Re: Aperture markings on vintage lens question

[Jan Faul <jan@xxxxxxxxxxx>]

You guys talk like everybody has always had precision tools to work with metal. One of my early East German cameras had a peculiar film gate. The shape of the resulting neg wasn’t quite a perfect rectangle. One end was noticeably taller.

I have a virtual duplicate of Andy’s Goerz lens and the f-stop numbers are quite strange. They begin at f2.6

Jan

 

On Oct 9, 2015, at 1:14 PM, PhotoRoy6@xxxxxxx wrote:

I agree. Even if they were odd f/stops they would be going up the scale be 1.41x for the next higher stop. Maybe it depth of field at different f stops?????

Odd if its F stops since they are not equa-distance.  What would be the reason to have a non linear aperture?  

Randy S. Little
http://www.rslittle.com/

http://www.imdb.com/name/nm2325729/

 

 

 

-----Original Message-----
From: Randy Little <randyslittle@xxxxxxxxx>
To: PhotoForum educational network <photoforum@xxxxxxxxxxxxx>
Sent: Fri, Oct 9, 2015 11:23 am
Subject: Re: Aperture markings on vintage lens question

Odd if its F stops since they are not equa-distance.  What would be the reason to have a non linear aperture?  

Randy S. Little
http://www.rslittle.com/

http://www.imdb.com/name/nm2325729/

On Fri, Oct 9, 2015 at 10:40 AM, Lea Murphy <lea@xxxxxxxxxxxxx> wrote:

Guessing…could they be related to EV numbers? Or something to do with Cine?

Lea

your kids . my camera . we'll click
www.leamurphy.com

On Oct 9, 2015, at 9:27 AM, Jan Faul <jan@xxxxxxxxxxx> wrote:

They’re f-stops. Not all manufacturers agreed to our usual numbering system today. I have a Leitz lens which begins with f2.2 and goes up to f19 

On Oct 9, 2015, at 10:10 AM, Andrew Davidhazy <andpph@xxxxxxx> wrote:

Somebody asked me what the markings on this lens meant - suggestions? 

Presumably they are f stops or light volume designations but the numbering system

is non-conventional at least to me. They double in value from step to step as one 

would expect f numbers to allow double the amount of light to pass but I don’t 

remember having seen this particular sequence. 

<2015-gunther-lens-1.jpg>

Andy

Art Faul

The Artist Formerly Known as Prints

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Art Faul

The Artist Formerly Known as Prints

------

Art for Cars: art4carz.com

Stills That Move: http://www.artfaul.com

Greens: http://www.inkjetprince.com

Camera Works - The Washington Post

http://www.washingtonpost.com/wp-srv/photo/battlefieldparks/front_qt.htm

ArtNet: http://www.artnet.com/artists/jan+w.-faul/

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