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Can inexperienced tackle disassembly of a Konica AR 50/1.7?
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PostPosted: Fri May 10, 2024 6:33 pm    Post subject: Can inexperienced tackle disassembly of a Konica AR 50/1.7? Reply with quote

Hello all,

New member here.

Little background: Newish to photography with a dedicated camera (late 2022). Decided to venture into these older manual lenses to slow down the process and learn. To put it short, my luck has been non-existent with these older lenses. Whether it be a local shop (here in the NYC area) or "reputable" (reputable meaning having 100% positive feedback on those auction sites) sellers I've ended up with issues.

Now onto this Konica AR 50/1.7. It's the latest/last version based on buhla.de and Konicafiles. It has internal haze based on the results I'm seeing a f1.7, bloomy and soft (from what I've been told and read/seen uncharacteristic for this lens). It makes focusing at f1.7 extremely difficult even with focus peaking and 10x magnification. It gets much better at f2.8.

Now the dilemma is do I attempt a repair with my lack of skillset. I've seen two videos on Youtube of disassembly (linked below) as well as links (mostly dead/dead pictures though). One of the videos the front elements came out very easily, on the other they came out in an assembly (element group) that seems like it might be trouble to take apart. Then there is the whole getting at the rear elements which is another can of worms.

Can someone that has taken these apart offer some words of wisdom. If they think it is doable for someone that has no prior experience? Pricing out the tools needed for this adventure; I could instead take another shot at a Konica AR 50/1.7, 50/1.4 or maybe 57/1.4 (though unlikely at my budget) and keep this one as a "character" lens. Knowing my luck the risks are about equal.Embarassed

Links to the disassembly videos I came across:
Makes it look easy
https://www.youtube.com/watch?v=Yp94P5Mp8A4

Looks tougher especially the front element group that comes out at 8:20
https://www.youtube.com/watch?v=BGhHt9DI06w

Sorry for the long post and thank you for any and all advice.


PostPosted: Fri May 10, 2024 6:46 pm    Post subject: Reply with quote

Here's a sample image with my camera's neutral jpeg profile.



PostPosted: Fri May 10, 2024 8:51 pm    Post subject: Reply with quote

Welcome DaveNJ!

Look into the lens off the camera using a flashlight to light up the interior to see where is the hazy lens element.


PostPosted: Fri May 10, 2024 9:28 pm    Post subject: Reply with quote

visualopsins wrote:
Welcome DaveNJ!

Look into the lens off the camera using a flashlight to light up the interior to see where is the hazy lens element.


Thank you for the welcome.

It looks like haze on both sides, underneath the first elements. Though doing another check right now. I noticed some maybe more concerning issues. I see a strand inside that looks suspiciously like fungus. Also when the light catches just right, marks that may be long scratches on the front element and smaller ones on the rear.

Edit: Though that strand of what might be fungus is on the top of the element underneath. At least looks that way.


PostPosted: Fri May 10, 2024 11:20 pm    Post subject: Reply with quote

There are lenses that are very easy to acces , I've watched part of the 2nd video and it seems like a very easy task.
You should buy just the minimum tools for now, you would need the rubber tools (a can that would fit inside the front ring with a rubber band underneath might be worth to try before buying the tool)..
You do need some jis screwdriver to remove the mount screws (if they aren't very tight, some other screwdrivers might work but with lots of gentle not to brake the head of the screw, in case they won't come out easily, you might need to use acetone and like a last resource proper screwdriver - In yashica ml 1.4 lens the mount screw I couldn't remove no matter what trick I've used, at least I didn't really need it). In your case ,to release the rear optic it seems like you have to remove the mount (Not the aperture ring) and nothing else, it should be easy. Just start with the front group and see how things going. You can do it.
One advice , I've learned to draw on the paper the type of the elements of each group ,so I wouldn't mix them up (more careful with the elements from the rear group , some of the are very easy to switch, as they look plane on both sides).

If you clean the affected element of the group , and you see that the others are clean, don't go further , stop there .


PostPosted: Fri May 10, 2024 11:30 pm    Post subject: Reply with quote

kiddo wrote:
There are lenses that are very easy to acces , I've watched part of the 2nd video and it seems like a very easy task.
You should buy just the minimum tools for now, you would need the rubber tools (a can that would fit inside the front ring with a rubber band underneath might be worth to try before buying the tool)..
You do need some jis screwdriver to remove the mount screws (if they aren't very tight, some other screwdrivers might work but with lots of gentle not to brake the head of the screw, in case they won't come out easily, you might need to use acetone and like a last resource proper screwdriver - In yashica ml 1.4 lens the mount screw I couldn't remove no matter what trick I've used, at least I didn't really need it). In your case ,to release the rear optic it seems like you have to remove the mount (Not the aperture ring) and nothing else, it should be easy. Just start with the front group and see how things going. You can do it.
One advice , I've learned to draw on the paper the type of the elements of each group ,so I wouldn't mix them up (more careful with the elements from the rear group , some of the are very easy to switch, as they look plane on both sides).

If you clean the affected element of the group , and you see that the others are clean, don't go further , stop there .


Thank you for the advice. I have a precision screwdriver set (not jis though) and can confirm that all the screws were able to be loosened fairly easily on the mount. That is as far as I went.

My biggest concern is those scratches I discovered in the latest look through. They appear internal and pretty large. I'm hoping it's just a reflection of something.


PostPosted: Sat May 11, 2024 12:19 am    Post subject: Reply with quote

Something tells me this lens has been opened before. Judging by how easy the screws broke loose and also the name plate ring on the front. The name plate ring came out safely with one of those cellphone plastic pry tool placed in the notch. But that is as far as I'm willing to go without proper tools.


PostPosted: Sat May 11, 2024 8:06 am    Post subject: Reply with quote

If you've removed the mount and the front group ring , basically you might not need any other special tools, with some rubber gloves ,try to release the optic group, but do one side at a time and be very gentle with the optics, remember ,only clean as far as necessary , if you find the troubles to be on the first/second element don't go further if the other elements are clean; doesn't matter what would you find out about the scratches, at least it would give you an idea on the future about possible issues lenses have , so it might be a very good practicing lens with limited (character) usage , for portraits it might do pretty well .
Pay attention that the repair guy from the video is using suction cups to remove the elements, especially the rear ones, i assume you don't have it , so be very gentle when removing those very tiny elements, never use force neither screwdrivers (maybe some Scotch tape might help) - try to remove the whole rear group at once , and from there you'd have better acces


PostPosted: Sun May 12, 2024 2:53 pm    Post subject: Reply with quote

kiddo wrote:
If you've removed the mount and the front group ring , basically you might not need any other special tools, with some rubber gloves ,try to release the optic group, but do one side at a time and be very gentle with the optics, remember ,only clean as far as necessary , if you find the troubles to be on the first/second element don't go further if the other elements are clean; doesn't matter what would you find out about the scratches, at least it would give you an idea on the future about possible issues lenses have , so it might be a very good practicing lens with limited (character) usage , for portraits it might do pretty well .
Pay attention that the repair guy from the video is using suction cups to remove the elements, especially the rear ones, i assume you don't have it , so be very gentle when removing those very tiny elements, never use force neither screwdrivers (maybe some Scotch tape might help) - try to remove the whole rear group at once , and from there you'd have better acces


No I wasn't able to remove the front group ring, only the name plate. I haven't messed with the lens further. I noticed after sitting for awhile, the aperture sticks and won't budge without lots of effort. After the initial break it moves fine and there is no oil on the aperture blades.

I've decided to hold off on this project as it'd need a complete overhaul. At this stage I'd rather get one that just works for a baseline.

Thank you all for the help.


PostPosted: Mon May 20, 2024 1:20 am    Post subject: Reply with quote

I ended up going ahead with the disassembly after ordering the proper tools especially the rubber and sucker tool. FWIW went with the tools I mentioned here:
https://cameraderie.org/threads/gas-please-share-your-latest-acquisitions-big-and-small.37224/page-339#post-632687

The haze cleaned up fine, it was light. The front element is indeed scratched internally. I don't even know how someone did that. One long scratch from end to end.

What is worse, the rear element was chipped. I saw that when I first got the lens but it looked like dried liquid/adhesive giving that reflection and wasn't worried about it at all.....well I was horribly wrong. Whoever was in before screwed up and maybe that is what caused the issues more than haze? Most of the chip is covered by that spacer.

So I'm at a loss right now. I'm thinking of using the lens to practice taking apart completely and then giving to a local camera shop to recycle. A disappointing find.

I'm also thankful the Konica 50/1.7 isn't radioactive otherwise, from what I understand, that chipped rear element could have been bad news and would've been even more upset.


PostPosted: Mon May 20, 2024 7:32 am    Post subject: Reply with quote

Congrats


PostPosted: Mon May 20, 2024 11:15 am    Post subject: Reply with quote

kiddo wrote:
Congrats


If only I found out better news though.

But thinking about it, that chipped rear element makes sense in what I was seeing. Bloomy and soft wide open and gets considerably better just stopped down even a tiny bit. Not sure I should use it as is or what.