Home

Please support mflenses.com if you need any graphic related work order it from us, click on above banner to order!
SearchSearch MemberlistMemberlist RegisterRegister ProfileProfile Log in to check your private messagesLog in to check your private messages Log inLog in

Rokkor-X PF 50mm f2 versus later versions
Post new topic   Reply to topic
Home   Manual Focus Lenses
View previous topic :: View next topic  


PostPosted: Thu May 09, 2019 2:51 pm    Post subject: Rokkor-X PF 50mm f2 versus later versions Reply with quote
I've been on a bit of a Rokkor spree lately, going back through my old lenses. I love my 55mm 1.7 with the silver nose and hill and valley knurled focus ring, but I am wondering about my MC Rokkor X PF 50mm f2 from the early 1970s. I know that lots of pundits class the later MD version as very sharp indeed, if not the sharpest of Rokkor lenses, but is the earlier MC version just as renowned in this sense? Given the change in size, from the 55mm filter to 49mm, and the lighter weight, I assume the optical formula was also changed for the later MD version?

I'd forgotten about this lens but am looking for a sharp 50 for the kit bag when I take out the Rokkor lenses. I have the 45mm f2 Rokkor and understand this is also sharp, but reports often find the MD 50mm f2 even sharper.

Looking forward to some thoughts.

Steve


PostPosted: Thu May 09, 2019 5:56 pm    Post subject: Re: Rokkor-X PF 50mm f2 versus later versions Reply with quote
quietsome wrote:
...
I am wondering about my MC Rokkor X PF 50mm f2 from the early 1970s. I know that lots of pundits class the later MD version as very sharp indeed, if not the sharpest of Rokkor lenses, but is the earlier MC version just as renowned in this sense?

No, it isn't! The MC-X (and the MD-I version as well!!) is optically different from the later MD-III version.

The MD-III 2/50mm is very balanced performer, AND it is virtually free from distortion (around 0.1% according to Minolta patent literature).

quietsome wrote:

Given the change in size, from the 55mm filter to 49mm, and the lighter weight, I assume the optical formula was also changed for the later MD version?

Yes, see above!

quietsome wrote:

I'd forgotten about this lens but am looking for a sharp 50 for the kit bag when I take out the Rokkor lenses. I have the 45mm f2 Rokkor and understand this is also sharp, but reports often find the MD 50mm f2 even sharper.

Looking forward to some thoughts.
Steve


The MD-III 2/50mm is not much sharper than e. g. the MD-III 1.4/50mm, but it has less CAs and much less distortion. Because of its low weight it is really a nice lens for outdoor & architecture.

Stephan


PostPosted: Thu May 09, 2019 8:29 pm    Post subject: Re: Rokkor-X PF 50mm f2 versus later versions Reply with quote
I agree with stevemark's general assessment of the MD-III 50/2.
It doesn't have a nicest bokeh or some truly outstanding sharpness, like some claim, but as for the everything else it's an indeed a very solid performer.
I'd especially recommend it for a SOOC JPEG shooters because of how clean the output is straight from the wide open relative to other fast F1.4 lenses.

One word of warning though: both front and back groups of MD-III are encased in plastic. Buy a clean one.

I have some full-size shots on A7R for pixel-peeping https://www.flickr.com/photos/curry-hexagon/albums/72157679866844698


PostPosted: Thu May 09, 2019 10:33 pm    Post subject: Reply with quote
I compared these two weeks ago, one MC Rokkor and two MD.

The MC has a bit more character to its bokeh and a tiny amount less saturated colors, better mechanical quality.
The MD slightly warmer and more saturation, smoother bokeh.

Sharpness was inconclusive, I have to redo the test so no 100% crops. But so far it looks like the MC has the flattest field.

MC Rokkor:



MD III



PostPosted: Fri May 10, 2019 2:08 pm    Post subject: Re: Rokkor-X PF 50mm f2 versus later versions Reply with quote
aidaho wrote:

...
One word of warning though: both front and back groups of MD-III are encased in plastic. Buy a clean one.


All elements of the MD-III 2/50mm are made from optical glass.

Four of its six lenses are made from Lanthanum glass (including both the front and back element).

The front element is made from a glass with nd=1.72 and v=50.3 (similar, but not identical to the Schott N-LaK10).
The back element is made from N-LaF2 (nd 1.74, v=44.85).

Stephan


PostPosted: Fri May 10, 2019 2:09 pm    Post subject: Reply with quote
blotafton wrote:
I compared these two weeks ago, one MC Rokkor and two MD.
...
Sharpness was inconclusive, I have to redo the test so no 100% crops. But so far it looks like the MC has the flattest field.


If you talk about central sharpness, i agree.
Corner sharpness is a different thing, though.

Stephan


PostPosted: Fri May 10, 2019 4:03 pm    Post subject: Re: Rokkor-X PF 50mm f2 versus later versions Reply with quote
stevemark wrote:
aidaho wrote:

...
One word of warning though: both front and back groups of MD-III are encased in plastic. Buy a clean one.


All elements of the MD-III 2/50mm are made from optical glass.

I may not have a perfect command over English, but I'm quite sure, I did not make a claim about lens material, just stated they are encased in plastic.
No threaded lens retainers of any sort in sight.

In other words, unless you possess some very advanced skills you will not be able to clean anything inside those plastic-encased blocks.
You may get lucky though, if only the outside lens surface of a plastic-encased block is affected.


PostPosted: Fri May 10, 2019 4:31 pm    Post subject: Re: Rokkor-X PF 50mm f2 versus later versions Reply with quote
aidaho wrote:
stevemark wrote:
aidaho wrote:

...
One word of warning though: both front and back groups of MD-III are encased in plastic. Buy a clean one.


All elements of the MD-III 2/50mm are made from optical glass.

I may not have a perfect command over English, but I'm quite sure, I did not make a claim about lens material, just stated they are encased in plastic.
No threaded lens retainers of any sort in sight.

In other words, unless you possess some very advanced skills you will not be able to clean anything inside those plastic-encased blocks.
You may get lucky though, if only the outside lens surface of a plastic-encased block is affected.


Sorry, my mistake! Thanks for the clarification!

Steve


PostPosted: Sat May 11, 2019 2:27 am    Post subject: Reply with quote
Thanks for all the helpful replies everyone! Looks like I'll be buying an MD version at some point. I'm only concerned about sharpness in certain lenses, not as a general rule. I have lot sof lenses to choose from, but I just need one in particular that is considered sharp for the SR mount.

Now, how does the MD version of the 50/2 compare to the 45/2 Rokkor X? The 45mm seems pretty darn sharp to me.

I did take out the Sears (Rikenon) 50/2 the other day, and boy is it sharp even wise open. Stop down a bit and everything is like a razor on APS-C. Super light too.

Steve
Post new topic   Reply to topic
Home   Manual Focus Lenses
Page 1 of 1