.2020 by Jordan Lockhart and was updated 27.1.2022 by Connor Brustofski.