The 15-45 switch.

why do lenses with the EF adapter require the lens cap when turning the camera off, but native lenses don’t?

Jayson A wrote:

why do lenses with the EF adapter require the lens cap when turning the camera off, but native lenses don’t?

What???

nnowak wrote:

Jayson A wrote:

why do lenses with the EF adapter require the lens cap when turning the camera off, but native lenses don’t?

What???

Every time I turn my camera off with an EF or EF-S lens on, it says "Keep the Lens Cap On after Camera is Off", but native lenses don't say that. The camera just shuts off normally. I thought the sensor is aways exposed whether you have the camera off or on since there's no mirror covering it. So why is it important to keep the lens cap on when an EF or EF-S lens is attached vs a native EF-M lens?

Jayson A wrote:

nnowak wrote:

Jayson A wrote:

why do lenses with the EF adapter require the lens cap when turning the camera off, but native lenses don’t?

What???

Every time I turn my camera off with an EF or EF-S lens on, it says "Keep the Lens Cap On after Camera is Off", but native lenses don't say that. The camera just shuts off normally. I thought the sensor is aways exposed whether you have the camera off or on since there's no mirror covering it. So why is it important to keep the lens cap on when an EF or EF-S lens is attached vs a native EF-M lens?

I noticed this myself recently. It shows the message with just the mount adapter, no lens.

Jayson A wrote:

nnowak wrote:

Jayson A wrote:

why do lenses with the EF adapter require the lens cap when turning the camera off, but native lenses don’t?

What???

Every time I turn my camera off with an EF or EF-S lens on, it says "Keep the Lens Cap On after Camera is Off", but native lenses don't say that. The camera just shuts off normally. I thought the sensor is aways exposed whether you have the camera off or on since there's no mirror covering it. So why is it important to keep the lens cap on when an EF or EF-S lens is attached vs a native EF-M lens?

Never noticed that before.

My guess it is due to the difference in aperture mechanisms.  The EF-M lenses stop down to the smallest aperture when powered down. EF and EF-S lenses are wide open when powered off.

Apparently Canon must be seeing a rash of people starting their mirrorless cameras on fire by mounting giant telephoto lenses and leaving the camera pointed at the sun while sitting on the dash of their car in Arizona in July.

nnowak wrote:

Jayson A wrote:

nnowak wrote:

Jayson A wrote:

why do lenses with the EF adapter require the lens cap when turning the camera off, but native lenses don’t?

What???

Every time I turn my camera off with an EF or EF-S lens on, it says "Keep the Lens Cap On after Camera is Off", but native lenses don't say that. The camera just shuts off normally. I thought the sensor is aways exposed whether you have the camera off or on since there's no mirror covering it. So why is it important to keep the lens cap on when an EF or EF-S lens is attached vs a native EF-M lens?

Never noticed that before.

My guess it is due to the difference in aperture mechanisms. The EF-M lenses stop down to the smallest aperture when powered down. EF and EF-S lenses are wide open when powered off.

Apparently Canon must be seeing a rash of people starting their mirrorless cameras on fire by mounting giant telephoto lenses and leaving the camera pointed at the sun while sitting on the dash of their car in Arizona in July.

You're closer to the equator than Arizona is. It was a standard warning / precaution for cameras with focal plane shutters in the days before instant-return mirrors and with rangefinder cameras.

EF and EF-S lenses open up to maximum aperture when the camera is switched off so that you can still see through the viewfinder. RF and EF-M lenses stop down to near minimum aperture without power. The Retract lens on power off menu option refocusses them to near infinity. There have been a couple of threads in the RF forum about unexpected melting damage to the plastic surround to the sensor.

In answer to your first question, it doesn't matter about retracting your lens when not using it, provided you're careful with it. The locking mechanism protects it somewhat from being broken by bumps. I always cap and lock my lenses (or zoom my 18-55mm to 18mm) before climbing around things, just as I always fasten my seat belt, it only takes seconds and it's a safe habit to get into.

nnowak wrote:

Jayson A wrote:

nnowak wrote:

Jayson A wrote:

why do lenses with the EF adapter require the lens cap when turning the camera off, but native lenses don’t?

What???

Every time I turn my camera off with an EF or EF-S lens on, it says "Keep the Lens Cap On after Camera is Off", but native lenses don't say that. The camera just shuts off normally. I thought the sensor is aways exposed whether you have the camera off or on since there's no mirror covering it. So why is it important to keep the lens cap on when an EF or EF-S lens is attached vs a native EF-M lens?

Never noticed that before.

My guess it is due to the difference in aperture mechanisms. The EF-M lenses stop down to the smallest aperture when powered down. EF and EF-S lenses are wide open when powered off.

Apparently Canon must be seeing a rash of people starting their mirrorless cameras on fire by mounting giant telephoto lenses and leaving the camera pointed at the sun while sitting on the dash of their car in Arizona in July.

Correct me if I'm wrong, but wouldn't stopping down create a smaller pin of light if your camera is facing the sun, causing more damage than a large amount of light evenly spread over the whole sensor?

I just don't see how stopping down is safer than wide open.

Jayson A wrote:

nnowak wrote:

Jayson A wrote:

nnowak wrote:

Jayson A wrote:

why do lenses with the EF adapter require the lens cap when turning the camera off, but native lenses don’t?

What???

Every time I turn my camera off with an EF or EF-S lens on, it says "Keep the Lens Cap On after Camera is Off", but native lenses don't say that. The camera just shuts off normally. I thought the sensor is aways exposed whether you have the camera off or on since there's no mirror covering it. So why is it important to keep the lens cap on when an EF or EF-S lens is attached vs a native EF-M lens?

Never noticed that before.

My guess it is due to the difference in aperture mechanisms. The EF-M lenses stop down to the smallest aperture when powered down. EF and EF-S lenses are wide open when powered off.

Apparently Canon must be seeing a rash of people starting their mirrorless cameras on fire by mounting giant telephoto lenses and leaving the camera pointed at the sun while sitting on the dash of their car in Arizona in July.

Correct me if I'm wrong, but wouldn't stopping down create a smaller pin of light if your camera is facing the sun, causing more damage than a large amount of light evenly spread over the whole sensor?

I just don't see how stopping down is safer than wide open.

Stopping down 6 stops reduces the power by a factor of 64. That makes a huge difference if the lens is focussed at infinity. As it will probably be, by Sod's Law, or if you have the Retract lens on power off menu option enabled.

If you have managed to leave the lens at minimum focus, opening up 6 stops increases the size of the bokeh circle from a point source by a multiple of 8, so it increases its area by a multiple of 64. It also increases the power by a factor of 64. That means the intensity of the light within the bokeh circle from a point source should in theory be constant. In practice, the Sun isn't a point source, and the bokeh circle isn't a uniform brightness, so there's definitely an advantage to stopping down.