Question about viewfinder size

[snerkler]

Ok so I thought I knew what viewfinder specifications meant and that the magnification is how large the subject is, so for example a VF with 0.75x magnification would show the subject at 75% of the size compared to the naked eye, and 0.5x magnification would show the subject at 50% size compared to the naked eye. Therefore if both show 100% of the frame then obviously the 0.75x viewfinder would be physically larger (assuming same format).

Well I’ve just been looking at some specs for the Fuji cameras and the X-T3 has a 0.75x magnification EVF and the X100V a 0.66x magnification EVF so you’d expect the X-T3 to have a physically larger EVF. However, according to the specs they are both 0.5”, so what does this 0.5” refer to?

 

[Caerus]

Isnt that because the magnification figure on the x-t3 assumes a 50mm lens set to infinity to come up with the 0.75x figure. ( that is how they come up with it on cameras )

the x100v has a fixed lens so I imagine they then use its native 23mm to come up with the figure.

the focal length affects that figure therefore it is different for both cameras even though both are 0.5" in physical size.

im 95% sure that is the reason

 

[snerkler]

Isnt that because the magnification figure on the x-t3 assumes a 50mm lens set to infinity to come up with the 0.75x figure. ( that is how they come up with it on cameras )

the x100v has a fixed lens so I imagine they then use its native 23mm to come up with the figure.

the focal length affects that figure therefore it is different for both cameras even though both are 0.5" in physical size.

im 95% sure that is the reason

Thanks for your reply, both are quoted in terms of 50mm focal length on a 35mm/FF camera.

The only thing that differs is the eye relief, but I can't see why that would make a screen appear larger?

 

[Mr Perceptive]

The shorter the eye relief the less the projected magnification. I've even had the time to make a drawing!!!

 

[snerkler]

The shorter the eye relief the less the projected magnification. I've even had the time to make a drawing!!!

View attachment 268962

Thanks for this, so whilst the viewfinders are physically the same size the one with the larger eye relief will appear bigger? Why then does the image not appear bigger if you don't put your eye right up to the eyecup, ie artificially make the eye relief larger?

 

[Mr Perceptive]

Thanks for this, so whilst the viewfinders are physically the same size the one with the larger eye relief will appear bigger? Why then does the image not appear bigger if you don't put your eye right up to the eyecup, ie artificially make the eye relief larger?

if you move your eye further away then you don't get the whole EVF, The optics may be different for each camera model.

 

[snerkler]

if you move your eye further away then you don't get the whole EVF, The optics may be different for each camera model.

Yeah I know, but what I meant is that the bit you do see doesn't appear to be enlarged. No biggie, was just curious. At least you explained why two EVFs of the same physical size can appear different