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EF-M lens on EOS Rebel T7 body

NyxisaNoodle
Apprentice

Hello All,

I am relatively new to macrophotography and currently own an EOS Rebel T7. I would like to use a Laowa 65mm f/2.8 2x Ultra Macro lens with a Canon EF-M mount, which seems to be incompatible with the T7. Is there an adapter that would allow for this lens to be used on my T7? 

 Thank you for any and all advice.

 

Cheers,

Nyx 

1 ACCEPTED SOLUTION

amfoto1
Authority

The reason it's not possible is actually pretty simple...

Your T7 is a DSLR. It has a mirror inside that has to swing up out of the way to take a photo. For that reason, the "lens flange to focal plane (sensor surface)" of the camera is 44mm. This is the distance where the lens is designed to "back focus", measured from the bayonet mount flange of the camera to the front surface of the image sensor.

EF-M mount cameras are "mirrorless", have no mirror inside and as a result use a much shorter flange to focal plane distance. In fact, I think it's 18mm with EF-M cameras and lenses. As a result, an EF-M design lens would have to fit INSIDE a DSLR in order to focus upon the camera's sensor! That ain't gonna work!

Venus Laowa makes that 65mm Macro for Canon RF mount, too... but it has the same problem. It's designed for mirrorless, so uses a very short flange to focal plane distance (20mm, if I recall correctly). They also make that lens for Sony E-mount and Fuji X-mount.... both also mirrorless systems. Slightly different flange to focal plane distances, but the same problem.

So unless you want to take a hack saw to your T7 and cut roughly an inch off of it 😋, shop around for a lens actually designed for use on it instead (Canon EF or EF-S mount).

You might consider the Venus Laowa 100mm f/2.8 2X Ultra Macro. That's available in EF mount. Like the 65mm, it's a manual focus lens, it's able to give as much as 2X magnification, and it gets very good reviews. Unlike the 65mm, the 100mm has an electronically controlled aperture (i.e., just like other lenses on your T7, you set the aperture via the dials on the camera, or can let the camera choose the aperture with Av mode or P mode auto exposure). The 65mm has a strictly manually controlled aperture. Another advantage of the 100mm is that it's  aperture remains open until the actual exposure. A fully manual aperture like the 65mm's actually stops down as it's set and darkens your viewfinder. Small apertures, as are often wanted shooting macro, make for a very dim viewfinder and a lot of difficulty focusing. This is probably why the 65mm is only offered for mirrorless cameras (which have electronic viewfinders that can brighten up to compensate).

Frankly, I think you'll find 100mm a more broadly useful macro focal length, anyway. For many people it's a better compromise... giving more working distance between the front of the lens and subject, without being so long as to be difficult to hold steady (like 180mm or 200mm macro lenses).

***********


Alan Myers
San Jose, Calif., USA
"Walk softly and carry a big lens."
GEAR: 5DII, 7DII (x2), 7D(x2), EOS M5, some other cameras, various lenses & accessories
FLICKR

 

 

View solution in original post

3 REPLIES 3

normadel
Authority
Authority

No. EF-M lenses cannot be adapted to EF/EF-S bodies.

AtticusLake
Mentor
Mentor

Sorry, no adapter is possible from EF-M lenses to just about anything else, including EF and EF-S.  If you want to know why, I wrote an article about it: https://moonblink.info/MudLake/gear/lenses

amfoto1
Authority

The reason it's not possible is actually pretty simple...

Your T7 is a DSLR. It has a mirror inside that has to swing up out of the way to take a photo. For that reason, the "lens flange to focal plane (sensor surface)" of the camera is 44mm. This is the distance where the lens is designed to "back focus", measured from the bayonet mount flange of the camera to the front surface of the image sensor.

EF-M mount cameras are "mirrorless", have no mirror inside and as a result use a much shorter flange to focal plane distance. In fact, I think it's 18mm with EF-M cameras and lenses. As a result, an EF-M design lens would have to fit INSIDE a DSLR in order to focus upon the camera's sensor! That ain't gonna work!

Venus Laowa makes that 65mm Macro for Canon RF mount, too... but it has the same problem. It's designed for mirrorless, so uses a very short flange to focal plane distance (20mm, if I recall correctly). They also make that lens for Sony E-mount and Fuji X-mount.... both also mirrorless systems. Slightly different flange to focal plane distances, but the same problem.

So unless you want to take a hack saw to your T7 and cut roughly an inch off of it 😋, shop around for a lens actually designed for use on it instead (Canon EF or EF-S mount).

You might consider the Venus Laowa 100mm f/2.8 2X Ultra Macro. That's available in EF mount. Like the 65mm, it's a manual focus lens, it's able to give as much as 2X magnification, and it gets very good reviews. Unlike the 65mm, the 100mm has an electronically controlled aperture (i.e., just like other lenses on your T7, you set the aperture via the dials on the camera, or can let the camera choose the aperture with Av mode or P mode auto exposure). The 65mm has a strictly manually controlled aperture. Another advantage of the 100mm is that it's  aperture remains open until the actual exposure. A fully manual aperture like the 65mm's actually stops down as it's set and darkens your viewfinder. Small apertures, as are often wanted shooting macro, make for a very dim viewfinder and a lot of difficulty focusing. This is probably why the 65mm is only offered for mirrorless cameras (which have electronic viewfinders that can brighten up to compensate).

Frankly, I think you'll find 100mm a more broadly useful macro focal length, anyway. For many people it's a better compromise... giving more working distance between the front of the lens and subject, without being so long as to be difficult to hold steady (like 180mm or 200mm macro lenses).

***********


Alan Myers
San Jose, Calif., USA
"Walk softly and carry a big lens."
GEAR: 5DII, 7DII (x2), 7D(x2), EOS M5, some other cameras, various lenses & accessories
FLICKR

 

 

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