Mamiya 110mm f2.8 portraiture...

[DavidClapp]

I have been recently dipping into some fashion photography with my Mamiya RZ67 Pro 2 / 110mm 2.8 and I would like to get some advice from anyone with the same setup .

Q. How far does the lens have to be stopped down to ensure both eyes are in focus, without loosing the wonderful out of focus background? At f2.8, if the subjects eyes are anything other than straight on to the camera, one eye begins to lose focus almost immediately.

I recently did a first roll at f2.8 and I am now thinking f4-5.6 would have been better.... I am just concerned I'll lose that 110mm OOF magic if I stop down too far.

 

[wiltw]

Assuming normal 20/20 visual acuity (which is the 'standard' your optometrist tries to get your eyes to)

• the 110mm lens at a shooting distance of 10' at f/2.8 has
  20/20 vision DOF Zone which is 11" deep in a FOV capture which is 63" x 73"
• the 110mm lens at a shooting distance of 10' at f/5.6 has
  20/20 vision DOF Zone which is 22" deep in a FOV capture which is 63" x 73"

 

[WilmarcoImaging]

Increasing the subject to background distance will increase background OOF, for a given f-stop and camera to subject distance.

 

[abruzzi]

how far is the subject from you?

if they are 2m from you, your total DOF at 2.8 will be 11cm, at 4 will be 15cm, and at 5.6 will be 21cm. Only about half of that is behind the plane of focus, so if you focus on the near eye the far eye won't be in the "zone of acceptable focus" unless it is at or closer than 5, 7, 10 cm.

Those are all a calculation from here: http://www.dofmaster.com/dofjs.html

You might want to test in the real world to see if their definition of "acceptable focus" is in tune with your definition.

 

[GLS]

Just stop the lens down to the working aperture and see how things looks before taking the shot, then vary the aperture as required. Unless your eyesight is poor this is much easier to do on the fly then looking at DoF charts.

 

[tedr1]

What viewfinder are you using? The regular screen is too small to see this kind of detail it requires one of the magnifying finders.

 

[wiltw]

The DOF calculation assumes a 8" x 10" print viewed from about 10". Looking at a 56mm tall 6x7 image on the viewfinder, you would need to view that screen with a 13X (area magnification) magnifier to assess final DOF realistically!

 

[DavidClapp]

The DOF calculation assumes a 8" x 10" print viewed from about 10". Looking at a 56mm tall 6x7 image on the viewfinder, you would need to view that screen with a 13X (area magnification) magnifier to assess final DOF realistically!

Yes this exactly my problem with this whole DOF chart stuff...

 

[DavidClapp]

What viewfinder are you using? The regular screen is too small to see this kind of detail it requires one of the magnifying finders.

It was the standard RZ focusing screen but this week I picked up a Beattie Intenscreen from EBay, which should help things further

 

[halfaman]

I never use this lens wide open for portraits, DoF is often too low.

I use at least f/4 and blurr is very similar. At f/5.6 if focus is critical (double the f/2.8 DoF).

 

[bluez]

David, try using this:

https://dofsimulator.net/en/