View Full Version : Cooke Process lens VB series

27-Sep-2004, 20:43
I found this process lens - a Taylor Hobson 1920's Anastigmat lens 18" f8 shutterless lens. It's also very heavy (feels like 800grams?) and will strain all the clips of a 5x4" monorail.

Having no experience with process lenses, it's curious seeing through the glass which seems like window glass rather than modern curved lens glass. The lens has a mild magnifying effect and is very flat which makes it look like it would be suitable for flat copy work or even short-range work, possibly up to a few metres. I did a brief keyword search on this lens and it looks like this lens is designed to cover at least 10x8".

This has me wondering if it would be effort to adapt into a lensboard for use. Its movement movements would be sufficient for 5x4 architecture" and possibly portraiture, although perhaps this lens isn't going to perform too well at longer distances.

Any ideas or thoughts on the above would be appreciated. Apparently it won't be cheap to carve a sturdy holder unit to lock this in a lensboard: its barrel diameter is at least 6 cm and has a lens mount around 7cm and doesn't look like it'll fit any Copal.

Ernest Purdum
28-Sep-2004, 12:19
The "mild magnifying effect" you mention is a function of the long focal length of the lens rather than any characteristic of the lens design. So far as I have been able to find out, your lens is a variant on the Cooke Triplet Ser. V, a distinctly asymmetric design. You can confirm this by closing the diaphragm and looking at reflections in the lens of a single small light. I think you will find them to be very different in the front than in the back. Lenses like this are quite sensitive to differences in subject/image ratio, so as you surmise, the performance at long subject distances would not be expected to be good.

The Cooke catalogs I have refer to "Cooke Process Lenses" rather than Series Vb, but I suspect they are referring to the same lens. If that is the case, the plate size covered wide open is 12" X 15" and at f16, 20" X 24". Thjis is the same as that listed for the basic Series V,and is a huge coverage for 4X5.

The "holder" you refer to is commonly called a "flange". You are quite correct in thinking that it would be expensive to have one made up, but it may not be necessary. Cooke lens flanges were well standardized. I don't know where you are located but if there are long-established dealers nearby, you might check with them to see if they happen to have an appropriate flange. Another possibility might be the Cooke firm itself. I think you will find them to be very helpful people. I don't remember their email address offhand, but you can surely find them by doing a search for "Cooke Lenses". They can probably also give you further (and more reliable) information on your lens.

Dan Fromm
28-Sep-2004, 13:16
www.cookeoptics.com Give them the serial number and any other information such as series number engraved on the lens..

The Vade Mecum, which is often somewhat muddled, says "Series V DENIC f8 This was a very sharp lens for professional, technical and process work and was made in 5.0-7.5-36in, and is still very sought after for use. It is a good lens for taking large groups and architecture and anywhere a slow lens is acceptable. It works well close up." and goes on to say that the 18" covers 12x10. Might, doesn't have to, be yours. TTH made other 18"/8 lenses.



28-Sep-2004, 15:02
Thanks Dan and Ernest.

I don't know what half of the large format forum would do without your erudite access to vintage lens and camera obscura knowledge.

Reading my own post again, I just noticed the faux pas I'd written: "Its movement movements would be sufficient for 5x4 architecture" That's a lot of movements for 5x4" if it covers 12"x10" then.

Your suggestions to contact Cooke Optics sounds promising although the writing and serial number are so eroded on the lens barrel. I didn't realise they were still in business so that's good to know. Thanks for the weblinks.