IIB or not IIB. A case study of Cooke Portrait Series II SF generation transitions

[mhayashi]

Out of my curiosity, I started to study the TTH cooke portrait soft focus Series generation transitions.
The original thread reply is here.
https://www.largeformatphotography.info/forum/showthread.php?143540-Cooke-Portrait-Lens-Serial-Numbers&p=1659587&viewfull=1#post1659587

I am hoping to sort things about what Barbara, the former historian of TTH Cooke (I heard from Ivan that she retired several years ago and resides in California), said about the “six incarnations” of Series II portrait soft focus lenes.

The whole archive was donated to Margaret Herrick Library, according to Ivan.
https://www.oscars.org

Here I decided to collect the facts of lenses, sample pictures and actual samples in hands of mine and others, rather than supposing how many generations existed. In the end, I could safely say how many there are….

One of my questions is now solved with two samples in hands about the title, if there are any soft focus generation differences between Series II Portrait knuckler and IIB knuckler.

Conclusion: no difference. This implies IIB and II knuckler soft focus lenses were not made at the same time.
PS: the aperture blades count the same for both, 12.

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[Tin Can]

U B OK

How about weight and flange dim

[mhayashi]

Good evening, Tin.
The weights with flanges are 4.35kg for II and 4.30kg for IIB.
The flange diameters are identical.
I also checked the internal mechanical differences at a glance but no difference.
They both are pretty much the same.

[Tin Can]

Thank you

I think all the very heavy lens should also have weights listed

As some of us know they are too heavy for most cameras

I know by experience my 11X14 Studio Deardorff can handle 20Lbs. tested with bar bell

[peter brooks]

The link to it is buried on page 4 of the very long Cooke Portrait Lens Serial Numbers thread but Karl's spreadsheet summation of all the serial numbers that people have sent him certainly helps - it is at

https://docs.google.com/spreadsheets/d/1Zan_PR-3rcPkejlblOhAjLPdZQ_saO3HLEG2a-dmsKc/edit?usp=sharing

As you suggest, there are are no more plain Series II serial numbers after the Series IIB badging appears (around row 129), so it could well just be a continuation of the previous design. They had already used the 'A' suffix, so that wasn't available!

[mhayashi]

Yes, Peter. Karl’s spreadsheet helps too.
i shall focus on the generation differences of Cooke soft focus lenses….
Up to now, I observe minor differences for Series II in hood designs, outer barrel aperture cone angles, screw or plate differences in the outer barrel to hold something, which I need to confirm the purpose as I don’t have one in hand for these generations.

Oh well, I found one very minor difference in the rear lens case….
The left IIB, right II. I think this is not considered a generation difference….
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