M-Rokkor 28/2.8: Spots, Schneideritis, Haze - How can I decide, what's what?

[JohnTF]

I had one I had bought new, accidentally -- it was shipped in a 40mm box, and my local shop gave it to me for the price of the normal lens with the CL kit I was buying.

I had it for years, and as I recall, the white spots appeared in a much reduced form.

I was told it was not repairable, and sold it on at a reduced price to a happy dealer, I probably should have tested the performance, but we are kind of hard wired to see any defect in a lens to be, perhaps, more important than the subject and the guy behind the camera.

At shows, people always want lenses and bodies to be pristine in looks, even above function.

My local shop knew I was looking for an M2 user, and took one in trade with scratches on the body and a hazy lens, they did not even ask, just shipped it to me for the trade in price,-- they did not want in in the shop-- new customer wanted to trade.

I got the lens cleaned, turned out to be a simple job, and found the camera had been CLA'd and had the M4 frames installed, all for a highly reduced price mostly because the PO had scratched up the top mainly from installing and removing the meter. Yeah, it has a few "experience" marks and a slight ding.

If I pull one out to use, this is a good choice.

I'll make up a different story if I put it up for sale.

And, now, I would not have sold the 28mm Rokkor, more hind sight?

-- OTOH, got a good deal on the CV 28, some wear showing, so got it right, with adapters and M8 UV filter--

BTW, Looks like a nice cleaning job, nice of you to keep things posted on the long term.

Raid, glad you got it worked out right.

Regards, John

 

[BenCviolin]

Has anyone had success in DIY repair of the white spots ?
I was thinking (as mentioned earlier in this thread) of cutting (using a grinder) the metal crimp which holds the front element in place.
I have two of these lenses, both same problem.
Another lens I have is Kowa Six 55 f3.5, which has Schneideritis too, same metal crimp which holds front element in place.

Thing is, if the metal crimp is ground off (very) carefully then the front element should just pop out for cleaning, and then it could be rehoused.

 

[kuuan]

Hi Ben, ^ right!
Schneideritis on my copy was rather severe:


Minolta M-Rokkor f2.8/28mm by andreas, on Flickr

IQ was impacted, specially handling of highlights and looking hazy


Untitled by andreas, on Flickr, Ricoh GXR M


grandpa by andreas, on Flickr, Sony A7


therefore I decided to clean the front glass, in the end used cerium oxide. The glass looks quite clean now
( if anyone wants I shall take and show a photo of the lens after cleaning )

Handling of highlights is a bit improved, still critical but it's not "blooming" as much. A few samples:


traditional weaving by andreas, on Flickr, Sony A7



Untitled by andreas, on Flickr, Sony A7

colors, generally, are "special", a bit weird, but striking too. Not sure if I like them, would say that depends on the subject.


traditional coffee farmer house by andreas, on Flickr, Sony A7

strong highlights are still quite problematic:


Phương Quỳnh by andreas, on Flickr, Sony A7

not only the white points, after cleaning with cerium oxide, entire coating must be gone.
- If anybody knows of a service that does coating for rel. little money please be so kind and let me know

here all the photos that I have taken with this lens: https://www.flickr.com/photos/kuuan/albums/72157644175227413
first to be seen photos taken 'after' cleaning, the last 15 or so 'before'

cheers, andreas