testing an M-Rokkor 28mm

[bkrystad]

I found one of these locally and have two weeks to try it out. It was priced reasonably well for having the white spots around/on the front element. I've got a roll of HP5 that I put through my CLE with the 28mm yesterday drying in my darkroom right now. I'm interested in anyone's experience with the following:

1. What should I look for in the exposures to indicate that the white spots are interfering, if they are?

2. I have some frames shot wide open, some frames shot closed; would the spots be more evident in one type of shot than the other? (I risked flare on purpose in some of them as well, heard someplace that they show up with flare.)

3. Has anyone sent their lens to a reputable shop to make the fix that Minolta used to do at the factory for this problem? I'm wondering if this is safe or risky for the integrity of the lens, reasonable or expensive compared to waiting for a clean lens to show up at twice the price, or other experiences.

 

[chambrenoire]

I have the M-Rokkor 28mm f/2.8 - ofcourse with a lot of very fine, small white spots.

I have never seen any indications that they have disturbed my pictures or anything, fully open or at f/22. It's a real nice lens and I really like the pictures I've taken with it.

 

[Ronchnam]

I use a 28/2.8 Rokkor with white spots on my epson R-D1. Not interfering.

 

[roundg]

No worry on the white spots. No effect on pictures at all. I tried all kinds of shoot with it.

 

[raid]

I have such a lens myself. There were no white spots for 15 years, and suddenly there are spots. I sold the lens and it was returned to me because of the white spots. Maybe I am lucky that I got back my lens?

I have lowered the asking price by $125 now.

It is a fine lens, as you know.

 

[f16sunshine]

I had the lens and sold it with much regret. The white spots had no effect in any way to the IQ.
We speak of tiny white spots that have a quite distinct size and pattern correct?

 

[kermaier]

3. Has anyone sent their lens to a reputable shop to make the fix that Minolta used to do at the factory for this problem? I'm wondering if this is safe or risky for the integrity of the lens, reasonable or expensive compared to waiting for a clean lens to show up at twice the price, or other experiences.

I contacted John Van Stelten at FocalPoint to ask about repair of the spots. He charges $250 and has only a 75% success rate, as sometimes the coating damage has resulted in etching of the glass. (If it turns out he can't fix it he only charges $75.) He said the reason it's so expensive a repair is that the front element of the M-Rokkor 28/2.8 is machined into the lens barrel, and so it can't be removed by simply unscrewing a couple rings like most lenses.

FWIW, I'm the one who bought Raid's lens (thinking that it was spots-free) and returned it. The spots issue just makes me uncomfortable, having read about it's potential to progress from the edge toward the center until it becomes a problem for picture taking. After reading the testimonials from all of you here, perhaps I'm being foolish.

Cheers,
Ari

 

[bkrystad]

Thanks, everyone, great input.

I just spent thirty minutes in my darkroom looking at negatives from my test roll projected on a clean sheet of white paper under the enlarger at f/2.8 (bright). I can't identify any consistent (or even varying) aberrations on the negatives, even in flared shots where I would expect some refraction or ghosting from the crystals on the lens surface. Though I'm only partly sure what I would be looking for on the negative if any defects were indeed present.

I agree that if the spots progressed and occupied more of the lens surface than the edge, that would be frustrating. Hearing from Raid that the spots can suddenly appear on a previously clean lens makes me think waiting for a clean one might not be worth it. And $250 is an awfully expensive repair for a lens that only fetches at most twice that when mint.

Hmm. I'm on the fence. I'm going to print some of my test frames next week and scratch my head some more. I'll post some scans on this thread when I have them.

 

[Beemermark]

I have the white spots and in the 10 years or so I've owned I haven't noticed any growth. In the last year or so I picked up a nice 28 Elmarit and I can tell no difference in identical pictures taken with the two lenses. The white spots are a non-issue, just like bubbles in the glass and dust specs on the inner elements.

 

[LChanyungco]

could someone post a photo of the spots ? thanks.

 

[raid]

I contacted John Van Stelten at FocalPoint to ask about repair of the spots. He charges $250 and has only a 75% success rate, as sometimes the coating damage has resulted in etching of the glass. (If it turns out he can't fix it he only charges $75.) He said the reason it's so expensive a repair is that the front element of the M-Rokkor 28/2.8 is machined into the lens barrel, and so it can't be removed by simply unscrewing a couple rings like most lenses.

FWIW, I'm the one who bought Raid's lens (thinking that it was spots-free) and returned it. The spots issue just makes me uncomfortable, having read about it's potential to progress from the edge toward the center until it becomes a problem for picture taking. After reading the testimonials from all of you here, perhaps I'm being foolish.

Cheers,
Ari

Ari,
Are you getting second thoughts!😀:angel:

 

[bkrystad]

Photo of the lens I'm testing (which shows I need to clean my lenses better!) attached.

 

[raid]

The spots do not seem to impact the image qualities at all based on what I have read online. My photos with my lens always came out great, even though I never saw before any spots until Ari told me about them.

 

[raid]

Here are some images taken with the Rokkor.

http://photo.net/photodb/folder?folder_id=605103

 

[kermaier]

Ari,
Are you getting second thoughts!😀:angel:

Raid, I believe it was you who posted in a similar thread a couple of years ago that you would never consider buying one of these with spots! 😱

But seriously, I think I would only buy one with spots if the price were quite low, such that the cost of having it repaired wouldn't end up making the total price too outlandish. Just my current feeling on the subject, which could change.

::Ari

 

[Krosya]

I dont understand - why play game and gamble when there are so many other good 28mm lenses out there that dont have any spots problems?

 

[raid]

Raid, I believe it was you who posted in a similar thread a couple of years ago that you would never consider buying one of these with spots! 😱

But seriously, I think I would only buy one with spots if the price were quite low, such that the cost of having it repaired wouldn't end up making the total price too outlandish. Just my current feeling on the subject, which could change.

::Ari

Ari,
I had the "spotless " lens at that time. I may have been mistaken in thinking that the spots cover up the area through which the light goes through.

 

[raid]

I dont understand - why play game and gamble when there are so many other good 28mm lenses out there that dont have any spots problems?

The spots seem to be harmless.
The Rokkor-M is of equal quality as a Leica 28mm lens of its time.
The built quality is excellent too.

 

[Krosya]

The spots seem to be harmless.
The Rokkor-M is of equal quality as a Leica 28mm lens ot its time.
The built quality is excellent too.

That MAY be true, but I'd prefer a "spotless" lens. 😉

 

[kermaier]

I dont understand - why play game and gamble when there are so many other good 28mm lenses out there that dont have any spots problems?

Well, I don't think there's any other 28mm out there to match the particular characteristics of the M-Rokkor, those being:

• Size - The CV Skopar 28/3.5 is smaller, but it's not as sharp across the field at wider apertures, and it's a half-stop slower.
  
• Speed - The Konica M-Hexanon is an f/2.8 lens also, but it's twice the size, and usually 1/3 more expensive. The Leica Elmarit is an f/2.8 lens, but at least 50% larger and 2-3 times the price.
  
• Performance - The older Elmarits are no better than the M-Rokkor. The M-Hex is probably sharper and more contrasty (more modern manufacture and coatings, of course).
  
• Cost - M-Rokkors go for $400-$600, Elmarits for $800-$1200, M-Hex for $500-700, Skopar for $300.

The combination of size, speed and performance at moderate cost makes it a very attractive lens, in theory -- if only one can be found with it's front element not a slowly ticking bomb. So, there are those who keep using a spotty M-Rokkor and hope to find a clean one, and those who give up and just get an M-Hex (or an Elmarit if they've got deeper pockets). I'm on the fence.

::Ari