What does auto lens mean on legacy?

Discussion in 'Adapted Lenses' started by ke7dbx, Jul 20, 2011.

  1. ke7dbx

    ke7dbx Mu-43 Regular

    76
    May 11, 2011
    I have been wondering, what does auto mean on legacy lenses? I have seen auto zoom, auto lens etc. I know what this means on the modern electronic lenses but on the old legacy glass. I am just plain confused.
     
  2. "Auto" on an older lens can refer to the automatic stop-down function where a lens remains wide-open for focusing and framing and is stopped-downed automatically when the shutter is tripped.
     
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  3. Warren T.

    Warren T. Mu-43 Veteran

    338
    Mar 10, 2010
    San Francisco
    hi, 'auto' on legacy lenses mean automatic aperture. On a slr, the aperture will remain remain fully open at all times so that the view through the slr's viewfinder will be unimpeded (brightest). This is necessary because you are viewing through the lens.

    When the shutter is released, a mechanism in the slr's body actuates the aperture blades to "stop" down the lens to it's preset aperture setting. After the shutter is released, the aperture blades return to the fully open position again.

    Does this explanation make sense?

    73,

    Warren
     
  4. ke7dbx

    ke7dbx Mu-43 Regular

    76
    May 11, 2011
    Yes it does, by your 73 I take it your also a ham? :)
     
  5. Warren T.

    Warren T. Mu-43 Veteran

    338
    Mar 10, 2010
    San Francisco
    Yes, I am, but I have not been active for many years even though my license is still good :smile:.

    --Warren
     
  6. Howi

    Howi Mu-43 Veteran

    208
    Feb 23, 2011
    Sheffield
    Howard
    Me too! used to be G4GPF, my licence expired quite a few years ago, but can be resurected at any time.
    I may well take up the mantle once again when I (finally) retire.....
     
  7. jambaj0e

    jambaj0e Mu-43 Top Veteran

    816
    Aug 31, 2010
    What good lenses have this function? I did see that the Olympus OM 50mm has this.
     
  8. Warren T.

    Warren T. Mu-43 Veteran

    338
    Mar 10, 2010
    San Francisco
    Practically all modern SLR lenses are 'auto'.

    The 'auto' (automatic diaphragm) function only works on the camera bodies that the lens was designed for. When adapted to our Mu-43 camera bodies, the legacy auto lenses work in non-auto fashion.

    --Warren
     
  9. Pan Korop

    Pan Korop Mu-43 Veteran

    479
    Mar 31, 2011
    Phare Ouest
    All modern SLR lenses. It's mostly during the transitional period--roughly, the sixties--when this feature was a new sales pitch that you could read "Auto--Zuiko/Topcor/Nikkor/Takumar/Gizmonar". In the seventies, it became expected from all lenses to be "auto", i.e. have a spring-loaded diaphragm.

    It is not totally a desirable feature, especially when adapted on :43:: auto irises as a rule count less blades (as little as five with early "auto" thingies) than manual diaphragms. On the other hand it arrived together with multicoating, which helped improve the contrast of lenses with a flare-prone design.
     
  10. jambaj0e

    jambaj0e Mu-43 Top Veteran

    816
    Aug 31, 2010
    Yea, but it's been rather annoying on my Konica Hexanon 40mm, 50mm, and 57mm to not have this auto-feature, especially shooting indoors at f8 and up. I usually have to open it up completely, focus and frame, then close it back down.
     
  11. Pan Korop

    Pan Korop Mu-43 Veteran

    479
    Mar 31, 2011
    Phare Ouest
    Er... Are you talking of this Hexanons (which I suspect ARE auto-preset) on a m43 camera?
    Most all adapted lenses behave the same way: a pin on the adapter cancels the auto feature, leaves with a simple manual iris drive (except on EOS or Pentax 110 stuck wide open).
    The only workaround for your demand would be old-style fully manual lenses with a preset ring, i.e. with a double iris ring. Or Auto Takumar screw mount lenses, playing with their Auto/Manual switch. Try one.

    Also, most of us I suspect zoom the finder for fine focus, but leave the diaphragm closed at working aperture. Incidentally, what kind of viewfinder do you use, Pan EVF, else Oly's, or back screen?
     
  12. jambaj0e

    jambaj0e Mu-43 Top Veteran

    816
    Aug 31, 2010
    I use the Oly's EVF-2 if I'm not using wireless flash triggers, in which I use the screen. I do have the ClearViewer magnifier just to help, but the problem is when stopped down, the screen, especially in zoom focus, gets grainy, which makes it hard to really get the focusing down pat.

    That's why nowadays, when I do shoots with f8 and up with my Einstein, I keep my E-Pl2 on a tripod, open up the aperture, focus, then close it back down. A lot more work, that's for sure.

    I just bought the Olympus OM 50mm f1.8 auto-lens. So the auto aperture won't work on the E-PL2?
     
  13. The automatic aperture functions on older lenses were triggered mechanically from the camera body by activating the stop-down pin on the back of the lens simultaneously with the release of the shutter. There is no such mechanism in a m4/3 lens adapter so the OM lens will work in the same way as your Hexanons.

    On an OM lens adapter it is possible to remove the internal tab that locks the stop-down pin in position. This means that the lens will always be wide-open until you press the DOF preview button which is located on the lens itself. Of course this also means that you need to press and hold the button on the lens while taking the shot - probably more of a pain than adjusting the aperture after focusing in low light.
     
  14. ke7dbx

    ke7dbx Mu-43 Regular

    76
    May 11, 2011
    Cool, I am too. Took 60 gigs of photos and videos of this years field with my Pen.

    Thanks again.
     
  15. ke7dbx

    ke7dbx Mu-43 Regular

    76
    May 11, 2011
    Err field day.