Mamiya rb67 lens coating question

[Durastudio]

for those that have experience with the rb67 system, how much of a difference to you feel the C multicoated lenses offer over the older non c versions? tia.

 

[djhopscotch]

I have never noticed a difference between my C and non C lenses.. I haven't compared the same focal length in C and non C versions though. I also always use a lens hood when using it out doors.

 

[M Carter]

This comes up on the internets often. I used C and non-C in the film days, shooting fashion and catalog work. Never noticed a difference, shooting mostly E6 so pretty demanding. One bonus to the "C" lenses is they'll be newer, so potentially a longer time til they'll need a shutter service. Though I'm not really sure why one RB lens eventually freezes up when the others don't. CLA and they're good as new if it's just a dirty shutter.

Keep in mind the non-C lenses are coated, just not the newer multicoating. I know some RB guys who are also darkroom printers say there's a difference, can't imagine it's wildly noticeable.

 

[flavio81]

for those that have experience with the rb67 system, how much of a difference to you feel the C multicoated lenses offer over the older non c versions? tia.

Consider that in some cases the C version is optically different; for example this happened with the 65mm and 90mm lenses.

 

[Neil Grant]

..huge difference - especially in high flare conditions. The C lenses hold contrast much better. The colour are truer and more vibrant.

 

[David T T]

I got mine with a 90mm non-C, and replaced it with a C version. Better contrast and color to a noticeable degree, but nothing wild.

 

[flavio81]

I got mine with a 90mm non-C, and replaced it with a C version. Better contrast and color to a noticeable degree, but nothing wild.

The C and non-C 90/3.8 lenses have entirely different optical design.

 

[Neil Grant]

The C and non-C 90/3.8 lenses have entirely different optical design.

..I'm sure that's wrong. The non-C is 'wasp waisted' - so appears very different, and of course it's only single coated. But, I think, optically they are the same.

 

[WilmarcoImaging]

Using the 90mm lens as an example:

Non-C model has 7 elements in 6 groups, largest aperture f/3.8, source: Mamiya via Butkus site
C model has 7 elements in 5 groups, largest aperture f/3.8, source: Mamiya via Butkus site
KL model has 8 elements in 7 groups with a floating element, largest aperture f/3.5, anomalous dispersion glass in some elements, source: Mamiya via helluin site

Plus differences in coating, which I did not take the time to decipher. Safe bet to say each model is a different lens.

 

[E. von Hoegh]

While I have no experience with the Mamiya lenses, the use of an efficient lenshood will reduce the difference between coated and multicoated lenses by a worthwhile margin. A hood will benefit any lens, the less efficient the coating, the more benefit, but even the best muticoated lenses will show improvement.

 

[flavio81]

..I'm sure that's wrong. The non-C is 'wasp waisted' - so appears very different, and of course it's only single coated. But, I think, optically they are the same.

I don't claim baseless things. They are entirely different optical designs and the C is going to be much more improved, with or without multicoating.

 

[David T T]

The C and non-C 90/3.8 lenses have entirely different optical design.

I did not know that, thanks. My 90mm is definitely a great lens, in any case. Sharp as a tack.

 

[Neil Grant]

While I have no experience with the Mamiya lenses, the use of an efficient lenshood will reduce the difference between coated and multicoated lenses by a worthwhile margin. A hood will benefit any lens, the less efficient the coating, the more benefit, but even the best muticoated lenses will show improvement.

...against the light, a hood doesn't help much. A flare buster is better - as long as it's not 'windy'

 

[Dennis-B]

There is a design difference between the 90mm "C" and "non-C" lenses. As to whether this really affects optical performance...

• The "non-C" lens is 7 elements in 6 groups. Coverage is 51 degrees, 50 minutes
  
• The "C" lens is 7 elements in 5 groups. Coverage is 52 degrees

I've used both, and never saw any real difference, but I shot mostly print film, only occasionally shooting transparencies.

 

[flavio81]

There is a design difference between the 90mm "C" and "non-C" lenses. As to whether this really affects optical performance...

• The "non-C" lens is 7 elements in 6 groups. Coverage is 51 degrees, 50 minutes
  
• The "C" lens is 7 elements in 5 groups. Coverage is 52 degrees

I've used both, and never saw any real difference, but I shot mostly print film, only occasionally shooting transparencies.

I've examined the designs a few years ago when i got the RB67 craze. I'm not a lens design expert, but the first design (7/6, non-C) looked like the old (first) retrofocus designs, in the sense that it had the structure of a gauss lens with a wide angle converter attached on the front (see, for example of this, the early Nikkor-S 35/2.8). While the newer 7/5 design looked more like your regular modern wideangle (see, for example, the late AI Nikkor 35/2.8).

(Note: while the 90mm is a normal lens, giving FOV equivalent to 45mm on a 35mm camera, the long flange-to-film distance on the RB67 means the 90mm must be a retrofocus design. The 127, being longer, does not need a retrofocus design and thus the optical formula is a far simpler 5 elements, 3 groups.)

 

[sixby45]

Interesting post - I used a 127 F3.8 non-C lens, and found that the portrait sharpness & color was excellent. There is a big difference between this and say a Fujifilm EBC coated lens I've found though. Each has their own characteristics, but non C lenses should be great performers across the board.