Sony A6700 + Canon EF 135mm f/2L via MC-11: Sleeper Reach
The Canon EF 135mm f/2L USM is one of the most respected telephoto primes ever made and one of the few legacy lenses where the secondary market price has declined meaningfully as photographers have migrated to mirrorless systems and RF glass. Used copies trade in the $600–$750 range — less than they commanded five years ago, and substantially less than the optical quality warrants. The Sigma MC-11 adapter, which communicates the EF protocol to Sony E-mount bodies with high fidelity, adds approximately $199. On the Sony A6700, the EF 135mm f/2L becomes a 202mm equivalent at f/2 — a combination that exists nowhere else in the market at any price.
Two hundred millimeters at f/2. The implications take a moment to process. Background separation at portrait distances is absolute; subjects appear to be photographed in front of a painted flat, except that the blur has the quality of the L-series glass that produced it — smooth, without the nervous edge-defining artifacts that cheaper telephoto glass generates. At this effective focal length and aperture, the compressed perspective changes the feeling of faces: features flatten slightly in the aesthetically pleasing way associated with longer glass, and the rendering of the relationship between subject and environment approaches what editorial photographers spend significant money to achieve with full-frame telephoto primes.
The Sigma MC-11 adapter’s EF-to-E conversion is the most reliable cross-manufacturer electronic adapter available. Phase-detect autofocus passes through with sufficient fidelity to make the A6700’s subject tracking genuinely usable, though the EF 135mm’s ring USM motor is faster than what the MC-11 protocol can fully exploit. In practice: single-subject face and eye tracking works well in good light; continuous tracking of unpredictable motion pushes the system toward its limits. For portrait and editorial work — the obvious applications — the AF performance is acceptable. For fast action, native glass is the correct answer.
The EF 135mm f/2L on any camera is a physically substantial lens — 750 grams, with a front element that communicates serious intent. On the A6700’s compact body, balance is front-heavy but manageable, and the A6700’s grip is deeper than it looks in promotional images. A half-day shoot is not uncomfortable.
What makes this combination worth documenting is the math. A Sony A6700 (approximately $1,400 new), Sigma MC-11 ($199), and used Canon EF 135mm f/2L ($700) arrive at a combined investment under $2,300. The effective output — 202mm at f/2, with A6700-grade subject tracking — has no direct native-glass equivalent in any system at any price. It requires comfort with cross-brand adapting, acceptance of AF that is good but not native-great, and willingness to shoot a lens that belonged to the previous generation. In exchange, it delivers something genuinely unique.