Estimating Focus

ransel · May 13, 2016

Ok, have had a few rangefinder-less 120 folders and just took delivery of another - a Perkeo II, which I think is just the cutest little 120 camera.
I don't know why I keep putting myself through this.
I just processed a roll of ISO 100 film I put through it, just to make sure it is functional - and it is. Problem is - my ability to estimate the focus distance, which is in meters, is horrible, especially at close distances. I know that close-up is where focus becomes more critical, but it is still very disappointing to be off by 6-8" and have your dogs or girlfriends face out of focus. Granted, both of those pics were between 1-2 meters. The pictures I took at distances of from a few meters to infinity look great.
I am trying to avoid using a shoe-mounted rangefinder, mainly because I no longer have one and am not in the mood to spend the money - and because I really want to be able to use the camera as it was designed to be used.

So, is there any tips outside of:
a - External mounted rangefinder
b - Use a tape measure for close-ups
c - Always shoot at small apertures
d - Always shoot at father distant subjects
e - Practice

I really want to love this camera...

Peltigera · May 13, 2016

The system I use is to image myself lying down between the camera and subject - how many of me would it take? I am very nearly 2 metres tall so at F/8 that will be close enough. If you are not happy with metres, you need to be 6 feet tall instead.

For close distances, my feet are a bit over a foot long - again, imagine how many of them and then convert to metres.

jeffreythree · May 13, 2016

I now slap a big note on the back of my rangefinder-less Isolette saying "meters, not feet" after using other cameras for a while and missing focus on a whole roll the next time I picked it up. I have a cheap, handheld, plastic Federal rangefinder($5 on ebay), and it is fairly easy to convert feet to meters at the distances where depth of field would be an issue.

paul ron · May 13, 2016

set up your dof settings so you can get rough blocks of distance in focus.

bvy · May 13, 2016

I did this recently when shooting portraits of children that I was in a show with. I tied a string exactly three feet long to the camera and asked them to hold the end of the string between their eyes, while I pulled the camera away till it was taut. They thought it was kind of fun and it kept them in good focus. Not practical for everything, but it worked in this situation.

Cycler · May 13, 2016

Hyperfocal Distance? If your camera has deoth of field scales upon the lens barrel for landscape you set the value for your aperture at the nearer distance, having ensured that the other end of the scale is on infinity.

gone · May 13, 2016

The problem is that the camera wasn't really designed for that. Scale focus folders were made for amateur snapshots. Think landscapes when traveling, and group portraits at 20'. At close distances w/ a MF camera, and no rangefinder.....even w/ a rangefinder, you have shallow DOF w/ MF, much smaller than w/ 35mm. Plus, nearly all MF folders have front cell focusing lenses that are not good at close distances. So a small, light 35mm SLR is what you want for closeups and portraits if you don't want to lug around a MF SLR (and I certainly wouldn't).

mdarnton · May 13, 2016

Hyperfocal?? And by doing so, guarantee that nothing at all is in focus? Hyperfocal is SUCH a bad idea for just about every use! I'm surprised that anyone ever mentions it at all, but it seems to be a favorite concept that won't die. . .

Like everything else, the more focus estimating you do, the better you get, and seems hopeless at first. I bought a small handheld rangefinder from the 1950s for $15, and pull it out once in a while to practice. Lots of people estimated successfully when hand cameras first came out---there's no reason one can't learn the skill today, with practice.

bunip · May 13, 2016

I'm afraid those cameras were designed to be used with an external rangefinder to be accurate on small distances. the voigtlander rangefinder is common and not expensive. even if you had a feet scale on the lens i think you'd asked the same question because in the range between 1.1 and 2 meters with that kind of camera is difficoult to guess the right distance. I use my Perkeo II very often and keep in my pocket the small rf i use only for short distance with not small apertures, this after a long time i'm trying, without any effect than luck, to have a spot-on focus in a portrait. I have also the Perkeo I and the Perkeo III, with uncoupled rangefinder, but think the II is the best.

ransel · May 13, 2016

I just got a Perkeo I also, have not shot any film yet, but the scale on it is in feet. Another question that may complicate close focus estimation - when estimating the distance, do you estimate from the lens or film plane. With the Perkeo II I had it on tripod, set the lens at 1m, measured 1m with a tape measure from my eye to the film plane, snapped pic with a long cable release, and I was way out of focus, probably by a few inches. Are the focus scales on these cameras notorious for being off?

wiltw · May 13, 2016

Peltigera said:
The system I use is to image myself lying down between the camera and subject - how many of me would it take? I am very nearly 2 metres tall so at F/8 that will be close enough. If you are not happy with metres, you need to be 6 feet tall instead.

For close distances, my feet are a bit over a foot long - again, imagine how many of them and then convert to metres.

He needs to be a bit taller... 6' 6"

For us vertically impaired, one can imagine a basketball player

paul ron · May 13, 2016

mdarnton said:
Hyperfocal?? And by doing so, guarantee that nothing at all is in focus? Hyperfocal is SUCH a bad idea for just about every use! I'm surprised that anyone ever mentions it at all, but it seems to be a favorite concept that won't die. . .

Like everything else, the more focus estimating you do, the better you get, and seems hopeless at first. I bought a small handheld rangefinder from the 1950s for $15, and pull it out once in a while to practice. Lots of people estimated successfully when hand cameras first came out---there's no reason one can't learn the skill today, with practice.

the op listed several things he doesnt want n one was an external RF.

For close objects your estimation would be better.

For longer distance, Hyper focal has worked just fine for these old cameras over the past 75 years... it doesn't work anymore? WHY?

If I estimate the distance to be about 20' and set my DOF so 20' falls somewhere in between, say 10' to 50'.. you say it won't be in focus? REALLY?

hahahahahahahahha

John Koehrer · May 13, 2016

Peltigera said:
The system I use is to image myself lying down between the camera and subject - how many of me would it take? I am very nearly 2 metres tall so at F/8 that will be close enough. If you are not happy with metres, you need to be 6 feet tall instead.

For close distances, my feet are a bit over a foot long - again, imagine how many of them and then convert to metres.

I use the same idea but use car lengths.Since I guesstimate anyway, I guess an average mid-size car is about fifteen feet long.
For closer, the calibrated string works very well.
FWIW, any measurement you make should be from the film plane.
I also use hyperfocal distance. Yes, using the scales on the lens. If the camera
doesn't have a scale, there are quite a few online.

ic-racer · May 13, 2016

Your eyes and a fixed object can be used as a rangefinder. That is how I do it, but after a while I'm good enough to guess. Teach your self to recognize common distances. 3', 6' 12' 25' etc.

Here is a link to make the paper rangefinder.
https://tomchuk.com/misc/rf/

bvy · May 13, 2016

ic-racer said:
Your eyes and a fixed object can be used as a rangefinder. That is how I do it, but after a while I'm good enough to guess. Teach your self to recognize common distances. 3', 6' 12' 25' etc.
https://tomchuk.com/misc/rf/

Will that work for those of us with diplopia?

GregW · May 13, 2016

There is also an app you can get for your phone. Use it to train yourself.

wiltw · May 14, 2016

paul ron said:
the op listed several things he doesnt want n one was an external RF.

For close objects your estimation would be better.

For longer distance, Hyper focal has worked just fine for these old cameras over the past 75 years... it doesn't work anymore? WHY?

If I estimate the distance to be about 20' and set my DOF so 20' falls somewhere in between, say 10' to 50'.. you say it won't be in focus? REALLY?

hahahahahahahahha

Hyperfocal does not always work well. One example:

135 format, 50mm f/4

assuming viewer has 20/20 vision (not the poor vision assumed in 'manufacturer standard'), Hyperfocal is 192'
when you focus at 192', the actual DOF is from 96' to Infinity
But what if the subject is really 25' away (but I guess the subject is at 30')?! Hyperfocal does not work, it falls far short of including anything at 25-30'!

OK, let's try using the DOF scale on the 50mm lens (in this case, I use an Olympur OM 50mm f/1.4 lens)...

put f/4 mark opposite Infinty
the other f/4 mark is about 10m away
but if the subject is really 25' away (and I again guessed wrongly 30'), the DOF scale on the lens does not work either!

That brings us back to the OP question

If I (poorly) guess the distance of the subject as 30', I put the focus index at 'about 9m' (my last foot distance is 12'...at least I have distances on the lens at 5m and 10m to place the scale index!)
the lens DOF scale for f/4 shows DOF to be about 7m to something >10m...have to guess, cuz the next distance on the scale is Infinity
have I guess well enough? well the same DOF calculator program shows that when we focus at 9m, DOF is 7.8 -10.6m
but if the subject is really at 25', not at 30' where I placed focus, the 25' distant subject is just barely inside the acceptable DOF

...which illustrates why the OP need for some reasonable way of distance estimation.

Back to the OP! Ask yourself this...

Assuming you CAN accurately estimate distances visually, e.g. 35',...
...on your camera distance scale can you FIND that distance to preset it to????

All of the examples above assumed 135 format. And THAT has deeper DOF than your 120 format camera, which uses a longer FL for the same FOV as 135, making it even harder to guess where to set your lens even when you CAN estimate distances with some accuracy!

Bill Burk · May 14, 2016

You can measure the distance between your eyes and follow a formula to draw lines with a ballpoint pen on your index finger to match the distance marks on your camera... holding your hand at arms' length with your thumb straight up... Then blinking your eyes you see which line an object that lines up with your thumb hits when seen with the other eye...

I've tried and it's not that easy to get an accurate reading.

But it's free, cheap and easy to try.

paul ron · May 14, 2016

wiltw said:
Hyperfocal does not always work well. One example:

135 format, 50mm f/4

assuming viewer has 20/20 vision (not the poor vision assumed in 'manufacturer standard'), Hyperfocal is 192'

when you focus at 192', the actual DOF is from 96' to Infinity

But what if the subject is really 25' away (but I guess the subject is at 30')?! Hyperfocal does not work, it falls far short of including anything at 25-30'!

OK, let's try using the DOF scale on the 50mm lens (in this case, I use an Olympur OM 50mm f/1.4 lens)...

put f/4 mark opposite Infinty

the other f/4 mark is about 10m away

but if the subject is really 25' away (and I again guessed wrongly 30'), the DOF scale on the lens does not work either!

That brings us back to the OP question

If I (poorly) guess the distance of the subject as 30', I put the focus index at 'about 9m' (my last foot distance is 12'...at least I have distances on the lens at 5m and 10m to place the scale index!)

the lens DOF scale for f/4 shows DOF to be about 7m to something >10m...have to guess, cuz the next distance on the scale is Infinity

have I guess well enough? well the same DOF calculator program shows that when we focus at 9m, DOF is 7.8 -10.6m

but if the subject is really at 25', not at 30' where I placed focus, the 25' distant subject is just barely inside the acceptable DOF

...which illustrates why the OP need for some reasonable way of distance estimation.

Back to the OP! Ask yourself this...

Assuming you CAN accurately estimate distances visually, e.g. 35',...

...on your camera distance scale can you FIND that distance to preset it to????

All of the examples above assumed 135 format. And THAT has deeper DOF than your 120 format camera, which uses a longer FL for the same FOV as 135, making it even harder to guess where to set your lens even when you CAN estimate distances with some accuracy!

Sure it doesn't work for you with such a poor choice of F stop in your examples. If you are unsure of the distance (estimate), why not increase your DOF with F 8, F 16 or even 22?

I dont have any 35mm cameras handy but just a quick look at a yashicamat 75mm f3.5 sitting on my desk...

F8 DOF is inf to 25'
F16 is Inf to 12'
F22 is inf to 8'

How can you miss? Doesn't work with shallow MF?

So being foolish spoiled the milk, not that DOF doesn't work.

bsdunek · May 14, 2016

Seeing as we Americans aren't used to the metric system, when I use a camera marked in meters, I just think of yards. I know, 36in compared to 39in., but it works fine for me.

wiltw · May 14, 2016

paul ron said:
Sure it doesn't work for you with such a poor choice of F stop in your examples. If you are unsure of the distance (estimate), why not increase your DOF with F 8, F 16 or even 22?

I dont have any 35mm cameras handy but just a quick look at a yashicamat 75mm f3.5 sitting on my desk...

F8 DOF is inf to 25'
F16 is Inf to 12'
F22 is inf to 8'

How can you miss? Doesn't work with shallow MF?

So being foolish spoiled the milk, not that DOF doesn't work.

Because we cannot always shoot with f/16, sometimes

1. you are not shooting in bright sun, you have ISO 100 film and you have no choice but to try to

a) hand hold with a relatively slow shutter speed or
b) open your aperture

...because we are shooting in shadowed area and we are trying to have some degree of subject motion control with shutter speed. Or...

2. you want some degree of creative control of your shot, via use of a larger aperture for more limited DOF

Also, you must keep in mind your Yashicamat uses the poorer visual acuity of 'manufacturer standard' in its DOF scale mark positions, and in reality most viewers have 20/20 vision, so what you THINK will be 'in focus', according to Yashicamat charts or DOF scale marks, will in fact be perceived as OUT OF FOCUS by a viewer with the corrected vision that our optometrists strive to achieve (or exceed!).

Consulting the Cambridge Color DOF calculator http://www.cambridgeincolour.com/tutorials/dof-calculator.htm we see that for 75mm lens on 6x6 at f/8...

At f/8 with 'manufacturer standard', Hyperfocal is 36.76', and if we focus at 36.76' the DOF zone is 18.44' - 5980'
At f/8 with '20/20 vision', Hyperfocal is 110.38', and if we focus at 110.38' the DOF zone is 52.5' - 1039

...a considerable difference, as with 'manufacturer standard' your main subject at estimated 25-30' is 'in focus', but for any viewer with 20/20 vision you have a blurred main subject at estimated 25-30' !

My Bronica 75mm lens has DOF scale marks for f/8 at about 25' - Infinity, too .
Actually it does not have marks for f/8, only f/5.6 and f/11 and f/22, and the distance scale only shows 15' and 30' and Infinity,
so -- to the point I raised in the earlier post -- I am in fact still entirely guessing at setting 37' on the scale, or determining if a 25' distance subject is within the looser manufacture standard DOF zone marks!

tedr1 · May 14, 2016

Getting back to the original question, this is a fine old problem that affected many generations of photographers, the challenge of getting portraits and close-ups in focus using a simple camera having no focus aids. In my opinion there is only one method and it is to become skilled at distance estimation, probably by practicing, but without a camera. You will need dedication to achieve this, it may take some time with a tape measure stretched out in front of you and no distractions while you train yourself to be able to estimate distances accurately. Begin by getting distances accurate down to half a meter, then try 10cm, this may be about the accuracy required for portraits. Dedication may be the way.

wiltw · May 14, 2016

tedr1 said:
Getting back to the original question, this is a fine old problem that affected many generations of photographers, the challenge of getting portraits and close-ups in focus using a simple camera having no focus aids. In my opinion there is only one method and it is to become skilled at distance estimation, probably by practicing, but without a camera. You will need dedication to achieve this, it may take some time with a tape measure stretched out in front of you and no distractions while you train yourself to be able to estimate distances accurately. Begin by getting distances accurate down to half a meter, then try 10cm, this may be about the accuracy required for portraits. Dedication may be the way.

But even if you use a laser rangefinder to determine actual distance with accuracy...HOW DO YOU SET the focus scale at a distance with sufficient accuracy, when only a few distances are listed
...5, 7, 10, 15, 30'...where is 24' or 37' on the scale??!

SalveSlog · May 14, 2016

ransel said:
I just got a Perkeo I also, have not shot any film yet, but the scale on it is in feet. Another question that may complicate close focus estimation - when estimating the distance, do you estimate from the lens or film plane. With the Perkeo II I had it on tripod, set the lens at 1m, measured 1m with a tape measure from my eye to the film plane, snapped pic with a long cable release, and I was way out of focus, probably by a few inches. Are the focus scales on these cameras notorious for being off?

There is a pdf on the net with the original 1950ies Watameter user instructions. It clearly states that the measured distance should relate to the distance to the lens. Not the film plane which most people nowadays assume. (Search with "watameter instructions".)

Dan Daniel · May 14, 2016

This looks like it might be worth a shot-

https://tomchuk.com/misc/rf/

Estimating Focus

Privacy & Transparency

Privacy & Transparency