Results 1 to 9 of 9

Thread: Are Compound shutter speeds tweakable?

  1. #1

    Join Date
    Apr 2013
    Posts
    181

    Are Compound shutter speeds tweakable?

    I have a #3 Compound shutter (top speed 1/100th) I believe is from the '60s according top the Heliar serial number. The speeds are slow all around. I've heard that there might be an adjustment I can make to adjust the tension.
    Is this true? And, if so, instructions appreciated.

    Also, it has a flash synch connection by nowhere is there an X-M switch. I see it fires the flash fine, but wondering if it will synch properly at all speeds.

  2. #2

    Join Date
    Sep 1998
    Location
    GA
    Posts
    12,219

    Re: Are Compound shutter speeds tweakable?

    First, your shutter is more then overdue for a CLA. Next your shutter may fire an electronic flash but not in synch. Your shutter is synched for flash bulbs. You need X synch. That means that your shutter may synch electronic flash at some slow speed but not at all speeds. To see, hook your flash up to your shutter, open to the largest aperture, remove your ground glass and fire the shutter while looking through the back of your camera. If it is in synch at that shutter speed you will see a bright circle of light when it fires. If you don't keep repeating this at lower shutter speeds until you find one that does show you a full circle of light. That would be the fastest shutter speed that your flash will work at.
    Unfortunately, since it will be a slow speed you may get double images as you will probably also get an exposure from the ambient light.
    Some repair shops can add X synch to your shutter and then you would be in synch at all shutter speeds with your strobe.

  3. #3

    Join Date
    Apr 2013
    Posts
    181

    Re: Are Compound shutter speeds tweakable?

    Thx Bob, will check the flash synch via suggested method.
    Do you know if there is a tension screw to self adjust? I will be getting it CLA'd shortly (Grimes), but want to use it for a week or so prior. Would love to adjust on this end if possible.


    Quote Originally Posted by Bob Salomon View Post
    First, your shutter is more then overdue for a CLA. Next your shutter may fire an electronic flash but not in synch. Your shutter is synched for flash bulbs. You need X synch. That means that your shutter may synch electronic flash at some slow speed but not at all speeds. To see, hook your flash up to your shutter, open to the largest aperture, remove your ground glass and fire the shutter while looking through the back of your camera. If it is in synch at that shutter speed you will see a bright circle of light when it fires. If you don't keep repeating this at lower shutter speeds until you find one that does show you a full circle of light. That would be the fastest shutter speed that your flash will work at.
    Unfortunately, since it will be a slow speed you may get double images as you will probably also get an exposure from the ambient light.
    Some repair shops can add X synch to your shutter and then you would be in synch at all shutter speeds with your strobe.

  4. #4

    Join Date
    Dec 2001
    Location
    NJ
    Posts
    7,381

    Re: Are Compound shutter speeds tweakable?

    If you have a shutter speed tester, test the shutter and make a table that gives actual speed vs. set speed. Then go shooting.

  5. #5

    Join Date
    Apr 2009
    Location
    Seattle area, WA
    Posts
    893

    Re: Are Compound shutter speeds tweakable?

    Unscrews both caps from the air retard cylinder on top. Clean the air retard cylinder with a tiny bit of solvent on a q-tip (be careful you don't want solvent going everywhere), that's probably all that's required to get your Compound moving a little faster. Compounds retard their action by using air resistance contained in that cylinder. If it's dirty it will likely run slower. If it leaks or one of the cylinder caps isn't screwed on, it will work way to fast.

  6. #6

    Join Date
    Apr 2013
    Posts
    181

    Re: Are Compound shutter speeds tweakable?

    Yes, did that. However fastest speed is about 1/30 sec. which severely limits what I can shoot (I shoot people).
    Having a decent 1/50th and 1/100 options makes it a relatively viable lens for me.


    Quote Originally Posted by Dan Fromm View Post
    If you have a shutter speed tester, test the shutter and make a table that gives actual speed vs. set speed. Then go shooting.

  7. #7

    Join Date
    Apr 2013
    Posts
    181

    Re: Are Compound shutter speeds tweakable?

    Thx. Will try that~

    Quote Originally Posted by domaz View Post
    Unscrews both caps from the air retard cylinder on top. Clean the air retard cylinder with a tiny bit of solvent on a q-tip (be careful you don't want solvent going everywhere), that's probably all that's required to get your Compound moving a little faster. Compounds retard their action by using air resistance contained in that cylinder. If it's dirty it will likely run slower. If it leaks or one of the cylinder caps isn't screwed on, it will work way to fast.

  8. #8

    Join Date
    Apr 2013
    Posts
    181

    Re: Are Compound shutter speeds tweakable?

    Thanks for the tip. I cleaned the cylinder with naphtha and it definitely improved performance. I'm still a full stop slow on the all important two top speeds (1/50th and 1/100th -- see attached speed chart), but at least it's in the right direction. And since it is an even full stop it's easy to compensate for when calculating exposure.

    That said, are there any other tips you might offer to increase that speed? I'm assuming graphite powder is a no-no in the cylinder, correct?

    Click image for larger version. 

Name:	IMG_6631.jpg 
Views:	25 
Size:	37.0 KB 
ID:	157764

    Quote Originally Posted by domaz View Post
    Unscrews both caps from the air retard cylinder on top. Clean the air retard cylinder with a tiny bit of solvent on a q-tip (be careful you don't want solvent going everywhere), that's probably all that's required to get your Compound moving a little faster. Compounds retard their action by using air resistance contained in that cylinder. If it's dirty it will likely run slower. If it leaks or one of the cylinder caps isn't screwed on, it will work way to fast.

  9. #9
    Ron (Netherlands)'s Avatar
    Join Date
    Nov 2011
    Location
    The Netherlands
    Posts
    253

    Re: Are Compound shutter speeds tweakable?

    These 'old' compound shutters were not meant to be lubed or anything. Also the naphtha might leave although little, residue - for cleaning the cylinder I always use alcohol.
    To get slow speeds right is less tricky than the faster speeds. In many cases - I repaired quite some older compounds and compurs - the ring driving the shutterblades might have just a little corrosion on the part where it resides against the housing. On can only clean that part by fully dismantling the shutter. Further the ring is driven by 2 springs: when the shutter opens the ring is driven by a bladespring which resides in the cylinder just under the tensioning lever. After opening the shutter is closed by another little steel wire spring.
    The blade spring might have become a little tired, and you cannot do much about that - I never found a replacement blade spring for my 1908 compound which has a broken spring inside. However you might be able to bend the wire spring a little in order to get is in a better original position - although of course this might only temporarily work.

    Here's one I recently cleaned/serviced - the shutter was fully stuck and the driving ring was quite corroded just as many other parts




    driving ring:


    cleaning the slow speed cylinder:
    __________________
    When day is done......

    My Flickr

Similar Threads

  1. Early Shutter Speeds
    By Jerry Bodine in forum Lenses & Lens Accessories
    Replies: 2
    Last Post: 11-Dec-2013, 18:01
  2. Shutter speeds on a Copal 1
    By numnutz in forum Lenses & Lens Accessories
    Replies: 4
    Last Post: 22-Aug-2010, 17:33
  3. Shutter Speeds
    By verbier123 in forum Lenses & Lens Accessories
    Replies: 2
    Last Post: 8-Nov-2007, 16:51
  4. Shutter speeds
    By Charles Forde in forum Lenses & Lens Accessories
    Replies: 10
    Last Post: 15-Dec-2004, 04:37
  5. Slow Speeds on a Compound Shutter
    By sheldon hambrick in forum Lenses & Lens Accessories
    Replies: 2
    Last Post: 10-Apr-2000, 05:24

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
  •