Luminous Landscape Forum

Equipment & Techniques => Medium Format / Film / Digital Backs – and Large Sensor Photography => Topic started by: Christoph B. on October 28, 2015, 03:18:27 pm

Title: AF fine tuning on Mamiya/PhaseOne cameras & focussing screens
Post by: Christoph B. on October 28, 2015, 03:18:27 pm

So today I finally got my 120mm (it really is as sharp as everyone says) and as my gear is now complete I wanted to fine tune my autofocus on the 645DF+.

Of course you can't tune the AF for each lens but I found that all my lenses were equally in point after the calibration, which leads me to believe that it's not necessary to do so.


Does anyone have a problem with the autofocus adjustment and different lenses?

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Second question:
As I also use the manual focus very frequently I was wondering whether the micro prism screen would help (especially in low light situations)  - and whether it could possibly interfere with any aspect of the camera, such as autofocus or metering or anything else.

Title: Re: AF fine tuning on Mamiya/PhaseOne cameras & focussing screens
Post by: Christoph B. on October 29, 2015, 05:48:46 pm

Hmm..really, no one?

I guess everyone already sold their 645DF and went straight to the XF system....   ;)

Title: Re: AF fine tuning on Mamiya/PhaseOne cameras & focussing screens
Post by: synn on October 29, 2015, 06:15:47 pm

I use a DF+ and have not needed micro adjustment for my lenses.

Title: Re: AF fine tuning on Mamiya/PhaseOne cameras & focussing screens
Post by: Christoph B. on October 29, 2015, 07:10:06 pm

Alright - and have you ever thought about exchanging the focussing screen for one with a micro prism?

From what I've read it should improve MF but I'd really like to know from someone with hands on experience...

Title: Re: AF fine tuning on Mamiya/PhaseOne cameras & focussing screens
Post by: Franzl on October 30, 2015, 02:48:43 am

I really enjoyed the micro prism screen. Can only recommend it.

Title: Re: AF fine tuning on Mamiya/PhaseOne cameras & focussing screens
Post by: Christoph B. on October 30, 2015, 03:34:48 am

Quote from: Franzl on October 30, 2015, 02:48:43 am

I really enjoyed the micro prism screen. Can only recommend it.

Did it interfere with any camera functions like autofocus?

Title: Re: AF fine tuning on Mamiya/PhaseOne cameras & focussing screens
Post by: synn on October 30, 2015, 06:09:56 am

I have a microprism viewfinder for my bronica etrsi and enjoy using it a lot for manual focus. I would think the same would apply for the mamiya.

A focus screen will not affect how autofocus works.

Title: Re: AF fine tuning on Mamiya/PhaseOne cameras & focussing screens
Post by: LasseDPF on November 02, 2015, 05:53:41 pm

Recomended. Its very easy to swap should you feel the need to put the original screen back.


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Title: Re: AF fine tuning on Mamiya/PhaseOne cameras & focussing screens
Post by: Paul2660 on November 02, 2015, 08:56:45 pm

If the screen is for the DF or DF+, I would add, it's easy to open the latch, but I find not so easy to close it.  Even with the tool Mamiya/Phase include with the screens.  I have changed out 35mm screens for years in Canon's, but on my DF, my latch never seemed to want to fully lock even though I could hear it click, and I would have issues with the screen dropping down on the mirror and jamming. 

Just be careful when making the change to assure that the latch has fully engaged. 

Paul C

Title: Re: AF fine tuning on Mamiya/PhaseOne cameras & focussing screens
Post by: Christoph B. on November 03, 2015, 05:20:34 am

Thanks Paul, I'll do that!!

Title: Re: AF fine tuning on Mamiya/PhaseOne cameras & focussing screens
Post by: Christoph B. on November 06, 2015, 06:23:50 am

So today I installed the screen - what a revelation!!!
Reminds me a bit of the screens in the Canon A1/AE-series cameras, really easy to get your focus on point and it's not really much darker.

I really wonder why they don't just ship the P1/Mamiya cameras with this screen installed, it's so much easier to focus, even on the sides!  :D