One of the best price/performance ratio and weight/performance ratio full frame cameras today is Canon EOS RP. In order to get the best price/performance ratio for lenses, one needs to use it with non-native EF mount lenses using the EF - EOS R adapter, for two reasons: (i) an equivalent lens for RF mount may not be available but an EF mount lens may be available, (ii) second-hand old versions of EF mount L lenses can be purchased relatively cheaply, whereas there are no old versions of RF lenses and the second-hand market for RF lenses hasn't established itself yet.

The EF - EOS R adapter is sold with Canon EOS RP in some kits, and also can be purchased separately.

However, most retailer images don't show the adapter with caps on both ends. This led me to wonder whether the adapter is sold with caps on both ends. If carried without caps in a camera bag, dust can get inside the adapter, thus giving the dust a direct path to the sensor that is not protected by a mirror or a mechanical default-closed shutter.

Do I need to purchase the caps separately for the adapter? Or is it sold with caps?

  • \$\begingroup\$ I think you’re blowing the dust (problem) way out of proportion here. \$\endgroup\$
    – OnBreak.
    Commented Jun 30, 2019 at 17:16

2 Answers 2


It's easy to see what comes with the Mount Adapter EF-EOS R at Canon USA's product listing.

Just scroll down and click on the "What's included" tab to see the following list:

enter image description here

The listings for the Control Ring Mount Adapter EF-EOS R, Drop-in Filter Mount Adapter EF-EOS R with Drop-in Circular Polarizing Filter A, and Drop-in Filter Mount Adapter EF-EOS R with Drop-in Variable ND Filter A, are similar.

Please Note: Camera Cover R-F-3 is the standard EOS EF camera body cover and has been so named since the EOS film era. It does not fit EOS R bodies. You need the Camera Cover R-F-5 for EOS RF mount cameras. In case anyone is curious, the Camera Cover R-F-4 is for EOS M cameras.


The answer is: caps do not need to be purchased separately, because the adapter comes with a cap attached to both ends in the sales package. Retailer pictures for some reason often don't show the caps (probably to show the internal parts of the adapter, or to avoid showing the true size of the adapter with caps attached).

Do remember that if using the EF - EOS R adapter, one has four caps that need to be carried somewhere:

  • EF lens rear cap
  • EF - EOS R adapter front cap (standard EF camera body cap)
  • EF - EOS R adapter rear cap (standard RF lens rear cap)
  • RF camera front cap

On the other hand, if using an EF mount camera with an EF mount lens, or an RF mount camera with an RF mount lens, there are only two caps to be carried:

  • Lens rear cap
  • Camera front cap
  • 1
    \$\begingroup\$ Nitpick: if you're using an RF camera only with EF lenses (using the EOS R adapter) and never take the adapter off the camera, then you still only need the EF camera and lens rear caps. \$\endgroup\$
    – scottbb
    Commented Jun 30, 2019 at 17:17
  • 1
    \$\begingroup\$ @scottbb further nitpick: leave a lens on the camera the whole time aaaaand never worry about the rear caps \$\endgroup\$
    – OnBreak.
    Commented Jun 30, 2019 at 18:41
  • 1
    \$\begingroup\$ @Hueco yeah, I was going to comment/add that only carry a body + rear cap pair when I carry around more than one lens, just in case I lose one in the shuffle of changing lenses. But if I only have one lens with me, then my camera ceases being ILC. =) \$\endgroup\$
    – scottbb
    Commented Jun 30, 2019 at 18:46
  • \$\begingroup\$ @scottbb yep. I generally remove all caps and prep all hoods on every lens in the bag before a gig. Lens swaps should be as fast as possible when in the action. Caps? Ain't no one got time for dat. \$\endgroup\$
    – OnBreak.
    Commented Jun 30, 2019 at 20:42
  • \$\begingroup\$ @Hueco I guess it all depends upon how many bodies/lenses one wishes to have with them. Sometimes the size limits of bags/cases require lenses and bodies to be stored separately in order to all fit inside. I don't have room in my bags to store any of my lenses with the hoods attached in shooting orientation rather than reversed (unless I'm willing to leave half the stuff I usually carry in them at home). \$\endgroup\$
    – Michael C
    Commented Jul 2, 2019 at 10:51

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.