Dallmeyer Serrac Age & Info?

[Forrest Cooper]

Hi Everyone, I'm new to this site and new to 8x10. I have an Eastman Kodak Century 7a studio camera to use for portraiture and recently acquired a Dallmeyer Serrac 12" lens serial# 345442. I was wondering if anyone knows the age of this lens and if it will cover 8x10? I have 5x7 backs for the camera if not. Also, it's missing the mounting flange and before I machine one just thought I'd check to see if anyone has one out there? The diameter outside of the threads is 75.85mm. Any info would be greatly appreciated. Thanks a bunch.
http://i190.photobucket.com/albums/z125/RepoocTserrof/Dallmeyer-Serrac-001.jpg
http://i190.photobucket.com/albums/z125/RepoocTserrof/Dallmeyer-Serrac-003.jpg
http://i190.photobucket.com/albums/z125/RepoocTserrof/Dallmeyer-Serrac-004.jpg

[Dan Fromm]

Per P-H Pont's Dallmeyer chronology, around 1946.

It is an f/4.5 Tessar type, should cover 110 % of its focal length. In other words, yes it should cover 8x10 but won't allow large movements.

[CCHarrison]

You have a # 6 Serrac, made to cover whole plate (6.5x8.5 inches). Introduced in 1915...Early 1930's cat page attached from Sean's site.

Dan

[Forrest Cooper]

Thanks a bunch for the info! I'll post some pics taken with it after the restoration.

[Andrew Plume]

Forrest

I've owned a couple of the 8 1/2" Serrac's - they're incredibly sharp, definitely covers 10x8 - it's also a convertible and with the rear element only, it's nice and soft

enjoy

regards

andrew

[Andrew Plume]

Forrest

I should have mentioned that from my research, I've found a difficulty in being able to trace any hard and fast info on dating Dallmeyer serial numbers with years of manufacture but that may just be my inefficiency here

andrew

[Forrest Cooper]

Andrew,
Thanks for the input. I'm curious about the convertible mode you mention? Would I just remove the front 2 elements and leave the rear in place? Does that change the focal length? I originally was looking for a soft focus lens, so to here of a "soft" trick for this lens, has me stoked! Again I'm new to this format and large barrel lenses so forgive my newbie questions, however I have shot a bit of 4x5 with my Graphic View and Speed Graphic.
Thanks again, I'm loving this forum.

[Andrew Plume]

Hi Forrest

thanks for your post

I've just tested a Serrac, to me definitely a convertible and with the rear element only, very much the opposite effect than with all elements in place

The focal length reduces to around 6" and at best whole plate size will be covered - the image on the ground glass is of distinct softness with some decent bokeh - great for portraits - to achieve this I removed the cells forming the front element

good luck and I hope that this helps

regards

andrew

[Dan Fromm]

Since when is a Tessar convertible? They certainly weren't intended to be.

[Andrew Plume]

Since when is a Tessar convertible? They certainly weren't intended to be.

Hi Dan - well this one certainly is

regards

andrew

[Dan Fromm]

Andrew, "convertible" has a meaning. Individual cells of lenses sold as convertibles are designed to be used by themselves. They're achromatized and anastigmatic. I don't believe that a Tessar's rear cell meets those conditions.

You guys are stretching the definition to mean "forms an image." I think you've all gone over the edge.

[Andrew Plume]

Andrew, "convertible" has a meaning. Individual cells of lenses sold as convertibles are designed to be used by themselves. They're achromatized and anastigmatic. I don't believe that a Tessar's rear cell meets those conditions.

You guys are stretching the definition to mean "forms an image." I think you've all gone over the edge.

Hi Dan - no doubt here that you're entirely right, as usual, and thx for your invaluable comment - yes I'm clearly stretching 'the definition' - the way that I use this Dallmeyer just gives a different image - something for others to possibly consider if they are looking for an alternative use

thx again and regards

andrew

[Lachlan 717]

How do the Serracs differ from the Pentacs? Not just in design, but also production dates?

[Dan Dozer]

So - I"m not sure about the 12", but I have a 14" Serrac and it covers 8 x 10 with ease. In fact, for closer up shooting for portrate type work, I've used it on my 8 x 20 camera. I belive that a lot of the Serracs were actually used in the Military for use back in WWII and there are a lot of them without the Dallmeyer name but with the AM (Air Ministry) on them. There have been threads before on either here or APUG about the AM lenses.

[Forrest Cooper]

Update: Here is the lens after stripping, polishing, and powder coat. I found a wonderfull gentleman in Olympia to machine the mounting ring and the lens hood. The hood accepts 72mm filters. He did awesome work!

http://i190.photobucket.com/albums/z125/RepoocTserrof/Cooper-Century-004.jpg
http://i190.photobucket.com/albums/z125/RepoocTserrof/Cooper-Century-003.jpg
http://i190.photobucket.com/albums/z125/RepoocTserrof/Cooper-Century-002.jpg
http://i190.photobucket.com/albums/z125/RepoocTserrof/Cooper-Century-005.jpg

[rosshj]

Looks amazing. How did you strip the paint?