Re: Why do DSLR's still use mirrors?

Discussion in 'Digital Photography' started by Don Stauffer, Nov 7, 2008.

  1. Don Stauffer

    Don Stauffer Guest

    Roger N. Clark (change username to rnclark) wrote:

    >
    > Why do DSLR's still use mirrors?


    Simple. If it didn't have a mirror (or surface that acts like a mirror)
    it wouldn't be a single lens REFLEX. The term reflex means it has a
    mirror in the viewfinding train. This is true film OR digital.

    Note that a "twin lens reflex" also generally has a 45 degree folding
    mirror also.
    Don Stauffer, Nov 7, 2008
    #1
    1. Advertising

  2. Don Stauffer

    dj_nme Guest

    Don Stauffer wrote:
    > Roger N. Clark (change username to rnclark) wrote:
    >
    >>
    >> Why do DSLR's still use mirrors?

    >
    > Simple. If it didn't have a mirror (or surface that acts like a mirror)
    > it wouldn't be a single lens REFLEX. The term reflex means it has a
    > mirror in the viewfinding train. This is true film OR digital.
    >
    > Note that a "twin lens reflex" also generally has a 45 degree folding
    > mirror also.


    The TLR (twin lens reflex) cameras which I've used or examined seem to
    have a fixed mirror in the viewfinder.
    It doesn't have to move out of the way, as does in a SLR camera.
    They may have a folding hood for the focus screen or an interchangeable
    viewfinder prism eyepiece or a peep-sight "sports finder" as accessories.
    dj_nme, Nov 8, 2008
    #2
    1. Advertising

  3. Don Stauffer

    Don Stauffer Guest

    dj_nme wrote:
    > Don Stauffer wrote:
    >> Roger N. Clark (change username to rnclark) wrote:
    >>
    >>>
    >>> Why do DSLR's still use mirrors?

    >>
    >> Simple. If it didn't have a mirror (or surface that acts like a
    >> mirror) it wouldn't be a single lens REFLEX. The term reflex means it
    >> has a mirror in the viewfinding train. This is true film OR digital.
    >>
    >> Note that a "twin lens reflex" also generally has a 45 degree folding
    >> mirror also.

    >
    > The TLR (twin lens reflex) cameras which I've used or examined seem to
    > have a fixed mirror in the viewfinder.
    > It doesn't have to move out of the way, as does in a SLR camera.
    > They may have a folding hood for the focus screen or an interchangeable
    > viewfinder prism eyepiece or a peep-sight "sports finder" as accessories.


    Yes indeed. That lens does not need to move, since it does not block
    the film/image chip area. The TLR preceded the SLR. The SLR mfgs had
    to come up with a reliable way to have the mirror flip up, and then
    return exactly to the same place it left (staying in alignment). And,
    at a price people could afford.
    Don Stauffer, Nov 8, 2008
    #3
  4. Don Stauffer

    dj_nme Guest

    Paul Furman wrote:
    > dj_nme wrote:
    >> Don Stauffer wrote:
    >>> Roger N. Clark (change username to rnclark) wrote:
    >>>
    >>>>
    >>>> Why do DSLR's still use mirrors?
    >>>
    >>> Simple. If it didn't have a mirror (or surface that acts like a
    >>> mirror) it wouldn't be a single lens REFLEX. The term reflex means
    >>> it has a mirror in the viewfinding train. This is true film OR digital.
    >>>
    >>> Note that a "twin lens reflex" also generally has a 45 degree folding
    >>> mirror also.

    >>
    >> The TLR (twin lens reflex) cameras which I've used or examined seem to
    >> have a fixed mirror in the viewfinder.
    >> It doesn't have to move out of the way, as does in a SLR camera.
    >> They may have a folding hood for the focus screen or an
    >> interchangeable viewfinder prism eyepiece or a peep-sight "sports
    >> finder" as accessories.

    >
    > Ah, that's what those are all about, thanks. Presumably they could use
    > cheaper optics in the viewfinder lens, or is it simply a duplicate lens?


    Keep in mind that TLR cameras almost exclusively use medium format
    roll-film.
    The really cheap end of the TLR camera market (EG: Kodak Duaflex) have a
    fixed non-focusing lens and a reflex viewfinder, sort of a "pretend" TLR
    camera.
    The serious-amateur/low-end-pro TLR cameras with a fixed lens (EG:
    Yashica Mat) tend to have a slightly faster viewfinder lens (EG: f1:3.2
    lens/f1:2.8 viewfinder) to exaggerate out of focus blur and make
    focusing easier.
    The top end of the market have interchangeable lenses and viewfinders,
    some even have accessory eye-level pentaprism finders and co-existed in
    the studio with medium-format SLR camera up until digital killed off
    most pro use of film.
    dj_nme, Nov 9, 2008
    #4
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Eric Stevens

    Re: Why do DSLR's still use mirrors?

    Eric Stevens, Nov 7, 2008, in forum: Digital Photography
    Replies:
    2
    Views:
    252
  2. Steve

    Re: Why do DSLR's still use mirrors?

    Steve, Nov 7, 2008, in forum: Digital Photography
    Replies:
    5
    Views:
    258
    David J Taylor
    Nov 8, 2008
  3. Jürgen Exner

    Re: Why do DSLR's still use mirrors?

    Jürgen Exner, Nov 7, 2008, in forum: Digital Photography
    Replies:
    28
    Views:
    812
  4. SMS

    Re: Why do DSLR's still use mirrors?

    SMS, Nov 7, 2008, in forum: Digital Photography
    Replies:
    5
    Views:
    287
    Me Here
    Nov 7, 2008
  5. RichA

    Why DSLR mirrors must eventually go

    RichA, Apr 21, 2009, in forum: Digital Photography
    Replies:
    46
    Views:
    1,275
    John A.
    Jul 31, 2009
Loading...

Share This Page