Please help with P30 problem

[bohngy]

Hi all, I would be VERY grateful if you would help me out with this problem... as I'm not sure where to begin to get it sorted!

Today I received delivery of a refurbished P30 in the UK, in mamiya fit. I'm using it with a 645 AFD (not AFD2) and am having some problems with it producing sharp pictures.

I noticed that objects I focus on are soft. Sometimes the objects behind plane of focus are alot sharper sometimes it's objects in front! - so it doesn't appear to be a single front/back focussing issue (does it?)

So I set up a little test. I put the camera on a tripod and shot tethered. I auto focussed on the top of a guitar head (the sixpence to be precise), about 60cm away and shot with the 55mm 2.8 AF lens at a variety of apertures. The viewfinder showed the headstock in focus... the pictures only begin to reflect this at f11!

Here are the results, a screen grab of C1 v4.

Please could you help me out? This is the first foray MFD - I've shot MF with film, and know equivalent DOF is narrow, but this looks like a focussing problem to me!

[Lust4Life]

I had the same issue with a NEW P45 - it's plane of focus was off from what was currect - was used on a H2 at the time.

Had to send back to Phase, they screwed with it and then sent a replacement unit.  I never heard what the problem was.

In short, reject the back if not focusing perfectly.

Jack

[patrickfransdesmet]

Indeed
It is a known problem with all MFDB on traditional MF camera's
I have the P20 on a 503CW and 503CX
I need to close aperture to minimum f8 before having in focus images 9/10 time
Wide open, f2.8 it's trial and error all the time
The focus point gets displaced by changing aperture, try to live with it...
I do not have that with MF film !!!

The only camera I know, that compensates for it, is the hasselblad H series with Ultra-focus

[free1000]

Indeed
It is a known problem with all MFDB on traditional MF camera's
I have the P20 on a 503CW and 503CX
I need to close aperture to minimum f8 before having in focus images 9/10 time
Wide open, f2.8 it's trial and error all the time
The focus point gets displaced by changing aperture, try to live with it...
I do not have that with MF film !!!

The only camera I know, that compensates for it, is the hasselblad H series with Ultra-focus
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I had this problem with my Aptus 75 at first. There is a tolerance level which the MFDB manufacturers feel is reasonable. And probably this may cause occasional problems at f2.8

I would think that if you are having to stop down at f8 to get images in focus then your back could well be out of the tolerance range. That seems very poor performance to me.

Leaf recalibrated my chip and I went from images out of focus to beautifully accurate focus. I haven't looked back since.

Note that its best to check focus on an SLR camera like the Mamiya, as it may be misleading to use a view camera or camera like the Cambo as a reference because the focal plane is not standardised on these cameras as they can be shimmed and differentially adjusted. The Mamiya/Hassleblad etc forms a standard point of reference.

At the price of MFDB's this has to be made as right as possible!