Soligor C/D 28-80 mm f3.8-4.8 (OM): Overhaul

A Soligor zoom came to me with an Olympus OM mount in clearly used - but not abused - condition:



Here the rubber coating of the focus ring has been removed in order to explore the screw connection.




The bayonet screws don't get stuck and can be loosened - a good start.


The zoom is dirty on the outside, the aperture ring is difficult to turn, there is a crackling noise when sliding zoom and focusing, and both seem tired or reluctant. The fungus sits somewhere on a lens, dust on the lenses glitters in the LED light:



I want to see what I can do to refresh it.

• Disassembly will be necessary to clean the zoom mechanism as well.
• Cleaning and greasing the helicoids.
• Clean and grease the inside of the aperture ring.
• Remove, disassemble and clean optics.
• Cleaning the inside, all rings and the outside surfaces.

There is also a review of this nice lens by Robert Allen Kautz:


However, the maximum aperture values of my lens differ slightly with f = 3.8 - 4.8.

But it should be the otherwise same lens, at least I think so.


Disassembling and reassembling zooms is exciting

If you have just understood one thing and put it back together correctly - who counts the hours - the next one presents you with problems again.

Each zoom is constructed slightly differently, the principle is similar, the implementation is colorful.

You can't rely on anything.

This time was no different.






Cozy start

I took off the rubber coating on the focus ring the day before.

The decorative ring can be easily unscrewed using the rubber cylinder.




The bayonet ring also poses no puzzles.

Loosen its three screws without any problems.




Part of the aperture mechanism and the rear optical assembly.




The aperture ring and the aperture stop ball.

It behaved tamely and didn't jump away when I took off the ring.

The old grease in the notch held it back.




Turned out the optical assembly.




In order to remove the front optical assembly, I have to deal with the focus ring and its coupling to the front helicoid.

There are two stops for maximum and minimum distance adjustment.

The focus ring is connected to the front helicoid via a cylindrical slipcase.

As far as I can see, I mark the infinity position for later assembly and hope that it will work.




The two plain bearings of the straight guide can be reached via two hatches.

The sliding zoom setting runs from 80 to 28 mm.

Both bearings are damaged but still holding.




Dismantled

That's always a bit of a clammy feeling.

„Once I understand the mechanism, can I put everything back together correctly?“

Photos help.




The helicoids are separated.

I have marked the jump point and remember a 3/4 turn to infinity for assembly.

The old grease has to go.




Position of the aperture in the tube.






Degrease the helicoid guides with Zippo lighter fluid.




Clean




The plain bearings for the zoom mechanism.

Cracks here too.




Fresh green grease: Castrol LMX










The front optical assembly cannot be separated.

But there is no need for this because everything is clear inside.

I just need to clean the outside of the rear lens.

Optical cleaning cloth, little isopropyl alcohol, wipe with a little Aqua Purificata.




Joining the two helicoids together.

The usual patience game.




The plain bearings receive some silicone oil.

I turn the crack in the middle towards the guide and hope that such a blockade can be held later.

The bearings should be replaced. But I don't have a replacement.




Cleaning the two rings with Zippo.

Then clean with Sonax foam cleaner, which brings the engravings back to life.






The rear optical unit comes back into place in the tube.

Here too, only the two outer lens surfaces had to be cleaned.




The two damaged plain bearings of the straight guide.




I turn the crack up because the zoom mechanism was blocked in the previous position.

Now zooming works again.

As soon as I have replacements I will replace the bearings.


Now it took patience

The alignment of the three front rings around the tube occupied me for a long time.

Only when I understood that the assembly only works at 28 mm zoom position was I able to do this.

Whoever came up with this, and other similar systems, probably wanted to have fun with anyone who tried to assemble it

I adjust the infinity position by focusing on the boom of a construction crane in the neighborhood

To do this, I rotate the front lens with the lens sucker until „infinity“ appears sharply in the viewfinder.

I fix this position with three small screws on the front ring around the helicoid.




Width of the screwdriver blade used for this purpose: 0.9 mm




I fix rusted screws with Ballistol universal oil.




I didn't have to look for this screw for long under the table.

The strong magnet took hold.




Drying the rubber coating treated with foam cleaner using the Dremel Versatip butane gas burner …




... which can be pulled into its final position with the strong tweezers.




Done


Conclusion

• The zoom is clean again so far. To clean it completely I would have had to fully disassemble it. I didn't do that because - apart from the oil - everything was in acceptable condition.
• The focus ring now rotates smoothly.
• The zoom mechanism is slightly affected by the damaged bearings. I'm looking for a replacement.
• The aperture ring clicks again.
• And the optics are clear again.
• The coupling of the focus ring to the front helicoid via a second ring is not easy to understand. But that's often the case with zooms.
• I'll do a correct adjustment to infinity, along with other lenses, on one of the next trips. High-rise buildings at greater distances are ideal for this purpose.

+++

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

I recommend wearing a protective mask and ensuring adequate ventilation, especially when cleaning helicoids with solvent. It takes quite a bit of solution to get the helicoids clean. And you shouldn't inhale the fumes.

You also have to consider the potential fire hazard, as eg. Zippo is actually intended for lighters.

I wear nitrile gloves, but they are not fireproof and can burn.

You should wear safety glasses at all times while working anyway.

Just put together the appropriate protective measures for your project and assess what makes sense in the situation. People might tend to forget about the protective measures.

What a meticulous work. Do you know the origin of this lens, was it made my by Tokina?

miha said:

Do you know the origin of this lens, was it made my by Tokina?

Click to expand...

Following


the manufacturer is Kobori and the lens was produced 1985.

If you want to do something yourself, a lens with problems is a good option. The work is varied, you never know if it will be successful and you won't get a professional service done for a few dollars' worth of zoom. Apart from the fact that no workshop will probably accept the order.

And it's a shame about these beautiful lenses. They usually come to a camera as bycatch and are little known. They are solid and of high quality.

As I understand it C/D either means computer design or compact design, I have a few in Konica mount, heavy and not that compact so I go with computer design to compete with Vivitar S1. At one time Soligor was owned by AIC who also owned Miranda, after Miranda left the marketing 1977 (?) I don't know who bought the name rights. But the late 70s version of C/D lens were likely designed my Miranda who designed all of their lens but were out sourced for manufacturing. This lens made in 1985 was not a Miranda design, which as far as I recall C/D until 1977 were constant aparutes. I have a 35 to 70 3/5 which I think is was pretty good for a 70s zoom but is not quite as sharp as the S1 version. Seems like a lot work for a middle of road 80s vintage zoom. Would like to see some of the images.

Paul Howell said:

As I understand it C/D either means computer design or compact design, I have a few in Konica mount, heavy and not that compact so I go with computer design to compete with Vivitar S1. At one time Soligor was owned by AIC who also owned Miranda, after Miranda left the marketing 1977 (?) I don't know who bought the name rights. But the late 70s version of C/D lens were likely designed my Miranda who designed all of their lens but were out sourced for manufacturing. This lens made in 1985 was not a Miranda design, which as far as I recall C/D until 1977 were constant aparutes. I have a 35 to 70 3/5 which I think is was pretty good for a 70s zoom but is not quite as sharp as the S1 version. Seems like a lot work for a middle of road 80s vintage zoom. Would like to see some of the images.

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Thanks for the information!

I'm interested in improving myself as a repairer, I bought some defective lenses specifically for this purpose. This Soligor is one from this collection.