Wide Angle Lens For RB67 Pro SD

I'm looking for a wide angle lens for my Mamiya RB67 but having trouble deciding between the 50mm F4.5 Sekor-C, the 65mm F4.5 Sekor-C and the 65mm F4 K/L. I'm tempted to go with the order 50mm lens as I do appreciate it's very wide view, and my favorite lens on my Nikon is 24mm. But my favorite on my Hasselblad is a 60mm lens. That brings me to the choice between the older Sekor-C and the more modern K/L. From my research I get the impression that the 50mm is superlative, but that the 65mm K/L might be sharper than the other two. The Sekor-C lenses are also less money, but being older they may have problems that need attention. What to do?

I have shot with RB67's since 1978 and have had 2 50mm f4.5 C lenses and both were/are superlative. I have seen some internet noise that they are junk but I think it is just noise. The 65mm K/L glass is supposed to be better and it may be I have never tried it. I had the 65mm C and liked it a lot when I used it, but since I didn't use it lot I sold it. I went though a spell that I thought that if I didn't use something a lot it need to go. It was a mistake. Unlike pets lenses don't have to be fed if you aren't using them. I have tried both the 180 and 127 K/L and really didn't see any difference and moved on. As far as repairs, parts for the K/L's will dry up too. Now days as reasonable as the lens prices are get both and sell the one you don't need.

..a good sample of the 50 C is a reasonable/ acceptable performer. Sharp in the centre, falling off towards the edges mostly due to lateral colour. Some barrel distortion too - the lens is quite asymmetric. Mamiya made an improved 50mm for the RZ - the shorter back-focus gave the optical designers an easier job.
The 65 C performs a little better than the 50 C and is good with the 6x8 cm back.

I have the 50mm Mamiya Secor C for my RB67 that I bought new 30 years asgo. Nice lens. Can't help you with the KL version.
Here are samples.

I have both the 50mm f4.5 Sekor and the 50mm f4.5 Sekor-C wide-angle lenses. For landscape work with the RB-67 on a tripod and the lenses stopped down for depth of field images from both lenses are superbly sharp. Close-ups are also good provided the floating element adjustment is taken care of.

My impression is that the lens coating on the Sekor-C is a little better in strongly back-lit situations but otherwise it's a tie.

I chose the 50mm over the 65mm for the pragmatic reason that I can crop a 65mm field of view out of the 50mm but not the other way around. The big RB-67 negative is quite generous when it comes to cropping.

Decided to go with the 50 C lens, MINT from Japan.

Arthurwg said:

Decided to go with the 50 C lens, MINT from Japan.

Click to expand...

Good choice, I don't think you'll be disappointed. I once owned that lens, and was quite happy with it.