Silly question about mirrorless systems

Discussion in 'Mirrorless Digital Cameras' started by MeDaZzA, Mar 1, 2018.

  1. Hi everyone

    I've used DSLR cameras for a long time but thinking of going mirrorless. However I have a question that I've never seen covered.

    The minimum focus distance of the eye varies but is around 25cm give or take (I think mine is higher than this). How then can the eye focus on an EVF in cameras that are smaller than this and with the EVF closer than this? Is it a problem in practice?

  2. SCL


    The answer, of course, is optics which allow one to focus on a screen which is much closer to the eye. Think of a magnifying glass. If it was a problem the cameras wouldn't have sold, but obviously it isn't a [rpblem
  3. There is a diopter adjustment. Like looking at a HDTV screen.
  4. Keep in mind that, when you use the viewfinder of your DSLR, you look at a screen which is also rather close to you, even if the path is lengthened somewhat by the pentaprism.
  5. Eyes' minimum focusing distance degrades with age. - Mine was significantly smaller during elementary school days; I almost didn't understand why people owned magnifying glasses back then. These days I'd wear reading glasses under my dark cloth and should probably wonder if I could focus a Graflex without them.
    Anyhow, just like old slide viewing devices everything tiny in photography comes with an optics system in front of it. be it WLFs with their flip in loupes to permit focusing screen viewing from an image width's distance or the already mentioned pentaprisms that place the screen virtually 1m away or EVFs. - If you look at an ancient video camera you might see an option to remove these optics from it's EVF. - Don't ask me why it is there. Like modern (D)SLRs mirrorless' EVFs provide a pretty huge diopter adjustment range.
    What they all are IMHO lacking is a collapsible hood with flip in loupe for their rear screens. There are aftermarket chimneys for those which might be worth getting. Beware of the cheapest Chinese ones; their optics distort a lot and the little iron frame, to be glued to your rear screen, is unlikely to stay in it's place for long. - The hood attaches to it via too strong for the glue magnets.
  6. Great answers, thank you everyone. Probably going with a new A7 III!
  7. Optics in the EVF place the plane of focus at about 1 meter, give or take. In addition most have a diopter adjustment, typically ranging from -2 to +3. With this adjustment on my Sony A9 and A7R2, I can use the viewfinder without glasses, or either my distance or reading prescription.

    Eually important is the eye relief distance. The longer the distance, the more likely you can see the entire field of view while wearing glasses. The range is typically from about 13 mm to 25 mm. The A9 is 23 mm, and I can see the entire frame while wearing glasses.

    It is hard to see the rear screen in daylight. A special loupe with 1x magnification allows you to hold the camera up to your eye and shield the screen from ambient light. If it can be fastened in some way to the camera (straps or elastic), it can be used with cameras which don't have an EVF, rather rely on the rear screen for viewing and focusing. A coupe used for viewing film has too much magnification, 3x to 6x, for use with an LCD screen. They magnify the pixels, obscuring the overall image clarity.

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