rb67 wide angle lenses

nwilkins · Sep 17, 2013

Hello everyone,

some months ago I bought the 50mm C lens for my RB67. It is a pretty nice lens, but I'm not thrilled with it. It has quite a lot of barrel distortion, and when I shoot colour film I notice a lot of chromatic aberration. It is also noticeably not as sharp as my 90mm KL.

So I am thinking of picking up a 65mm KL lens - does anyone know if the CA and/or distortion are signifcantly better with the 65mm KL than with the 50mm C?

Thanks!

jdsanika · Sep 17, 2013

Never owned the 50mm and I don't often shoot color, but I do have a 65mm and it is my most used lens (also have 90, 127, and 180), I'm sure the 65mm has some barrel distortion but it has never been a problem for me with landscapes.

rbultman · Sep 17, 2013

I've got the 65 C. I'll be posting some scans taken with it in the next week or so to my flickr account. (Can I say that here?)

Sent from my Nexus 4 using Tapatalk 2

Alan Klein · Sep 17, 2013

Are you adjusting the floating element ring?

Shawn Dougherty · Sep 17, 2013

I also never owned the 50mm and do not use color film...

But, looking through images on flickr made using the 50mm C convinced me to buy the 65mm C. I'm glad I did. It is a very sharp lens (as sharp as my 90mm C) and I have not experienced any obvious barrel distortion.

Alan Klein · Sep 17, 2013

PS This is one of my favorite shots taken with the 50C. I usually don't shoot with it but I really should use it more.
http://www.flickr.com/photos/55760757@N05/5270429762/in/photolist-92Jk9E-921HXF-924GU7

rjs003 · Sep 17, 2013

My 50C works without a flaw, just make sure that you adjust the floating element.

Shawn Dougherty · Sep 17, 2013

nwilkins said:
It is also noticeably not as sharp as my 90mm KL.

The 90mm KL also has a floating element so I'm assuming the OP is not forgetting to adjust it.

nwilkins · Sep 17, 2013

no I am not forgetting to adjust the floating element - not sure that would do much in the way of helping the chromatic aberration anyway, would it? I think it's just for corner sharpness.

nwilkins · Sep 17, 2013

has anyone here used both lenses?

Shawn Dougherty · Sep 17, 2013

There are several threads about the differences between these lenses right here on APUG. Do a quick search while you are waiting for others to reply to this thread.

nwilkins · Sep 17, 2013

Hi Shawn,

I have started a few threads about the RB67 wide angles (particularly when I was looking to buy), and I have looked through some others, but I don't recall ever seeing a post from someone who had both lenses (the 50 C and the 65 KL). I was just hoping there was someone who has used them both.

Shawn Dougherty · Sep 17, 2013

nwilkins said:
Hi Shawn,

I have started a few threads about the RB67 wide angles (particularly when I was looking to buy), and I have looked through some others, but I don't recall ever seeing a post from someone who had both lenses (the 50 C and the 65 KL). I was just hoping there was someone who has used them both.

I did a lot of looking around before buying my 65mm and if memory serves (and often times it doesn't... =) APUG member keithwms has used both.

nwilkins · Sep 17, 2013

okay thanks very much Shawn!

1+2äugig · Sep 19, 2013

In the infos about the lenses from Mamiya (found in the web) you will be informed about the advantages and disadvantages of the lenses. The 65 mm wide angle is described to have not the distortion than the 50 mm lens. Therefore I have bought the 65 mm lens and are more than satisfied with it.

whlogan · Sep 19, 2013

The lighthouse shots and the other ones next to it are suitably sharp and free of chromatic distortion. The guy with both types of problems may have a vision problem, a cockpit problem or a bad lens. Check those out first.
Logan

Shawn Dougherty · Sep 19, 2013

whlogan said:
The lighthouse shots and the other ones next to it are suitably sharp and free of chromatic distortion. The guy with both types of problems may have a vision problem, a cockpit problem or a bad lens. Check those out first.
Logan

I wouldn't make those judgements based solely on a couple of images on the web. Viewing a negative on a light table with a loupe might be a better way to go...

nwilkins · Sep 19, 2013

Shawn Dougherty said:
I wouldn't make those judgements based solely on a couple of images on the web. Viewing a negative on a light table with a loupe might be a better way to go...

yes that's what I was going to say, or at least a 100% crop of a high res scan. otherwise those are some big assumptions. Also what kind of vision problem could possibly cause me to see CA in negatives taken with my 50mm lens, but not in those taken with my other lenses? Could such an eye condition really exist?

rbultman · Sep 19, 2013

FYI, some notes on the 50mm: http://rb67.helluin.org/lenses/50mm-f4-5c/

rbultman · Sep 19, 2013

And another site mentioning the use of the ring to correct for chromatic aberation: http://www.seanesopenko.ca/2011/10/long-term-review-mamiya-rb67-pro-s/

nwilkins · Sep 19, 2013

thanks for the review link - I have been setting the floating element correctly every time with the 50mm but I still find it has quite a bit of CA. My experience seems quite similar to that of the reviewer - the 90mm is a great lens, the 50mm leaves something to be desired. I just wish I knew whether the 65mm KL would be closer to the 90 in terms of performance.

Xmas · Sep 20, 2013

nwilkins said:
thanks for the review link - I have been setting the floating element correctly every time with the 50mm but I still find it has quite a bit of CA. My experience seems quite similar to that of the reviewer - the 90mm is a great lens, the 50mm leaves something to be desired. I just wish I knew whether the 65mm KL would be closer to the 90 in terms of performance.

A more modern lens should be better.
The floating element optimises all aspects of performance.
I get trouble with wide apertures and film flatness. But my 90 is better than the 65 or 50 and you need to stop down more with the wides.
Are you taking close ups with wides?
How large are your prints that you see the problems on and are you rubbing your nose on the prints?

xtolsniffer · Sep 21, 2013

I have a 65mm C and a 50mm C, as well as a 90mm C and a 140mm KL. Both the 65 and 50 are lovely lenses. I've never had any problems with them. I print up to 12"x16" and at that scale they give me all the resolution and quality I could hope for.

nwilkins · Sep 21, 2013

okay thanks xtolsinffer - do you notice more CA with your 50 than with the other lenses?

xtolsniffer · Sep 21, 2013

nwilkins said:
okay thanks xtolsinffer - do you notice more CA with your 50 than with the other lenses?

No, no difference at normal viewing distances on the print - and these would be 10"x8" or 12"x16" prints...

rb67 wide angle lenses

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