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Mirror Position Affects Image Aspect Ratio - EOS 70D

rpmelvin
Apprentice

I’m shooting a copy stand project of thousands of pages from an old diary. You can see examples of this work HERE.

I’m using the remote app so I can trigger the shutter with my phone. That app provides the option of shooting with the mirror up or down. I have the camera set to shoot in the 4x3 aspect ratio, because that best fits the diary pages I am shooting.

If I shoot with the mirror up, I get a 4x3 image at 2432x1824 pixels, which is exactly what I want. However, if I set the camera to shoot with the mirror down, I get an image with 2736x1824 pixels. This is not 4x3, nor is it 16x9. It's somewhere in between.

Why is this happening?

Is this something I can prevent?

1 ACCEPTED SOLUTION

rpmelvin
Apprentice

Well how about that! I missed that almost hidden statement in the manual. That certainly describes exactly what’s going on here.

Thanks, Ricky. We can consider this one solved!

View solution in original post

5 REPLIES 5

SamanthaW
Moderator
Moderator

Hi!

To have a better understanding of your issue, please let everyone know the model of camera you have.

If this is a time-sensitive matter, please check out your other support options here.

Thanks!

rpmelvin
Apprentice

Sorry, I thought I had it in my profile, but I don't. It's an EOS70D.

rs-eos
Authority

According to the User Manual (see page 181), when you're using Live View shooting, the aspect ratio will be fixed at 3:2. I believe when you shoot with the mirror up, that will use this same ratio as Live View.

--
Ricky

EOS 5D IV, EF 50mm f/1.2L, EF 135mm f/2L, 600EX-RT (x6), ST-E3-RT
EOS C70, RF 24-70 f/2.8L IS, EF-EOS R 0.71x

rpmelvin
Apprentice

Well how about that! I missed that almost hidden statement in the manual. That certainly describes exactly what’s going on here.

Thanks, Ricky. We can consider this one solved!

rpmelvin
Apprentice

Actually, it is not solved. Upon re-reading this, I realized that my camera is bahving exactly backwards from what the book says.

If I shoot with the mirror UP (Live View on the screen) I get a properly sized 4x3 image at 2432 x 1824 pixels.

If I shoot with the mirror DOWN (view through the viewfinder) I get a 3x2 image at 2736 x 1824 pixels.

For my purposes it no longer matters because I know what to do to get consistently sized images. However, it seems strange that the camera is doing exactly opposite of what the book says it should do.

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