[troglodyte]

I was just hoping someone made an adapter like the Pentax 110 MFT one which controlled the iris with the adapter. Controlling the aperature with the ring is so clunky. I've used an auto Zuiko before. Almost easy as an A lens.

[Mike Cash]

It's impossible to focus wide and then turn to the aperture I want. It's all metal and very stiff. When I try, the whole camera moves from the effort.

Mike,
The lens is mint. It's just old. That's how it was made 60 years ago. Done on purpose as not to accidently move the aperture ring. It's like comparing the TOS Enterprise to TNG Enterprise. It's all metal and glass. Works the way it did brand new.

Forgive my impertinence, but unless you had one 60 years ago you'd probably not be in a position to make that statement.

The aperture ring shouldn't be that stiff.

[Lowell Goudge]

Are there two aperture rings or one

Preset lenses have a stiff aperture ring and a soft (maybe not best description) actuating ring

We need to see a photo or two of the lenses

[erkie]

I have two Isco Gottingen lenses. Both are of the early "auto" variety. There is a lever that must be pressed to "ARM" the Iris. if used on an old film body such as my praktica FX3 or Asahi Pentax H3v the camera depresses the pin and the iris fires into position. Of course on a digital body you simply never arm the Iris and the aperature assumes whatever position you select via the aperature ring. If you hand the camera to someone and out of curiousity they arm the iris you have to remove the lens and manually depress the pin so the iris fires. (irritating but for some reason everyone immediately sees the arming lever and it's the first thing they want to play with)

However both lense have SILKY SMOOTHE But Well Dampened focusing and Aperature rings. A stiff aperature ring WAS NEVER a FEATURE built into an Isco screw mount lens. As thy would unscrew from the camera in use. Over time the lubricants used can dry out and gum up so a CLA sounds in order if the Aperature ring is that stiff

Eric

[troglodyte]

Eric, seems the problem with movement is the clicks for each fstop. 3.5, 4, 5.6, 8.... At each fstop it is hard to go over this 'bump' between stops it's smooth like the focus. Wonder why each stop has a grip like that?

[stevebrot]

...Wonder why each stop has a grip like that?

Old grease turns to glue.


Steve

[newarts]

newarts,
The problem is, I would like a lever to push. That opens and shuts. either a push or release to open to f3.5 and the other to say f16. The lens has only one aperature ring. no auto. no auto lever switch. how do they add such on auto-taks?

I think the probability of being able to modify the lens as you'd like is very small, that's why I recommended lubrication. The lens will most likely be easy to use as originally intended when the aperture ring is lubricated.

Like Steve said, old grease turns to glue.

The aperture ring probably won't be hard to remove; just don't lose the little ball.

Dave

[erkie]

Eric, seems the problem with movement is the clicks for each fstop. 3.5, 4, 5.6, 8.... At each fstop it is hard to go over this 'bump' between stops it's smooth like the focus. Wonder why each stop has a grip like that?

Old grease turns to glue.


Steve

I think the probability of being able to modify the lens as you'd like is very small, that's why I recommended lubrication. The lens will most likely be easy to use as originally intended when the aperture ring is lubricated.

Like Steve said, old grease turns to glue.

The aperture ring probably won't be hard to remove; just don't lose the little ball.

Dave

That is very much my assesment as well ! The old grease turns to a thick paste as the petroleum base has evaperated leaving only the solids and the Ball has a very hard time at the detents. The lenses are well crafted and the machining is quite well done but with pretty close tolerances. Once the grease thickens it really makes it stick. But once properly lubed they are as fine a lens to use as any I have found. To be honest both of mine are at least the equal of my takumars. One thing the Taks have over almost all other lenses was the lubricants they used. Even after years of use they seem to perform wonderfully. The German lenses used very fine premium grease but time isn't as kind to it. I can literally use my index finger to focus and the aperature ring takes very little effort with thumb and forefinger. It doesn't just spin because it's well damped but it is effortless.

Well worth the trouble of a CLA either done yourself or professionally.

I personally wouldn't use the lens much until I lubed it as you could easily Gall the ball or detents and it might not ever be as easy as it should. Just my 2cents

Eric

[erkie]

Out of curiosity what model is yours? As in Westromat, Westron, Westrocolor, Iscotar, Isconar, Westanar. It sounds like something Just after the Westanar with the Lever operated Iris pre arming. Which would be like an "Auto Takumar" . Which I really like on old film bodies.

Thanx

Eric

[Just1MoreDave]

Forgive my impertinence, but unless you had one 60 years ago you'd probably not be in a position to make that statement.

The aperture ring shouldn't be that stiff.

I have an Auto-Takumar 135/3.5 that had three bearings in the aperture ring instead of the single one I've seen. Why, I don't know, but it definitely made for a stiff action. I left a couple out when reassembling, partly because I was too lazy to keep track of all three when sliding the ring back on.

The aperture ring typically does benefit from cleaning and relubing. It's easy for dirt to get in there. Some lenses make this easy, some a little hard. It would be the first thing I'd try.