Mamiya 90/3.5L lens problem

[jmendez]

Hello to all, I am not sure if I have a problem. I just purchased some mamiya gear. The lens in question came with the gear. The aperture and speed settings look/sound good, however this lens has a front ring that would appear to let you adjust the focus with this ring instead of using the bellows?? However I cannot turn the ring and will not force it. Am i missing something or did i get damaged goods.

Thanks, Jorge

 

[nemo999]

Focus is by bellows. The ring in the front should be set to the distance you have focused on, the effect of the ring is to bring a floating element inside the lens into the position for best sharpness (flatness of field) for the distance in question. You will probably not be able to see the effect of this on the focusing screen. If you cannot turn the ring, this is presumably because it is stuck due to the fact that the previous owner never bothered to turn it!

 

[jmendez]

Well, maybe i have an answer to myself, could it be that the "problem" is, that this lens could be used on the RZ??

 

[archphoto]

I take it that you are talking about a RZ lens ???? (Please state that, please )

Focus is done by the bellows.
After focusing you transfer the distance to the front ring of the lens.

It has a floating elements system, so worry !

Peter

 

[nemo999]

I take it that you are talking about a RZ lens ???? (Please state that, please )

The front ring on the 90mm is for the Depth of Field, so you can visualize it.
So use the bellows to focus and use that ring to see how much DOF you have.

I don't believe the 90mm has floating elemens, so don't worry.

Peter

I have a 90 mm KL lens for my RB67 and it definitely has a floating element

 

[beriguu]

jmendez mentioned that the lens has aperature and speed settings, so it's a RB67 lens.

Like archphoto stated above, you use the focus knob on the body to set focus then read off the distance scale by the focus knob and set the distance on the lens to match the distance scale. Use of the distance scale on the lens is optional for "better sharpness" on floating element lens, however it is advised that you leave it on infinity on the lens if you are not going to bother with reading the distance scale on the body and setting it on the lens.

I have this lens as well and have forgotten to set the distance scale on the lens, but have got "sharp" pictures.

I've read that setting the distance scale on the lens really helps when you are taking close subject pictures. I haven't done that yet, so can't really tell you if setting the distance scale on the lens will yield better results.

In case you don't have a manual for your RB67/RZ67, you can download it at www.mamiya.com.

RB67 lenses can be used on RZ67, but RZ67 lenses can't be used on RB67 because RB67 can't set shutter speeds on RZ67 lenses. From what I've read, RZ67 lenses get their shutter speed set by the electronics in the RZ67 body. And RB67s do not have those electronics in the body.

Cheers!

 

[ath]

Isn't that ring for reading the depth-of-field?

 

[archphoto]

Actualy yes, TOO.

I had to do some reading myself first, and I am interested in getting a KL lens for my RB.

It is as beriguu said.

Peter