Looking for accurate focus

[aparat]

A chimney finder makes the biggest difference for me.
The AE Focusing Hood is designed for the RZ67 Pro.
I believe that you can also use the PD Magnifying Hood designed for the RB67.
The additional advantage is that both provide you with through the lens metering - no more bellows extension compensation calculations.

That's what I use with my Pentacon Six for macro photography, and I find it more accurate than using either the WLF or prism.

 

[holggger]

I have recently finished developing a couple of rolls shot with my Mamiya RB67, and everything looked good on the contact sheets, but after enlarging many of the photos I have realized that focus is more off than on, which is very annoying in some cases. Shooting mostly wide open (because I was shooting handheld, overexposing a stop and having 4 stops worth of filters in front of the lens) did not help, needless to say. It is mainly a front focusing issue as far as I can tell now, with the occasional shot with correct focus or back focusing.
I am going to shoot a focus chart at home on a tripod to clarify any technical problems, but since it is going to take a long while until I can see the results of that:

1) does having bad eyesight (I see well but not perfect) change the focus plane in any way (I assume not)
2) what is the correct way to insert the Mamiya focusing screen – plastic bottom glass top or the other way around? Does it make a difference?

 

[DoryBreaux]

I've never used an RZ but isnt there a distance scale on the bellows? Could you measure your focus distance?

 

[Alan Edward Klein]

Do RB67 and RZ67 have problems where the focus on the prism finder is "off" from the actual focal point on the film?

 

[btaylor]

A flipped focus screen would certainly cause a focus error- frosted side is always towards the lens.
I don't see how a prism could cause a problem, the frosted side of the focus screen is the plane of focus which is what you are looking at through the prism.
Put a groundglass or other translucent material (like magic tape) at the film plane, focus on a target and see if the groundglass and plane of focus agree. If they don't something is wrong with the mirror, gg or body alignment.