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Needing Help with loose focusing ring Carenar 135mm f2.8
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PostPosted: Tue Feb 22, 2022 1:22 am    Post subject: Needing Help with loose focusing ring Carenar 135mm f2.8 Reply with quote
Hello,

I'm having a lot of difficulty with a recently acquired Carenar 135mm F2.8. The focus ring has play.
When I remove the front lens assembly, I can't see how the focus ring attaches, or how to tighten it.

Likewise, when I remove the rear lens assembly, I'm not seeing a clear attach point.

Does anybody have experience with this lens and can help me?

Thanks in advance,

CN


PostPosted: Tue Feb 22, 2022 5:21 am    Post subject: Reply with quote
Hi and welcome, CN.

Does your Carenar have a removable rubber focus grip? Often there are attachment screws under focus grips.

If you can post some photos of your lens, it's likely someone here could help you.


PostPosted: Tue Feb 22, 2022 8:47 am    Post subject: Reply with quote
Perhaps
miran wrote:
For sale Carenar 135mm/2.8 lens, M42 screwmount in good condition. 10€ (EUR)



From http://forum.mflenses.com/carenar-135mm-2-8-m42-t75064.html


PostPosted: Tue Feb 22, 2022 12:45 pm    Post subject: Reply with quote
Good morning 55! I very much appreciate your help.
I have uploaded a view from the front with the main lens assembly removed, and one from the rear where nothing has been removed.

I have also looked closely at the focus ring and it's made of what feels like plastic. It's tight against the main ring.

The focus ring can be manipulated front to back and some side to side. It's enough play that I'm getting some weird effect when I tested the lens. I learned in my Astrophotography hobby that if the front and rear lens is not aligned, you get a ton of problems.

I'm sure it's the focus ring, but I don't see how to get to it. Is there a way safely remove the plastic/or rubber on the focus ring???
#1


#2


Thank you again!

CN


PostPosted: Wed Feb 23, 2022 6:02 am    Post subject: Reply with quote
Cheesenacho wrote:
. . .
I have also looked closely at the focus ring and it's made of what feels like plastic. It's tight against the main ring.

CN, yes, the grip may be vinyl or somesuch material, but if the barrel above and below the grip feels like metal, the grip will probably be removable.

When I want to remove a focus grip, I first heat it to help make it more flexible. A hair dryer for a minute or two should help.
Then, a pry tool can lift up the edge of the grip until you can fold it back on itself to reveal any screws. Or sometimes grips can just be wriggled off the barrel without folding.

So what sort of pry tool to use? I usually try first with a small, flat blade screwdriver. Or a wood toothpick might work. Sometimes it's necessary to reach down inside a couple inches / cm to disengage adhesives which may be holding the grip in place.

Most grips I've dealt with have been flexible enough not to tear, but sometimes they do rip. A couple times I've had to glue a torn grip back in place.

If your grip is removable, I'd start peeling at the bottom and fold upward - or start lifting at the top and tug upward. Screws might be anywhere under the grip, but it seems to me they're more often at the bottom half of a focus barrel. Then again, sometimes the whole grip needs to be unpeeled / removed to be sure no screws are still hiding.

If the grip comes off and there are loose screws underneath, after tightening you might secure the heads with a drop of glue or clear nail polish - the same way (it appears) as the three screws inside the barrel in your first photo. If needed, most glues or nail polish will loosen up with a drop of acetone.

Tightening grip screws would be a simple solution. I hope that's the problem.


Cheesenacho wrote:
The focus ring can be manipulated front to back and some side to side. It's enough play that I'm getting some weird effect when I tested the lens. I learned in my Astrophotography hobby that if the front and rear lens is not aligned, you get a ton of problems.

With the lens intact, do the front element and accessory thread rotate along with the focus ring? If you have a single focus helicoid lens, something else may be causing the looseness.

Were the front elements securely fastened in the barrel before you removed them? Did you notice any rattling sounds from the lens?


PostPosted: Wed Feb 23, 2022 12:20 pm    Post subject: Reply with quote
[quote="55"]
Cheesenacho wrote:
. . .

With the lens intact, do the front element and accessory thread rotate along with the focus ring? If you have a single focus helicoid lens, something else may be causing the looseness.

Were the front elements securely fastened in the barrel before you removed them? Did you notice any rattling sounds from the lens?


Good morning 55,

With the front lens assembly reinstalled into the body, it does not rotate when the focus ring is turned. It remains still.
The front lens assembly did not have any issues with installation when I purchased it. It was secure. Also, there are no rattling sounds, as I did check this thinking maybe a screw or something had fallen out.

So, hair dryer, I will need to try this, but before I do, how does the plastic focus grip get secured again? Does it need adhesive as well afterwards?

Again, THANK You for helping me. I have only recently jumped in with both feet and no scuba tank into this world of vintage lenses and am very excited about breathing life into these old lenses. Sadly, I have 3 now, and all have some issues. At least the others have fungus/haze, and maybe that will be easier to fix!

CN


PostPosted: Wed Feb 23, 2022 6:19 pm    Post subject: Reply with quote
Cheesenacho wrote:

So, hair dryer, I will need to try this, but before I do, how does the plastic focus grip get secured again? Does it need adhesive as well afterwards?

CN


That focus grip material looks suspiciously similar to the one Minolta used for their manual focus lenses.

If it is, it is likely a fairly stretchy vinyl with lots of plasticiser that can simply be pulled & manipulated off the focus ring (like a very wide rubber-band that is stretched around it).

Feel it with your finger nail: if it does feel a bit soft and slightly rubbery, it is probably a soft stretchy vinyl that has just been loosely fitted like a wide rubber-band. If it feels quite hard it is likely a hard vinyl that has been glued down. The latter will have a tell-tale join somewhere, but that can be hard to spot if they fitted it very neatly.


PostPosted: Wed Feb 23, 2022 7:31 pm    Post subject: Reply with quote
55 and Rokkor Doctor,

The problem is in fact under the rubber grip of the focus ring. I found three tiny screws that go through the plastic focus ring and push against the aluminum frame below.

I loosened two of the three and the ring nearly falls off.
I tightened these two and the problem was better, but still there.

The last set screw is stuck, and now a bit mangled. Well, maybe more than a bit and I am unsure what to do next.

So I ended up at Biggs Camera and told them my problem and they told me they had a junk aisle full of stuff, maybe I could find something there.

Sure enough, I found a JCP 135mm f2.8 prime lens that looks nearly identical, with Japan optics as well. I rolled the rubber grip up and saw the same three tiny set screws. I got the lens and came home.

Now I was thinking about drilling out the one bad set screw on my original 135mm lens and use a set screw from the JCP lens, or using epoxy in the set screw hole it the plastic threads became a mess.

At then realized after looking over the JCP lens that it appears to be in really good shape.
However, I don't know what kind of mount it is. I'm new to the Vintage Lens hobby and can't identify them yet.

At the moment, I want to thank both of you for putting me on the right track. However, I may abandon this lens and figure out which adapter I need for the JCP. This may be a much less painful exercise.

Thanks again!!

CN
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