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12-18-2018, 11:16 PM   #1
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Disassembling Takumar 24mm f3.5.

Can anyone please tell me how to disassemble Takumar 24mm f3.5? Lens has haze on the internal element. Other than regular lens cleaning liquid, do I need anything else to clean haze???

12-19-2018, 12:46 AM   #2
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It is highly likely the haze in the cement of a doublet - if so, the two elements need to be separately, cleaned, then recemented. You will need balsam to recement these elements. Are you prepared for this?
12-19-2018, 01:05 AM - 1 Like   #3
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It's possible it's not cement I have a night vision monocular, and it has two lenses in the eye piece which don't contact each other and It's hazed inside, I've since cleaned it.
12-19-2018, 01:26 AM   #4
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QuoteOriginally posted by pentax360 Quote
It's possible it's not cement I have a night vision monocular, and it has two lenses in the eye piece which don't contact each other and It's hazed inside, I've since cleaned it.
The probability is that hte haze in in the cemented doublet. I have treated three of these already. The lesser probability is thin oil deposited on an outer surface of the doublet.

12-19-2018, 01:46 AM   #5
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QuoteOriginally posted by Wild Mark Quote
It is highly likely the haze in the cement of a doublet - if so, the two elements need to be separately, cleaned, then recemented. You will need balsam to recement these elements. Are you prepared for this?
I'm prepared! How do I do it? What do I need? Point me in the right direction.

---------- Post added 12-19-18 at 01:46 AM ----------

QuoteOriginally posted by Wild Mark Quote
The probability is that hte haze in in the cemented doublet. I have treated three of these already. The lesser probability is thin oil deposited on an outer surface of the doublet.
I hope it's just oil! That would be easier!

---------- Post added 12-19-18 at 01:47 AM ----------

QuoteOriginally posted by Wild Mark Quote
The probability is that hte haze in in the cemented doublet. I have treated three of these already. The lesser probability is thin oil deposited on an outer surface of the doublet.
How did you do it. Please tell the procedure!
12-19-2018, 02:17 AM - 1 Like   #6
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First unscrew the name ring. I use a K mount end cap with some small blobs of blu-tak around the rim to give it grip.

With the name ring off, you'll see three screws that attach the front barrel/filter ring. Unscrew those carefully (they are tiny) and remove the front barrel.

Now, with rubber gloves on for grip and to avoid finger grease, you will probably be able to unscrew the front lens element assembly by hand. The front group is an airtight sealed unit, so it's unlikely that the problem will be in there. At this point you can clean the back element of the front group and the first element of the rear group, and it's quite possible that this might get rid of the haze without any further disassembly needed. Any fungus that Takumars get is usually in that air gap between the front and rear group, and maybe your haze will be in there too.

I won't go any further at this point, because it's probably best to try that simple solution first. As a general note though, if anyone owns a Takumar that doesn't seem quite as sharp as they expect, it's always worth taking the front barrel off and making sure that the front element group is screwed in tight. Over the decades they can work very slightly loose, causing a loss of sharpness especially at the edges.
12-19-2018, 02:44 AM - 1 Like   #7
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QuoteOriginally posted by Dartmoor Dave Quote
First unscrew the name ring. I use a K mount end cap with some small blobs of blu-tak around the rim to give it grip.
Good start.

QuoteOriginally posted by Dartmoor Dave Quote
With the name ring off, you'll see three screws that attach the front barrel/filter ring. Unscrew those carefully (they are tiny) and remove the front barrel.
Likely unnecessary. Use a lens wrench to unscrew the element assembly situated forward of the aperture assembly (comes out in one big group).

Inspect the rear element surface - if dirty - clean and reinspect with strong light to see if the haze is totally removed. If not undo the retainer ring to gain access to the doublet. Remove and inspect to see if this holds the haze.

If the double holds the haze then you need to separate. Here it gets tricky (and some risk). Place double in a pot of water and gently bring to boil. The idea here is to weaken the cement to a point where the lements separate. Once separated, use acetone to clean the cement off both inner surfaces.

Obtain some 100% filtered Canadian balsam glue. Place a small amount on the surface to be glued and reconnect. Align the elements carefully and then allow to dry. Can take a couple of weeks.

Await the bond to cure then re-assemble.

---------- Post added 19-12-18 at 08:48 PM ----------

I have one to do and will so so soon. I might do a pictorial to share that shows the appraoch taken. Meanwhile I recommend getting the tools.

Lens wrench
Very small Japanese Industrial Standard screw driver (moody's is best)
Some kind of implement to remove the name ring
100% Canadian Balsam glue (filtered)
Lens cleaning papers
Lens cleaning solvent
Acetone

---------- Post added 19-12-18 at 08:49 PM ----------

Some guidance on the tools is located here

Remove fungus and mold from 8-element Super Takumar 50mm 1.4 - PentaxForums.com

---------- Post added 19-12-18 at 08:52 PM ----------

balsam

Canada balsam, neutral, filtered, mounting medium, Microscopy Grade | eBay
12-19-2018, 03:20 AM   #8
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QuoteOriginally posted by Wild Mark Quote
Good start.

Gosh, thanks! Knowing that I got at least one tiny bit of it right gives me such a warm glowing feeling inside.

12-19-2018, 03:27 AM   #9
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QuoteOriginally posted by Dartmoor Dave Quote
Gosh, thanks! Knowing that I got at least one tiny bit of it right gives me such a warm glowing feeling inside.
LOL. You might need to unscrew the screws - it will depend on how tight the front retainer ring is. If it is loose then the lens wrench will remove the ring only, not the whole assembly. This scenario simply adds an extra step.
12-19-2018, 03:23 PM   #10
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QuoteOriginally posted by Wild Mark Quote
moody's is best
I can also vouch for Vessel:

VESSEL precision screwdriver 6pcs TD-56S From Japan | eBay
12-20-2018, 04:25 AM   #11
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QuoteOriginally posted by Dartmoor Dave Quote
First unscrew the name ring. I use a K mount end cap with some small blobs of blu-tak around the rim to give it grip.

With the name ring off, you'll see three screws that attach the front barrel/filter ring. Unscrew those carefully (they are tiny) and remove the front barrel.

Now, with rubber gloves on for grip and to avoid finger grease, you will probably be able to unscrew the front lens element assembly by hand. The front group is an airtight sealed unit, so it's unlikely that the problem will be in there. At this point you can clean the back element of the front group and the first element of the rear group, and it's quite possible that this might get rid of the haze without any further disassembly needed. Any fungus that Takumars get is usually in that air gap between the front and rear group, and maybe your haze will be in there too.

I won't go any further at this point, because it's probably best to try that simple solution first. As a general note though, if anyone owns a Takumar that doesn't seem quite as sharp as they expect, it's always worth taking the front barrel off and making sure that the front element group is screwed in tight. Over the decades they can work very slightly loose, causing a loss of sharpness especially at the edges.
I have seen countless videos. So this part, is doable. It's what comes next. Is completely alien to me! But I will try to understand as much as possible, before going to the next part. If the haze is because of oil, I'll be relieved. And if not I'm prepared to learn something new!

---------- Post added 12-20-18 at 04:29 AM ----------

QuoteOriginally posted by Wild Mark Quote
Good start.



Likely unnecessary. Use a lens wrench to unscrew the element assembly situated forward of the aperture assembly (comes out in one big group).

Inspect the rear element surface - if dirty - clean and reinspect with strong light to see if the haze is totally removed. If not undo the retainer ring to gain access to the doublet. Remove and inspect to see if this holds the haze.

If the double holds the haze then you need to separate. Here it gets tricky (and some risk). Place double in a pot of water and gently bring to boil. The idea here is to weaken the cement to a point where the lements separate. Once separated, use acetone to clean the cement off both inner surfaces.

Obtain some 100% filtered Canadian balsam glue. Place a small amount on the surface to be glued and reconnect. Align the elements carefully and then allow to dry. Can take a couple of weeks.

Await the bond to cure then re-assemble.

---------- Post added 19-12-18 at 08:48 PM ----------

I have one to do and will so so soon. I might do a pictorial to share that shows the appraoch taken. Meanwhile I recommend getting the tools.

Lens wrench
Very small Japanese Industrial Standard screw driver (moody's is best)
Some kind of implement to remove the name ring
100% Canadian Balsam glue (filtered)
Lens cleaning papers
Lens cleaning solvent
Acetone

---------- Post added 19-12-18 at 08:49 PM ----------

Some guidance on the tools is located here

Remove fungus and mold from 8-element Super Takumar 50mm 1.4 - PentaxForums.com

---------- Post added 19-12-18 at 08:52 PM ----------

balsam

Canada balsam, neutral, filtered, mounting medium, Microscopy Grade | eBay
How will i store the lens with balsam? You said not to re assemble. So how will I store it? & how much should I apply? What should be the temperature of the warm water.
12-20-2018, 01:17 PM   #12
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I will attempt to document the process this weekend (if I can find an hour or so spare). It is easier with pictures

Mark
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