With the larger negative size the field of view of medium format lenses is much wider than the field of view with the same focal length on 35mm. To make a comparison with 35mm film SLR fields of view multiply the focal length by 0.48. For instance, 90mm is ~44mm in 35 film SLR terms.

I do not see a consensus on which lens series is the best. The non-C single anti-reflective coating lenses seem to be the “worst”, but the optical difference between the K/L and C lenses is not so clear. Some commentators have indicated that the C series had poor quality control, whereas the K/L lenses–being optically the same–are better by virtue of better quality control.


Single anti-reflective coated lenses released in 1970 with the original Pro


These lenses are optically identical to the original lenses, but have a newer barrel design (NB) that matches the later C lenses. They only were produced briefly and are comparatively rare on the market.


C, apparently, stands for “Design Improvement”. These lenses are multi-coated. Released with the Pro-S in 1974. Has a “C” on the front name ring.


Most recent. These lenses are, apparently, a slightly newer design with better coatings than the C lenses. The K/L is a code to indicate which bodies the lenses are compatible with. K indicates the Pro/Pro-S bodies and L indicates the Pro-SD bodies. KL lenses all shipped with an adapter attached to the lens so that they can be mounted to Pro-SD bodies. This adapter should be removed to mount to Pro/Pro-S bodies. This adapter is a fairly simple rubber O-ring for light sealing rather than for any mechanical reason. I, personally, have not had any issues using C lenses on my Pro-SD body without the small adapter ring.

Has a “K/L” on front of the barrel.

L lenses

Compatible with Pro-SD *only*; these are the 75mm Shift lens and 500mm APO only.


Apochromatically corrected lenses. Sometimes known as A lens. More expensive, heavier, but chromatic aberrations are better corrected.

Length (mm)Maximum ApertureGenerationAngle of View (in degrees)Weight (g)DetailsNotes
37f4.5C1801240Details fisheye distortion
50f4.5C82960More details
65f4K/L681070Details This is a new, different optical design than the earlier original and C 65mm lenses
90f3.5K/L52960More details
100f5.2C471660Details100mm-200mm Zoom
127f3.8Original38 655Details
127f3.5K/L39780More details
140f4.5C36800DetailsMacro lenses with floating element to adjust plane of focus curvature.
150f4C33790DetailsSoft focus lens
180f4.5K/L28900More details
210f4.5APO/L241020 More detailsApochromatic correction
250f4.5APO/L211370More detailsApochromatic correction
250f4.5K/L201130More details

Lens Accesories

Auto Extension Tubes

Two extension tubes–for use in close up photography–were produced, the No. 1 (45mm) and No. 2 (82mm).

Extension tubes were produced for the Pro and Pro-S and a different model for the Pro-SD. The Pro-SD extension tubes fit the larger lens throat of the Pro-SD body. Because of this the Pro-SD extension tubes do not fit on Pro or Pro-S bodies.


Mamiya Corporate Website

DiSante, T. (1981). How to Select & Use Medium-Format Cameras. HP photobooks. Tucson, AZ: H.P. Books.


  • Bulent Celasun
    April 12, 2012 - 4:19 am | Permalink

    Thanks for the informative and nicely designed site.
    I wonder if you could also add a note on the lenses marked as “A” (in addition to others); like K/L A.

  • Ivan Farkas
    May 28, 2012 - 4:59 pm | Permalink

    The answer is “yes” to “Extension tubes were produced for the Pro and Pro-S and a different model for the Pro-SD.” The SD extension tube will not fit on the Pro.

    Thanks for the info. Recently I have acquired a Pro with 2 90mm lenses, on NB and the other not. Yours was the only explanation I’ve found for this abbreviation.

  • Nanzetta merriman
    June 12, 2012 - 7:17 pm | Permalink

    Just received a c 50mm lens the rest of my lenses are Kl so I am not use to C lenses and I have a question.

    On the base of the lens there is a dial labled M and N – is the the miror lockup – how does it work?

    • jodys
      June 13, 2012 - 9:58 am | Permalink

      That is correct. I added a description of how to use mirror up mode to the Using page. I hope that answers your question!

  • Michael
    July 7, 2012 - 12:51 pm | Permalink

    Hey…thanks for the info on the rubber ring on KL lenses. Had just bought an RB No. 2 extension tube and it wouldn’t fit until I simply slid off the ring. Works perfect now!

  • dan
    July 20, 2012 - 7:45 am | Permalink

    Thanks for the information. I just bought a mint 65mm 4.5 I was basically just looking to see if there was anything wider than the 50mm.

  • Jacek
    August 19, 2012 - 8:37 am | Permalink

    I have search many websites, i found ONLY at this site, that Sekor C 50mm has filter 80mm.
    Other sources suggest, that 50mm C has 77m.

    I make some plans to B/W photography, it is important for me.

    What is correct information?

    • jodys
      August 19, 2012 - 12:38 pm | Permalink

      My apologies, I had it wrong. The 50mm C definitely has a 77mm filter. Thanks for catching the error!

    • Jacek
      August 24, 2012 - 7:50 am | Permalink

      I reply myself.
      I;m almost sure, focusing screens are compatible Pro/S/SD, but in years of “SD” have different marketing names.

  • July 20, 2013 - 1:17 am | Permalink

    i have a Mamiya RB67 Pro SD.
    i would like to ask if i can use this lens —- Mamiya Shift C 50mm F4 to my RB67 Pro SD.


    • jodys
      July 22, 2013 - 5:28 am | Permalink

      No. The Mamiya Shift C 50mm is a lens for the Mamiya 645 series. There is no compatibility between the 645 and the RB67. The only shift lens offered for the RB67 is the 75mm f4.5 S/L

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  • March 5, 2014 - 10:48 pm | Permalink

    I just received a sekor c 100-200mm lense for my mamiya pro s. It came with an adpater ring. How does one safely remove the ring?



    • jodys
      April 20, 2014 - 7:33 pm | Permalink

      There is nothing special, just gently pull.

  • Dennis
    July 26, 2015 - 3:46 am | Permalink

    Great website, it’s been very helpful as I begin learning about my new RB67. Just a note, there is a 127mm f/3.8 Sekor NB lens. I don’t have any details as to weight and etc., but I have one sitting on my camera so I know it exists!

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