Locking DOF preview on Mamiya RB Lenses?

[Kirks518]

For my RB67 PSD system, I have the 50mm, 65mm, 90mm, 150mm SF, 180mm, 250mm, and the 360mm.

I recently picked up the Fotodiox RZ to EOS adapter so I could use the lenses on my Canons (film and DSLR). As there is no camera to lens control, I have to stop down the lens for metering and shooting. This hasn't been a problem, as I've only played with the 150mm on the adapter. On this lens, when I move the DOF preview lever, it locks when it gets to the end. However, I can't seem to get the lever to lock on any of the other lenses.

Is this the way they are supposed to be, or do my other lenses have issues (that would really be unlucky for me)? I know that the DOF lever is just to quickly check DOF, and not for stop-down metering, and I also know why the 150mm Soft Focus has the lock (focusing aid with the disks). But since there are metering prisms available, I would have thought all the lenses would have the locking feature, or am I just missing something?

 

[largely]

For my RB67 PSD system, I have the 50mm, 65mm, 90mm, 150mm SF, 180mm, 250mm, and the 360mm.

I recently picked up the Fotodiox RZ to EOS adapter so I could use the lenses on my Canons (film and DSLR). As there is no camera to lens control, I have to stop down the lens for metering and shooting. This hasn't been a problem, as I've only played with the 150mm on the adapter. On this lens, when I move the DOF preview lever, it locks when it gets to the end. However, I can't seem to get the lever to lock on any of the other lenses.

Is this the way they are supposed to be, or do my other lenses have issues (that would really be unlucky for me)? I know that the DOF lever is just to quickly check DOF, and not for stop-down metering, and I also know why the 150mm Soft Focus has the lock (focusing aid with the disks). But since there are metering prisms available, I would have thought all the lenses would have the locking feature, or am I just missing something?

I have the same lenses except the 360. None of mine lock except the 150. I don't think they are supposed to.

 

[Janelectro]

The aperture lever does not lock on RB-Sekors.

I locked my preview lever some months ago when I used my RB to watch the solar eclipse. Locking the aperture is straight forward: put a rubber band around the lever and also around the mirror lock-up switch, done.

 

[Kirks518]

Thanks guys.

Good tip Janelectro!

 

[paul ron]

your 150mm the soft focus lens by any chance? its suposed to lock so you can stop it down to f8 to focus in the sharp area of the lens.

its the only lens in the line up that does that.