testing an M-Rokkor 28mm

[Krosya]

You left out CV 28/2 lens which seems to be a good one. Plus I believe that Rokkor brings out wrong frames on most leicas. - correct me if I'm wrong here , as I never had one.

 

[kermaier]

You left out CV 28/2 lens which seems to be a good one. Plus I believe that Rokkor brings out wrong frames on most leicas. - correct me if I'm wrong here , as I never had one.

Yes, I left out the CV 28/2 and 28/1.9, which are in a whole 'nother size class; and I left out the Summicron 28/2 which is in a whole 'nother price class. The f/2-ish lenses aren't really appropriate comparison points, IMO.

And you're right: The M-Rokkor brings up the 35mm frame lines on Leica bodies, which is a non-trivial usability issue. It didn't occur to me, because I use an R-D1 which has manual frame selection (like the CV Bessas, et al.) Anyway, I think there are a number of the usual suspects among repair shops that are competent to make a simple modification to the mount to bring up the 28mm frame on a Leica.

::Ari

 

[raid]

The Rokkor is now on sale for $450.
First come, first served.

 

[Palaeoboy]

There are a few different stages to the white problem but the first stage is where the white spots form on the sides of the front lens element. Because it its not in the optical path most dont see any degradation in their pictures. The problem arises from crystals forming from the black paint that was used as anti reflection blackening. It is heat activated, so you may have a lens with no spots whatsoever and you take it out on a hot day in the car or something and get home and there they are! The fix is a matter of having the front element removed, cleaned and the sides repainted, but as someone mentioned before the lens cell is difficult to dismantle but not impossible. If the crystals get really bad then they break off and move onto the lens surface and sometime etch the coatings, its this stage where it can affect image quality but most dont seem to get to this stage fortunately.

 

[DougFord]

[FONT=&quot]Mine had started to develop the dreaded white spotted disease so I sent it off to [/FONT][FONT=&quot]John Van Stelten.[/FONT]
[FONT=&quot]He had a hell of a time getting mine dismantled. But persistence and perhaps a few choice cuss words later he had it apart and was able to commence with the repair. The lens is compact and light weight. I ultimately chose the rokkor over an elmarit 2.8 asph that I had at the time. Very different rendering/performance between these lenses. Both are excellent. [/FONT]

 

[bkrystad]

test prints (first of two posts)

test prints (first of two posts)

Spent some time in the darkroom making straight prints of some frames from my test roll that I thought might push the boundaries of the lens. These two are flare tests.

The first one is the only frame I found on the roll that I thought might have a ghosting/flare artifact from one or more white spots (circled in red in JPG).

The second shows flare where you would expect it (no hood, straight into direction of sun), but I don't see any candidates for artifacts, maybe the very upper-right corner by the boat railing?

 

[bkrystad]

test prints (second of two posts)

test prints (second of two posts)

Now, here are a couple prints from frames made with the M-Rokkor 28mm that gave me a good feel for the lens, one in a contrasty setting, the other wide open indoors with shallow depth of field.

I think after evaluating this test roll I'll go ahead and keep the lens (good price compared to other white-spotted M-Rokkor 28mm sales in the past few months) and I might consider the fix with John Van Stelten at some point.

Disclaimer: I'm generally a sucker for Rokkor glass. I wouldn't suggest everyone should be. But I'm enjoying the prints I'm getting with this and other lenses from the same era.

Thanks again to all for your input and information! Great stuff!