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Phase One DF+ critical focus with MF only lenses?

buggz

New member
Hello,

Hoping everyone is safe and well.

I have recently gotten a Phase One DF+ body.
I use it with my Mamiya DM33 digital back, works good.
At this time, I only have a few manual focus only M645 lenses.

- QUESTION -
I was wondering how everyone achieves critical focus with MF only lenses.
I have the standard focusing screen, and without magnification, I find it VERY difficult to achieve critical focus.

- QUESTION -
Do the old microprism focusing screens work with this body?
 

steve_cor

Member
There is a magnifier you can buy for the viewfinder. It flips up so you can see the whole screen. Bring it down to focus, then push it up to see everything again.

You can replace the focusing screen yourself. You could try the micro prism screen if you want.

Even with manual focus lenses, the focus assist lights work. While holding the shutter release button half way, the arrow lights show you which way to turn the focusing ring. The green dot is illuminated in the viewfinder's LCD to signal that a picture is in focus.


--Steve.
 

dougpeterson

Workshop Member
I have recently gotten a Phase One DF+ body.
I use it with my Mamiya DM33 digital back, works good.
At this time, I only have a few manual focus only M645 lenses.

- QUESTION -
I was wondering how everyone achieves critical focus with MF only lenses.
I have the standard focusing screen, and without magnification, I find it VERY difficult to achieve critical focus.

- QUESTION -
Do the old microprism focusing screens work with this body?
Welcome to the Phase One family. Phase One now owns Mamiya and Leaf (the two partners involved in your kit).

Various thoughts...

For many kinds of shooting focus-confirmation (which is available even for manual focus lenses) works quite well. It will indicate a range (the bullet point will illuminate for a small range of radial positions of the focus ring) so just jog it to both sides of that range and then land in the middle and you're very likely to be in perfect focus.

The flip down magnifier can help, though it does prohibit seeing the full frame.

On more recent backs the CMOS live view at 100% is a great way to check/set fine focus with a manual lens.

Practice makes perfect; it's a new kit to you, so give yourself a chance to acclimate to the new kit before expecting yourself to meld with it perfectly. More time behind that viewfinder will improve your manual focusing with it; I can't tell you in advance if it will improve it to a 95% hit rate or improve it to a 50% hit rate, but it will improve it; that will depend a lot on you, your eyes, your definition of a "hit" and the style of shooting you do.

For closer focus distances consider the "lean" method where, after a rough focus, you lean your body toward or away from the subject (we're talking about small movements of a cm or two) rather than trying to rack the focus ring. This can often lead to a more and less distracted view and an easier ability to pull the trigger at the moment the focus is perfect, at least for some people.

By the way, we are still able to ship from our eStore such as the refurbished P1 lenses: https://www.dtcommercialphoto.com/p...s-bodies-lenses/refurbished-phase-one-lenses/. Older manual focus lenses are a great way to flesh out your lens line at a low cost, but for your most used 2-3 lenses I'd really suggest (over time) investing in the more recent autofocus versions.
 

anwarp

Well-known member
Hello!

Before I moved to MF, I used a canon 5d mk2 with ziess lenses. I found manual focus very easyonce i changed focusing screens - Canon made dedicated screens for manual focus - they were dimmer, but more contrasty.

When i got my used df+ and iq260 back a few years ago I had to go for the cheaper MF lenses initially. I managed to find a couple of older microprism focusing screens on ebay.
They were dimmer than the original focusing screen, but easier to use in good light.
They fit but are slightly thinner. The tension on the mounting clip holds the screen firmly enough.

The mamiya screen with the split prism and 2 microprism collars is quite good. I think its a type e.

I finally managed to gethold of a britescreen version a couple of years ago. I now use it instead and it works very well with the 200 2.8 apo and 80 1.9 lenses.

The replacement focus screens do affect the prism metering, but yiu learn to compensate.
My screen was very slightly off critical focus, but i quickly learnt to focus a hair closer and achieve critical focus.

Hope this helps.



Hello,
Hoping everyone is safe and well.

I have recently gotten a Phase One DF+ body.
I use it with my Mamiya DM33 digital back, works good.
At this time, I only have a few manual focus only M645 lenses.

- QUESTION -
I was wondering how everyone achieves critical focus with MF only lenses.
I have the standard focusing screen, and without magnification, I find it VERY difficult to achieve critical focus.

- QUESTION -
Do the old microprism focusing screens work with this body?
 
Last edited:

buggz

New member
Thanks to everyone for the replies and information.
I have the Mamiya 645AF Magnifier FD402 on it's way.

I have found that the Mamiya Magnifier on my RZ67 kind of fits, but is loose,
as it is slightly a bit wider than the M645 view finder.

This should work well for me, as I use it in conjunction with the microprism focus screen on my RZ67.
 

buggz

New member
Oh yes, the magnifier is an essential piece of kit for me.
Received today.
Now I can capture with confidence, as I do on my Mamiya RZ67 Pro II kit.
 
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