XR Rikenon 50mm 1:2 L, S & P versions

XR Rikenon 1:2 50mm L

Score
IQ: 9.0/10 
Build: 8.5/10
Overall Rating: 9.0/10

Specs
Focal length: 50mm
Aperture: 2 min - 16 max
Mount: M42 screw type




I personally use the 'P' version of this lens because there is no where the pin can get stuck on my PK - 4/3 lens adapter. Yet for other Pentax owners the pin is not a problem at all if it resembles a small ball bearing.
Whatever the case, the XR Rikenon 50mm f2.0 (and hence the Rikenon P 50mm f2.0) is said to be the sharpest lens in this range of any brand! The bokeh on this is fairly different to other similar lenses and is considered to be 'busy' - some like it while others hate it!

As visible from the test shots below, it appears razor sharp. I hope to run some tests against the SMC Tak and will publish the results later.

Rikenon P 50mm 1:2 @ f2

Temp adjusted to 7600

B&W layer overlayed

Rikenon P 50mm 1:2 @ f2

Temp adjusted to 7600

B&W layer overlayed

Other photo samples elsewhere on the web:
- http://forums.dpreview.com/forums/readflat.asp?forum=1041&message=35709282
- http://farm3.static.flickr.com/2242/2397544501_bf1bb9fcaf.jpg
- http://forums.dpreview.com/forums/readflat.asp?forum=1022&message=34454579&q=rikenon+50mm&qf=m

To-mioka or not To-mioka...

Recently as DSLR users have started to suddenly acquire legacy lenses, buyers are seeking better quality glass for their money. Quite often a legacy lens will gain reputation and thus price through word of mouth over the various forums dedicated to the topic of legacy glass. This sees prices soar on ebay as hundreds and thousands of ebayers try to strike gold. The classic example is the Carl Zeiss Jenna DDR Flektogon 35mm 1:2.4. More about that lens later since there appears to be a new contender in the market at the moment.

Tomioka, a well respected Japanese company, made lenses for Carl Zeiss Jenna which must be saying something! Often other brands like Ricoh, Sears, Chinon etc contracted Tomioka to manufacture lenses for them. This resulted in re-branded Tomioka lenses with Sears, Rokinon, Chinon etc labels. For example the Carl Zeiss Jenna Plannar is often thought to be the same lens as Chinon 55mm 1:1.4 inflating prices  for this particular Chinon in the used lens market.



There are certain clues or giveaways that help decide whether a lens is made by Tomioka or not. Most of this is hearsay but it is the best we have to go by and also of course the image quality. One or more of these may be true for a Tomioka made lens.

• Clockwise swirl of aperture blades

• Rubber grip with irregular texture
• Plain rubber grip with silver bands on either side

• Rear element very flat
• Black seal around the rear element

• Wave-like auto/manual switch

I have attempted to gather a list of all the Tomioka manufactured lenses I can find and link the references here.

• Sears 28mm 1:2.8 with the aluminum knurled barrel is supposedly Tomioka made.
• Sears 55mm 1:1.4
• Rikenon 50mm 1:1.4 on PK mount may be a Tomioka
• Chinon 55mm 1:1.4 comes in many shapes of the barrel. Of utmost certainty among experts is the one with the coarse rubber focus ring with silver rings on either side.
• Mamiya may or may not have had their some lenses made by Tomioka as this poster suggests. The jury is still out and the wait seems to be a long one!

OM 50mm 1:1.4

I have attempted to summarize all the information I could gather about these lenses' serial numbers and how they correspond to their image quality (IQ). I hope this summary serves its purposes when you are buying these lenses.

Serial Numbers:

• less than     1,xxx,xxx  - single coated unless it has the MC label. 
• higher than  1,xxx,xxx  - most likely multi-coated. 
• higher than  1,050,xxx  - definitely multi-coated.  

Varieties:

• Silvernose - these versions are identified by the chrome/silver edge of the filter rim. They are the earlier versions (s/n usually below 5xx,xxx) the OM 1.4 and usually preferred for B&W photography or Videoing using DSLRs these days.  
• Blacknose - these versions are identified by the black edge of the filter rim and due to being the later versions are thought to be sharper having better image quality than their silvernose cousins.

IQ by serial & varieties:
s/n less than      1,xxx,xxx non-MC -- Low contrast. Moderately sharp.
s/n less than      1,xxx,xxx MC       -- High contrast except @ f1.4. Noticeably sharper than above.
s/n greater than  1,xxx,xxx MC       -- High contrast. Sharper than the one above.
s/n greater than  1,050,xxx MC       -- High contrast. A tic better than the one above only on corners.

Really low serial number non-MC

Serial number under 1,xxx,xxx MC version

Serial number over 1,xxx,xxx MC version
- notice the green cyan tint on the front element

Although these lenses are not as sharp as the f1.8 version they are on par with them @f2.8 onward. The multi-coated version is however significantly sharper than the single-coated version and slightly sharper than the f1.8 at f2.0. The best and most consistent performers are the one with serial number higher than 1.1Million and multi-coating. Although the single coated ones are, relatively speaking, not too impressive some users have compared them to CZJ lenses and found their performance fairly decent (yet not on par) in comparison. Single coated lenses are also often used for black&white photography or videoing on modern DSLRs due to their lower contrast.

Personally, I believe that even though the difference is just perceivable between the single-coated and multi-coated versions, it is not extremely noticeable unless the photograph is blown up to poster sizes. It is definitely not noticeable for video purposes making it a very handy lens for videoing snippets of weddings.