Mamiya Press 50mm 6.3 Lens: How to Zone Focus? Markings don't make sense.

cayenne

Member
Joined
Dec 13, 2019
Messages
212
Location
New Orleans
Format
Hybrid
Hello all,

I'm sure being a noob, this is likely a stupid question, but I've been practicing zone focusing other cameras, my digital M10M for the most part.

I'm confused on how do do this for the Mamiya 50mm Press lens. I just got my PressPan camera body in, to shoot panoramic 35mm images (https://emulsive.org/reviews/camera...lad-xpan-alternative-introducing-the-presspan). which has a 3D printed housing on top of a highly modified Nikon FE camera....and you mounts the Mamiya Press 50mm lens to it.

Now, I"ve zone focused, as best I understand it with my Leica M10M.
As an example on that camera first. I have a 35mm f/2 Ultron lens. Say I want to zone focus for highest f-stop on that lens, which is f/16.

So, I put the infinity symbol on aperture dial at f/16 on the right side of the zone focusing marks, and I look over to the other side and where f/16 is marked there indicates 1.2 meters.

So, with this, I should have zone focus..."acceptable" focus for anything from 1.2 meters away from to to infinity, right?

Ok, with the Mamiya lens. I'm looking to attempt the same thing.

First on the lens, the maximum aperture is f/32. On the zone focusing area, there is no 32 marking. There is, however, a white line coming from f/22 and going out to each side where I'd expect 32 to be....can I assume that is where f/32 would be?

Second...the markings around the zone focus area markings doesn't see to work like I understand them.
Example:
I set infinity mark on aperture control to f/22 on the right side of the markings in the same manner I did above.
However...on the left side, the numbers on the aperture dial don't reach all the way over to the f/22 mark over there?!?!?

So, I dunno how to figure what the minimum focus at f/22 is?

In fact, I cannot get a reading on the left size of that set of numbers till I put the infinity symbol over f/11 on the right and then on the left, it reads maybe just a bit shot of 1.3 meters.

I just dunno if I've misunderstood zone focusing this whole time, or what.

The lens does have a big red arrow dead center of all the zone numbers....what is that for? Is that exactly how many feet I"m focused at?

I'm sure these are very stupid noob questions...but I would greatly appreciate help, or links to more info.
I can't really find much on YouTube on this lens by itself describing the markings....

Thank you in advance, for any help.

I'm VERY anxious to load this thing up with film and start shooting....I have the view finder mounted on top, ready to go.

cayenne
 

Nicholas Lindan

Advertiser
Advertiser
Joined
Sep 2, 2006
Messages
4,215
Location
Cleveland, Ohio
Format
Multi Format
Could you post a picture of the lens and the depth of field scale?

The focus setting you are using - with one end of the depth of field set to infinity - is called the "hyperfocal distance." "Zone focusing" usually refers to the 3 position focus setting - usually shown with symbols of a head, group of people and mountain range. It was common on low end consumer cameras in the 1950's and 1960's. I think it only shows up on Holgas these days
 

BrianShaw

Member
Joined
Nov 30, 2005
Messages
16,339
Location
La-la-land
Format
Multi Format


There are no “zone numbers”.

In the row with the red triangle, is the depth of field/depth of focus scale, the numbers are aperture numbers on both sides.

On the focus ring, the row with two colors, are focus distance in either feet or meters.

Hyperfocal focus works the same as on your Leica.

That’s a very interesting camera!
 
Last edited:

reddesert

Member
Joined
Jul 22, 2019
Messages
2,316
Location
SAZ
Format
Hybrid
What you're calling the "zone focusing area" is called a depth of field scale by most people. The red mark in the center is the distance you're actually focused at. The lens was originally designed for use on a rangefinder camera, the user would focus with the rangefinder, the focused distance would align with the center mark, and the other numbers indicate the range of distances that are in acceptable focus. It works the same way as the DOF scale on most other cameras and lenses. You can search "hyperfocal distance" as Nicholas suggests to understand more.

The issues you're probably having are that:
1. The DOF scale on all the Mamiya Press lenses I've used are about 1 stop optimistic (that is, they used a larger circle of confusion to calculate the DOF markings than most people would). So if you set the lens at f/16, use the markings for f/11. I haven't used the 50mm but the picture BrianShaw posted shows it's the same way.
2. The 50mm is a really wide angle lens. So it has very broad depth of field. This means the DOF markings are far apart and in principle, if you set infinity at the far f/22 mark, the near f/22 mark may be closer than the minimum focus distance of the focusing ring. As above, that's a bit optimistic.

It would be better to set the focus ring at the distance of the most important subject and then choose an aperture that brings the desired near and far distances into the DOF markers (keeping in mind the 1-stop optimism issue).
 

BrianShaw

Member
Joined
Nov 30, 2005
Messages
16,339
Location
La-la-land
Format
Multi Format
… and to do zone focus is easy. If shooting stuff close to you, say 10 feet away for the subject-of-interest just set the 10 ft (Orange scale) to align with the red triangle. Etc.
 
Last edited:
OP
OP

cayenne

Member
Joined
Dec 13, 2019
Messages
212
Location
New Orleans
Format
Hybrid

Yes, thank you, here are some pics of the lens.
 
OP
OP

cayenne

Member
Joined
Dec 13, 2019
Messages
212
Location
New Orleans
Format
Hybrid


Hmm...ok interesting.

So, with the images I've posted here....there is no way to set hyperlocal distance (thank you for the correct terminology for what I'm trying to do, like I said, I"m a bit of a noob on this)....for f/32 - f/16, the closed down stops?

Ok, thank you for the info about the red triangle....I'm planning to get one of those DeWalt small laser measuring devices and velcro it to the camera somewhere..I can use that to get the distance and then set the focus distance on the lens based on that.

I'm thinking of getting this one as that it is small:
https://www.homedepot.com/p/DEWALT-...MERCH=REC-_-searchViewed-_-NA-_-312165148-_-N

Looking at the images I've posted...any ideas how to set hyperlocal on this lens since the numbers on the focus dial don't all match both sides of the depth of field scale?

Thank you again everyone!!

C
 

BrianShaw

Member
Joined
Nov 30, 2005
Messages
16,339
Location
La-la-land
Format
Multi Format
In your 3rd and 4th picture, where infinity seems to be set at the f/22 dof marker, the close focus just isn’t calibrated on the scale. It is quite a bit less than 1meter, which is the closest calibration mark provided. I’d guess that a linear extrapolation is appropriate and the close focus distance at f/22 is very close… nearly zero… so your hyperfocal distance at f/22 is from infinity to your toes.
 

Nicholas Lindan

Advertiser
Advertiser
Joined
Sep 2, 2006
Messages
4,215
Location
Cleveland, Ohio
Format
Multi Format
Yes, you run out of focusing distance markings for f22 -- at a guess the low-end distance is 2 feet or so. Just because the distance marking isn't engraved on the lens doesn't mean it isn't there in a 'virtual' sense.

The optimistic DOF for this lens is likely due to the Mamiya 23/Press/Universal being meant for press photography. A 2x enlargement was probably be as big as a picture of "Mayor Tompkins leaving the courthouse after being charged with ..." would get in the evening edition of the newspaper.
 
Last edited:

wiltw

Subscriber
Joined
Oct 4, 2008
Messages
6,366
Location
SF Bay area
Format
Multi Format

If you take a good look at Photo 2 in post #6, the settings show Hyperfocal distance focus for f/6.3... the far DOF scale mark for f/6.3 is opposite Infinity, and the near DOF scale mark for f/6.3 is opposite about 7'...at that focus setting (about 14') from 7' to Infinity is 'in focus' with f/6.3 for an 82mm x 108mm frame area.

Most DOF scales assume 'manufacturer standard vision' which is about 3x worse than than a US optometrist strives to achieve for patients (20/20) That is why standard DOF scales are overly optimistic!. 20/20 vision would say DOF is only 10'-22'! And that is why so many photographers use the DOF marks for about +2EV faster aperture.
 
Last edited:

reddesert

Member
Joined
Jul 22, 2019
Messages
2,316
Location
SAZ
Format
Hybrid

I don't know 100% how to answer your question because I don't understand which conceptual problem you're having. Have you used a manual focus wide-angle SLR lens before? The DOF marks on it aren't really different from those on a typical manual focus SLR lens.

If you focus at the hyperfocal distance, for a given f-stop, then the depth-of-field just barely covers from infinity to half the hyperfocal distance. For example, for your lens, if you focus at 3 meters (10 feet) by putting the 10 foot , then the DOF markings will show that at f/11 the DOF extends to infinity on one side, and 1.5 meters (5 feet) on the other. Try it. (Remember that Mamiya was a stop optimistic, so you'd really need to shoot at f/16 instead of 11).

There's no law that says you have to focus at the hyperfocal distance. If your subject extends from 10 feet to infinity, then you can focus wherever you want that keeps both 10 feet and infinity within the DOF marks. Often you'll want to just focus on the main subject to get it as sharp as possible.

If you stop the lens way down and set infinity at the f/22 mark, like in your photo, then the red triangle is at about 1.3 meters so that's where focus will be sharpest. The near-side depth of field will extend closer, to about 0.65 meters. This is closer than the focusing travel of the lens and the marked focus scale, but that's not an optical limitation. It's just the mechanical limit of how far the lens will turn.
 
OP
OP

cayenne

Member
Joined
Dec 13, 2019
Messages
212
Location
New Orleans
Format
Hybrid

Thank you, interesting observation.

Ok, well, it appears that my first roll through this thing, will largely be experimental shots that I log and see what happens after development. Trying to shoot close up with f/22, etc.
And I also need to see how well the viewfinder, with the mask on actually mimics what the lens is seeing.

Thank you for the insight!!

cayenne
 
OP
OP

cayenne

Member
Joined
Dec 13, 2019
Messages
212
Location
New Orleans
Format
Hybrid
halfaman said:
This is really important. I shot this lens trusting the marks and the images were clearly out of focus.
Click to expand...

Ok, good to know!!

Just to ask. Is this just saying the DOF marks are off...of is the actual distance, ie putting the thing on 6ft on the red triangle, that that won't actually be the real distance and I need to put it +/- by some amount?

Again, I apologize for being confused, I am very new to this focusing by distance, with no rangefinder or actually focusing through the lens.


Like I mentioned, my first roll will be me experimenting and trying to remember to log everything to figure out what this thing actually shoots at.

Thank you and everyone helping me out so far!!

Very much appreciated!!

C
 

BrianShaw

Member
Joined
Nov 30, 2005
Messages
16,339
Location
La-la-land
Format
Multi Format
Just one last piece of advice, if I may… spend some time perfecting the art of estimating distance. No matter how appealing a rangefinder is, and it IS an appealing option, it takes so much time that one tends to get constrained to static subjects only. That’s been my experience with a 1930’s era camera. Then set relatively close and stop down. Save the rangefinder or tape measure for when critical focus or small DOF is needed.

Enjoy… that looks like a swell camera!

The actual distance marker should be exact, if they engineered that camera correctly. I’d assume that they did. The DOF markings are based on computation with assumptions that can vary, as mentioned earlier. Follow the good advice previously mentioned.
 
OP
OP

cayenne

Member
Joined
Dec 13, 2019
Messages
212
Location
New Orleans
Format
Hybrid


Thank you!!
Great advice!!

I think I mentioned earlier that I'm going to run (likely today) to Home Depot and pick up one of those very small DeWalt laser distance measurers that run to about 55ft.
I plan to try to maybe velcro that to the camera somewhere and with that I can hit a button and find distance, of course, being careful for eyes, etc....

But I figure with that to help get critical focus I can also practice guessing distances before hitting the button.....maybe a good learning tool.

Again, I very much appreciate all the insight and suggestions here!!

cayenne
 

gordrob

Subscriber
Joined
Jan 29, 2005
Messages
989
Location
Western Cana
Format
Multi Format
cayenne said:
I think I mentioned earlier that I'm going to run (likely today) to Home Depot and pick up one of those very small DeWalt laser distance measurers that run to about 55ft.
cayenne
Click to expand...
I have the Bosch version laser for measuring distances and the one thing that I have found is that it is difficult to see if you have the red dot on your target in brighter light. Other lasers used to measure distances or levels have a set of glasses to allow you to see the dot on the target.
 

reddesert

Member
Joined
Jul 22, 2019
Messages
2,316
Location
SAZ
Format
Hybrid

No, that's not what saying "the DOF marks are off" means. Look, do you have an SLR with a manual focus lens that has a depth of field scale that you can practice with to understand? Because this scale is the same thing, and with the SLR focusing screen maybe you can focus the lens back and forth to understand depth of field.

The red mark in the center indicates the distance you are focused at. That should be correct if the camera was made properly. The aperture numbers to the sides indicate the range of distances that will be in acceptable focus. What we are saying is that Mamiya's idea of "acceptable" was too broad, so you have to use the marks for one stop closer together. You could do something like put a piece of tape over the f/11 mark that says "16" to remind yourself of this.
 

halfaman

Subscriber
Joined
Sep 22, 2012
Messages
1,338
Location
Bilbao
Format
Multi Format
cayenne said:
Just to ask. Is this just saying the DOF marks are off...of is the actual distance, ie putting the thing on 6ft on the red triangle, that that won't actually be the real distance and I need to put it +/- by some amount?
Click to expand...

The first thing, DOF marks are way off. You can try what suggested before, add one stop to all of them. This means that f/11 mark corresponds to f/16, f/16 to f/22 and so... Or just use a rangefinder.
 
Last edited:

pbromaghin

Subscriber
Joined
Sep 30, 2010
Messages
3,775
Location
Castle Rock, CO
Format
Multi Format

I have always mistakenly used the term "zone focusing" when using hyperfocal distance, such as with folders. Thank you for this.
 

pbromaghin

Subscriber
Joined
Sep 30, 2010
Messages
3,775
Location
Castle Rock, CO
Format
Multi Format
For close focusing accuracy, you could try testing to compare known, measured distances with that actually is happening at the film plane. Gin up some kind of ground glass (or substitute - several threads on apug), put the camera on a tripod, bring the image into focus and compare the lens setting with a tape measure.
 
Last edited:

Nicholas Lindan

Advertiser
Advertiser
Joined
Sep 2, 2006
Messages
4,215
Location
Cleveland, Ohio
Format
Multi Format
I should mention that when you run out of focus distance numbers on the lens, and you are using hyperfocal setting with one of the DOF points at infinity, the close end of the scale will be at 1/2 the distance the lens is focused for. In the above photos f22 and infinity are lined up. The red diamond shows an optimum focusing distance of a bit over 4 feet. The close DOF distance will then be one half of four-and-a-bit feet or roughly equal to two-and-a-smidge.

The hyperfocal method is generally not a good idea unless you want to use your camera like a box camera. The lens should always be set to the actual distance to the subject. If you want great depth of field then pick the f-stop that gives the DOF to the near or far point you desire. If you can't reach it with the lens focused at the subject distance then consider the best compromise you can reach with the subject distance as close to the focusing distance as possible.

DOF scales can be just as useful for making sure something is blurred. I use the DOF preview on a camera a lot as I find the pleasantly blurred background I see in the finder pops into distracting focus when the lens stops down. That was nice thing about Exaktas with their external stop-down/shutter release button - you always got a DOF preview of the picture.

Preseting a lens to be in focus from say 4 feet to 20 feet can be useful for street photography or other situations where you won't have time to focus. Realize, though, that only things about 8 feet away will be in really sharp focus. Henri Cartier-Bresson used preset focusing for many of his shots and it is the reason so many of his photos are slightly fuzzy; I got so used to HCB's fuzzies that I find the occasional in focus shots to be somewhat jarring and lacking in that HCB 'look.'
 

John Koehrer

Subscriber
Joined
Apr 3, 2004
Messages
8,280
Location
Aurora, Il
Format
Multi Format
It seems everything is explained so.......
It seems that there is a small white line past each f22 on each side of the depth of field scale
If there are and it's not just my imagination those are the dof indicators for f32.
 
You must log in or register to reply here.
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…