Results 1 to 8 of 8

Thread: What is what? - Petzval lenses pron

  1. #1
    cyberjunkie's Avatar
    Join Date
    Mar 2010
    Location
    Bologna, Amsterdam, Chiang Mai
    Posts
    335

    What is what? - Petzval lenses pron

    I always read with interest the responses about identification of old Petzval lenses.
    Many of them have no inscriptions, and many small workshops made them, so a correct identification is not easy.

    IF some of the "sauvants" out there are willing to help, i propose that those interested could post here the pictures of their unidentified Petzvals, asking for some help about the identification of their lenses. I guess that a few pictures of the "naked" lens (i.e. with its innards exposed) would be of great help in the identification of the maker, or at least of the approximate age of production.

    It would be a nice quiz for Christmas vacation
    I have identified only one of my Petzvals, with the help of some experienced forum user. All the others are of unknown maker.
    I'll post the pictures of a couple of them, if somebody volunteers for help.

    cheers

    CJ

  2. #2

    Join Date
    Jan 2009
    Location
    Denmark
    Posts
    5,834

    Re: What is what? - Petzval lenses pron

    I think the idea of naked lenses has shocked use! Seriously I don't think the variation in the arrangement of the rear pair will help much in identification:
    First, these are often mixed up due to reassembly during the decades - they get quite grubby. Secondly, the Dallmeyer innovation was quickly picked up by others - and by those not necessarily interested in the soft adjustment possibilities.
    I know something about the different varieties of Petzval - but not the details of the brass finishing and design of adjusting wheels, which other seem to have. And I can recognise some of the more odd trademarks or stampings. Post some and we can all take part - even if we guess wrongly!

  3. #3
    cyberjunkie's Avatar
    Join Date
    Mar 2010
    Location
    Bologna, Amsterdam, Chiang Mai
    Posts
    335

    Re: What is what? - Petzval lenses pron

    Thanks very much.
    I see that the Petzvals i have at home have two different arrangements: with the two back glasses in contact, and with a distancer ring between the two elements.
    Both configurations are reported on dioptrique.info, as early patents by Petzval.
    I know that some later objectives have the two elements assembled in a single cell. This arrangement allows, in some examples, to use the front cemented doublet in the back, as a landscape lens. I'd love to have one of those lenses, but i've never seen one, just some pictures on the Web.

    I'll take a few photos of my lenses, and post them.
    I have very limited knowledge, but i'd be very happy to see some pictures of other Petzvals. Better if the maker and/or date of production is known. That could evidence some common features that would help in the identification of unmarked lenses.

    have fun


    CJ

  4. #4

    Join Date
    Jan 2009
    Location
    Denmark
    Posts
    5,834

    Re: What is what? - Petzval lenses pron

    I don't think a "Petzval" with the two rear lenses in direct contact can be called a Petzval! R2 and R3 (the radii of the back of the first lens and the front surface of the second lens) are not the same in a traditional Petzval - so there will always be an air space.
    I don't believe there was much difference between the front achromats of the various Petzvals during time. This means that they are all very useful as landscape meniscus lens. The thread is often the same - front and rear on the barrel. The length of most petzvals makes it difficult to use the Petzval barrel though - unless some provision is provided to split the barrel. Short focal length/large aperture projection Petzvals have a shortish barrel which are suitable - both as regards the total barrel length and the positioning of aperture stops (at about 3-6cm - depending on focal lengths - from the lens).

  5. #5
    cyberjunkie's Avatar
    Join Date
    Mar 2010
    Location
    Bologna, Amsterdam, Chiang Mai
    Posts
    335

    Re: What is what? - Petzval lenses pron

    Quote Originally Posted by Steven Tribe View Post
    I don't think a "Petzval" with the two rear lenses in direct contact can be called a Petzval! R2 and R3 (the radii of the back of the first lens and the front surface of the second lens) are not the same in a traditional Petzval - so there will always be an air space.
    Of course with "in contact" i meant that the rim of the two glasses were touching one another. So there is a space between the lenses, because the curvature is different. Nevertheless, those with a spacer ring have a bigger distance between the lenses.

    You mentioned projection Petzvals, i just purchased two of them (Ross, one 8" and one 10"), and i am very curious to see if the coverage is slightly bigger than the early examples for wet plate cameras and magic lanterns.
    I have already at home a Bush cine projection Petzval of long focal (and slow speed, given its small dimension), but it came without focusing tube, and has no attachments thread, so i have to ask some machinist to make a threaded tube, to be able to fit it into a lensboard. Until i get it, i can't check the coverage, but i have seen B&L projection Petzvals of similar vintage, in black and chrome, on sale on Ebay.
    Those B&L Petzvals, bigger and faster than my lens, should cover 8x10 only when the focal is at least 15/16"; that's what i have read, but i understand that the coverage of Petzval lenses is a subjective issue. Somebody wants to use them as they were used in the ancient times, and somebody accepts (or may even search) a higher degree of swirliness (a word that's starting to make me a little sick) or maybe some degree of vignetting.
    I'll see how it works for me, i expect to see that the 10" projection Petzval should not vignette on 8x10, only when used for head and shoulder portraits... but at close distance there is very little depth of field, with no waterhouse stops!

    Did you test projections Petzvals on 8x10?
    Any difference in coverage between early examples and mid '900 projection Petzvals?


    have fun

    CJ

  6. #6

    Join Date
    Jan 2009
    Location
    Denmark
    Posts
    5,834

    Re: What is what? - Petzval lenses pron

    I am way behind with checking illumination circles of bought-in projection Petzvals.
    I will have a go at one that is related to yours - Busch k1 (l?) - but 4 1/2" and F.4.
    Temporary mounts is my excuse for not doing it earlier! I'll do a couple of others with longer focal lengths if I have time.

  7. #7

    Join Date
    Jan 2009
    Location
    Denmark
    Posts
    5,834

    Re: What is what? - Petzval lenses pron

    No need for an 8x10 ground glass for this one.
    Busch "F1" , F.4 and 4 1/2". On a 5x7 glass. As you can see it won't cover 4x5 corners either! I suppose this is the 1900 equivalent of gem lenses for carte de visite?

  8. #8
    cyberjunkie's Avatar
    Join Date
    Mar 2010
    Location
    Bologna, Amsterdam, Chiang Mai
    Posts
    335

    Re: What is what? - Petzval lenses pron

    There is something that i don't understand about Petzvals, it's the relation between coverage and focal lenght.
    Here is an example.
    I purchased a projection Petzval from a fellow forum member, it's marked L. Kamm, and probably was cine projection lens made by Bush. I think i've found the same lens on a Bush catalog on cameraeccentric, after a suggestion i was given on this forum. My example is probably a 16" EF (from a quick test using a sheet of white paper, not an exact measure), but i couldn't find out about coverage because i still don't have a way to attach the lens to a lensboard. What's very strange is that Bush literature reports the same coverage for very different focal lenghts: from 5 1/2" to 20". All have a reported coverage of 3 1/4 x 3 1/4 inches. AFAIK if the design is the same, increasing the focal should give a corresponding increase in coverage.

    In the meantime, in my quest for the "perfect Petzval", i have found on Epay another long (18") Petzval from B&L. It comes with a focusing tube and no flange, hopefully it will fit on my iris-shaped lens retainer, so i hope i will not have to wait forever to check for coverage.
    Serial is 2890625. Is there a list of B&L serials that can help in finding the age of the lens?
    I post a couple of photos, do you have any clue about this objective?

    have fun

    CJ

Similar Threads

  1. Commissionned new lenses, foolish ?
    By Jan Van Hove in forum Cameras & Camera Accessories
    Replies: 76
    Last Post: 8-Sep-2009, 17:18
  2. As expected: another LF newbie :)
    By Mikuda in forum Cameras & Camera Accessories
    Replies: 14
    Last Post: 26-Sep-2007, 22:57
  3. updated links to vendors' LF lens info
    By Oren Grad in forum Lenses & Lens Accessories
    Replies: 3
    Last Post: 17-Oct-2004, 11:02
  4. Rodenstock"Digital" Lenses - The Best (?)
    By Mike Foster in forum Lenses & Lens Accessories
    Replies: 16
    Last Post: 18-Dec-2000, 16:42

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
  •