Benro has announced The Aureole, “The First Detachable Multi-functional Filter Mount Adapter System”. It’s a lens adaptor and rear filter holder all in one (though at this stage we would like to point out that Canon already makes a similar EF-RF adaptor that takes drop-in filters).
Benro’s pitch seems to be that a lens adaptor is a much better place to put filters than on the front of the lens, saving both weight and bulk in the process. Adaptors like this only work, however, where you are using a lens with a long flange distance, e.g. a DSLR lens, on a mirrorless body with a shorter flange distance – there needs to be space to insert the adaptor between the lens and the body.
At the moment, Benro has announced two adapters – an RC1 Canon EF to RF adapter, and RE1 Canon EF to Sony FE adaptor, though it hints that more might follow. Both have slots at the top and the side to allow the insertion of Benro’s new filter range.
How the Benro Aureole works
The filter frame itself can accommodate a single round or square filter, two round filters or a square and a round filter. Benro mentions polarising filters, ND filters and ND grad filters, but has not so far mentioned variable NDs or indeed pricing for these filters.
We assume the ND filters can be slid up and down to adjust the transition point – the filters have a gear 'rack' in the frame – and CPL filters can be rotated by a knurled wheel. There is a 1/4-inch tripod screw socket in the base, which could be useful for balancing heavier lens combos more effectively, and we like the idea that filters can be inserted from the top or the side.
Benro is very keen to point out the weight and size saving of a system like this over conventional front-mounted filters, but we’re not so sure about sliding filters in and out BEHIND the lens – mirrorless cameras have enough sensor dust issues as it is, without giving dust an even better way to get in.
Other things you could add to a lens adapter
How about a leaf shutter for flash sync at any speed? No, we're serious! Or dual base and side tripod sockets to replace an L-bracket for vertical shooting? Or a set of rig mounting points for videographers (who also love mix'n'matching lenses via adaptors)?
What will it cost?
The Benro Aureole seems a pretty niche proposition. It only works for users who want to use Canon EF lenses on Canon RF or Sony FE bodies, and who are tempted by the idea of rear filters.
Maybe Benro thinks the same way, because the Benro Aureole website is a separate campaign page and not on the main site. We don’t know the launch date yet, but Benro is quoting a price of $249 – but with a special price of $180 if you sign up now.