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Exposure problems with adapted lens

Discussion in 'Adapted Lenses' started by Tecpatl4, Jan 18, 2011.

  1. Tecpatl4

    Tecpatl4 Mu-43 Veteran

    292
    Oct 16, 2010
    Midwest
    I've attached a couple of my OM lenses and it appears that it is not adjusting the shutter speed correctly. When aperture is wide open it looks fine, but when stopped down to f11 or f16 the image is much darker. It does this in Aperture priority, P or i-auto. I've been through the forum and the settings and can't find anything that might affect this.

    Any help would be appreciated.

    Edit: I should have added it's an E-P1. The images are underexposed..
     
  2. Do you mean your images are underexposed or just that the viewfinder/LCD is very dark.
     
  3. Tecpatl4

    Tecpatl4 Mu-43 Veteran

    292
    Oct 16, 2010
    Midwest
    Underexposed.
     
  4. Tecpatl4

    Tecpatl4 Mu-43 Veteran

    292
    Oct 16, 2010
    Midwest
    I played around with it some more today. When using the kit lens I usually have exposure compensation set to -0.3. I changed it to +0.3 and it helps quite a bit. There is still a noticeable difference in the exposure. Not sure if this is normal or not.

    I took a set as an example. This is from a Soligor 28mm OM mount that I bought in 1985.

    28mm at f4:
    28mm-f4.

    Same lens at f8:
    28mm-f8.
     
    • Like Like x 1
  5. Hikari

    Hikari Mu-43 All-Pro

    Nov 26, 2010
    It is difficult for the exposure system to work properly at very small apertures as you are starving the sensor for light.
     
  6. Tecpatl4

    Tecpatl4 Mu-43 Veteran

    292
    Oct 16, 2010
    Midwest
    Ok, if this is normal that's ok, I can work around it. I thought maybe there was a problem with a setting somewhere. Thanks for the response.
     
  7. Hikari

    Hikari Mu-43 All-Pro

    Nov 26, 2010
    I have the same "problem" with my E-P1 with small apertures on manual lenses.
     
  8. russell

    russell Mu-43 Regular

    98
    Dec 28, 2010
    Victoria, Australia
    Did you get the image labels the wrong way round above? It looks like f4 is underexposed, not f8.
     
  9. Tecpatl4

    Tecpatl4 Mu-43 Veteran

    292
    Oct 16, 2010
    Midwest
    I think you are right. I went back and checked EXIF, and they are labeled correctly, based on the shutter speed. These were taken after I changed exposure compensation. I guess it had more of an effect than I thought. These are the only two I took after changing it. So it appears the conclusion is that it's inconsistent, and bracketing is your friend.
     
  10. drpump

    drpump Mu-43 Regular

    154
    Oct 28, 2010
    It's my understanding that with adapted lenses, you need to use Aperture Priority mode for automatic exposure metering to work.

    Note also that in P mode, if you hit the info button you get a 4-frame live view of the effect of increasing the exposure (and changing white balance). This is one of the key reasons I like to use P mode.
     
  11. scott

    scott Mu-43 Veteran

    332
    Nov 15, 2010
    Tecpatl -- try the same test with the white balance on a specific setting, rather than on AWB. Also try it with a fixed ISO, rather than automatic. I had a similar problem with an adapted lens.