M-Rokkor 28mm f/2.8 lens: White spots-- are they an issue?

filmfan · 02-06-2012

Hello,
I am looking for a good/inexpensive (aka value) 28mm lens for my M6 and I have noticed that the Minolta 28mm lenses go for reasonable prices considering their white spot issue.
I just checked ebay and noticed that almost every lens for sale has a case of the spots (in the $400-550 range). Do widespread spots have an impact on image quality? What should I avoid? If the spots do have an impact, to what degree does it occur? Do they spread?
Thanks,

-Sam

Phil_F_NM · 02-06-2012

They don't degrade the image past what haze can do. And not even that bad too. A case of bad white spots will just increase flare some and reduce overall contrast but it's not a dire problem like separation.

Phil Forrest

roundg · 02-06-2012

Almost all the Rokkor 28 have the famous white spot issue. I only saw one said free from White Spots and went for premium price (I think it was 2 year ago on RFF).

I used to shoot intensively with a Rokkor 28 with white spot, nothing I can really see or detect on the final pictures.

Most of white spot should be stable as so many years. But I am not sure how it will be if it's used in a very hot climate.

maddoc · 02-06-2012

I bought one copy of that lens from Yahoo ! auctions last year, it was announced as having "a couple of something that looks like white spots" ... What I received was a lens with an about 3mm wide white ring on the rear-side of the front-element, where the white "spots" had grown together ...

Kavenzmann · 04-05-2012

I got one last year. With white spots and haze...
I sent it in for service, where they repaired both of the problems. It wasn't cheap, but worth every penny. It's still one of my favourite RF lenses. It renders so beautiful even on digital cameras like my NEX-7.

Kavenzmann

rbelyell · 04-05-2012

how are 'white spots' 'repaired'? is it similar to fungus removal?

Beemermark · 04-05-2012

I had one with a lot of white spots and regret selling it (but I have the 28 Elmerit). Never noticed any difference between the two lenses on film or digital.

KoNickon · 04-05-2012

Mine is sorely afflicted by the white spots, and the effect is a fair amount of flare. I have not tried it indoors or on overcast days, but I expect I will see the effect there too. Unfortunately, John van Stelten told me not to bother having him open it up. I do wish I could get it cleaned, but if he's saying it's not worth the trouble then I guess it's too far gone.

Yachah · 04-20-2012

I had rokkor 28 from ebay one year ago
it came with a thousand of small bubble haze and white spot...

I took it to my camera man (in Thailand of course) for an emergency job...
after one hour.... he clean all the haze and painted the black color over the white spot..
it was 20$ for fixing the problem..

The lens is now clean and clear... no problem of flare
White spot never come back.. (of course it has been paint black)

beware of the haze... it can come back anytime..

Lflex · 04-20-2012

Not as compact, but why not consider the nice current Voigtlander 28/2?

krötenblender · 04-20-2012

Mine had the white spots an Schneideritis (the bigger white spots where the lenses are glued to the tubus). They were not a real problem, but I had them fixed. The most important difference is, that the lens looks much better now, but impact on image quality is minimal (maybe a little bit less flare and more contrast in complicated light). See my experience in this thread:

http://www.rangefinderforum.com/foru...d.php?t=101359

staal571 · 04-25-2012

I have since 4 weeks also an 28 mm M-Rokkor with white spots, I asked the camera repair man in the Netherlands what it will cost to repair, he came with a price nearly € 150,-- to € 200,-- including an CLA for the lens.
Will that be worth it?

Gr peter

sleepyhead · 04-25-2012

Peter, I would shoot a few rolls with the lens before doing anything.

My impression of the white spot problem is that it is the PRESENCE of the spot that bothers people more than any effect of the spots themselves on image quality.

krötenblender · 04-25-2012

That is correct. I don't regret paying for the repair, but iq-wise, it did not have that much effect. Maybe one can find a positive effect because it does not flare as easily as with the spots, but I can not really see much of an effect there.

Yachah · 05-01-2012

can anyone give the comments about the image characteristics of this lens ?

Phil_F_NM · 05-01-2012

It's remarkably close to the Leica 28mm Elmarit (pre-asph) but a bit smaller. I had the opportunity years ago to use one on long term loan and it was a fantastic lens. I had a Kobalux 28 at the time so purchasing the Minolta wasn't as big of a deal and I didn't go through with it. Now I'm wishing I had since the price of that one was about half the price they run these days.

As for the images themselves, it made a slightly lower contrast photo than my Kobalux did (but the Minolta had white spots.) Aperture-for-aperture the Minolta outclassed the Kobalux, slightly in the center of the image and all the way out to the edges it was much better. The Kobalux showed a bit of spherical aberration that "smeared" the corners but sharpened up a lot by f/5.6 and like most lenses, at f/8 I couldn't tell the difference.
Minolta had the edge in edge performance (pun intended) as it vignettes less and is sharper.

Since this is a late 70's design it shows that old glass can still hold its own. It is a fantastic performer but would be outclassed by the new ZM 28mm f/2.8, the Konica 28mm and possibly by the three CV lenses of the same focal length. Modern coatings, modern designs, less use than a 30 year old lens.

Aside from the tiny Kobalux 28mm, the CV 28/3.5 and the small Canon 28mm lenses, this is definitely one of the smallest 28mm lenses and probably the smallest with an f/2.8 aperture.

I still long for my old Kobalux which I sold years ago because of its size but in spite of the white spots, I really want a Minolta 28 because of its size, reputation and what I have seen it capable of capturing.

Phil Forrest

sleepyhead · 05-01-2012

I second Phil's assessment above.
I bought mine because of it's small size, but the images are plenty sharp enough, with a more mellow contrast than a more modern lens (I prefer mellow) - by the way, my example lacks the spots.
The bokeh is very pleasant.

JayM · 05-01-2012

Quote:

Originally Posted by Lflex

Not as compact, but why not consider the nice current Voigtlander 28/2?

Yeah! You should think about this lens as it is really great. Seems to be only a little bit longer than the Elmarit ASPH (elmarit with hood of course.)

I use it every time I take a picture of something

raid · 05-02-2012

I sold my Canon 28/3.5, but I kept the Kobalux, which is in like new condition. My Rokkor has a very small amount of white dots that I never identified for many years. When I sold the lens at RFF, the buyer returned the lens because of them. I am so glad that he did. It has a Leica look to its images, and it is small.

Quote:

Originally Posted by Phil_F_NM

It's remarkably close to the Leica 28mm Elmarit (pre-asph) but a bit smaller. I had the opportunity years ago to use one on long term loan and it was a fantastic lens. I had a Kobalux 28 at the time so purchasing the Minolta wasn't as big of a deal and I didn't go through with it. Now I'm wishing I had since the price of that one was about half the price they run these days.

As for the images themselves, it made a slightly lower contrast photo than my Kobalux did (but the Minolta had white spots.) Aperture-for-aperture the Minolta outclassed the Kobalux, slightly in the center of the image and all the way out to the edges it was much better. The Kobalux showed a bit of spherical aberration that "smeared" the corners but sharpened up a lot by f/5.6 and like most lenses, at f/8 I couldn't tell the difference.
Minolta had the edge in edge performance (pun intended) as it vignettes less and is sharper.

Since this is a late 70's design it shows that old glass can still hold its own. It is a fantastic performer but would be outclassed by the new ZM 28mm f/2.8, the Konica 28mm and possibly by the three CV lenses of the same focal length. Modern coatings, modern designs, less use than a 30 year old lens.

Aside from the tiny Kobalux 28mm, the CV 28/3.5 and the small Canon 28mm lenses, this is definitely one of the smallest 28mm lenses and probably the smallest with an f/2.8 aperture.

I still long for my old Kobalux which I sold years ago because of its size but in spite of the white spots, I really want a Minolta 28 because of its size, reputation and what I have seen it capable of capturing.

Phil Forrest

Gazzah · 05-22-2012

I have just had delivered a Rokkor 28 2.8. Tried it out on the R-D1 - boy is that a contrasty (?) lens, unless all my other ones are full of haze... Apart from the fact that I managed to under expose by 1/2 -1 stop (forgot Id been playing with the compensation dial - silly boy) I very happy with it - no haze no white spots, lovely little hood...

Gary NH

astro8 · 06-03-2012

I just now opened up, cut the front element out and cleaned the haze out of my 28 M-Rokkor. It was useless the way it was...although the procedure is not for the faint of heart!

before and after surgery

raid · 06-03-2012

The improvement is amazing, Greg.
Well done.

sleepyhead · 06-03-2012

Amazing difference! What did you use to do the cleaning?
A solvent of some kind?

astro8 · 06-03-2012

The haze wasn't easy to budge. I used window cleaner, then methylated spirits, then acetone, then acrylic laquer thinners, then a 3M product that removes residue. I'm sure it was the acetone that worked the best. The coatings on these things must be pretty tough!

That was the easy part. The hardest, well, most demanding part was cutting slits through the collar that captures the front element to release it. There might be another way, but I couldn't figure one out for fear of breaking the element.

I don't recommend anyone try this. There is no way I'd try this on my leica lenses but as you can see from the before pic, this lens was toast. I won it in on ebay for $235.

All my lenses are leica from 1966. I wanted a v1 elmarit to match their rendering but they are expensive and big. From everything I've seen and user's opinions, the rokkor's rendering is very, very similiar and it's nice and compact for a 28.

I had a canon 28/2.8 but sold it here on rff, for some reason I just didn't get on with it.

sleepyhead · 06-03-2012

Even though the lens was a loss - you're a bold man!

I wish I had the skills to open lenses up and do surgery...