How to focus people with Mamiya 7 II

[tara_ratliff]

I have been having problems with focusing the Mamiya 7 II. It's my understanding that if I want to focus

on a person's eyes, I point the small focusing square to the eyes and focus and move it back to the

composition I want. So far the only pics in focus were the ones I shot horizontally and where I was as

close as I could get to the subject. Any tips?

[Scott Ridgeway www.Scott]

Your understanding of how to focus is correct. What lens are you using?

[knp125]

Tara,

 

I prefer to focus on lines (whether horizontal, vertical, or irregular). They are much easier to

see when using the rangefinder focus system (focusing square). Look for the edge of the

mouth, nose, neck or anything else like a zipper or collar that have a well defined line (with

color or contrast). Remember to recompose before shooting.

 

Regards,

[christoph_hammann]

The focus-recompose method is fraught with errors when using shallow depth of field

because of ... uhm<br>

... well let's just say because of Mr. Pythagoras.<br>

I get this error even with f/1.2 and 35 mm film. One needs to remember to shift out focus a

bit after recomposing. You say you have success focussing at close distance where it should

matter most, so I think your technique is good. I'd have my rangefinder checked or do it

myself.

[victor_moss]

Focusing and recomposing can lead to errors if you are tilting the camera to recompose (as opposed to sliding it in the original plane). The error will show up more when shooting at close quarters, since the error percentage is higher. To counter you can (a) not tilt, (b) stop down, © bracket focus, (d) find something else to focus on near the center of the frame etc. But, there is always a risk with rangefinders for this kind of situation. Btw, when you are shooting vertically, I am assuming that you are matching horizontal lines (as opposed to vertical).

[stefano_kovacs]

Tara,

 

The problem you are experiencing is likely due, at least in part, to the fact that you are

focussing and then recomposing before taking the picture. This can cause wrong focus

because of the way photographic lenses are designed. The vast majority of lenses,

including your Mamiya 7 lenses, are designed in such way that the area of sharp focus lies

on a plane perpendicular to the axis of the lens. To explain what this means and what the

implications are let me give an example.

 

Let's say that you are on a street and pointing the camera at a building across the street,

about ten meters away. If you focus on a ground floor window, at your level, you would

thus be setting the focus at about ten meters. If you now take a picture of the building

keeping the camera horizontal without tilting it, the whole facade of the building will be in

focus. This is what I was referring to before: everything in the plane perpendicular to the

lens' axis at a distance of ten meters is in focus. In the situation I just described this plane

coincides with the facade of the building. Now suppose that you first focus on a window

on the fifth floor and then recompose to frame the same picture as before, i.e. pointing

the camera straight at your level without any tilt. In this case you would have set the focus

at about 20 meters, i.e. the distance of the fifth floor window. The picture will result out

of focus. Not only the window on the ground floor is out of focus, but also the one on the

fifth floor on which you focussed. What is in focus is a vertical plane at a distance of about

20 meters, i.e. 10 meters behind the facade of the building.

 

The same problem occurs when you focus on the eyes of you subject and then recompose

to take the picture. If you first focus on your subject and then recompose so that the

subject is not in the centre of the frame, you will find that the focus is a little behind the

subject. With a rangefinder camera such as the Mamiya this problem is difficult to avoid

because the rangefinder forces you to use the centre of the frame to focus. You should try

to focus on something which is in the same plane of your subject in the final frame, but

this may not be easy. In order to minimise the issue you can use a smaller aperture (larger

f-number) to increase the depth of field.

 

Stefano

[Scott Ridgeway www.Scott]

We still don't know what lens she is using. If it's the 150mm, isn't it notoriously difficult to focus? I'm using the 65mm, and getting correct focus is a breeze. I used to own the 80mm. I don't remember it being difficult. I don't shoot wide open, though.

[ben_pater]

It's more difficult to focus when in vertical position. Sometime when I focus horizontal and

then turn the camera, it will go out of focus because of movement of the lens.

 

Ben

[mohir_ali]

I had no problem focusing a Noctilux (that's f/1.0, you slow mf folks ;*p ) up close and reframing my Leica, something else, like rf calib., may be at fault.

[fotografz]

Mohir, DOF with MF optics is shallower than 35mm at any given f stop and distance... just

like APS sized formats have greater DOF than 35mm for the same reason. The bigger the

format the shallower the DOF ... and the Mamiya 7 is a 6X7 format.

 

Most of the Mamiya 7 glass is f/4 and if used wide open & close up can be challenging.

Two or three things could be at work here: the already mentioned recomposing. Solution

is to physically move parallel to the subject when recomposing rather than shifting the

camera position. Another may be that the rangefinder is out of calibration. Solution would

be to bench test the camera on a tripod shooting a ruler on a 45 degree angle while

focussing on the 6" mark. The last may simply be slightly off technique combined with

either of the two possibilities mentioned.

[mark liddell]

Do any of the mamiya 7 lenses suffer a lot from backfocus?

[david_rees]

Mark -- it is possible for an M7 lens to be out of focus alignment (yielding either front- or back-focusing), but typically it is the rangefinder in the camera body which is at fault, if focusing is a problem. I've had this with 2 of my 3 M7 bodies. The good news is that it is fixable by Mamiya relatively easily and inexpensively.

 

To determine if the camera rangefinder is out, try a couple of simple tests. First, put a lens (any lens -- it doesn't matter, because it's a rangefinder!) on the camera, then focus on an object at infinity -- at least 100m away. If the distance marker is not pointing at infinity on the lens distance scale, then there is an issue.

 

It is also worth placing the camera on a tripod, a distance (say 10ft) away from an object (measuring from the film plane, not the front of the lens), then carefully focus on it. Again, if the distance on the scale does not match the observed distance, there may be a problem.

 

Finally, if you really want to be sure, place the camera (with lens) on a tripod, open the camera back and place a 6x9cm ground-glass screen onto the film runners (small magnets can hold it in place), set the aperture as wide as possible, then activate the shutter whilst set to B (I find a cable release, with a lock to keep shutter open, quite helpful for this). With the help of a focusing loupe, you can match the focus of an object in the rangefinder with the equivalent upsidedown image on the ground glass.

 

The last method is the one I use annually, to ensure my M7 bodies haven't drifted off-true. I use the first (focus on infinity) every couple of months, as a simpler check.

 

Finally, to offer a thought to Tara: if the rangefinder is set up properly, then it is possible to focus on your subjects eyes, then recompose, but with a caveat: depth of field may well be very shallow.

 

For example, with a 65mm lens, set wide open at f4.5, and with the subject 6 ft away, the depth of field is about 7in (assuming a CoC of 0.03mm). With an 80mm lens set to f4.0 and focused at 4ft, the DoF is 2in! As others have pointed out, recomposing after focus may well move the plane of focus, and with a shallow DoF, it is easy to end up with slightly out-of-focus shots.

 

It might be worth using a smaller aperture if light and aesthetic needs permit (for example, at f8, DoF for the 65mm example above is about 15in, and 30in for f16). Alternatively, determine a focus point below the eyes, which is in the same place of focus as the eyes, and then focus on that instead, in order to reduce or eliminate the recomposition you are doing.

 

Whatever you do, have fun with your M7, and do post the solution you settle on when you find it, for the benefit of others.

[tara_ratliff]

I am shooting with an 80mm standard lens. Thank you for all of your posts.

[paul_mchardy1]

Hi Tara,

 

I've had no issues with focus on using the 80mm yet, but like Kenneth I tend to look for an area of the subject with a distinct 'boundary' (i.e. the line of a mouth). Like Ben, I too find it more difficult to focus using the camera in a vertical format. From experience I would also recommend stopping down a bit to improve your chances - the plane of focus is really quite visible on some of my available light 'wide open' portraits. Happily, (and probably by chance), my quota of 'keepers' is still far higher with the M7 II than with any of my other cameras.

 

I bless the day I bought it.

 

Best regards,

 

Paul

[peternador]

If you focus on the moon with a Mamiya 7, and it's not in perfectly focus at infinity, but you have move it back from the middle of the infinity sign like two millimeters. Is that a sure sign that the camera needs calibration?

[Jochen_S]

75% "yes". - IDK who messed with your camera previously, so there is a faint hint of a chance that person compensated a too short lens mount with an RF adjusted to reality as seen on a ground glass at the film plane. My RFS (no Mamiyas) have hard infinity stops only some SLR glass hasn't.