Mystery Lens: massive Double Gauss

[heritagefutures]

Hi all,

Any idea what this is/where this lens might be from?
It's a double-Gauss lens with eight elements in six groups
http://www.flickr.com/photos/heritagefutures/5017011205/

details on measurements and lens cross-section accessible from the above image.

It's an aerial lens, I am sure but from which camera does it stem??

Also, does anyone out there own
Rudolf Kingslake, A history of the photographic lens, Academic Press 1989
If so, could I ask for a digital photo (readable) or scan of page 151 please. Google books lacks that page which may be significant in me being able to identify this double Gauss eight-element lens that I am struggllng with.
Thanks!

PS
I posted the ID query already on flickr and APUG, alas to no avail so far. Hoping amongst this crowd ore those who know.

[kansalliskala]

Something wrong with your link, post it again.

[heritagefutures]

fixed
(finally)

[Sevo]

That doubtlessly is something aerial, and modernish - positively jet age (given the pressure compensation vents). Aerial photography or military aviation history forums are more likely to be able to identify it - the more so as it will probably have been classified until ten or twenty years ago...

As it will have come from some high-speed or high altitude recon plane flown in Australia, it might be worth while to investigate into what cameras the RAAF flew in their F-111's and Phantoms.

[heritagefutures]

Sevo
very intriguing.. no, I got it from the US. I always thought the vents were for cooling or heating. Never thought of pressure compensation.., but with high altitude that might make sense...
Dirk

[Sevo]

Heating/anti fog vents are usually behind a front cover glass or the front element - these vents throughout the barrel usually were put there to prevent warping due to pressure differences.

But if it is from the US, it can be anything - nobody else produced as much recon gear in cold war times...

[heritagefutures]

Indeed. I recall having seen some lenses with heating wires stretched across them....

so now then on to which cameras that could have come from. The only identification is the number in the cast middle section...

[SXR_Mark]

Hi Dirk

I have the Kingslake book. Unfortunately, the Wild Aviogon is not your lens.


I've had a quick flick through the book and can't find a match. The Leitz Summar looks similar if you add an meniscus lens at each end.



Mark

(Unfortunately, I can't see how to add pictures to the reply)

[mo]

Hi Mark
Post them now as the first post you make can not contain images or links as it is an anti spam feature.

[heritagefutures]

[SXR_Mark]

This is the Wild Aviogon (from P150 of Kingslake). As you can see, not at all like the mystery lens. It is a Biogon type.



To quote Kingslake:
"One of the most important new types of lens to be developed since WWII is a kind of double-ended reversed-telephoto objective, consisting of a compact central positive structure with one or more large negative menisci at each end, making a roughly symmetrical arrangement. The back focal distance is so short that the lens cannot be used on an SLR, but it has been used on a rangefinder camera and on many aerial cameras where freedom from distortion is mandatory. "

This is the Leitz Summar f/2 of 1933 (Kingslake p125), a double Gauss of 6 elements in 4 groups. Add menisci at each end and it looks very like the mystery lens.

[heritagefutures]

Indeed. Much appreciated!

So it's a Summar (or a Xenar) derivative...that throws the timeline back and thus the door wide open again...

[heritagefutures]

There has been some literature on the fact that surveillance camera lenses experience delays in responding to thermal shock (i.e. when quickly taken to altitude with concomitant rapid drop in ambient air temperature), and that by the time the lenses have adjusted the recon mission is commonly over. Thus the lenses are then often out of calibration and hence under-perform.

I now wonder, whether these vents were included for high altitude surveillance lenses not just to allow the pressure to equalise, but also to allow a pre-cooling of the lens cells before the mission commenced. Note that the vents are between the thinner of the elements...