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  1. #1
    Join Date
    Dec 2008
    Posts
    3

    Sony A700 and Tamron 18-250 Problem

    Hi
    Has anyone got the above combination and how is it working for you?

    I have this combo, but cannot get the MF to work, even when the camera in on MF mode. The MF ring on the lens stays locked.

    thanks
    Ron

  2. #2
    Join Date
    Feb 2006
    Location
    Des Plaines, IL
    Posts
    9,560

    Lightbulb Focus Ring release

    Okay ... I am supposing that this problem is kind of in the way you may be doing this.

    If you have the α700's focus mode in the "MF" position ... WHEN YOU TURN IT ON ... it will immediately release the focus ring on the lens and you should be able to manually focus at will.

    BUT ... if you switch the focus mode from "S", "A", or "C" -> "MF" with the α700 STILL ON, then the lens focus ring will still stay engaged. You have effectively told the α700 to quit autofocusing ... but, it has not released the lens. You should shut it off and turn it back on (provided the focus mode is now set to "MF"), then it should allow you to manually focus at will.

    Now, let me offer this caveat. If you have the α700 on and the focus mode switch in either the "S", "A", or "C" position, you can also press and hold the "AF/MF" button, on the upper right-hand back of the α700 and the lens focus ring should also immediately release AF-lock (if you maintain pressure on the rear "AF/MF" button with your right thumb)



    (Advanced focusing) There is a mode called "DMF" (Direct Manual Focus) ... and I recommend you look it up in the User Manual for a better understanding of it. It is set up through use of the Menu System ... and only works when you are in AF-A mode (not "C" or "S" positions). It allows you to change the focus once the autofocus has done it's job and you are still at the shutter "half-press." You may then manually fine-tune the focus (perhaps to catch a subject closer to you ... that was not focused on initially). It works most excellently with MACRO photography and is my preferred operation. It still autofocuses perfectly, but you have the option and I kind of prefer that.

    Hope this helps ...
    Last edited by DonSchap; 12-11-2008 at 12:03 AM.
    Don Schap - BFA, Digital Photography
    A Photographer Is Forever
    Look, I did not create the optical laws of the Universe ... I simply learned to deal with them.
    Remember: It is usually the GLASS, not the camera (except for moving to Full Frame), that gives you the most improvement in your photography.

    flickr & Sdi

  3. #3
    Join Date
    Dec 2008
    Posts
    3
    Thanks for all that info' But still can't get the MF to unlock.
    Beginning to think that there is a problem with the lens mechanism, may have to have it looked at.

    regards
    Ron

  4. #4
    Join Date
    Feb 2006
    Location
    Des Plaines, IL
    Posts
    9,560
    Well ... my 18-250/A700-combo works as advertised. It could be a dirty contact between the lens and the camera. Try cleaning them gently. Also, look for wear on the contacts. If one looks a little too clean ... it may not be touching.

    Also, do you have another lens to try out this response on?
    Don Schap - BFA, Digital Photography
    A Photographer Is Forever
    Look, I did not create the optical laws of the Universe ... I simply learned to deal with them.
    Remember: It is usually the GLASS, not the camera (except for moving to Full Frame), that gives you the most improvement in your photography.

    flickr & Sdi

  5. #5
    Join Date
    Sep 2006
    Location
    Oregon
    Posts
    72

    Unhappy A200 - similar, but different

    With the Tamron 18-250 on my camera, it focuses manually yet the AF screw is still connected. So MF works, but I have the added torque of the camera's focus drive.. kinda spooky to me. When the lens is off the camera it's free and easy, like all my other lenses. So your condition is more extreme than mine, unless your focus-screw is just really, really tight..?
    JimR - gear list changes daily
    http://picasaweb.google.com/alphaPDX

  6. #6
    Join Date
    Feb 2006
    Location
    Des Plaines, IL
    Posts
    9,560
    Ron ... any update on this apparent malfunction? The lens has a 6-year warranty on it ... and the camera has a year.
    Don Schap - BFA, Digital Photography
    A Photographer Is Forever
    Look, I did not create the optical laws of the Universe ... I simply learned to deal with them.
    Remember: It is usually the GLASS, not the camera (except for moving to Full Frame), that gives you the most improvement in your photography.

    flickr & Sdi

  7. #7
    Join Date
    Jun 2008
    Posts
    2,204
    Strange. I actually have no idea how MF is supposed to work. I always thought the screw remained attach. But perhaps when I switch to MF, that's the slight mechanical noise I hear.
    flickr

    Canon 7D - 5D | 550EX - 430EX II - (2) PW FlexTT5 | 24-105 f4L | 70-200 f2.8L IS | 100 f2.8L IS | 50 f1.8 II

  8. #8
    Join Date
    Sep 2006
    Location
    Oregon
    Posts
    72

    only the 18-250 does this w/my A200..

    It's a curious thing. My other (Minolta) lenses feel exactly the same whether on the camera or off, and previous Tamrons (17-35 and 28-200 Di) did too. This was my first lens to act this way while in manual-focus mode. Someone on another forum noted the K-M 7D has a feature to retract the screw, but that didn't seem to come across to Sony - or was another a100 feature lost, I wonder?
    JimR - gear list changes daily
    http://picasaweb.google.com/alphaPDX

  9. #9
    Join Date
    Feb 2006
    Location
    Des Plaines, IL
    Posts
    9,560

    Cool Operational differences

    There is a lot going on in the α100, when you use the focus mode switch to go from AF to MF or vice-versa ... and it happens immediately upon the change of setting. You can actually feel the drive screw change condition when the camera is on and you are switching back and forth.

    The α700, on the other hand, does not do this. Its control is not as mechanical with its rotating four-position ("S", "A", "C", "MF") focus mode switch. You do hear it changing from AF to MF ... or vice-versa, though. I have to correct something I said, earlier ... You do not have to shut the camera off to actually complete the change to "MF" ... after testing, again, I found that it does release the AF-lock when you rotate the focus-mode switch to the "MF" position ... you can also use the "AF/MF" push button on the rear.

    Let's face it, some days you get the bear ... and on other days ...
    Last edited by DonSchap; 12-11-2008 at 09:38 PM.
    Don Schap - BFA, Digital Photography
    A Photographer Is Forever
    Look, I did not create the optical laws of the Universe ... I simply learned to deal with them.
    Remember: It is usually the GLASS, not the camera (except for moving to Full Frame), that gives you the most improvement in your photography.

    flickr & Sdi

  10. #10
    Join Date
    Nov 2008
    Location
    Monmouthshire, UK
    Posts
    2,152
    The Camera Drive (A700 anyway) should disengage immediately you select manual focus. If it doesn't you have a problem.

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