The Canon R100 is the least expensive entry point in the RF mirrorless system, and Canon has been reasonably candid about what corners were cut to get it there. No in-body stabilization. A single card slot. A relatively modest sensor at 24 megapixels. An electronic viewfinder that experienced photographers will find cramped. And yet, mated to a used EF 85mm f/1.8 USM via the Canon EF-EOS R adapter, it becomes one of the most compelling portrait setups available for under $700 combined.

The EF 100mm f/2.8 Macro USM — not the L version, the original — is the overlooked sibling of Canon’s more celebrated L-series macro. At used prices around $350, it delivers 1:1 macro reproduction with optical quality that the price differential does not adequately explain. Via the Canon EF-EOS R adapter on the R50, it becomes a 160mm equivalent macro lens with full electronic communication and a use case that extends well beyond close-up work.

The arithmetic of cropped sensors and telephoto glass is one of the more useful free lunches in photography. The Canon R7 — a serious APS-C body with genuinely professional-grade autofocus and a 32.5-megapixel sensor — transforms the EF 70-200mm f/4L into a 112–320mm equivalent. A zoom range that, on full frame, would require an expensive, heavier f/2.8 lens or a dedicated super-telephoto prime. Here it arrives via a quarter-century-old zoom that trades used for well under $600.

Telephoto zoom ownership typically involves a familiar trade negotiation: reach versus weight versus cost, with meaningful performance in all three simultaneously requiring a budget that narrows the market to professionals and committed enthusiasts. The Nikon Z50 II paired with a used Canon EF 70-300mm f/4-5.6 IS II via the Sigma MC-21 EF-to-Z adapter disrupts that negotiation in a way worth examining. The EF 70-300mm f/4-5.6 IS II is one of Canon’s most undervalued lenses.

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.