Results 1 to 5 of 5

Thread: DOF knob

  1. #1

    DOF knob

    DOF knob

    Hi in the warmth of the summer!

    I try to find out how to make DOF knobs for my cameras, an Arca Swiss 6x9, 1982 model, and a Century Graphic 6x9.
    I have looked at Hayashi's DOF knob

    http://www.largeformatphotography.info/dofknob/

    and wonder about the reference point. Hayashi uses a mark on the tension control knob. But when I loosen this knob on my Arca, it moves as I turn the focussing knob. Is there something I have overlooked or misunderstood? Or is this knob just different on more recent Arcas? To work as the "carrier" for the reference point, it would have to snap into a well-defined position when loosened, or?

    Another option I have thought of, would be using a turn counting dial mounted onto or instead of he focussing knob. It would imply a counting dial that could be zeroed, preferably by the push of a button, as a second choice by turning back to some sort of indent or mechanically defined stop. Would anybody know of a source for such a knob?
    I have browsed the hardware places listed on this site

    http://www.largeformatphotography.info/lfforum/topic/498619.html

    as well as some others in Europe, but without success. At least, I can not determine from the specs if they have a way of zeroing.
    From

    http://www.hinkel-elektronik.de/shop/1399.html

    I bought their model 15-1-11 by mail-order, believing, that the little black thing that can be seen at the bottom of the picture, was the desired zeroing button; but it is just a lever to adjust friction.

    I feel that for 6x9, just a millimeter scale is not precise enough. It would have to be to 0.1 mm.

    Good light! - Hening.
    Hening

  2. #2

    Join Date
    Mar 2004
    Location
    Maine
    Posts
    190

    DOF knob

    I use a modified digital caliper; $16 from harbour frieght. I cut off the ends and have a simple digital axis read out that can be zeroed anywhere. People may find this over kill but, I find it fast and presice. Reads in metric or english. Could be perminatley mounted? I use it like a depth guage from the front end of my Shen-Hao to the optical bench. I used a similar setup on a graflex view II, mounted on the side, but removable.
    Regards,
    Dan Jolicoeur

  3. #3

    Join Date
    Mar 2004
    Location
    Maine
    Posts
    190

    DOF knob

    I believe what you are refering to is called a travel dail. They are a bit bulky and expensive. They can be zeroed by moving the face of the dail, which is essentially similiar to a dail indicator.
    Dan Jolicoeur

  4. #4

    DOF knob

    Thank you for your answer, Dan. - Would you care to post the URL of Harbour Freight? My googling does not bring up anything that has to do with tools. - I have tried with a hand-held caliper, but would prefer something that is fixed on the camera.

    Kind regards - Hening.
    Hening

  5. #5

    Join Date
    Mar 2004
    Location
    Maine
    Posts
    190

    DOF knob

    http://www.harborfreight.com/cpi/ctaf/Category.taf?categoryid=551&pricetype=S&categoryname=MEASURING%20EQUIPMENT

    If you want this attatched to the camera you will have to make a bracket to hold it. I cut off the jaws with an abrasive grinding wheel. You will then have to make mounting brackets and a bracket to attatch to the back of the readout to the camera movement. It will be helpfull if you know someone with a milling machine or access to a machine shop. Every camera presents it's own mounting problems. It worked well on a grahic view II mounted as I said. Now I use it as a depth guage and it is just as fast.
    It works well and fast for me.
    Good luck,
    Dan Jolicoeur

Similar Threads

  1. Brass Knob for Calumet folding field camera
    By Charlie Taylor in forum Cameras & Camera Accessories
    Replies: 4
    Last Post: 31-Mar-2005, 21:39
  2. Focusing Knob on TK45S
    By Scott Rosenberg in forum Cameras & Camera Accessories
    Replies: 52
    Last Post: 15-Mar-2005, 22:19
  3. Focus Knob Stuck on Wisner TF
    By Brian Vuillemenot in forum Cameras & Camera Accessories
    Replies: 8
    Last Post: 10-Feb-2004, 21:30
  4. Discovery focus knob loose
    By Mike Mahoney in forum Cameras & Camera Accessories
    Replies: 2
    Last Post: 23-Jul-2001, 15:21
  5. Copal 1 Shutter - what's the large triangular knob for?
    By Simon Rodan in forum Lenses & Lens Accessories
    Replies: 1
    Last Post: 29-Sep-2000, 23:56

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
  •