Tamron SP 60-300/3.8~4.5 Adaptall-2: Cloudiness and separation, replacement of lenses

An SP 60-300 with a heavily clouded lens and separation is on my table.



Beautiful, mechanically ok, but with an optical handicap ...




... which occurs in a place that is difficult to reach ...




... although I'm wondering whether the clouding is between the cemented lenses ...




… because then trying to get there from the rear and clean the cemented lens would be of no use.

Here, assuming disassembly is successful, only the Optik-Labor in Germany could help.

Is it worth it?

Yes, since this tele has excellent reviews.

Apart from the cost of this treatment.


What do I do now?

1. Leave it as is and put it in the spare parts box? > I can still do that if 3 isn't successful.
2. Or take photos with it in this state? > A significant reduction in contrast is to be expected.
3. Or open it and see if the lens can be removed successfully? > The only option that makes sense. Because there is nothing to lose.

So 3!

And if it works, the lens has a treatment with Optik-Labor.

How to open?

First from the rear, that's easier.

And if things don't go any further, from the front.

I see openings for the spanner wrench.

Lets see what happens

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This project reminds me of the picture for another project:


Commander Walter M. Schirra Jr., aboard Apollo 7


He also looks through glass into the unknown …

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I only found this one report to disassemble:



Perhaps I will come from the front, by diassembling the front lenses, to this point without having to remove the focus ring.

My hope are these two openings (green), which probably serve as holds for the spanner wrench.

So I should be able to get the optical construction unit out there:




And there's an exploded view with parts list on Learn Camera Repair:



Broken lens extracted: Advance to the base of the fog

I was able to get the lens out with separation and fog.

As expected, these are two cemented lenses that show signs of separation.

I managed to remove the coating on the outside, but I can't solve the problem with the separation.

The zoom was easy to disassemble.

The high quality of the workmanship is striking.

Exclusively metal, solid construction, all lenses installed in heavy mounts.

Nothing is cheap there

I'll let the pictures do the talking and comments where necessary.


First attempt at access via the rear

I couldn't reach the lens this way, but here is the disassembly sequence for anyone who is interested in the structure there:

Second access attempt via the front



The inner retaining ring fixes the front lens.

It can be loosened and unscrewed using the spanner wrench via two recesses.




This makes the recesses in the second retaining ring accessible, which turns out to be a solid mount for the second front lens.

I was only able to loosen the socket after applying plenty of WD-40, waiting a long time and using force.

The spanner wrench slipped off

Apart from a few superficial abrasions on the thread of the tube, nothing happened. This can be touched up later with a touch-up pen






Now the two round openings for the spanner wrench were accessible.






A heavy, solid group of components came to light.




Now I had arrived at the „problem lens“.

There are two shallow grooves on the socket, but none of my tools worked.




This is how the large flat-nose pliers with rubber cylinder came into play.




By turning the cylinder, the socket came loose via friction.




The cemented component group ...








… which I dismantled, this time with the help of a slightly smaller rubber cylinder.

The lens with separation is to see in the middle here.

As is the case with separation, the cement between two lenses comes loose.

Unfortunately I can't do anything here






But at least I was able to remove the coating from the outside.




Overview


Since I can't leave the parts on the table until the defect lens is repaired, I remounted the zoom.

The applied WD-40 must be removed from the threads. Otherwise it will crawl and possibly contaminate the lenses.

This is easily done with Zippo lighter fluid:








And the traces of the adjustment key are erased as best as possible ...






On the Nikon F3/T, the cloudy lens is clearly noticeable in the viewfinder image. The lens cannot be used for photography in this condition:




The included Nikon Ai Adaptall-2 adapter, however, works perfectly.

And after a refresh with Zippo, it shines again:

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Since I have a second 60-300 with perfect lenses, I decided to give up on this zoom. It would be possible to repair the fogged lens group in the optics laboratory, but the costs would be too high for me in this case.

A pity


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All information provided without guarantee and use at your own risk.

You could try heat soaking these elements slowly and gently returning them to room temperature to see if the cement would dispel the fog.

Not much to lose now...

Kino said:

You could try heat soaking these elements slowly and gently returning them to room temperature to see if the cement would dispel the fog.

Not much to lose now...

Click to expand...

Yes, that would be an option to play with. But I give up on cemented lenses, that's for the specialist who maintains the optical properties.

I have seen people demonstrated how they use uv glue re-bonding the lenses. It's a bit risky by works. I am Not sure if I would try this later since there is a separated voigtlander Ultron and I wish to glue them back again

Have you tried soaking the elements overnight in alcohol?
If you can get the balsam to dissolve, you can then re-cement them together.
It won't be as good as new, but it could turn out to be interesting.

Xylo said:

Have you tried soaking the elements overnight in alcohol?
If you can get the balsam to dissolve, you can then re-cement them together.
It won't be as good as new, but it could turn out to be interesting.

Click to expand...

Thanks for the tip! Since I saw the effort that goes into professional repairs of cemented lenses, I don't want to try anything myself.

kl122002 said:

I have seen people demonstrated how they use uv glue re-bonding the lenses. It's a bit risky by works. I am Not sure if I would try this later since there is a separated voigtlander Ultron and I wish to glue them back again

Click to expand...

This affects the optical calculation. I lack the knowledge and skills to do this.

Andreas Thaler said:

This affects the optical calculation. I lack the knowledge and skills to do this.

Click to expand...

I've seen people lay the glass elements in front of a printed crosshair target that's set on a level table and visually align the elements so that they don't "break the line". Gravity holds the elements together until ready.
The glass glue is often UV curable, so unless it's hit with a UV lamp, it stays liquid so that you can move the lenses around as much as you want.

Excellent news!

A friend unexpectedly sent me an abandoned Tamron 60-300 that he no longer wants to work on. The lenses are better than on my copy.

So a repair attempt can be made soon

Quick review of Tamron zoom for spare parts



This lens had already been worked on by one of the previous owners; it came to me partially disassembled.




I'm only interested in the condition of the inner front lenses.

They are clear, some separation is visible in one of the front lens elements (under LED light). But no clouding that makes my repair candidate unusable for taking photos.




An attempt has already been made to remove the front ring. The spanner wrench has obviously slipped in the process. This is a sign that the ring is stuck. I will use WD-40 as before to make the ring easier to remove.




The exceptional material and manufacturing quality of this SP Tamron is clearly visible here. The lens is made entirely of metal and is accordingly heavy. A hallmark of Tamron's premium line for Adaptall-2.




If I can't remove the front ring, I'll cut through the tube here with the Dremel to get to the inner front lenses.

From then on, I'll continue as described above.

Since I reassembled my repair candidate last year after the inspection so that all the parts can be removed easily, I don't expect any difficulties in replacing the lenses.

But you can never be sure what to expect

Andreas, do you ever record or film yourself while dismantling cameras or lenses? I imagine it might be useful to have a reference for putting everything back together?

miha said:

Andreas, do you ever record or film yourself while dismantling cameras or lenses? I imagine it might be useful to have a reference for putting everything back together?

Click to expand...

No, that would be too much information for me, I only take photos.

But for disassembling and assembling a complex zoom eg. it would be worth considering.

Removing the optical parts for replacement from the donor lens



I start disassembling from the front but can't loosen the front lens with the spanner wrench; it only moves a little and then gets stuck.

I apply plenty of WD-40 to the thread and let it soak in for a few minutes.




Now the lens can be unscrewed.




As soon as the lens rotates freely, I continue with the plastic spudger which does not scratch. This is quicker than using the spanner wrench, which is only intended for initially loosening screw connections.




The front lens has been removed.








We continue with the removal of the optical unit underneath.








I try to unscrew the next optical unit below with the rubber cylinder. But no success.






So I have to disassemble the lens further to get to that spot.

All the plain bearings have to come out so that I can separate the tubes from each other.






Two of the plain bearings cannot be unscrewed. I drill into the screws and remove them using the screw extractor bit on the cordless screwdriver. Since I no longer need the screws, I can use this destructive method.




All plain bearings with their screws are out. They go into my spare parts inventory.

The tubes are separated.








After removing the aperture register I arrived at the optical unit.




The lower lens can be removed after loosening its retaining ring.




Here is the view through the tube from the other side on the upper part of the optical unit.




WD-40 helps again.




Now this part can also be unscrewed with the rubber cylinder.

The lens in the middle is cemented and shows separation.




Here it can be seen in the picture on the right, to the left of it is the lens from my repair candidate, which is in worse condition.

To fix the separation, the lenses would have to be separated and re-cemented. There's nothing I can do about it, but replacing the lenses will make a difference.




There is also a problem with clouding in the first optical unit. I take the unit from the donor lens (right) to replace it, although there is clouding around the edge.






I disassemble the optical unit I am replacing to take a closer look at the problem. It is again a cemented lens.


Replacing the lenses and assembling





The cemented lens is set in the second optical unit.

Assembly of the second optical unit.










The first optical unit is also back in its place.




Some cleaning.








On the second lens from the front there are traces of a lens sucker. Removal and cleaning.




The assembly is complete. Next to the lens are the replaced parts.




Fire of lens coating.

Attaching the Adaptall-2 adapter for Nikon F and testing it on the Nikon FM3A.

Everything looks good in the viewfinder




I thought it would be a short project today. But I was wrong, it took all of today's afternoon to complete

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Conclusion

• I had already put this nice Tamron zoom in my box for spare parts until I unexpectedly received a donor lens.
• By replacing the two optical parts I was able to improve the lens. In any case, I can take photos with it again.
• I cannot repair the cemented lenses myself. I also don't believe in trying to heat them in the oven to achieve a fix.
• This job belongs in professional hands. I might send the two removed cemented lenses to the OPTIK-Labor in Görlitz/Germany to be re-cemented. Then I will have replacements that are as good as new.

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All information provided without guarantee and use at your own risk