Minolta M 90mm f4 clean

[Ibanez]

Hello all.

I recently purchased the above lens to be used with my newly purchased M5 which is currently being CLA'd. I am aware of the potential focusing issues of using a lens made for the CL/CLE lens system on a fully fledged M camera. I am not too fussed by this as I bought the lens on a whim as it had haze, not fungus (which I am certain of!)

I have some experience of lens repair, but this is the first time I have tried to clean a M mount lens. I cannot find any repair manuals on the internet (excluding the purchase of a rare repair book from 1999) on how to access the rear/front element to allow a thorough clean to be done. I have attempted to remove the rear bayonet to see if this would allow access to the rear lens element, but I could not see a logical way to disassemble the lens.

Could anyone please provide some steps/tips on how to disassemble the lens to access the lens elements? I am reluctant to send the lens away for a full CLA as it is not economically viable and my other lens (nikkor 5cm f2 ltm) is currently being CLA'd, which I use as my main lens for the M5.

Kind regards

Ibanez.

 

[gone]

I am aware of the potential focusing issues of using a lens made for the CL/CLE lens system on a fully fledged M camera.

I'm not aware of that, and have used lenses from screw mount cameras on M cameras w/ no issues (w/ an adapter), FSU screwmount lenses on Ms, swapped lenses from my CL, I don't see why there should be a problem. An M mount is an M mount.

 

[projectbluebird]

I am aware of the potential focusing issues of using a lens made for the CL/CLE lens system on a fully fledged M camera.

I have heard this the opposite way; using 'regular' M lenses on the CL might cause issues, especially with longer/faster lenses, because of the shorter RF baseline.
As momus points out, an M mount is an M mount - using a 90/4 on the M5 should not be a problem at all.

 

[gone]

This is what I figure is the deal, from a quote from Robin Smith on another forum:
"Leica used to say that the C lenses should be used "with care" on regular M's because they might not be accurate, but it is generally believed that this was said to discourage other M users from buying the bargain lenses....."

I can't really find anything on the web in regards to taking your lens apart to clean. I've never had one apart, only the R lenses, and I'll only clean the rear elements on those. You often need special tools to take those apart (and special knowledge too).

 

[John Koehrer]

In days of yore.........
Just for giggles tried a rokkor lens on an M body with some ektachrome at near, mid and infinity. showed 'em to a fella from the local Leica nerd group & in their utterly non scientific method couldn't tell it from any that they were using.
I guess under more critical testing YMMV