I haven't read the CZ patent for one-touch zoom, but I suspect that zoom creep is a design requirement. My VS28-85 C/Y is essentially new, but creeps slowly when vertical except at shortest extension.
rico wrote:
I haven't read the CZ patent for one-touch zoom, but I suspect that zoom creep is a design requirement. My VS28-85 C/Y is essentially new, but creeps slowly when vertical except at shortest extension.
Yes, actually it's kind of a non-issue, really, since you're holding the focusing/zoom barrel anyway.
If you want some extra support (for tripod work) then sliding one of those wide rubber rings onto the end of the one touch barrel could work.
Mine will extend very slowly in both directions held in a vertical orientation - but very slowly, like honey dripping off a spoon on a cool day. My new-in-box 35-70/3.4 does not move a millimeter and has a luscious liquid movement to both zoom and focus, so perhaps it's not yet broken in - or more likely is not heavy enough. The focus ring is differentiated well from the zoom function for both.
But none of this is a problem in usage, whereas the 21mm does suffer a lack of focus ring damping, and it matters much more - focus it then fingers off!.
Bifurcator wrote:
No, not separation but it's old enough and the construction is open enough that the humidity over the years can leave grime and mineral deposits on a few of the inner rear surfaces. I haven't tried to open one but it doesn't look easy. So I guess there will be a high percentage of them with some layers of film over some of the element surfaces which will look very similar to separation - only more evenly distributed. I guess it will be extremely rare to find one with none. And such shows up best with a bright flashlight shinning up through it toward your face but tilted a little to one side.
I do this with all old lenses unless I forget or something....Show more →
At least on the 35-70 there a patches / strips of felt inside the one-touch barrel. They are not placed continuously (i.e. it's not their purpose to 'seal' the lens) so I think they determine the friction that stops the creep. If one wanted these could be swapped for larger pieces, or maybe slightly thicker one.
I also suspect this can be done on the 100-300 to stop creep, if it really bothers you that much.
rico wrote:
I haven't read the CZ patent for one-touch zoom, but I suspect that zoom creep is a design requirement. My VS28-85 C/Y is essentially new, but creeps slowly when vertical except at shortest extension.
I asked an ex-zeiss (Cosina?) employee who I now do business with weekly this same question. He looked at me like I was asking a silly question and stated very a-matter-of-factly: "Of course there's no zoom creep in new ones!". He used to work on the factory floor and now owns a used lens shop of some repute.
That is an impressive magnification inglis! But I guess this really needs a tripod so that the focus can be set accurately. Or you might put the camera on a table and place a matchbox holding the key in front of the lens. Then get the focus right and use the selftimer.
It's easy to remove rear group, but as it was pointed out, it consists of 2 elements. I am not sure if they are cemented in the retention ring - I really have worries about prying those out.
Checking with Zeiss atm if it can be done...
I haven't, so easy trigger..
The last group is buggered. Good thing is Zeiss got back to me and said they will provide me a spare part...for a price of course, but so much less than buying a new 100-300 (check the auction btw)....
That's exactly my thought.. Service would cost 130 euro including element installation.
Just trying to contact Japanese service about it - don't really fancy sending it abroad, but should I have no choice...well...
My VS28-85 C/Y is essentially new, but creeps slowly when vertical except at shortest extension.
Service would cost 130 euro including element installation.
