Results 1 to 10 of 10

Thread: Searching for info on BL 4.5 lens with minimal markings...

  1. #1
    Embdude's Avatar
    Join Date
    Mar 2018
    Posts
    305

    Searching for info on BL 4.5 lens with minimal markings...

    The lens is marked BL and has no shutter and aperture is marked 4.5-16. It is a very dark olive drab color.
    It has a date painted near the mount- Nov 28 1966 and a -8 is painted on the side as well as written in pen on an inspection sticker.

    From what little I have found online it likely came from a Xerox machine.

    I held it up to a piece of printer paper and to my surprise it covered it with no problem. I had assumed being a 4.5 it was likely a Tessar design but it is about a third smaller than my other Tessars with similar coverage.

    If anyone knows about this lens I would really like to know-

    Focal Length
    Lens Design
    Best way to open it for cleaning
    impressions of it as a camera lens
    what the -8 is indicating

    Click image for larger version. 

Name:	IMG_7101.jpg 
Views:	39 
Size:	57.4 KB 
ID:	224544 Click image for larger version. 

Name:	IMG_7099.jpg 
Views:	44 
Size:	33.7 KB 
ID:	224545 Click image for larger version. 

Name:	IMG_7093.jpg 
Views:	41 
Size:	41.6 KB 
ID:	224546

  2. #2

    Join Date
    Aug 2018
    Posts
    350

    Re: Searching for info on BL 4.5 lens with minimal markings...

    I assume it's close to later Fujinon-Xerox lenses, 240mm f4.5 to f16, or 260mm?

    Meant for high contrast, low resolution use in a Xerox machine.

    https://www.photo.net/discuss/thread...-board.256822/



    Sent fra min SM-G975F via Tapatalk

  3. #3
    Embdude's Avatar
    Join Date
    Mar 2018
    Posts
    305

    Re: Searching for info on BL 4.5 lens with minimal markings...

    Thanks!
    Quote Originally Posted by Oslolens View Post
    I assume it's close to later Fujinon-Xerox lenses, 240mm f4.5 to f16, or 260mm?

    Meant for high contrast, low resolution use in a Xerox machine.

    https://www.photo.net/discuss/thread...-board.256822/



    Sent fra min SM-G975F via Tapatalk

  4. #4
    Embdude's Avatar
    Join Date
    Mar 2018
    Posts
    305

    Re: Searching for info on BL 4.5 lens with minimal markings...

    Ok so I took the lens apart for cleaning, it is not a Tessar as I had thought. I don't recognize the layout... kinda of a symmetrical Tessar... Anyone know this design?
    Click image for larger version. 

Name:	BL Xerox 4.5 Lens.jpg 
Views:	14 
Size:	77.2 KB 
ID:	224578

  5. #5
    Embdude's Avatar
    Join Date
    Mar 2018
    Posts
    305

    Re: Searching for info on BL 4.5 lens with minimal markings...

    Click image for larger version. 

Name:	IMG_7107.jpg 
Views:	19 
Size:	44.0 KB 
ID:	224579Click image for larger version. 

Name:	IMG_7110.jpg 
Views:	18 
Size:	22.2 KB 
ID:	224580Click image for larger version. 

Name:	IMG_7109.jpg 
Views:	19 
Size:	23.1 KB 
ID:	224581Click image for larger version. 

Name:	IMG_7111.jpg 
Views:	19 
Size:	28.3 KB 
ID:	224582
    The one on the end on the right is just the retaining ring not a lens. There are spacers on either side of the concave element...

  6. #6

    Join Date
    Aug 2018
    Posts
    350

    Re: Searching for info on BL 4.5 lens with minimal markings...

    Reminds me of most modern plasmat and macro lenses. Take a look for your self http://www.prograf.ru/rodenstock/largeformat_en.html

    Sent fra min SM-G975F via Tapatalk

  7. #7
    Embdude's Avatar
    Join Date
    Mar 2018
    Posts
    305

    Re: Searching for info on BL 4.5 lens with minimal markings...

    Thanks, yes it looks very much like the first one - Apo-Sironar-N

    Looking over the diagram I drew in comparison to the Sironar I have tried to redraw it a little...

    Click image for larger version. 

Name:	BL Xerox 4.5 Lens redux copy.jpg 
Views:	8 
Size:	87.6 KB 
ID:	224645

    Also some searching on the web shows similar but likely later model BL lenses in the focal length of 209mm... I will need to test out the FL of mine to see if it is the same..

  8. #8

    Join Date
    Sep 2015
    Location
    College Park MD
    Posts
    70

    Re: Searching for info on BL 4.5 lens with minimal markings...

    This is very interesting. By coincidence I was bored today and pulled out some old lenses I squirreled away and just rediscovered this lens. Click image for larger version. 

Name:	IMG_6857.jpg 
Views:	22 
Size:	55.3 KB 
ID:	224646

  9. #9
    Embdude's Avatar
    Join Date
    Mar 2018
    Posts
    305

    Re: Searching for info on BL 4.5 lens with minimal markings...

    Quote Originally Posted by profvandegraf View Post
    This is very interesting. By coincidence I was bored today and pulled out some old lenses I squirreled away and just rediscovered this lens. Click image for larger version. 

Name:	IMG_6857.jpg 
Views:	22 
Size:	55.3 KB 
ID:	224646
    Yes that is the same lens as mine except yours is a +2 and mine is a -8... I wish someone could explain the significance of the number...

    There is an auction on ebay with a similar but not quite identical lens set...

    "5 Bausch & Lomb (B&L) copy lens set with mount. They are all the same lens: 209mm F4.5 BUT they have different visual corrections. Corrections on the lens: -3 ,-8 ,+4, +4, +12"
    https://www.ebay.com/itm/26500101100...rEeqDADhx1iSqY

  10. #10

    Re: Searching for info on BL 4.5 lens with minimal markings...

    Corrections on the lens: -3 ,-8 ,+4, +4, +12" did you find an explanation? whats the IQ like.

Similar Threads

  1. searching for lens board for Heliar 240 / Compound
    By olk in forum Lenses & Lens Accessories
    Replies: 2
    Last Post: 1-Feb-2022, 12:14
  2. F stop markings on lens board
    By Alan Klein in forum Lenses & Lens Accessories
    Replies: 27
    Last Post: 16-Jan-2020, 14:51
  3. Unusual markings on my 1/4 Plate CC Harrison portrait lens
    By CCHarrison in forum Lenses & Lens Accessories
    Replies: 10
    Last Post: 18-Sep-2013, 06:06
  4. Minimal Flange Focal Distance for a short telephoto lens
    By Nigel Sutton in forum Lenses & Lens Accessories
    Replies: 5
    Last Post: 27-Apr-2002, 10:20
  5. Minimal Flange Focal Distance for a sort telephoto lens
    By Nigel Sutton in forum Lenses & Lens Accessories
    Replies: 1
    Last Post: 26-Apr-2002, 13:00

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
  •