Apeture won't change....

Discussion in 'Photography Equipment & Products' started by Nygdan, Mar 15, 2005.

  1. Nygdan

    Nygdan TPF Noob!

    Joined:
    Mar 7, 2005
    Messages:
    14
    Likes Received:
    0
    I had bought two Chinar lenses on ebay. One is a 135mm. When i turn the apeture ring, nothing happens, I don't see the diaphram closing. Whats going on? Are 'long' lenses somewhat different than normal and wide lenses? This is the first long lens I've had. I suspect that they don't behave any differently, and that I should be able to see the apeture diaphram stopping down and opening up.


    Here are two photos I took of the lens, the first is at f2.8, the next at f22. They're not different, and there is no movement inside the lens as I stop down. The photos are moderately large files, it was a rush job.

    This is definitely a problem right?

    f2.8


    f22
     
  2. Kent Frost

    Kent Frost TPF Noob!

    Joined:
    Jan 27, 2004
    Messages:
    572
    Likes Received:
    21
    Location:
    Springfield, MO USA
    Can others edit my Photos:
    Photos NOT OK to edit
    What camera mount does it fit to?
     
  3. Nygdan

    Nygdan TPF Noob!

    Joined:
    Mar 7, 2005
    Messages:
    14
    Likes Received:
    0
  4. Kent Frost

    Kent Frost TPF Noob!

    Joined:
    Jan 27, 2004
    Messages:
    572
    Likes Received:
    21
    Location:
    Springfield, MO USA
    Can others edit my Photos:
    Photos NOT OK to edit
    On the mount end of the lens, if you place the red dot at 12 o'clock, you'll see the lever at 3 o'clock. Set the aperture to 22 and lightly flick the lever to see if you can manipulate the opening. Feel for spring-loaded action, it should push against you. If it doesn't work, your lense is faulty.
     
  5. Nygdan

    Nygdan TPF Noob!

    Joined:
    Mar 7, 2005
    Messages:
    14
    Likes Received:
    0
    Dang, I suspected as much.
    I did what you suggested, moving the lever down has no effect on the diaphram in the lens. It seems like its a little springy, but, again, no change in the opening in the lens.

    I think I am going to have to contact the seller. Thanks for the help.
     
  6. Kent Frost

    Kent Frost TPF Noob!

    Joined:
    Jan 27, 2004
    Messages:
    572
    Likes Received:
    21
    Location:
    Springfield, MO USA
    Can others edit my Photos:
    Photos NOT OK to edit
    I'm willing to bet that some of the lubricant in the lens has seeped into the blades of the diaphragm, which is typical if it's been in a heated spot for too long, like a car or near a heating vent. However, if that's true, you should get some sort of reaction. Dunno, could easily just be a mechanical issue. But if it's a 135mm, you shouldn't have a hard time replacing it. Although if you're wanting the 2.8, you're probably looking near $50-70 for a good used one.
    I assume that it's manual focus?
     
  7. Mad_Gnome

    Mad_Gnome TPF Noob!

    Joined:
    Mar 14, 2005
    Messages:
    209
    Likes Received:
    0
    Location:
    So. Maine
    Can others edit my Photos:
    Photos OK to edit
    This also happens sometimes when a lens ages, especially with lenses from the 80s. The helicoid grease breaks down, and one of the elements is oil, which contaminates the aperature blades. I have a Vivitar zoom lens with this problem, which I'll have to have srviced at some point. :grumpy:
     
  8. Nygdan

    Nygdan TPF Noob!

    Joined:
    Mar 7, 2005
    Messages:
    14
    Likes Received:
    0
    Its manual, yes. I had gotten it and a 28mm f2.8 lens for aroudn 10$. But now this.

    See, I have a pentax k100. It came with a 50mm lens. I bought a 28 mm lens a little while ago. When I saw this deal up, I figured, heck, its worth it just for the 135mm, and it might be interesting to have a somewhat longer lens to play around with. So I figured, what the heck.

    I'm not trying to build some great glass collection or go overboard on anything, I just figured that it was worth trying out something different.

    Now I have to deal with this issue. Usually E-bay itself is good with this, and will refund a buyer.
     
  9. Kent Frost

    Kent Frost TPF Noob!

    Joined:
    Jan 27, 2004
    Messages:
    572
    Likes Received:
    21
    Location:
    Springfield, MO USA
    Can others edit my Photos:
    Photos NOT OK to edit
    I agree, but that's only if it's been in that condition for some time. Most of the time when it happens, the diaphragm reacts very slowly. After time, like you said, it acts like more of a glue and just keeps the blades open all the time.
     
  10. Kent Frost

    Kent Frost TPF Noob!

    Joined:
    Jan 27, 2004
    Messages:
    572
    Likes Received:
    21
    Location:
    Springfield, MO USA
    Can others edit my Photos:
    Photos NOT OK to edit
    Something to consider: The newer auto focus pentax cameras still use the K-Mount. You may consider getting a zoom lens. If you ever decide to upgrade to a new camera later on, an auto focus pentax would be an option since you'll have the lens for it.
     
  11. Nygdan

    Nygdan TPF Noob!

    Joined:
    Mar 7, 2005
    Messages:
    14
    Likes Received:
    0
    I'm actually considering something like that now, getting a zoom that starts above 50. I guess it'll depend how this turns out tho!
     
  12. Kent Frost

    Kent Frost TPF Noob!

    Joined:
    Jan 27, 2004
    Messages:
    572
    Likes Received:
    21
    Location:
    Springfield, MO USA
    Can others edit my Photos:
    Photos NOT OK to edit
    Actually, my girlfriend bought a 28-105 Promaster lens for her Pentax ME Super and she loves the thing. If you want to cover as much focal length as you can, a good setup to start with would be something like a 28-80mm and an 80-200mm. That's 2 lenses that will take you from 28-200 pretty economically, and they're super light weight.
     

Share This Page

Search tags for this page

searchwhy wont diaphram blades stop down