Cooke Speed Panchro - Eyemo lens - help or service needed
Posted 16 September 2018 - 02:10 PM
The Lens is in good condition and focus + aperture works nice.
Problem is, that inside it is dusty and needs cleaning.
Someone here who could give me some tips how to open it or a good adress for a service point?
Posted 16 September 2018 - 03:35 PM
While not specific to cine lenses, https://richardhaw.com/lens-repair-articles/ is a good site to learn basic lens disassembly and cleaning.
Now, while most people on this site would probably rather throw their mother on the streets than crack open a lens themselves, it can be done IF you are careful and use the proper tools.
You can also watch a series of Youtube videos by Mikeno62 (https://www.youtube....3Sdai8zvA2iJGQg) which deal with many types of lenses that are far more complex than your lens.
Do a lot of research before you start and gather the right tools. Work in a place with good light, a work surface that will stop small bouncing parts and screws and document every step with a digital camera or video camera or both.
It is imperative that all rings, lens elements and focusing helicoils are returned to their proper orientation. Carefully note each lens element orientation and if there is room, draw a pencil arrow showing the direction the lens faced outward. Pay particular attention to the videos where they show how to mark where infinity is and where the helicoils separate from each other.
Sounds scary but with practice, it not only makes sense, it is fairly easy to do. Do yourself a favor and go buy a junk store lens to practice on BEFORE you work on this lens.
Buy small plastic containers or a parts bin to place each part in sequence (I use dollar store plastic parts bins) and anchor them to the table with gaffer tape! Nothing like hitting your carefully segregated, in sequence parts bin and tossing it to the floor! Ask me how I know...
Always remember, when you get frustrated, walk away and come back in an hour. Don't get in a hurry.
Posted 17 September 2018 - 05:14 AM
Taylor Hobson Ltd
PO Box 36, 2 New Star Road
Leicester, LE4 9JQ
Posted 17 September 2018 - 10:46 AM
Frank's links to lens repair sites are interesting - they deal with more modern stills lenses, and so may not be that relevant to old cine lenses like a Speed Panchro, but practicing on cheap stills lenses might be a good idea.
If it's only a bit of dust, and the mechanics are otherwise fine, I would probably suggest leaving the Speed Panchro alone. Even early series Panchros like this are becoming quite valuable, and you wouldn't want to ruin a lovely vintage lens if you don't actually need to get inside. A little dust is virtually invisible, and even a lot will usually only reduce the contrast a bit.
Having said that, those old Cookes were very nicely made, with the element groups in housings that easily screwed apart, usually held in place by a kinked wire circlip. So they aren't that hard to disassemble. The trickiest part is accessing the optical block within the mechanical housing, usually a case of undoing small set screws, maybe removing an iris pin, and unscrewing helicals. Mark and/or measure infinity and where the helical threads engage. Use acetone and patience on set screws, if you strip a screw head you'll be in trouble.
Be careful with old lens coatings, as they are softer than modern coatings and easy to damage. A WW2 era Panchro like that one may well be uncoated, I'm not sure when Taylor, Taylor & Hobson began coating their elements.
Posted 19 September 2018 - 03:23 PM
Anyway, I found a company here in Germany that can service this old lens, they also do glas polishing and recoating if necessary.
P+S Technik GmbH Feinmechanik
Edited by Stefan Fischer, 19 September 2018 - 03:24 PM.
Posted 19 September 2018 - 03:32 PM
good to hear Stefan. Would you mind post some pics from your process in case you took some?
I m also checking options for cleaning lenses and also found P+S, but till now they didnt answer to my emails ;(