Disassembling a Dallmeyer 6D

[Tim Meisburger]

I have a beat up Dallmeyer 6D I am trying to rescue. It is the aluminum version. As you can see from the picture below, I have been able to loosen one joint. My questions are:

Is there a joint at A? If there is, is it threaded normally or left-hand?

I believe there is a joint at B. Is that correct? Is it threaded normally?

For the front, it seems the joint should be at C, not D. Is that correct? Is it threaded normally?

Regarding the lens elements. They look like air spaced elements. How to remove them?

Any help from someone that has a working model of this lens would be appreciated. Tim


72474

[Steven Tribe]

Some are right and some are left, I think. Serial number? Surely the sequence of graduation marks (clockwise/anticlockwise) will indicate the thread type? * through to **** is softening/increase distance between the lenses in the rear double cell = unscrewing.
Dallmeyer seem to have received many complaints about the front adjusting system and changed quite a lot.
Based on just tampering with a 3B, I would say.

A - yes, this is the soft adjustment thread.
C - definitely and it would be a normal thread.
D - Doubtful.

It does say turn for soft somewhere? Some 6Ds ( and others) where made without the soft focus fitment.

[Tim Meisburger]

Thanks Steven. I'm afraid to crank to hard on anything until I am sure of the soft-focus direction. It does say "Turn for Soft Focus", but I don't see any gradation marks anywhere. I'll get out the loupe and have another look.

Maybe Eddie or Mark has one of these and they could weigh in.

[Steven Tribe]

I received a lot of help from some of our Dutch (sorry, Netherland's) members. There may be something in the old 3B "contruction" thread?

[eddie]

do not bother. you will f it up. the aluminum has corroded onto each other. nothing short of a destructive force will get them apart.

i have seen this in many of the aluminum lenses....use it and be happy. trying to "fix" it will render it useless.

i have seen aluminum on aluminum and aluminum on to steel corrosion in my work as a mechanic/ auto body tech. they do not come aprt without super forces.

FWIW the rear SF mechanism is left hand thread.

[goamules]

I agree. Tim, many of these soft focus mechanisms are stuck, and I've never gotten it loose on some of mine. If the glass needs cleaning and you can't remove the back, you're in trouble. But if it's just the SF threads, leave them. It's never used by anyone I know anyway.

[Tim Meisburger]

Well, that was what I was afraid of. I read up as much as I could on the internet on aluminum corrosion, and that was the general impression. I don't have much use for a 600mm lens that covers 15x18, so I'll probably just pass it along.

[Tim Meisburger]

Thanks Garrett. What do you mean by "remove the back". I've unscrewed the rear lens mount from the barrel as a unit, but is there a way to remove the rear element withough loosening the soft-focus mechanism?

[goamules]

Yes, the very back part should unscrew, unless they radically changed the design after the one's I've seen. You get that back off, and you should be able to get to all lens surfaces to carefully clean, if needed. If that's stuck too, you're out of luck.

[Tim Meisburger]

Yes, the very back part should unscrew, unless they radically changed the design after the one's I've seen. You get that back off, and you should be able to get to all lens surfaces to carefully clean, if needed. If that's stuck too, you're out of luck.

Thanks Garrett. Does the element unscrew at the point indicated on the photo below? If so, I will concentrate on that.

72506

[goamules]

You know, I sold my last "turn for soft focus" type a while ago, and don't want to lead you astray. But all of them that I've had unscrew at the very rear, and a piece comes off with at least the rearmost glass. Maybe someone that has one in had can unscrew it and tell you for sure.

[Jason Greenberg Motamedi]

I agree with the others, these will crack if forced. These aluminium barrels were lemons, fortunately their glass remained top quality.

[alex from holland]

Tim, i have a 3d and a 5d. Both the black alu versins.
They were both stuck but in good working order now.
It took me a few days using a lot of silicon spray.
I am abroad at the moment but can post some pictures of a opened 5d within a few days

[Tim Meisburger]

Thank you Alex. That would be excellent! I was thinking about cutting this thing open and making a new housing, but if I can get it unstuck that would be much better. I'll wait until you get back and have a chance to post pictures.

[Steven Tribe]

Looking at the condition of the barrel and the thread that you have unscrewed, I don't think that you have an impossible job in front of you. I have seen far worse condition aluminium that had become completely porous, loosing all metallic qualities.

[eddie]

Thank you Alex. That would be excellent! I was thinking about cutting this thing open and making a new housing, but if I can get it unstuck that would be much better.

oh please! do not destroy the lens! there are only so many of them around. why f up one just to open it? if you did cut it open and make a new housing (and you did not f it up) it would be totally worthless to sell. no one would pay much for it.

why not just try shooting with it and see how the pics look?

i totally disagree with steven. i will be good money it will not open.

you can try soaking the sh!t out of it like alex said....but the issue there is if you can not get it opened sometimes the oil travels inside of the barrel and then coats the glass....making it even worse than it originally was.

[Tim Meisburger]

Well, I have already tried penetrating oil and a few specks of that have already gotten in between the lenses, but it is already pretty filthy in there. Alex seems like he has had some luck getting these apart, so I'll wait to see his photos. I'll pick up some silicone next time I'm out.

[eddie]

Well, I have already tried penetrating oil and a few specks of that have already gotten in between the lenses,


you can lead a horse to water........