advice on Cooke with stuck Soft focus

[Emil Schildt]

I have a really beautiful 14.5" (370mm) Cooke Series II portrait lens.

the condition on the lens is really fantastic, with a deep warm glow to it - it looks like a lens that havn't been used much..

However, the soft focus mecanism is stuck - as firmly as it can be.. which obviously is a shame..

I have tried to soak the soft focus with oil, but it is atill stuck.

The condition of the lense is so fine, that I actually don't think old dust or something similar would cause this problem.

on the back of the lens ther is a little plate with what it seems like two screws screwed into the glass (the moving part of the lense?)

I am tempted to try and remove these screws, but I think I have read somewhere, that they are there for a reason to begin with..
That Cooke did this , as the moving lense had to be placed with much precision...

So, my question to you is: would there be a way to make the soft focus work, without destroying the lense all together?

(I have another, slightly smaller Cooke, I can use.. so I won't risk too much..)

I have taken some pictures of the stuff mentioned above..

[Steve Hamley]

Given the value of the lens, I'd send it to a professional like S.K. Grimes, or sell it as-is. Especially since the screws seem to be "jailhouse" screws that can't be removed by conventional means.

You're looking for the second of three possible outcomes (which is fine, I'd do exactly what you are).

1. Send it to Grimes and stop worrying. Downside is time and money
2. Fix it yourself if there's an easy fix.
3. Try to fix it yourself and destroy a rare and valuable lens, not to mention a beautiful one.

Cheers,

Steve

[Emil Schildt]

Given the value of the lens, I'd send it to a professional like S.K. Grimes, or sell it as-is. Especially since the screws seem to be "jailhouse" screws that can't be removed by conventional means.

You're looking for the second of three possible outcomes (which is fine, I'd do exactly what you are).

1. Send it to Grimes and stop worrying. Downside is time and money
2. Fix it yourself if there's an easy fix.
3. Try to fix it yourself and destroy a rare and valuable lens, not to mention a beautiful one.

Cheers,

Steve

Thanks Steve.
You're right of course.
My problem is, that S.K.Grimes is far, far away, it would cost me a fortune in shipping - repair costs and not to mention taxes and customs fees to do this....

On the other hand, I got this for free (!!!) as a gift from a student, so maybe that could be an argument to send it to repair....

I've taken a snap og the other lense screw holder so you can compare.. this liiks original.
The ""jailhouse" screws" you mention; is that a sign of a later fixation on the lense?

[Ken Lee]

Perhaps someone who repairs old clocks or watches, could do a fine job in repairing the lens. There must be many such people, close to your home.

[John T]

I had a similar problem with my lens. I took it to Rudy Lingg in California and Focal Point in Colorado. Neither one could free the mechanism. I ended up trading it for a couple Daguerreotype era lenses to a guy who just wanted a display lens.

Mine didn't have the two chips in along the lens edge.

[Gene McCluney]

When making recommendations, you should be aware the OP is in Europe, not the USA. I think it would be good to always mention "where" you are located if you are seeking recommendations for vendors of services.

[Archphoto]

I think I might have the solution, will look at the lens when I am in Europe in July again.

Greetings,
Peter
The Hague, The Netherlands, Goiânia, Brazil

[Mark Sawyer]

I wonder whether Cooke Optics would accept it in their service shop? From their site:

"All new products are provided with a 12-month warranty that includes parts and labour when returned to Cooke in the UK or an authorised warranty service agent. Beyond the first 12 months, Cooke provides a rapid-service facility in the UK at a competitive hourly rate plus parts. Call or e-mail for prompt answers to any questions."

It could be worth asking them. They might have the original design specs still on file, too. (I'd guess the lens is a little bit beyond the "first 12 months...")

[jnantz]

jim galli i think has this same lens .. and maybe has
taken his apart to work on it. maybe if he sees this thread
he can suggest what the screws should look like.

[Toyon]

I remember talking to Adam Dau about a Cooke he had on the bench. The mechanism was stuck. They managed to unstick it, but it took very careful and powerful incremental force. This is not a Do-it-yourself job.... that would be a major mistake. Get it fixed properly or sell it.

[Emil Schildt]

I remember talking to Adam Dau about a Cooke he had on the bench. The mechanism was stuck. They managed to unstick it, but it took very careful and powerful incremental force. This is not a Do-it-yourself job.... that would be a major mistake. Get it fixed properly or sell it.

you're proberly right, but there is a third option: just to keep it, and use it as a normal big lense...

[Ole Tjugen]

Forsøk å spørge Cooke. Det kunne jo være at de tar det som en utfordring? :)

[Steve Hamley]

Gene,

Yes I knew he was in Europe. You can send and import for repair without duty.

But his location doesn't change the available options really. Shipping both ways is still a small faction of what a working lens is worth. But if he wants to bail, I'm interested at an appropriate price, and will pay his shipping! ;)

Cheers,

Steve

[jnantz]

If you still want to use it before sending it off Saran Wrap and a rubber band to hold it tight makes a very nice soft focus attachment.

you are correct!

[Jim Galli]

Hi Emil.

No I don't have an early one like that. I would do this before give up;

Remove the front and the back glass but leave the center one alone. The helical inside would hopefully then be seen. I use a product made for cleaning the rubber for tyre repair. It is a liquid called Rubber Buffer (http://www.blackjacktirerepair.com/detailed.asp?pchild=36&code=242). This stuff is tri chloro-ethylene. It leaves no residue and doesn't harm non metal parts if there are some. I have had some luck by soaking then working then soaking then working until finally things begin to move. You need a good vise so you can get some serious torque on the ring. I squirt the stuff outside and inside, any place 2 metals come together in the mechanism. It will start to "wick" the century of dirt out from underneath. Cooke was famous for their tolerance in machining. Everything is almost zero tolerance, no slop to work with at all.

I hope that helps. I use this stuff for sticky shutters too. Good stuff. Probably kills a few brain cells. You and me got none to spare.

[Emil Schildt]

If you still want to use it before sending it off Saran Wrap and a rubber band to hold it tight makes a very nice soft focus attachment.

Proberly.

If I only knew what "saran wrap" is....:rolleyes:

[Jim Galli]

Don't put the saran wrap on the lens. For your style wrap up the model instead. :D:D

[venchka]

Proberly.

If I only knew what "saran wrap" is....:rolleyes:

Clear, clinging, plastic film used to cover left overs in the 'fridge or fix old Cooke lenses. :D

[goamules]

I'd like to add two other possible helpers to Jim's good advise.

If you find his substance doesn't work, I've had luck with CLP Break-free. http://www.break-free.com/?location=/global/sitemap.asp

Also, when I want to get a stronger torque than can be applied with my hand and a rubber grippy material (like the back of a mouse pad), I make a tool out of a couple of pieces of wood, such as 1x4, about 3 feet long. Cut a semi circle in each board, about 1 foot from the end, that is slightly larger than the barrel you need to unscrew. Line with rubber grip material. Wire the ends near the cuts together. Grip the barrel in the cuts, and squeeze the other ends (non-wired). Of course, you may need two sets, or a vice.

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[Emil Schildt]

Don't put the saran wrap on the lens. For your style wrap up the model instead. :D:D

like this?:D

[Emil Schildt]

Hi Emil.

No I don't have an early one like that. I would do this before give up;

Remove the front and the back glass but leave the center one alone. The helical inside would hopefully then be seen. I use a product made for cleaning the rubber for tyre repair. It is a liquid called Rubber Buffer (http://www.blackjacktirerepair.com/detailed.asp?pchild=36&code=242). This stuff is tri chloro-ethylene. It leaves no residue and doesn't harm non metal parts if there are some. I have had some luck by soaking then working then soaking then working until finally things begin to move. You need a good vise so you can get some serious torque on the ring. I squirt the stuff outside and inside, any place 2 metals come together in the mechanism. It will start to "wick" the century of dirt out from underneath. Cooke was famous for their tolerance in machining. Everything is almost zero tolerance, no slop to work with at all.

I hope that helps. I use this stuff for sticky shutters too. Good stuff. Probably kills a few brain cells. You and me got none to spare.

Hi jim

Thanks for this.
I really had to use my dictionaire here... all those foreign words.. but I think I got it..

I have never seen the Rubber Buffer here in Denmark, but maybe I can find something similar (we do have cars here...)

Mentioning this here, it that a sign that you don't think it is due to replaced newer screws; too large?

[Jim Galli]

Hi jim

Thanks for this.
I really had to use my dictionaire here... all those foreign words.. but I think I got it..

I have never seen the Rubber Buffer here in Denmark, but maybe I can find something similar (we do have cars here...)

Mentioning this here, it that a sign that you don't think it is due to replaced newer screws; too large?

Now I am not understanding. Do you think there is something not original to the lens that has mechanically locked the moving parts?

[Gene McCluney]

I have had very good success with using aerosol cans of "Zero Residue Contact Cleaner" which is available at electronics parts stores. Also there is a super penetrating oil type product available in the USA calle "PB Blaster" which will loosen up about anything, but it leaves an oily residue that you will have to clean up.

[Emil Schildt]

Now I am not understanding. Do you think there is something not original to the lens that has mechanically locked the moving parts?

yes - as Steve said: "since the screws seem to be "jailhouse" screws that can't be removed by conventional means"...

I think these types of screw types are not 100years old.. (but I can be wrong..)

My other upload shows how the screws and the plate looks on another Cook lense..

[Steven Tribe]

I have asked the Mod on "watch" call to move this to the DIY thread as I have something to contribute tomorrow!

[Ralph Barker]

I have asked the Mod on "watch" call to move this to the DIY thread as I have something to contribute tomorrow!

Sorry, but it isn't your thread to move.

I'd suggest starting a new thread in the DIY section if you have a DIY suggestion on soft focus.

[William Whitaker]

On the other hand, I got this for free (!!!) as a gift from a student, so maybe that could be an argument to send it to repair....

Used to be that an apple for the teacher was adequate. But that may be just an American custom.

I'll bet Steve will give you double your money for that lens!

[Steven Tribe]

Of course, it's not mine to move!

I quite agree that there are things in this thread that deal with other aspects than DIY, like the varying designs of the early Cooke series II and the availability and "success" with professional repair.

In the run-up to the establishment of the DIY thread, I was a avid supporter of a more "project" oriented thread - not specifically dedicated to things one could do oneself.

Anyway, I would like to continue the discussion here for while - in close proximity to Gandolfi's 2009 OP.

[Steven Tribe]

First of all, there appears to have quite a lot of variation amongst the early (pre knuckler) series II Cookes.

I have recently got hold of an early one, in fabulously bad condition, which allows me to experiment a little.

The early series II for full plate was a 10.4"" rather than the later 10.5", which gandolfi's lens was a very early example of. I cannot put an exact date on mine as they forgot to put a serial number on it! The exact position and detailed text is probably the best way to put an age on it? It also differs from gandolfi's as the iris scale is reversed.

What is obvious at the moment (in contrast to some of the coments earlier in this thread) is :

- the sharp/soft adjustment is a simple normal thread. Unlike the knuckler model, many turns will have to made to reach the equivalent of 5 in the knuckler model.

- the central lens is mounted in a setting which is held by six screws to a flange in the barrel, which makes it easy to remove and remount correctly.

The direction of soft turning is clockwise. However this thread is normal one (see photo 4). This means that the maximum soft position is when the middle/front lens barrel unit is nearest the rear cell. My lens is stuck in the maximum screwed-in position - as soft as it can get. Only the "ARP" of the full tekst "SHARP" is visable.

Comparing this with a knuckler IIE, I see that the likely free movement of this thread should be over a centimeter.

[Steven Tribe]

I have managed to release my jammed soft mechanism. Will be posted in the DIY section as soon as possible.

[Emil Schildt]

The early series II for full plate was a 10.4"" rather than the later 10.5", which gandolfi's lens was a very early example of. I cannot put an exact date on mine as they forgot to put a serial number on it! The exact position and detailed text is probably the best way to put an age on it? It also differs from gandolfi's as the iris scale is reversed.

.

just a note: mine (the stuck one) is a 14.5"

My 10.5" 3.5 is not stuck.

I'll follow your experience in the DIY

[Steven Tribe]

I'll post you the piston ring clamp if you like, Emil? You should use a rubber seal (I'll make one) the whole way round as yours has the original finish, whilst mine was pure cra*!

It was hard to believe the series II was basically the same as a IIE. It looked half the size of the IIE.

A comparison of weights (minus flange) showed an even bigger difference:

Series IIe (efl 10.5") 1,480g

Series II (efl 10.4") just 840 g.