MC Rokkor-X lenses sharper than MD Minolta series?

Hi there

 

Amatuer lens test: No mirror lock up, but no wind either...

Reasonably sturdy tripod. Timer engaged (X-70 or X-GM). Results?

 

50mm 1.4 and 1.7 MC Rokkor-X and MD Minolta

135mm 3.5 MC Rokkor-X and MD Minolta

 

Well it looks like the MC rokkor-X (letter variants) versions of 50

and 135 mm lenses are sharper than latest MD Minolta versions (same

max. apperture lenses). I got as "scientific" as I possibly could

(Now I know why people go nuts with the performance of their lenses).

 

Color rendition and contrast? That is beyond my 'authority' at the

moment (although the MD Minolta versions do better as far as I am

concerned).

 

Am I way off, or on to some pattern here. How do MC Rokkor-x vs. MD

Rokkor-x and MD minolta series compare with regard to sharpness in

your experience?

 

I used to read postings like this one with amusement in the Canon EOS

forum (where gains in sharpness will cost you thousands of dollars) -

but hey, with the used manual Minolta line up, lenses are cheap and

it actually makes sense to obsess over sharpness.

 

Thanks

I always heard that the MC and MD lenses were both good...The old cheaper Celtics were good to; but had more illumination falloff at wider apertures

Hi Askin, I am pleased to see that I am not the only person in the world trying to get the best possible kit.

 

<p>First of all, with respect to Celtic lenses. They were NOT different designs to the Minolta MD Rokkor-X series, they simply had different cosmetics and less sophisticated lens coatings. Accordingly, the images obtained will be every bit as sharp as the equivalent Rokkor or Rokkor-X lens (obviously sample variation applies).

 

<p>The difference between Rokkor-X and the later MD is not related to the lens series per se but to the fact that most lenses were redesigned when the MD series was released, to incorporate weight (and presumably cost) saving measures. The lighter lenses are certainly more suited to the later lightweight bodies than many of the earlier lenses.

 

<p>Visit here on my "Rokkor Files" website for a full history of the lens series which talks about the differences:

 

<p><a href="http://users.bigpond.net.au/antony_hands/Lens%20History.html">Rokkor Files - Minolta Lens Series History</a>

 

<p>At my site you can also have a look at several of the lens reviews that I have conducted. Have a wander around there is loads of info there for the Minolta manual focus user.

 

<p>Personally, I prefer the Rokkor-X series lenses, because I like the metal construction, and I simply prefer the way they feel in my hands. However, many of the later lenses are just as sharp as the earlier ones as far as I know, and another contributor on here (Frank Mueller) has mainly MD series lenses and prefers the results he gets with them. Your plan to test and then keep the best lens sounds like the best approiach to me.

 

<p>Best regards, Antony Hands

I'd like to amplify on what Askin has said. You'll find that the main difference between the Rokkor-X series (both MC and later MD Rokkor-X lenses) and the later Minolta MD lineup is in the mechanical construction. The Minolta MD lenses are lighter and more cheaply made. Optically, they were probably equal when brand new, and/or the Minolta MD lens might be slightly improved due to improvements in computer design and/or coating technologies. However, these improvements, if they existed at all, were very slight. However, you are obviously testing individual samples, and they are used. Sample to sample variation probably outweighs any very slight systematic improvements that might have been incorporated in the newer lenses. And finally, and MOST IMPORTANTLY, the more rugged construction of the OLDER lenses means that there is much less likelihood that the older lenses might have gone slightly out of alignment due to the bumps and jolts of normal use over many years. The fact is, when brand new, the Minolta MD lenses were likely as good or slightly better than the Rokkor-X lenses. But sprinkle in to the mix 10-20 years of normal use, and the Rokkor-X lenses are likely alot closer to their original when-new performance than are the Minolta MD lenses, as a result of their superior construction.

 

I would also add that the other difference between the Rokkor-X and Celtic lenses is that the focusing helicals were cheapened slightly in the Celtic lenses (generally brass and steel was replaced with just steel), but they still seem to me to be better constructed than the Minolta MD lenses. They WERE optically identical to the Rokkor-X lenses which were made at the same time, and thus, they represent great bargains.

The Modern Photography test reports of April 1975 and others showed that the Minolta Celtics had more illumination fall off; than the Minolta Rokkor-X lenses; they were also lower in cost; and had less robust mounts. The illumination difference was mostly seen at the widest two apertures...........The Celtics were a different optical scheme; slightly...they had more spherochromatism; purple fringing ...The Celtics also had more decentering in tests...The alignment dots on the celtics were sunken; instead of raised....

According to my Minolta lens brochure, which shows the optical formulas for the lenses, the Rokkor-X and Celtic lenses DID have the same optical formulas. The lensmounts were definitely better made on the Rokkor-X lenses, and the Q-A tolerances were clearly more stringent as well on the Rokkor-X line. But they were the same optics. De-centering could cause more light fall-off.

I cherry picked my lenses and retained Rokkor X glass with the exception of a MC 58mm f/1.2. I recommend standardizing on the 55mm diameter lenses for filter standarization, reduced vignetting and distortion. Coating improvements in the MD mounts are minor. The smaller diameters may increase contrast but something had to give to make the lenses shorter with less circumference. I used a sharp MD 35mm f/2.8 which had too much distortion. I replaced that lens with a flat field Rokkor X 28mm f/3.5. Besides the outstanding 58mm f/1.2 I have the 135mm f/3.5 with 4 in 4 construction. This is a very underrated lens as it has high contrast and light weight. The $35 135mm is sharper at f/5.6 then the legendary 85mm f/1.7 set at f/8.

As mentioned, the MD mounts feel cheap next to the Rokkor X and MC mounts.

<p>Som other gems are the old radioactive MC 28/2.5 and the MC 135/2.8 PF. The wide is super-sharp and is fairly well-corrected for distortion. The tele is sharp in the center from wide-open and by f/5.6 is sharp to the corners. What makes the 135 so great though is the bokeh, which I like better than the famous 4/4 135mm.</p>

I started off with a Minolta SRT-101 and MC Rokkor-X lenses back in 1972 but once I borrowed a friend's Nikon F2 and a couple of lenses I realized just how much better Nikon was. Minolta's coatings sucked compared to Nikon and the sharpness in the corners was noticeably softer. I ditched all my Minolta gear and replaced it with Nikon and have been a loyal Nikon user ever since.