Mamiya M645 45mm Lens Versions

Discussion in 'Medium Format' started by timwitt, Apr 20, 2010.

  1. I find 3 versions of the 45mm lens.
    Mamiya-Secor C f2.8 45mm S
    Mamiya-Secor C f2.8 45mm
    Mamiya-Secor C 45mm f2.8 N
    Is the N a newer lens, S the older lens and the other lens in between?
    What size filter ring does each lens have?
  2. Tim,
    the "N" is the last version, the "S" is the same optical design as the "N", but from the looks it is more like the "C" version, which is the oldest.
  3. Christoph is correct. "C," "S," & "N" refer to age and lens coatings. The "C" versions are the originals. "S" versions had the same metal (heavy) housing as the "C" versions, but the updated lens coatings you'll find on newest "N" versions.
    I think you need to consider your film choice and shooting style when choosing which versions to purchase though. I shoot Velvia, always use a tripod and small apertures, and color is paramount to me. I've found that I much prefer the "C" versions for their stabalizing weight and warmer colors. If you prefer to shoot handheld and wide open, the "N" versions have more contrast and weigh noticeably less.
    I know the "C" version takes 77mm filters. I believe the "S" and "N" versions are 67mm.
    Mamiya-Sekor C 45mm f/2.8
    1 second @ f/16
    Velvia 50

  4. I can confirm the "N" version has a 67mm filter thread. I use this lens a lot for landscapes:
  5. In the case of the 45mm, the shift from "C" to "S" meant an optical re-design, hence the switch from a 77mm filter to a 67mm filter thread. That is not true for all lenses. The "N" versions are more plasticy, but of very good mechanical quality, so that's not a problem.
  6. By the way, "S" stands for "steep" meaning a strongly curved front element due to the new optical formula. Together with the new housing and coatings it became the "N" (new) version.
  7. The original large fronted 45mm f/2.8 Mamiya Sekor C was inferior optically to the newer "S" (presumably for small) design and weighed about twice as much. Centre definition is about the same for both lenses, but the older version had terrible field curvature, and hence it was almost impossible to get the corners in acceptable focus. As has already been stated the N version is exactly the same as the S, except for the cosmetic appearance of the barrel.
    If you don't care too much what the lens looks like, then you can save quite a bit of money by going for the S version, since sellers tend to ask more for the Mamiya N lenses. Incidentally some of the N lenses (not the 45mm) have a plastic barrel and filter thread, which IMHO makes them more prone to wear and accidental damage.
  8. Thanks everyone for the responses. I'll look for the S or N depending on cost and avoid the "no letter" version.
    I have been looking at the 35mm lens but they are costly. That may be too wide on the 645 but I do like a 24mm lens on a 35mm camera.
  9. Hello,
    I want to add some additional questions
    - Does the "S" have the same coatings as the "N"? There are 2 different answers above
    - I have a 45 "S" (bought used). Filtersize 67. A very good lens, also sharp in the corners, but yet not used wide open.The "S" is not engraved on the lens like the "Sekor C" Text, but only applied as 2 small golden round stickers glued next to the "C" and near the mount to the aperture setting. Is this normal? Are there also lenses with engraved "S" out there?
    - I also have a 55mm with such a "S" sticker? Anobody knows about this?
    Greetings Waldemar Schmid
  10. Tim for what it is worth I find I use my 35mm and 55mm lenses more than the 45mm. I find both the 35mm and 45mm a bit soft but my 45mm appears softer. Mine is the N type but may be a poor copy.
  11. Thanks to everyone.
    Philip, I haven't used my Canon FD 28mm since I got a 24mm lens. That may be the case with the M645 as well. I'm not going to purchase either right now unless an offer is too good to pass.
  12. Bueh and Rodeo, I don't believe the "S" stands for either "steep" or "small". Mamiya was regularly slapping an "S" suffix onto any revised accessory for this system, from waist level finders to extension tubes (compare old M645 user manuals, brochures or system charts to see what I mean). It might have meant "super-improved", for all we know.
    I never had a 45mm S or N; I once had a 45mm C, and it was pleasingly sharp centrally wide open, but very astigmatic in the corners (Rodeo says field curvature - perhaps that was there too). My 35mm N, which is the same optically as the 35mm C, behaves similarly.
    Waldemar, the same revision history applies to the 55mm as the 45mm: the 55mm S has the revised optics of the N, and a metal barrel like the C. The S line was short-lived - an intermediate stage en route to the Mamiya 645 Super and its N lenses - so it would not surprise me if "S" stickers were used instead of engravings.
    I have a 55mm N and it is an exceptionally good retrofocus wideangle - superb centre to corner at f5.6 and smaller. Curiously, the 55mm N is not as sharp wide open as the 45mm C or 35mm C/N; but beats the pants off them stopped down a little. From this limited sample, I might conclude that the C line of wideangles is best for central performance, while the revised S or N 45mm and 55mm lenses are optimized for balanced sharpness across the field.
  13. BTW - Beautiful pics, Adam and Lex!
  14. I don't think the difference between the coatings on the N and earlier lenses is a big issue. The difference is quite noticeable when you look at the lenses, but makes almost no difference when you look through them and take a picture. And I guess we might never find out what Mamiya had in mind with the "S" suffix, since I've never seen it explained in any of their brochures or instruction books, but I, for one, won't be losing any sleep worrying about it!
  15. Thank you Ray,
    really interesting. This is what I wanted to know.
  16. regarding what Ray wrote, viz:- ' once had a 45mm C, and it was pleasingly sharp centrally wide open, but very astigmatic in the corners (Rodeo says field curvature - perhaps that was there too)' .
    I very recently came back to MF with a 645PRO & three lenses, one of which is a 45 mmC. So, yet to discover those problems with the corners. From general experience I expect the curvature/astigmatism can be eliminated by stopping down, say to f8 - but for now I'm going to experiment with wider apertures than that. May be I'll be driven to swap the C for an N... (The other two lenses are a 150/3.5 C and an 80/2.8 N)

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