Taylor-Hobson Cooke Series II Portrait Anastigmat 12.75" F/4.5 lens query

[fredlicht]

I own a Taylor-Hobson Cooke Series II Portrait Anastigmat 12.75" F/4.5 lens, the "Brass Knuckle" variety. The glass is very clean, the diaphragm blades and mechanism are perfect, but the Brass Knuckle soft focus mechanism is frozen. Does anyone know of someone that can repair this? The brass of the lens is not in great shape, but the lens is otherwise in good shape. Does anyone happen to know if it is best to repair the soft focus mechanism before sale (if I choose to sell it), or does it make more sense to sell the lens in it's current state? Thank you. Fred Licht

[LabRat]

If the seam where the rotating barrel threads are visible, you can take a hypodermic needle with a couple of drops of silicone spray (contains acetone) and put a couple of tiny drops in the seam and wait a few minutes, then repeat over some time... Then try to rotate the ring... Do not just spray directly from can as too much comes out of can...

But for resale, best to let new owner deal with it, as bad work is worth less than no work done... ;-)

Steve K

[Mark Sawyer]

But for resale, best to let new owner deal with it, as bad work is worth less than no work done...

Agreed. A little too much penetrating lubricant can fog a lens inside the barrel, necessitating disassembling and cleaning.

[Ron (Netherlands)]

I would definitely leave it to the new owner :-)
I've bought and buy many old camera stuff, but never look at the offerings saying the lens or camera had just a CLA etc....

[Steven Tribe]

This is an Easy service and is illustrated here in a number of threads!

[Tin Can]

Yes, someone here talked me through a similar problem and I still have the special grease he recommended, a long time ago

But I have not done it on my 2 Cooke II SF

[fredlicht]

This is an Easy service and is illustrated here in a number of threads!

I have been searching around but have not been able to find anything on the forum.

A friend has suggested the following:

"It 'sounds' like the focus helicoid is gummed up, probably with old grease etc. Can the cells be removed from the barrel? If so I'd take them off and then pour some lighter fluid in the slit/space by the knuckle and see if it can penetrate and wash out some of the grease, that can be followed up with some liquid wrench. AFter that some silicone grease on the threads and it'll be good as new...maybe even better :-)".

Does this sound right to you?

I see that you are in Denmark. I lived there for seven years some time ago.

Thank you.

Fred Licht

[Steven Tribe]

Yes, the problem is solidified grease. Can only be Solved by mechanical removal. There is a small Ball bearing which allows the rotation to stop in the 1 - 5 positions. Don’t loose it.

[fredlicht]

Thank you for your response. Do you believe that the solidified grease can be dislodged through chemical means (lighter fluid) as my friend suggests?

[Steven Tribe]

No.
These lens deserve a proper clean - solvents will move grime elsewhere.

I think Ron’s advice is great if you are not confident about the servicing. The lens is very attractive as most on offer are the smaller 10.5” version, and the New owner will be glad to accept a minor fault.

[michael_los_angeles_photo]

Oddly enough I’m in Los Angles as well and had the same issue with the same lens — same focal length even. I had the guy who runs the camera club here — who also does repairs from home — fix it, and it worked perfectly. This was a few years back, but I can check with him if you’d like.

[fredlicht]

No.
These lens deserve a proper clean - solvents will move grime elsewhere.

I think Ron’s advice is great if you are not confident about the servicing. The lens is very attractive as most on offer are the smaller 10.5” version, and the New owner will be glad to accept a minor fault.

Would you suggest that eBay is the proper venue to sell the lens, or do you recommend another means of offering the lens for sale? I am very appreciative of your insight and assistance (hvis du forstår dansk, mange tak for hjælpen).

[fredlicht]

Would you suggest that eBay is the proper venue to sell the lens, or do you recommend another means of offering the lens for sale? I am very appreciative of your insight and assistance.

[ghostcount]

Oddly enough I’m in Los Angles as well and had the same issue with the same lens — same focal length even. I had the guy who runs the camera club here — who also does repairs from home — fix it, and it worked perfectly. This was a few years back, but I can check with him if you’d like.

Michael,

I'd be interested in his info if you have it and he is still arounf - I've got a Cooke II 13" that has a sticky aperture ring. PM me if you can.

Thank you.

[Steven Tribe]

The repair is basically - screw apart, find the steel Ball, clean all surfaces, lightly Oil the contact surfaces , replace the Ball and screw back together.
Perhaps an hour’s light work.

Here is the best place to sell things - as Long as the Price is realistic in these falling marketing times!

Have you Found post #10 here?

https://www.largeformatphotography.info/forum/showthread.php?127948-Cooke-Portrait-Anastigmat-Series-IIE-15-quot-knuckles-repair-info

[Tin Can]

Just a small warning. The NOT a Cooke lens I fixed with advice had one really tiny screw locking the elements and needed to be removed FIRST

With my poor vision, I never saw it

But I was successful!

Use the big money grease

[ghostcount]

The repair is basically - screw apart, find the steel Ball, clean all surfaces, lightly Oil the contact surfaces , replace the Ball and screw back together.
Perhaps an hour’s light work.

Here is the best place to sell things - as Long as the Price is realistic in these falling marketing times!

Have you Found post #10 here?

https://www.largeformatphotography.info/forum/showthread.php?127948-Cooke-Portrait-Anastigmat-Series-IIE-15-quot-knuckles-repair-info

Fantastic! Thank you Steven.