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Keep the lens cap on after you turn the camera off


That's what it says when I turn off my R5. Problem is, the two lenses I am most likely to use with the camera are the 100mm macro and the 180mm macro. Both have the Canon Ring Lite flange attached, and there is no lens cap that fits the flange. I am loath to remove the flanges due to the possibbility of misplacing them. Advice? Thanks!



I haven't dealt with mirrorless yet but I suspect that caution is to protect the sensor since it isn't protected by a mirror in front of it like a DSLR and could be damaged by a strong light source even when the camera isn't powered up.  I am surprised they don't design in an internal cover that flips into place when the power is off to prevent light/laser etc. from hitting the fragile image sensor.


You could use a lens "hoodie" which fits somewhat like the old style lens covers for the earlier great white primes, it is just a cloth "sack" that covers the lens which snugs up via a drawstring and doesn't need to clamp to anything.  I have EF 100 2.8 IS and EF 180 Macro lens also and I really don't care for the Canon macro flash adapter design.  Most of their accessories are well thought out from a human factors/ergonomics standpoint but that isn't true of those two adapters.



EOS 1DX M3, 1DX M2, 1DX, 5DS R, M6 Mark II, 1D M2, EOS 650 (film), many lenses, XF400 video


Thanks to all for taking time to reply! OK, as I suspected, I shouldn't aim the camera at the sun. I haven't accidentally done that in the 54 years that I have been making pictures, so I'm scratching the lens-cap warning off my list of things to worry about.

You are welcome and I am with you about not aiming at the sun in all my years of photography.  However the image sensor is more sensitive than a mirror so the caution makes sense especially for people new to photography. 


This constantly exposed sensor worries me a little because I shoot sports with two or three bodies at a time so inadvertent aiming at the sun with a camera not in use is a possibility.  I assume you need to exercise the same level of caution with a mirrorless that you would with a camcorder which is effectively a mirrorless setup.


I do wish Canon had designed a better flash mount system for the EF 180 which is a wonderful lens.



EOS 1DX M3, 1DX M2, 1DX, 5DS R, M6 Mark II, 1D M2, EOS 650 (film), many lenses, XF400 video

I thought one of the features or the Canon R series was that they did have a shutter, which helps to protect the sensor. I believe that you can burn a hole in the shutter by pointing a lens at the sun.

It does look like its mechanical shutter defaults to a "shut" position with the camera turned off looking at the Lens Rental teardown of the R5 which makes sense but maybe it is mode dependent?  Based upon that I don't know why this lens cover caution appears in the R5 manual. 


Any shutter or mirror assembly could be damaged by strong sun exposure through a lens so I am not sure why Canon feels the need to make the statement in the R5 manual unless it is related to cooling.  A black heat absorbing shutter is probably more prone to damage than a mirror (change in metal clearance due to expansion) so maybe that is the reason.


Canon knows the reason but they probably won't disclose 🙂



EOS 1DX M3, 1DX M2, 1DX, 5DS R, M6 Mark II, 1D M2, EOS 650 (film), many lenses, XF400 video


Incidentally, I remember the days when I would photograph the sun with a Topcon RE Super on a Questar 89mm telescope with no filter. I used what was known as the "hat trick." Hold a hat or other light blocker in front of the telescope objective, remove it, snap the shutter immediately, and immediately cover the objective again. Never had a probblem.

There is a shutter so the sensor isn't exposed.  I can't see a Sun ever burining a hole in the shutter unless you leave it exposed to the Sun for an extended period. I would guess and this is just a guess it has to do with the AF sensors that are always fully exposed.  I don't own a mirrorless so this is just, as I say, a guess.

EOS 1DX and 1D Mk IV and several lenses!

The R5 has DPAF, which means that the AF sensors are on the sensor itself.


As an aside, I believe that this is what causes the issue in the "blue line in my image" thread, for some reason the DPAF sites are showing up in the RAW data.


Up until today, I got the warning to leave the lens cap on when I turned the camera off. Today, the warning disappeared, but the sensor cleaning message still appeared. I put the lens cap on when I need to protect the lens and otherwise use a lens hood and keep the lens pointed down and away from light. 


Maybe the camera gave up teling me to do what I wasn't going to do. They are very smart.