How critical are eye piece covers?

[Ramsden]

Hello

Currently re-reading my EOS90D manual and user guide and came across a short paragraph on the eye piece cover. 

I haven't used this in almost 2 years - but as I continue to learn what this camera can do - I ask a basic question: is this a critical attachment for getting a good exposure. Any good examples welcome.

Ramsdeb

[kvbarkley]

Only if the camera is on a tripod. With a penta mirror, stray light can enter through the eyepiece and affect the exposure. What kind of shooting do you anticipate this to be an issue?

[Ramsden]

Hi 

I just read about it being a general issue, letting more light into the camera and thought Id better investigate further. I work hard and practice quite a lot to master the exposure triangle and depth of field, so I'm going to start using it straight away and see how it goes.  I feel a little bit annoyed with myself for not using it earlier. 

Re photography: wildlife, landscape and a lot of railway stock and architecture.

I can't remember if Canon put a note in when I bought the camera - but its threaded through the small strap that came along with it.

Thanks

Ramsdsn

[jrhoffman75]

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@Ramsden wrote:

Hello

Currently re-reading my EOS90D manual and user guide and came across a short paragraph on the eye piece cover. 

I haven't used this in almost 2 years - but as I continue to learn what this camera can do - I ask a basic question: is this a critical attachment for getting a good exposure. Any good examples welcome.

Ramsdeb

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Daylight photography where you would not have your eye to the viewfinder, like using a remote release or time lapse for example. 

[Ramsden]

Thanks John

[Waddizzle]

Consider this. This diagram is of a film SLR camera. In a DSLR, the metering sensor is located at the top of the viewfinder, just above the pentaprism, (7). 

See the spot where light is being reflected between the (7) and (8)?  Other items sre the focusing screen (5) and a focusing lens (6) exclusively for the viewfinder.

 

[Ramsden · Accepted solution]

Hi Waddizle

That’s a really useful diagram and I’m certainly in the park for explanations like this. I now have the small camera strap with the gadget attached fastened to my camera. As I said earlier, I’m just bemused with myself for taking 2 yrs to find this. When the camera arrived, I immediately bought a more substantial strap, and this one stayed in the cupboard.

Ive just checked the small Getting Started book that came with the camera, and there’s no mention of it in there.

Thanks as ever for your help as ever. 

Very much appreciated.

Ramsden

[Ramsden]

Last word… P157 in the big manual. 

[kvbarkley]

My understanding is that this is not an issue with the penta prism as shown. Only the cheaper penta mirrors have this issue. 

[jrhoffman75]

The 1D series have a lever actuated curtain to close the eyepiece.