Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 68,694   Posts: 1,482,500   Online: 998
      
Page 1 of 3 123 LastLast
Results 1 to 10 of 30
  1. #1
    Tom1956's Avatar
    Join Date
    May 2013
    Location
    US
    Shooter
    Large Format
    Posts
    1,687

    Cleaning or repairing dirty shutters

    I wish I could think up a better title to this thread to get it to show up in the most internet searches on the subject of old, sluggish shutters. You know--the old lighter fluid trick; naptha, paint thinner, or your favorite potion. Well I have news for you: say you've done the lighter fluid trick and have got your shutter nice and snappy again, and you're happy.
    Truth is, NOT A CHANCE. It's nowhere near accurate, I promise you. And if you go off and start your film speed and development testing based on that shutter, and reporting your results on these forums, then you're totally polluting the information supply. And your tests will be so fouled up, a good actual photograph will be 75% luck.
    I performed an experiment and sat here for hours testing press and view camera shutters, and you won't believe how far off most of them are. Of note, I've got a Compur here for a 135 Schneider from a Graphic Special. Absolute mint, never-used condition. And every speed on it is nearly exactly 1/2 as fast as the dial says. That means whatever film you thought was ASA 100, is really ASA 50.
    The moral is, to either make a shutter tester from the photodiode of an old computer mouse and find out what your speeds are, so you can paste a chart on the camera, or send the lens off for a proper CLA.
    Good luck.

  2. #2
    Ken Nadvornick's Avatar
    Join Date
    Mar 2005
    Location
    Monroe, WA, USA
    Shooter
    Multi Format
    Posts
    2,801
    Images
    46
    Don't mess around. Just do it right from the get-go...

    Flutot's Camera Repair, ask for Carol.

    Ken
    "Hate is an adolescent term used to stop discussion with people you disagree with. You can do better than that."
    —'blanksy', December 13, 2013

  3. #3
    Tom1956's Avatar
    Join Date
    May 2013
    Location
    US
    Shooter
    Large Format
    Posts
    1,687
    While I'll second Ken's input, I also would like to say that when you get to a certain age, 1 year is equal to 5 actual years. And the shutter you "just sent off for CLA not long ago" was actually 5 years. And then you realize it's probably out-of-whack again. It's for the best to cut up an old computer mouse for a photodiode and use the computer you are reading this thread with, and hook up your little home made tester. With a couple search-engine searches, you can get it all working, and know where you REALLY stand.
    Sure would make darkroom test strip labors a whole lot easier. So if you're too poor to send the shutter off, you are not too poor to scrounge up an old computer mouse, a piece of cardboard, and a little wire, and find out for sure. There's really no excuse for NOT doing it.

  4. #4

    Join Date
    Jun 2009
    Shooter
    Medium Format
    Posts
    733
    Old leaf shutters that run a stop off are normal. I clean shutters w/ lighter fluid or high proof alcohol or carb cleaner or whatever is needed not to make the speeds accurate, but to clean the blades mostly so they don't stick. You need to buy or build an inexpensive electronic shutter tester that runs on Audacity (free download) so you know at what speeds the shutter is really firing at, and write them down on a piece of paper when you go out. 1/60=1/25, 1/125=1/60, that sort of thing. I can usually leave the cheat sheet in my pocket, as the speeds are often one stop off consistently, at least above 1/60. This goes for focal plane shutters in SLRs. Old cameras have weakened shutters, and you need to compensate. Even the electronically timed shutters I test, and they tend to be off too. Beware of leaf shutters that exhibit bounce (two peaks on your Audacity histogram, or whatever it's called). I know of no way to fix that, as it's usually due to worn parts. Better to sell it and get another. Some of my old folders have had 1/500 only get to 1/175 or 1/200. I don't care, since when I know the REAL speed I set my light meter accordingly and just shoot away.
    Last edited by momus; 09-29-2013 at 02:02 AM. Click to view previous post history.

  5. #5
    mr rusty's Avatar
    Join Date
    Sep 2009
    Location
    lancashire, UK
    Shooter
    35mm
    Posts
    564
    Images
    91
    There's two sides to this. Undoubtedly shutters need a complete CLA and adjust IF the value of what they are being used for justifies. So if it is a shutter on a ULF and the film is ££s a sheet you don't want to waste it and need the best accuracy possible.

    But, if we are talking about getting an old Retina or a folder with a prontor or compur working again so we can use it, then the lighter fluid process is fine. I recently did a Zeiss Nettar - when I got it is was gummed solid. Removed and soaked in alcohol followed by careful oiling of the pivots and contact surface bits I could see and it's snappy and taking great photos. Stripping a shutter right down is a bit too much for me - I have done it once but time/eyesight make it tough. My results from the cameras I have just cleaned are fine and don't point to massive discrepancies. Perhaps there is a stop error somewhere, but with most film exposure latitude and variability achieveable in the darkroom, I don't worry about it.

    So, if anyone reads this thread, don't be put off. Give that stuck shutter a good soaking in lighter fluid or whatever, oil the pivots with a little light oil. If it works, go and take pictures. If it doesn't you are no worse off and can still go for the full CLA if it's worth it.

  6. #6

    Join Date
    Feb 2011
    Shooter
    Multi Format
    Posts
    63
    There may be a considerable performance discrepancy between simply dousing the shutter in lighter fluid, which will remove soft surface contaminants, and actually cleaning the shutter thoroughly. The latter involves using metal polish on the blades to remove hardened contaminants, which will impede travel due to drag and surface irregularities. For focal plane shutters the problem can be more complex.

    All that said, proper testing is absolutely the way to go to determine just how accurate things really are. But having a shutter that doesn't stick is better than having one that does.
    ----------------------------------------------------------------------
    http://filmosaur.wordpress.com/

  7. #7

    Join Date
    Jul 2013
    Location
    Michigan
    Shooter
    Medium Format
    Posts
    107
    I have not looked at the mouse audacity method.

    I made a tester using a photodiode and oscilloscope, after some trials.

    1. The light hitting the photodiode must be collimated so that the light received off the groundglass is from a small spot (1.2 mm) and nearly at 90 degrees.

    2. The photodiode must be biased so it is always in its active region. It must not be in off state in the dark, and it must not be saturated in the test light.
    That requires adjustment of both the bias resistor and the test light intensity.

    These are necessary for the photodiode current pulses to be accurate analogs of the light pulse, otherwise it can give pulses longer than the incident light.

    Once I had the tester sorted out, I was able to reset the blind tension on the Speed Graphic to the spec in the service manual.
    above 1/100,there is a fair amount of penumbra on the focal plane shutter, and some on the lens shutter, so I used a visual average of the pulse width on the oscilloscope.
    Here are the measurements from the last test of the focal plane {setting, measured millisecond)
    {1/30, 55}, {1/50, 30}, {1/125, 11), {1/250, 5}, (1/500, 2.2}, {1/1000, 1.3}

    So the Graflex focal plane shutter is less than +1/3 of a stop in error.

    Here are the measurements from the last test of the Graflex Wollensak shutter on the Optar 1/4.5 135mm {setting, measured ms)
    {1/1, 900}, {1/2, 400}, {1/5, 180), {1/10, 103}, (1/25, 32}, {1/50, 19}, {1/100, 10.5}

    So the Graflex Wollensak shutter is quite accurate, plus 5%, minus 20% in time which is less than +/- 1/3 stop

  8. #8
    Rick A's Avatar
    Join Date
    Mar 2009
    Location
    north central Pa
    Shooter
    Multi Format
    Posts
    5,555
    Images
    23
    By cleaning the shutter with any solvent you are removing the lubricant and leaving a dry mechanism, which causes other damage and ultimate failure of the shutter.
    Rick A
    Argentum aevum
    BTW: the big kid in my avatar is my hero, my son, who proudly serves us in the Navy. "SALUTE"

  9. #9

    Join Date
    Sep 2009
    Location
    Washington, the state
    Shooter
    Multi Format
    Posts
    1,066
    Images
    16
    I was looking at the manufacturer's service manuals for my press camera shutters, and "that lighter fluid thing" is NOT a recommended service practice.

    Those people that recommend the lighter fluid flush must know more about the shutter than the original manufacturer.
    Dave

    "She's always out making pictures, She's always out making scenes.
    She's always out the window, When it comes to making Dreams.

    It's all mixed up, It's all mixed up, It's all mixed up."

    From It's All Mixed Up by The Cars

  10. #10
    Tom1956's Avatar
    Join Date
    May 2013
    Location
    US
    Shooter
    Large Format
    Posts
    1,687
    Now mind you, I'm rather early on in my shutter studies and work. But it's becoming more evident that spring replacement is the correct remedy for getting these shutters back to speed--the Betax. Rapax, Compur, etc. This of course is leading to the need to learn spring fabrication, since no parts I know of are available.
    If regular users are going to do the naptha-related tricks to get a dead shutter at least working again, then fine. But if you are not following it up with a little tester, so you can make a conversion chart to stick on the back of the camera, then you still don't have much of nuttin'. You'll be all over the place on finding film speeds and development times. Banging your head against the wall.
    Find out where your shutter really is, and the rest of procedure will start clicking into place. Voice of experience.

Page 1 of 3 123 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin