Results 1 to 9 of 9

Thread: How did they blacken the metal stops & caps of the Daguerre era lenses?

  1. #1
    Ron (Netherlands)'s Avatar
    Join Date
    Nov 2011
    Location
    The Netherlands
    Posts
    562

    How did they blacken the metal stops & caps of the Daguerre era lenses?

    Have found a nice old lens of the Daguerre era which is missing its stop disk (is that the right word?). I guess these disks/plates were made from brass but I'm not sure since I have no original to compare.

    Questions:

    1. From which metal was the stop disk made?

    2. How was the metal blackened?

    3. Is there a source for the screw used to attach the plate to the lens? (the screw has a little tapered base - guess it could also be replicated by a machinist)

    Here is a picture of an early achromat with a metal stop disk - at one end it is fastened to the lens with a screw, so it can open/close the lens:
    (If anyone has one laying in a parts bin I would be most interested of course....)

    __________________
    When day is done......

    My Flickr

  2. #2

    Re: How did they blacken the metal stops & caps of the Daguerre era lenses?

    Liver of sulfur,
    Richard T Ritter
    www.lg4mat.net

  3. #3

    Join Date
    Mar 2005
    Location
    Newbury, Vermont
    Posts
    1,331

    Re: How did they blacken the metal stops & caps of the Daguerre era lenses?

    Richard...ya gotta give us more details - otherwise "liver of sulfur" just sounds...really unappatizing!

  4. #4

    Join Date
    Dec 2006
    Location
    Hamilton, Canada
    Posts
    1,781

    Re: How did they blacken the metal stops & caps of the Daguerre era lenses?

    https://www.amazon.ca/BeadSmith-XTL-...95612066&psc=1
    from Wiki - Liver of sulfur is a poorly defined mixture of potassium sulfide, potassium polysulfide, potassium thiosulfate, and likely potassium bisulfide

  5. #5

    Re: How did they blacken the metal stops & caps of the Daguerre era lenses?

    lamp black

    Antique & Classic Camera Blog
    www.antiquecameras.net/blog.html

  6. #6

    Join Date
    Nov 2017
    Posts
    492

    Re: How did they blacken the metal stops & caps of the Daguerre era lenses?

    Lots of options here. One from a 1936 lab manual: https://aip.scitation.org/doi/pdf/10.1063/1.1752115 Selenium dioxide is another one and you can find that around in ready-made products (poisonous!).
    Expert in non-working solutions.

  7. #7

    Join Date
    Jun 2001
    Location
    North of Chicago
    Posts
    1,550

    Re: How did they blacken the metal stops & caps of the Daguerre era lenses?

    You can try this— https://www.birchwoodcasey.com/produ...oz-bottle.html

    I used to use this in antique restorations. It may not be quite as black as the original you showed, but the blackness can be enhanced a bit with a clear top coat.
    ____________________________________________

    Richard Wasserman

    https://www.rwasserman.com/

    http://richardwassermanphotographer.tumblr.com

  8. #8

    Join Date
    Sep 2007
    Location
    AZ
    Posts
    4,417

    Re: How did they blacken the metal stops & caps of the Daguerre era lenses?

    They painted or treated the inside of brass barrels in a variety of ways. Waterhouse stops were done chemically to retain the black, when they scrape in out and out of the slot. Selenium Dioxide is reputed to work well today, read the MSDS.

    See https://books.google.com/books?id=EV...lacken&f=false

  9. #9

    Join Date
    Jan 2009
    Location
    Denmark
    Posts
    6,107

    Re: How did they blacken the metal stops & caps of the Daguerre era lenses?

    There are two previous threads on the permanent blackening of brass!
    Here is my contribution on a previous occasion!

    Yes it is ordinary sheet brass.
    Ordinary small Metric screws.
    Thread cut in top plate - if necessary. Oversized thread, perhaps - only 3/4 through.

    Remember there is a smart variant with different sized apertures - as well as the basic “shutter”.
    Attached Thumbnails Attached Thumbnails 6BEE7A59-F9C4-416A-BE4B-487F6D327DE0.jpg  

Similar Threads

  1. Blacken Petzval Inside
    By Two23 in forum Lenses & Lens Accessories
    Replies: 13
    Last Post: 15-Feb-2017, 09:20
  2. Metal Lens Caps
    By Lachlan 717 in forum Gear
    Replies: 27
    Last Post: 4-Feb-2009, 20:30

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
  •