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Weird Em-1 Manual Focus Aperture Quirk, both on Mk I and Mk II!

Discussion in 'Olympus Cameras' started by Jason Stamper, Feb 12, 2018.

  1. Jason Stamper

    Jason Stamper Mu-43 Veteran

    Mar 13, 2014
    Hi All,
    So I recently bought a Oly 75mm f1.8 from a member on this site. It is a beautiful lens, and wow what a gorgeous front element! I only got to experiment with it a little over the weekend, but I think it will be a very nice addition to my kit.

    Anyway, while messing with it in my kitchen last night I noticed something odd. It seemed to be making a fast clicking noise just with me moving the camera around and not touching any buttons. What I found is that it was the aperture opening and closing. As I pointed the camera towards the light over the sink the aperture would close down, and as I pointed towards a darker area it would open up. I have never noticed this kind of behavior before with my lenses so I thought it was the new lens.

    However, after a bit of sleuthing I figured out that it was actually my Em-1 mark II. It seems that when you put it into manual focus mode it adjusts the aperture according to the available light. I've no idea why it does this in manual focus mode, but I am sure there is a reason. The other funny quirk is that it continues to do this even after you put the camera back into AF. But when I put the camera back into SAF +MF mode (my usual focussing mode), turned the camera off and back on the behavior stopped. Then no matter where the camera points the aperture remains wide open till you take the shot (this is what I deem normal behavior). I think it might have been due to the strong light difference in the overall low light of the kitchen last night vs the bright light over the sink.

    I wanted to verify that it was not the 75mm lens, so I tried several of my lenses and saw the exact same behavior. I even tried a few different lenses on my Em-1 mark I and found the same behavior. I think the only reason I actually noticed this is because those big ol' aperture blades on the 75 are a bit noisier than say my 12-40mm f2.8 pro. I don't really think its a problem since I never notice it before, and have been shooting with my Oly gear for several years now. I just though it was an odd little quirk that perhaps some of you might have noticed too.
  2. Growltiger

    Growltiger Mu-43 All-Pro

    Mar 26, 2014
    I cannot find any way to make my camera do what you describe. It sounds a bit like the DOF Preview function, that closes down the aperture.
    Perhaps you should try a full reset, I suspect you have some setting that makes it do that.
  3. Giiba

    Giiba Something to someone somewhere Subscribing Member

    Aug 19, 2016
    New Westminster, BC
    I think it is flicker reduction myself. Though I forget where it is in the menu, that sounds like the trouble a number of older system lenses have when it is enabled.

    Turn it to off and see if it persists.
    • Like Like x 1
  4. PakkyT

    PakkyT Mu-43 Hall of Famer

    Jun 20, 2015
    New England
    I don't have that lens, but I have noticed that same behavior before as well. I think I noticed it on my 45/1.8 if I am recalling correctly (on my E-M1 mk1). I will have to check it again and see and then try it with some of my other lenses. But the quick answer is that this I believe is a normal operation, I just don't know if it is specific lenses and if there are specific features or settings that need to be in place.
    • Like Like x 1
  5. DennyVanNostrand

    DennyVanNostrand Mu-43 Regular

    Jan 3, 2018
    I think it might be called aperture flutter or something similar. I read a posting some time back about a Fuji camera doing this. I think it's normal.
    • Like Like x 1
  6. slob

    slob Mu-43 Rookie

    Jul 5, 2013
    Search for "rattlesnake" noise. Happens with all my lenses, but the original EM5 + PL 25 f/1.4 is loudest. Same lens on an EM1-II, is much better behaved.
    • Like Like x 1
    • Informative Informative x 1
  7. PakkyT

    PakkyT Mu-43 Hall of Famer

    Jun 20, 2015
    New England
    I tried it last night with my f/1.8 primes and couldn't get it to do it again. Tried manual, AF, P, A, S, M, nothing made it happen. I do seem to recall that I was outside during the day when I noticed it so perhaps it wasn't bright enough in my house even when I aimed the lens at a lamp?
    • Like Like x 1
  8. Jason Stamper

    Jason Stamper Mu-43 Veteran

    Mar 13, 2014
    I think it does have to do with the intensity of the light for sure. I have been shooting around the house and outside and have not had the issue. I'll be interested to see if it comes up in any other situations. Odd little quirk for sure.
  9. pdk42

    pdk42 One of the "Eh?" team Subscribing Member

    Jan 11, 2013
    Leamington Spa, UK
    Turn off flicker reduction. That will fix it.
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