• Members 482 posts
    Feb. 19, 2024, 11:34 a.m.

    Looking through the viewfinder of my Olympus E-M1.3, with the eyepiece adjusted to suit my vision, the image is life-size when the focal length is somewhere around 35mm (70mm FF). This corresponds to an angle of view (diagonally) of about 34 degrees.

    I wonder if this is typical of modern digital cameras. At what focal length (FF equivalent) do you see a life-size image in the viewfinder of your camera?

    I have already posted this on dpreview, but this thread is for anyone who is not on dpreview and would like to contribute.

  • Members 293 posts
    Feb. 19, 2024, 1:06 p.m.

    What do you mean by "life-size?"

  • Members 482 posts
    Feb. 19, 2024, 1:24 p.m.

    If you keep both eyes open and look in the viewfinder with one eye and at the scene directly with the other eye, the image you see in the viewfinder is the same size as what you see with the other eye.

  • Feb. 19, 2024, 3:45 p.m.

    Around 50mm (so 75mm FF) on my X-T5. It's hard to be exact.

    Alan

  • Members 482 posts
    Feb. 19, 2024, 4:15 p.m.

    That's a nice wide angle, around 45 degrees by my calculation.

    Yes, Alan, it is surprisingly hard to be accurate! That's about the same as my E-M1.3.

  • Members 206 posts
    Feb. 19, 2024, 4:32 p.m.

    Viewfinder magnification is spec'd at 0.74 for the EM1.3
    70mm FF * 0.74 = 51.8 mm FF ("normal FL")

    BTW: Canon R6 is spec'd at 0.76x magnification.
    So the viewer 's individual eye has a significant part in this.

  • Members 300 posts
    Feb. 19, 2024, 4:33 p.m.

    In my Sony I can only magnify the viewfinder to 14x, not to life size.

  • Members 118 posts
    Feb. 19, 2024, 4:44 p.m.

    On my X-T4 it's 37.4mm (56mm in FF)
    Here's how I did it:
    - I have a 45mm x 30mm drawing plate (so 3 x 2 like the sensor).
    - I set the EVF to show 100% of the image.
    - With both eyes open, I moved the camera closer until the plate seen directly by my left eye filled the entire EVF seen by my right eye. At this point I covered the lens with my hand so that I couldn't see any image in the EVF, just some light. Even so, this is difficult because the images don't overlap, I suppose because of the parallax effect.
    - In this position, I uncovered the lens and adjusted the focal length until the image of the plate completely filled the EVF.
    - I took a shot and read the EXIF of the photo.

  • Members 118 posts
    Feb. 19, 2024, 5:41 p.m.

    I'm not an expert on the technicalities of cameras, but I think 75% means the EVF is only being used for 75% of its size. So the focal length found is 25% longer.
    In practical terms:
    50mm x 75% = 37.5mm
    37.5mm x 1.5 (crop factor) = 50mm 56,25mm in FF

    While looking through the EVF, press the display button to switch between 75% and 100%.

    As I've already said, I'm not an expert and I could be making a big mistake.😀

  • Feb. 19, 2024, 5:55 p.m.

    What do you mean by 75%? It's not something I mentioned

    Alan

  • Members 118 posts
    Feb. 19, 2024, 6:09 p.m.

    I made a reading error. You wrote 75 mm and I read 75%. I apologize.

  • Members 482 posts
    Feb. 19, 2024, 6:13 p.m.

    It's the diopter adjustment on the viewfinder that makes the difference, but I'm not sure how much.

  • Members 206 posts
    Feb. 19, 2024, 6:27 p.m.

    There are actually even more factors involved.
    e.g. inner-focused zooms reduce their effective FL when focused closer. Zoom ring markings and EXIF data show nominal FL if focused at infinity, not their true values when focused closer.

  • Members 482 posts
    Feb. 19, 2024, 6:44 p.m.

    Yes, of course! I should have made clear that the camera lens should be focussed at infinitely to eliminate these variations.

  • Foundation 1244 posts
    Feb. 19, 2024, 7:01 p.m.

    I was focussed on my computer screen. I cant see oo from my study window!

    David

  • Removed user
    Feb. 19, 2024, 7:56 p.m.

    Maybe 60 mm equiv. ... [edit] ... but I had a magnifier on the VF, so maybe not! [/edit]

  • Removed user
    Feb. 19, 2024, 8:42 p.m.

    What is the formula for 'angle of view' in this context, please?