Differences btw Mamiya RB lenses

[fmajor]

Hi everyone,

I'm wondering if anyone has information about whether Mamiya RB K/L lenses have all metal shutter or apertures?

frank

[EdColorado]

I've never taken one apart Frank but I've been told that the K/L lenses have more plastic in the shutters than the older C lenses and that the K/L shutters are non reparable, to be replaced as a unit.

[fmajor]

Thanks Ed -

I'm fairly ignorant about these things, but do the plastic shutters have the same "longevity" as the non-plastic shutters? Thats really my concern - i don't want to be in a situation where the camera/lens can't repaired w/o having to buy expensive parts. I'd take a little loss on optical coatings/IQ for longer life mechanics.

[EdColorado]

Plastic versus metal can be debated forever. Some plastics are pretty tough, some metal isn't. Overall though I like metal, which is one reason why I like older cameras too I guess. I've read conflicting reports on whether the K/L lenses are really any better optically than the C series lenses, and considering the costs of each I stay with my C lenses, and even still happily shoot with non C lenses on my RBs. I like the idea that my local repair guy can fix a broken shutter if need be as opposed to having to find a full replacement. Plus considering the cost of the C lenses, I can probably just get another for less than the repair cost.

[keithwms]

I don't think you can predict the reliability of shutters without factoring in the age of the lenses that you're comparing. The original all-metal lenses might have been better out of the box, but... they're also now considerably older than the KLs and possibly well used. If an older lens craps out on you, you wouldn't even both to repair it, you'd simply replace it. The older RB lenses are a dime a dozen.

Anyway, as someone who has a lot of new and old RB lenses, I see no important difference in build quality between them. I am 100% pleased with the performance of the KLs, and they do offer very real optical advantages, to my eye. I don't concern myself with hypothetical disadvantages, when I have plenty of real advantages to enjoy e.g. better coatings, better colour neutrality.... and fresh warranties! And the peace of mind of knowing that the lens wasn't beaten within an inch of its life before I picked it up used.