A Look at the Uniquely Useful Canon Drop-in Filter Adapter

One of the most annoying aspects of using front-mounted circular filters is that there are many different common sizes, which can quickly add up in cost and make you carry around a bag with a bunch of different filters. Canon's unique Drop-In Filter EF-EOS R Mount Adapter solves that issue, allowing you to use a single ND or polarizing filter with any EF lens. This excellent video review takes a look at how it holds up in the real world.

Coming to you from Deaf Director, this great video review takes a look at the Canon Drop-In Filter EF-EOS R Mount Adapter. This adapter is quite neat, as a lot of Canon users who have switched to the RF mirrorless system still use large libraries of EF lenses via adapters. Autofocus performance via such adapters has generally been quite strong or even above that of a DSLR, but the drop-in adapter takes it a step further, allowing the ability to put a polarizing or variable ND filter in between the lens and the body, making it both far easier and more cost-effective if you have a variety of lenses that require different filter sizes. Check out the video above for the full rundown. 

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Alex Cooke is a Cleveland-based portrait, events, and landscape photographer. He holds an M.S. in Applied Mathematics and a doctorate in Music Composition. He is also an avid equestrian.

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9 Comments

The idea is great, but the VND filter itself is horrible. It's ok for a few stops and then it turns blue, and the adjustment wheel is extremely easy to move just by touching it. There is also no stop marks on the wheel which makes the adjustments absolutely unpredictable. I have it and I hate it.

I appreciate your input. Perhaps a third party will design a better drop-in.

It´s such a good idea but so expensive... Can anybody tell me why it is not possible to just darken the sensor digitally? Something like a negative ISO? So physical ND Filters would´nt be needed anymore

Because ND and CPL are part of optical physics. In case of ND, You have to reduce the light coming to the sensor since tthe sensor itself iis like a bucket that collect light.

Totally sure! That´s how ND Filters work and I use them a lot. I was just wondering why it seems like it is not possible to make the sensor itself less sensitive than the usual ISO100. So ND Filters would become unnessecary... I guess there might be technical issues

I have two of these adapters. One lives permanently attached to my portrait fast prime (slow the lens while wide open in strong day light) and the second one for the wide angle zoom (long exposures under any light condition). It is by far the most user friendly implementation of filter use I have experience. I have used thread to the lens and magnetic mounts too over the past 20 years. The use of these adapters is the primary reason I would not consider upgrading those 2 lenses to native RF. I absolutely love them.

Canon should make this electronically adjust automatically in their next version.

Very innovative idea.

Major concern is dust might get inside the sensor when switching them in dusty or moist environment but so does when switching lenses anyway. Just my two cents :)