About lensmount — a neutral cross-brand camera-mount adapter reference

lensmount is a cross-brand camera lens-mount and adapter compatibility reference. Every common DSLR ↔ mirrorless and rangefinder ↔ mirrorless adaptation path is mapped here, with flange focal distance, autofocus level, image stabilisation pass-through, aperture-control method, infinity-focus feasibility, and crop factor surfaced for each combination.

Why this site exists

The search-engine top ten for queries like “canon ef to rf adapter autofocus” or “sony a mount to e mount adapter” is dominated by camera-manufacturer own-brand pages, commerce listings, and brand-by-brand blog posts. None of them ship a neutral, scannable matrix that answers the user's real question: “I have this body and these lenses — what's the best adapter and what do I lose?” lensmount fills that gap.

How the data is built

Each compatibility cell is computed from the two mounts' flange focal distances and electronic protocols. The feasibility rule is straightforward: a mechanical adapter needs at least 2 mm of flange clearance; a focal-reducer (Speed Booster) can correct up to ~12 mm of flange deficit; mirrorless lenses cannot be mounted onto DSLR bodies because the rear element collides with the mirror box. On top of the computed base, curated overrides layer in documented smart-adapter SKUs — Canon EF-EOS R, Nikon FTZ II, Sony LA-EA5, Sigma MC-11 / MC-21, Metabones, Viltrox, Fringer EF-FX and EF-GFX, Voigtländer M-mount, Techart LM-EA9, and others.

What we don't do

• No affiliate links. Adapter SKUs are named for reference. lensmount earns nothing from your purchase.
• No buy buttons. Verify availability and current pricing on the manufacturer or your retailer of choice.
• No vendor sponsorship.No adapter maker pays to influence what this site shows. If a vendor's SKU is omitted, it's because we couldn't verify the compatibility claim from public documentation — not because of a commercial relationship.

API access

Every cell in the matrix is also reachable as JSON. Pass the lens-side mount id and the body-side mount id as query parameters, and the response carries the same feasibility, autofocus, image-stabilisation, aperture-control, infinity-focus, adapter SKU list, caveats, and format-mismatch warning that the visible page surfaces. No auth, no sign-up, no rate limit at low volume.

See the full API documentation for the endpoint signature, the complete list of 27 accepted mount ids, the response schema (every field typed and described), and the two error shapes (400 / 404). One quick example — Canon EF lens on a Canon RF body:

curl 'https://lensmount.hk2.ai/api/compat?lens=canon-ef&body=canon-rf'

Contact

Spot an error, see a missing SKU, or want a mount added? The contact page lists the three email addresses we route to — adapter-data corrections, press and general enquiries, and privacy / data requests.