Meike has announced the MK-EFTR-C Drop-in Filter Mount Adapter which allows for Canon EF and EF-S lenses to work with RF-mount cameras with aperture control and autofocus and image stabilization support along with the ability to use drop-in filters.
Kolari Vision has developed a filter that works with Canon's EF to RF adapter with support for drop-in filters that can add a swirly bokeh effect to any EF lens. This would theoretically let those who enjoy the unique bokeh of lenses like the Petzval 80.5mm or 55mm achieve that effect with any EF lens.
My name is Pierre-Louis Ferrer, and I am a professional French photographer specialized in infrared and ultraviolet photography for ten years now. I spend a large part of my free time experiencing and testing new filters and equipment to see behind the visible. My work is mostly divided between artistic photography, dermatologic photography for cosmetic brands, and infrared photography workshops in Paris.
Breakthrough Photography has just unveiled its own RF-to-EF adapter with a slot for drop-in filters: the first such adapter to hit the market from a third party, and a slightly more affordable alternative to Canon's own version.
Kolari Vision has just unveiled a line-up of high-end, ultra-rugged drop-in filters for Canon's special EF-to-RF mount adapter with a built-in filter slot. According to Kolari, not only are these the first third-party drop-in filters actually shipping to consumers, they're also some of the most durable and high-quality filters money can buy.
The filter maker Breakthrough Photography has just released the first third-party drop-in filters for Canon's popular EF-RF adapter, greatly increasing the number of options available to Canon EOS R, RP, R5, and R6 shooters who want to keep using their EF glass.
For telephoto lenses with huge front elements, screw-on filters aren't very practical or economical. Thus, for certain lenses, companies like Canon and Nikon offer drop-in filters that slide into a slot close to the rear element.
There's a new product that hopes to use this same style of filter for smaller camera-and-lens combos. Called OWL, it's the first drop-in filter adapter.