Page 1 of 2 12 LastLast
Results 1 to 10 of 11

Thread: Vogtlander Petzval rear optical element dimensions

  1. #1
    Scott Davis
    Join Date
    May 2002
    Location
    Washington DC
    Posts
    1,739

    Vogtlander Petzval rear optical element dimensions

    https://dcphotoartist.files.wordpres...313525.mp4?_=0

    I have a friend in Colombia who just recently bought a Voigtlander nearly identical to the one I bought. His is missing the rearmost element in the rear group. He has someone who is willing to try and make him a new element, but he needs the specifications for it. Assuming it is the same as my lens (pictured below - they're only a few digits apart in serial number), mine looks to be an 11 inch f3.4 (I don't know what model number it is, because there's no model number marked on the barrel, just a serial number). I'd pull my rear element out to take measurements off of it but the retaining ring is completely stuck and I don't want to force it and damage something in the process.

    Do any of you all know the formula and specifications for the rearmost element on such a beast? I'm sure they are public domain by now but I don't know enough to know how to find them. I've included the video of the lens he sent me so you can see exactly what he's looking for.

    Click image for larger version. 

Name:	VoigtlanderPetzval.jpg 
Views:	19 
Size:	55.1 KB 
ID:	207080

    My serial # is 16311. I believe his is 16631 or 16637. If someone has a reference to look those two lenses up by serial # and confirm exactly what they are, it would be even more appreciated!!

  2. #2

    Join Date
    Jul 2001
    Location
    San Francisco, CA
    Posts
    700

    Re: Vogtlander Petzval rear optical element dimensions

    LOL. Good luck with that. Actually, I do have one of these as well (286mm f3.6) for which I swapped out the horrible front achromat for something better. I do have the rear air spaced pair from the donor lens still. I'll see if the rearmost element fits into the Voigtlander housing as well...

  3. #3

    Join Date
    Jul 2001
    Location
    San Francisco, CA
    Posts
    700

    Re: Vogtlander Petzval rear optical element dimensions

    Nope. Too small.

  4. #4
    Scott Davis
    Join Date
    May 2002
    Location
    Washington DC
    Posts
    1,739

    Re: Vogtlander Petzval rear optical element dimensions

    Quote Originally Posted by karl french View Post
    Nope. Too small.
    Well, thanks for trying!

  5. #5

    Join Date
    Jul 2001
    Location
    San Francisco, CA
    Posts
    700

    Re: Vogtlander Petzval rear optical element dimensions

    Happy to take whatever measurements your friend needs from my lens. You shouldn't worry too much about giving that retaining ring on top of the rear group a good hard twist. Put some dishwashing gloves on, get a good grip on the face of the retaining ring and twist. It's a stack inside with the inner most element proud of the lens carrier. The ring holds the stack in place.

  6. #6

    Join Date
    Jan 2009
    Location
    Denmark
    Posts
    5,996

    Re: Vogtlander Petzval rear optical element dimensions

    Unfortunately, physical size ( diameter of lenses ) doesn’t identify the specific 1864 Petzval you (by proxy!) have!

    Voigtlander was already making many versions of Petzvals (Speed/Focal length). For instance, the front lens with 79.3 mm diameter was made in versions with 214, 305 and 362 mm focal lengths (D’Agostini page 78).

    Replacing a missing lens in any antique lens is a lost cause! Many have known radii and, sometimes, known refractive index, but there is no availability of original glass sources. Attempts to create replica Dallmeyer Patent Petzval lenses have used alternative glass designs to mimic the original lens effect, rather than replicate.

    What might be possible is to replace the rear air-spaced group with another pair, taken from a scrap projection/photographic Petzval. It is no secret that Petzval Used the known balsam achromat as a basis for developing the combination with the innovative rear air cell. It could be argued that the Petzval design is such that any achromat from any maker - combined with a rear cell from another maker - would make a workable Petzval lens! I certainly have found that Petzvals made up from orphan achromat and orphan rear cells do produce OK images.

  7. #7

    Join Date
    Jul 2001
    Location
    San Francisco, CA
    Posts
    700

    Re: Vogtlander Petzval rear optical element dimensions

    Yes, it's definitely better to try find a complete rear group that will fit the Voigtlander barrel. I'm surprised how good the image quality is on my hybrid Voigtlander 286.

  8. #8

    Join Date
    Sep 2007
    Location
    AZ
    Posts
    4,385

    Re: Vogtlander Petzval rear optical element dimensions

    "He has someone who is willing to try and make him a new element, but he needs the specifications for it."

    The specifications for a petzval should be in lots of optical writings, it was a mathematical formula. But based on the refractive indexes of the two types of glass.

    Is his person an optical engineer or manufacturer? Because if he wants to actually use the lens, not sell it to some sucker, the cost of making a rear group from scratch that is any good will be a lot more than the lens is worth. The sharpness of a lens with the rear made by a novice will be pretty suspect.

    Voigtlander Serial No. 16673 it appears to be, if it every shows up on the market, buyer beware.

  9. #9
    Scott Davis
    Join Date
    May 2002
    Location
    Washington DC
    Posts
    1,739

    Re: Vogtlander Petzval rear optical element dimensions

    Quote Originally Posted by goamules View Post
    "He has someone who is willing to try and make him a new element, but he needs the specifications for it."

    The specifications for a petzval should be in lots of optical writings, it was a mathematical formula. But based on the refractive indexes of the two types of glass.

    Is his person an optical engineer or manufacturer? Because if he wants to actually use the lens, not sell it to some sucker, the cost of making a rear group from scratch that is any good will be a lot more than the lens is worth. The sharpness of a lens with the rear made by a novice will be pretty suspect.

    Voigtlander Serial No. 16673 it appears to be, if it every shows up on the market, buyer beware.
    My understanding is that he wants to use the lens, not re-sell it. He's in Colombia- the optician (I think that's who's making the element for him) is in Brazil. I think the optician already has a blank of glass that's a reasonable approximation, and is willing to do it for the love of the exercise, rather than for profit, so he may be able to get it done at a cost-effective price. If he goes ahead and does it, I'll recommend to him that he includes some documentation in/with the lens to let people know the rear element was re-created.

  10. #10

    Join Date
    Jan 2009
    Location
    Denmark
    Posts
    5,996

    Re: Vogtlander Petzval rear optical element dimensions

    Here are the best optical formulae Available for early Petzvals!

    You can choose between various Voigtlander and others.

    http://www.dioptrique.info/base/obj_1914/avant-1900.HTM

Similar Threads

  1. Dimensions of B&J Rear Standard Please
    By Fragomeni in forum Cameras & Camera Accessories
    Replies: 3
    Last Post: 27-Mar-2011, 16:28
  2. Stuck Rear Element
    By PeterJ in forum Lenses & Lens Accessories
    Replies: 2
    Last Post: 22-Dec-2006, 06:28

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
  •