6 Mounts in a Trenchcoat

This month for Adapt Club, we're talking about our favorite mounts. And while I want to bring The Canon EF mount in particular, it's because it opens the door to other mounts.

Flange focal distance continues to be the biggest challenge for lens adapting. Medium format seldom runs into issues because of how long their flange focal distances tend to be (for a DSLR mount), but a lot of vintage lenses from SLR systems need an internal glass element to allow for infinity focus. For those in search of the highest levels of optical fidelity, the glass elements are a no-go, and it's a common solution to make the jump to mirrorless cameras.

But that path is not always inevitable.

Some systems do have longer flange focal distances longer than the Canon EF's system, which is 44mm. And if there's space for an adapter, you can count on us offering it! All have their pros and cons, so I'll categorize the adapters by things they share in common:

Nikon F and Pentax K

These two mounts are the most popular of our glassless adapters for Canon EF. Vintage Nikon and Pentax glass can be found on most secondhand marketplaces, as well as with a variety of third-party options as well. Though not limited to these two adapters, the narrow space between the two systems doesn't allow for a whole lot of room for a release mechanism, so a more conventional way to release the lens won't be found on these two. Instead, there are dedicated latches and levers to remove the lens:

Given that the unmounting and remounting can be tricky, some users opt to just have an adapter for each lens, but if you have a larger collection, that adds up very quickly.

The Pentax K adapter is also unfortunately designed for APS-C cameras only. The longer aperture arms of the Pentax K lenses can interfere with the mirror reflex when taking pictures, so sometimes you'll find that a frame is only half-exposed, and because of the placement of the bayonet flanges, the Pentax K lens will have a slight rotational offset.

The Nikon F and Pentax K mounts are also lucky to be one of the few mounts where the lenses had multiple generations of advancement. The original film lenses will work fine with our adapters for EF, but once you get the more modern glass (designed without a physical aperture arm), you'll bump into functionality concerns. For example, the Nikon G-type lenses default to the narrowest aperture value when not coupled to an aperture mechanism, so you'd need an adapter like this to use your aperture with the G-type lenses.

Contax/Yashica

The Contax/Yashica mount is similar to the Pentax K and Nikon F adapters in that it doesn't have a release mechanism similar to a CY-mount camera. It's another latch:

Anecdotally, it does seem that there are less third-party options for this mount, though that may not be the case in reality. The beauty of this mount is that it never reached the digital age, so there's no issue of compatibility or the possibility of a lens without an aperture ring.

M42 screw mount

The M42 mount is another one of our more popular slim adapters for the Canon EF system. There are two major types of M42 lens adapters, and it really all depends on how the lens functions. What we call V1 is just a standard M42 thread (42mm x 1mm); the V2 has an extra flange that's meant to push down on a lenses aperture pin:

For a lens like this, you could turn the aperture ring all you want, and it wouldn't stop down to your desired aperture value until this pin is pushed down. The flange on the V2 adapters remedies this issue, at least.

One gripe I have is really more of a quality-of-life thing, really. Most systems use a bayonet fit, so a simple line-up-and-twist movement for mounting is so much more convenient (to me, at least), than turning until the lens hits the right amount of resistance. Alternatively, one quirk of some M42 adapters is that the top of the lens doesn't always align with the top of the camera, so the aperture settings/focus ranges may not be visible from the user's point of view. M42 adapters for mirrorless cameras can have that rotation adjusted, but for the EF system, that orientation is not movable.

Leica R

Leica's DSLR R-mount lenses are already have better handling than the adapters above. It has a dedicated release, so the adapter can basically live on your camera if you need to switch between Leica R lenses. This adapter is great if you've already amassed a good deal of lenses in the system or are just looking to adapt your old glass, but third party options are few (if existent at all, even).

Olympus OM

It doesn't get easier than the Olympus OM mount. The adapter is slim, glassless, and doesn't need its own release method, since the release button is on the Olympus OM lenses.

Why does it matter?

I think it's easy to dismiss DSLR systems as relics from a bygone era, but that's just not true. Plenty of older DLSR cameras are still beloved to this day, and even adapting is not impossible for them despite plenty of adapters requiring the built-in glass? In future posts, we'd love to see what sort of effects one can expect from the glass elements, but the point of this one is to highlight how one mount (and its compatible adapters) can open up new possibilities.

Double adapting was a staple when we initially launched our adapters for the L-mount. The offerings were few, and one of the only adapters we offered was our adapter for Canon EF. Thanks to the slimmer adapters for the Canon EF system, this opened up some different lens avenues for our L-mount shooters.

Specialty Adapters

If you shoot on a mirrorless system, you might be a fan our specialty adapters, such as ND Throttle, TLT ROKR, DLX Stretch, RhinoCam Vertex, and more. Some of them add up very quickly if you have multiple mounts, but if you get the Canon EF version of any of these specialty adapters, the mounts featured in this article are generally also compatible!