Results 1 to 2 of 2

Thread: Bausch & Lomb BE4800 f/2.1 3.5 EF Projection Lens

  1. #1
    dpn's Avatar
    Join Date
    Jan 2012
    Location
    Sacramento, CA, USA
    Posts
    150

    Bausch & Lomb BE4800 f/2.1 3.5 EF Projection Lens

    Hi all,

    I recently acquired a very inexpensive Bausch & Lomb projection lens. It's my intent to figure out a way to mount it to a 2x3 Speed Graphic to see if I can generate those magical swirlies that people have such strong and ambivalent opinions about.

    The lens is marked "Bausch & Lomb Optical Co. Rochester, N.Y. U.S.A. BE4800 f/2.1, 3.5 in. E.F." The diameter of the rear element is 31.8mm, and the diameter of the front element is 42.6mm.

    I believe that it only has two groups of lens elements, so I'm hoping that it's a petzval and not a triplet. Reflections I can see in the elements are bright, dim, dim ... I think?

    The barrel feels like aluminum. The whole assembly feels a lot newer in my hand that it looked in the pictures. The finish is a nice textured bakelite or plastic.

    There are slots for spanners on the front and rear of the lens, along with a single flathead screw. The whole rear of the lens is a screw mount with a 53.9mm (2.10 inch) maximum diameter. If the rear screw mount were removed, it looks like the outside diameter of the barrel surrounding the rear element would be 38.8mm (1.44 inch).

    I may be able to remove the rear screw mount by futzing with the flathead, but I may be stuck with it. If I'm stuck with it, I'm guessing that there's no way to mount it to a piece of wood or aluminum that'd have the same dimensions of the (correct me if I'm wrong) 2.25" square original 2x3 lens board?

    In sum:
    1. Is this lens a petzval?
    2. Does anyone know how to remove the rear screw mount from this lens?
    3. If the rear screw mount can't be removed, is there a way to install this lens on a 2x3 speed graphic lens board?
    4. Inexpensive digital calipers from Harbor Freight supply are a significant source of amusement.

    Pictures follow.

    Thanks,

    Dan

    Click image for larger version. 

Name:	Screenshot-2012-09-17_16.58.03.png 
Views:	11 
Size:	131.4 KB 
ID:	80672Click image for larger version. 

Name:	Screenshot-2012-09-17_16.58.23.png 
Views:	12 
Size:	130.0 KB 
ID:	80673Click image for larger version. 

Name:	Screenshot-2012-09-17_16.58.38.png 
Views:	10 
Size:	134.5 KB 
ID:	80674Click image for larger version. 

Name:	Screenshot-2012-09-17_16.58.54.png 
Views:	11 
Size:	158.6 KB 
ID:	80675

  2. #2

    Join Date
    May 2007
    Location
    20mins north of boston
    Posts
    496

    Re: Bausch & Lomb BE4800 f/2.1 3.5 EF Projection Lens

    to mount it try black foam core board and under cut the hole and screw it in and see what Happens
    Lauren MacIntosh

    Whats in back of you is the past and whats in front of you is the future now in the middle you have choices to make for yourself:

Similar Threads

  1. Bausch & Lomb Projection Lenses
    By rob_gervais in forum Lenses & Lens Accessories
    Replies: 5
    Last Post: 5-Jan-2011, 21:12
  2. Bausch and Lomb Projection Lens
    By Brian Bullen in forum Lenses & Lens Accessories
    Replies: 5
    Last Post: 28-Feb-2008, 12:12
  3. Bausch and Lomb 30" E.F. Projection Lens
    By Robert Oliver in forum Lenses & Lens Accessories
    Replies: 11
    Last Post: 7-Aug-2007, 20:35

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
  •