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Sep 03, 2023

What Are Lens Mount Adapters? What You Should Know Before Buying One

Lens mount adapters adapt your lenses to camera bodies from different

Lens mount adapters adapt your lenses to camera bodies from different manufacturers. Here's what you need to consider before getting one.

Whether it's a hobby or a profession, photography can get to be expensive. Lens mount adapters are an easy way to help cut costs by letting you adapt the lenses you already have to the camera you want to use it with or vice versa. Here's what you need to know before you buy one.

Cameras come in all shapes and sizes and so do the lenses that they use. This means that by buying into one camera system, you're making a long-term commitment to the lenses that go with the camera you selected.

For instance, Fujifilm uses X-mount for its modern mirrorless APS-C cameras, while Canon uses EF-mount for its full-frame DSLRs.

The good news is that despite the different sizes and shapes of the mounts, most modern cameras and lenses use the same mounting mechanism—the bayonet-style—where lenses align to camera bodies using a marker and then twist to lock into place.

The bad news is that despite having the same mounting mechanism, the size and shape of these mounts still vary, making swapping lenses between different manufacturers impossible.

Well, luckily enough, some very intelligent and economical bunch have taken it upon themselves to create adapters that bridge the interface of cameras with lenses from different manufacturers. It's not without some caveats, however.

Lens mount adapters are tools that bridge the interface between different types of camera body types to lenses from different manufacturers. Depending on the level of complexity and cost of the lens mount adapter, you may or may not be able to take full advantage of all the original features of the lens when adapting to a different camera body.

Speed Boosters are lens adapters from a company called Metabones that are similar to lens mount adapters in that they allow you to adapt different lens types to different camera bodies. However, Speed Boosters add a lens element that changes or adapts the image size from the original lens to match the camera sensor it's being used with.

Some Speed Boosters can also adjust the aperture of the lens by changing the lens speed or amount of light that travels through the lens when the shutter is opened.

When looking for a lens mount adapter, including Speed Boosters, one of the first things you need to consider is which lens you want to adapt to which camera. You can then narrow down the adapters by the features that are important to you and which adapter best bridges the lens to the camera body to produce the best images.

There are plenty of great camera lenses for all types of photography with useful features built into them, like autofocus and auto exposure, that can help users get the best possible shot. This is possible because modern lenses have pins that interface with camera bodies, allowing them to talk to each other, sharing information needed to make those auto adjustments.

If having the autofocus feature is important to you, for example, look for mount adapters or Speed Boosters that support the function using pass-through pins that can send relevant autofocus information to the camera body from the lens.

One thing to note here, though basic autofocus features may work, certain types of advanced autofocus features (including autofocus for video recording or continuous autofocus) may not work with the specific cameras you want to use the adapters with.

Although beauty is in the eye of the beholder, using the right camera and lenses plays a big part in the quality of the image that's produced. But no matter how good your equipment is, you’ll still be dealing with some image degradation or distortion because all camera and lens systems have their flaws—no matter how minuscule.

This gets exacerbated when combined with a low-quality lens mount adapter. Here are some issues you might run into.

Vignetting is the gradual darkening of an image towards the corners as a result of the light diminishing over distance as it travels from the center out. This occurs naturally due to how lenses focus light in a middle focal point before spreading outward, hitting the sensor of the camera (or film in the case of film cameras).

When it occurs naturally from the lens, it shows up as a subtle, gradual effect that some consider pleasing. In fact, vignetting is often used in post-production to add a dramatic effect or focus on the main character. If done as a result of an equipment error, however, this can result in harsh, dark corners.

Make sure the lens mount adapter you pick does not introduce more vignetting from light bleed or imprecise opening size. You can do this by checking the inside diameter of your camera's lens mount and making sure the lens mount adapter will match it perfectly.

Some lens mount adapters just normalize the different mountings among the manufacturers and not much else. The upside to these types of adapters is that they are often cheap. The downside is that they leave out features like the autofocus and auto exposure previously mentioned.

Worse still, some of these cheap mounts can introduce more image degradation like reduced sharpness and distortion. This happens because each lens type is designed specifically to match the camera systems they are being used with. This includes important considerations like the distance from the lens to the camera sensor or flange focal distance (FFD).

An image comes into focus because light is focused through the lens at a particular angle and distance. When that's altered without being adapted for, the focal distance changes and the image takes a hit by losing sharpness.

Lens adapters that take FFD into account can be paired with an additional corrective lens adapter to ensure the angle and distance of the light hitting the sensor matches the way it was intended.

With Speed Boosters, this is less of an issue because the lens elements inside them are designed to work for specific cameras and lenses.

Chromatic aberration or color shifting happens when the lens doesn't properly refocus different wavelengths of light (RGB) back onto the same focal point. In photos, this shows up as colored outlines on the fringes of an object.

Similar to the vignetting, focus, and distortion, using lens mounts adapters that improperly adjust for FFD can introduce chromatic aberration in your photographs.

Find an adapter that accounts for this or ones that can be used with additional adapters to fix this issue. If chromatic aberration persists, photo editing software like Photoshop have simple tools to fix this in post.

Another thing to keep in mind is the possibility of degraded image quality as well as image cropping. Learning the basics of photography will teach you no matter what lens mount adapter you use, you’re introducing new elements between the lens and camera.

Whether that's added distance or a new lens element, the camera sensor will be receiving new light information different from the one the manufacturer originally intended with their proprietary lenses.

This could result in worse image quality or even cropped images. Using a lens mount adapter to use a full-frame camera lens on a camera with a smaller sensor, for example, will result in the complete loss of image data where the light goes beyond the sensor.

If you're in the market for a new camera, check out our top DSLR camera recommendations.

High-quality adapters are normally going to do a good job keeping the image intact, but image quality and cropping are some issues that can occur even with the best adapters.

For best results, do some research to make sure the adapters you want to use were specifically designed to work with your cameras and lenses. Of course, strong foundational photography skills will help you mitigate some problems you may run into or even help you fix them in post.