Page 1 of 2 12 LastLast
Results 1 to 10 of 12

Thread: Focusing adjustment is too tight on field camera

  1. #1

    Join Date
    Apr 2015
    Location
    Purcellville, VA
    Posts
    105

    Focusing adjustment is too tight on field camera

    Although the focusing on my Tachihara Hope is smooth when the lens is little extended, it grows tighter as it moves out, growing uncomfortably tight by the time I reach the area I'll be using most, about 8 1/2 to 10 inches of extension (with my 210). By uncomfortably tight, I mean that the I can turn the knurl but the movement is quite stiff and causes just enough jitter -- because of the friction, it jumps a bit rather than moving continuously -- to make fine focusing difficult as the image on the ground glass jiggles. It's not clear to me where the friction would tend to be and, therefore, what to try to do about it. There's probably an ordered series of things to try.

    I am grateful, as always, for the voice of experience here.
    Philip U.

    Sine scientia ars nihil est.

  2. #2

    Join Date
    Feb 2015
    Location
    Sheridan, Colorado
    Posts
    887

    Re: Focusing adjustment is too tight on field camera

    On my field camera, the locking/loosing knob is on the left and the focusing knob is on the right. If I don't loosen enough on the left, and focus too much on the right, the left will frequently tighten on its own. Then I just loosen the knob on the left a little more. Perhaps your camera works the same.

  3. #3

    Join Date
    Jun 2001
    Location
    Northwest of Chicago
    Posts
    1,280

    Re: Focusing adjustment is too tight on field camera

    Is the knob that locks the focus tightening at the same time you are extending the bed by any chance? I have had that happen on similar cameras.

  4. #4

    Join Date
    Jun 2001
    Location
    Northwest of Chicago
    Posts
    1,280

    Re: Focusing adjustment is too tight on field camera

    Darn, I need to type faster....

    or

    2 great minds and all that go with them

  5. #5

    Join Date
    Apr 2015
    Location
    Purcellville, VA
    Posts
    105

    Re: Focusing adjustment is too tight on field camera

    Gents, thank you both, but that is not the issue; the problem exists entirely independent of the looseness of the locking knob (which, indeed, is on the left). I got the camera used, this year -- my first field camera -- and have had to sort through a number of little issues with it to bring it up to par. I have not had sustained periods of days to work with it, so our making friends is taking a long time. Someone prior to me was, I think, a bit rough with it; possibly dropped it. There are friction plates on the back base for swing, and I'm going to need to figure out how to remove the rear standard and very gently flatten the upper plate on one side to make the back a bit more solid; the plate bows up very slightly, maybe a half-millimeter, just enough to allow some play when locked (the locking cam is centered).

    Anyway, I am hoping that I don't need repair on the focus, just some proper lubrication or a fairly simple adjustment I can make myself. The budget for repair is out to lunch...
    Philip U.

    Sine scientia ars nihil est.

  6. #6

    Join Date
    Sep 2014
    Location
    North Dakota
    Posts
    513

    Re: Focusing adjustment is too tight on field camera

    Might try taking the extension tracks off and lubricate them with silicone lubricant or with a good wax buffed well. Could be that on extension they put some pressure on the track they ride in.
    I tend to procrastinate on stuff. One of these days I'll do something about it.

  7. #7

    Join Date
    Feb 2015
    Location
    Sheridan, Colorado
    Posts
    887

    Re: Focusing adjustment is too tight on field camera

    You need to carefully check to see if the bolt is bent. That might be very hard to determine. Try to loosen the nut on the RIGHT side. You might need to figure out how to keep the bolt from moving without damaging it. If the bolt or nut can't be moved, you have a problem. If you can loosen the nut, you might be OK. Just loosen it a little and see if that solves the problem. Locking it again is easy -- with LOCK-TITE.

  8. #8

    Join Date
    Apr 2015
    Location
    Purcellville, VA
    Posts
    105

    Re: Focusing adjustment is too tight on field camera

    I tried loosening the nut, as suggested, but that's not it. I got it all the way off with no change. silicone similarly did not help. I can't see anything in the motion that appears bent or "cam-like". I am beginning to assume that some of the wood along the track has swelled and will require sanding by a qualified technician, which will have to wait. Still open to other ideas.
    Philip U.

    Sine scientia ars nihil est.

  9. #9

    Join Date
    Feb 2015
    Location
    Sheridan, Colorado
    Posts
    887

    Re: Focusing adjustment is too tight on field camera

    I'm out of ideas -- but I've been told that many times in my life. Good luck!

  10. #10

    Join Date
    May 2015
    Location
    SooooCal/LA USA
    Posts
    1,001

    Re: Focusing adjustment is too tight on field camera

    The first thing to do is to obtain a machinist's square, but the adjustable sliding blade model from the home store (about $10) should be OK...

    Check to see if all of the rail + bed are square to each other, then remove blade to use as a straight edge to check the sliding surfaces for bumps etc, then check to see how flat the bed + rail on the bottom + top... See if the glue joints are not loose on the rail or bed, and slightly changing angle/shape and enlarging when extended... Something may have swelled, expanded, warped, or some debris stuck there, too...

    I think it might be something like the rail corners are not perfectly perpendicular, so a corner plane might be slightly larger than another, causing binding...

    If you don't figure it out, or send to a camera tech, a local acoustic musical instrument tech should be able to find the bind...

    Happy hunting!!!

    Steve K

Similar Threads

  1. Options For Field Camera Focusing Hardware?
    By brandon allen in forum LF DIY (Do It Yourself)
    Replies: 30
    Last Post: 13-May-2015, 00:39
  2. Focus Adjustment for Metal Camera
    By Ari in forum LF DIY (Do It Yourself)
    Replies: 57
    Last Post: 8-Apr-2013, 11:47
  3. Wooden field cameras always light tight?
    By jvuokko in forum Cameras & Camera Accessories
    Replies: 11
    Last Post: 2-Feb-2013, 12:08
  4. Wooden Field camera + 150mm. Tight budget!
    By Peter Josefsson in forum Cameras & Camera Accessories
    Replies: 12
    Last Post: 13-Jun-2010, 00:02
  5. Replies: 8
    Last Post: 20-Aug-2009, 19:03

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •