Is it time to end the old f/stops?

[Tom Axford]

...

I think you must be pretty bored :-D

That applies to all of us who keep these threads going! ;-)

 

[mamallama]

Anyone getting into photography can't figure out where the numbers come from.

They don't need to know the origin, only how to use them. Most instruction manuals give a decent outline.

Actually, I think Olympus tried to fix that by using numbers from 1 to 6 in their PenF film cameras. Can't we come up with something new that would make more sense?

OK, you go first.

But it probably won't come from the US. We keep on using the archaic inches, feet, mile, oz., gallon, etc. Only two other countries besides us do't use the metric system, they are Burma ( Myanmar for the young whippersnappers! ) and Liberia.

I know of at least three more countries that do not use metric for everything. And US currency is metric already.

Using quarters and nickels is not exactly metric.

We're in good company!

Let me know what your thoughts are.......

I think you must be pretty bored :-D

 

[NickZ2016]

You've never measured a quarter cm?

 

[Mark B.]

Anyone getting into photography can't figure out where the numbers come from. Actually, I think Olympus tried to fix that by using numbers from 1 to 6 in their PenF film cameras. Can't we come up with something new that would make more sense?

But it probably won't come from the US. We keep on using the archaic inches, feet, mile, oz., gallon, etc. Only two other countries besides us do't use the metric system, they are Burma ( Myanmar for the young whippersnappers! ) and Liberia. We're in good company!

Let me know what your thoughts are.......

Nope, f/stops are based on a physical attribute so there's no reason to change it.

As for the metric system, it's only because of our stubbornness and ignorance the US never switched.

Mark

 

[Tom Axford]

With all the discussion of metric versus imperial units, it may be worth repeating what Mark Scott Abeln said earlier:

"The f/stop is a dimensionless number, and by definition is the same in every system of units."

All this long discussion of metric units is a complete red herring. It makes absolutely no difference to f-numbers or f-stops.

 

[Fotoni]

Camera and lenses can communicate to know optical properties of each aperture, exposure can be calculated on fly and focus peaking can tell the DOF.

35mm equivalence has been there so long that it would be the most convenient way for focal length and aperture. Megapixels should have pixel pitch included like 108 MP (0.8µ) and 100 MP (3.76µ). This also tells the projected area to compare how well optical performance can be applied with current technology. Bigger lenses are easier to make sharp and clean.

 

[Gerry Winterbourne]

I know of at least three more countries that do not use metric for everything. And US currency is metric already.

No it isn't. Metric means based on the metre invented during the French revolution; most metric units are in factors of ten (decimal) from their base.
Insofar as the US currency is based on the dollar and cents (1/100ths) it is a centimal system; as 100 is 10 x 10 it could be called a decimal system but not a metric system.

 

[NickZ2016]

Kilogram aka a litre of water aka 1000 cubic centimetres is metric.

How does Celcius fit into that?

 

[Charlie BRM]

Lenses are metric. All millimeters as far as I know. F-Stop math was learned in elementary school. Once someone is shown what it is, it’s really easy.

Modern lenses are metric. When the US and the UK had larger optical firms they sold in inches.

F/Stops are the "new" answer. There have been other methods in the past.

The only real problem is making people understand bigger is smaller.

I learned "bigger is smaller" sometime in the dark ages before I was 8. My mom asked me to get knitting needles out of the cabinet drawer. They use inverse size numbering. I dealt with it. By 12 I was building Heathkit educational kits to learn electronics. Gee, wires are just like mom's knitting needles because those larger numbers in gauge mean thinner wire. I got it.

I will confess here and now I can't figure out f-stops on the fly but I know which way is more and which way is less of respective factors involved. I have difficulty with "equivalents" of focal lengths but I choose fixed lens gear so I don't let it drive me crazy. In my case it's as pointless as if I kept trying to figure out what everbody weighs in stone. (Scots still reserve the right to use 'stone' when mentioning a person's body weight, not for much else.)

Rant over. I'm going to have my cereal now, using a #3 spoon.

 

[Gerry Winterbourne]

I know of at least three more countries that do not use metric for everything. And US currency is metric already.

No it isn't. Metric means based on the metre invented during the French revolution; most metric units are in factors of ten (decimal) from their base.

Insofar as the US currency is based on the dollar and cents (1/100ths) it is a centimal system; as 100 is 10 x 10 it could be called a decimal system but not a metric system.

Kilogram aka a litre of water aka 1000 cubic centimetres is metric.

A centimetre is 1/100 metre (or 1/10/10) - factors of ten, just as I said. A litre is the name given to that unit of volume in the metric system. A kilogram isn't also known as a litre; it is the mass of a litre of water.

In practice the original metric system has been used as the basis of the SI system.

How does Celsius fit into that?

It is an entirely independent system of measuring temperature, alongside Fahrenheit, Reaumur, Kelvin etc. The basis of many temperature systems is the range from the (normal) freezing and boiling points of water. Celsius chose 100 as the number of divisions; as that fits with the decimal basis of the metric system Celsius was adopted into it.

 

[JustUs7]

I know of at least three more countries that do not use metric for everything. And US currency is metric already.

No it isn't. Metric means based on the metre invented during the French revolution; most metric units are in factors of ten (decimal) from their base.

Insofar as the US currency is based on the dollar and cents (1/100ths) it is a centimal system; as 100 is 10 x 10 it could be called a decimal system but not a metric system.

Kilogram aka a litre of water aka 1000 cubic centimetres is metric.

A centimetre is 1/100 metre (or 1/10/10) - factors of ten, just as I said. A litre is the name given to that unit of volume in the metric system. A kilogram isn't also known as a litre; it is the mass of a litre of water.

In practice the original metric system has been used as the basis of the SI system.

How does Celsius fit into that?

It is an entirely independent system of measuring temperature, alongside Fahrenheit, Reaumur, Kelvin etc. The basis of many temperature systems is the range from the (normal) freezing and boiling points of water. Celsius chose 100 as the number of divisions; as that fits with the decimal basis of the metric system Celsius was adopted into it.

 

[Gerry Winterbourne]

I know of at least three more countries that do not use metric for everything. And US currency is metric already.

No it isn't. Metric means based on the metre invented during the French revolution; most metric units are in factors of ten (decimal) from their base.

Insofar as the US currency is based on the dollar and cents (1/100ths) it is a centimal system; as 100 is 10 x 10 it could be called a decimal system but not a metric system.

Kilogram aka a litre of water aka 1000 cubic centimetres is metric.

A centimetre is 1/100 metre (or 1/10/10) - factors of ten, just as I said. A litre is the name given to that unit of volume in the metric system. A kilogram isn't also known as a litre; it is the mass of a litre of water.

In practice the original metric system has been used as the basis of the SI system.

How does Celsius fit into that?

It is an entirely independent system of measuring temperature, alongside Fahrenheit, Reaumur, Kelvin etc. The basis of many temperature systems is the range from the (normal) freezing and boiling points of water. Celsius chose 100 as the number of divisions; as that fits with the decimal basis of the metric system Celsius was adopted into it.

The only thing Celsius chose is that 0 is freezing, 100 is boiling.

That's exactly what I said.

The rest just kind of fell where it may. At least that’s my very limited understanding. But even numbers like that is why they likely say it’s more metric in nature.

No; read what I said. Such systems are decimal, not metric. The metric system is, of course decimal.

Whereas Fahrenheit is 32 freezing and 212 boiling. Which I totally get why people outside the US think it’s silly. But when I hear it’s in the 70’s I know it’s a nice day, grab a jacket below 50 or a coat below 30. That’s just intuitive to me being in the US. If hear an non- US forecast - I know the 30’s is warm but really no idea between pleasant warm or uncomfortably hot.

There's nothing silly about it. However, apart from learning a few points along the way (like blood temperature is about 98F, 37C) that don't matter for everyday living, a decimal system is much more convenient for any calculation that uses computers.

The UK used the Imperial system (still does, for many things). The construction industry formally changed in 1971. Up till then quantity surveyors worked ls largely manually; they could work roughly twice as fast in yards, feet and inches than in any decimal system; but once all the calculations (of strength etc) were metric the situation flipped.

Anyone over about 50 who has had anything to do with construction in the UK is bilingual: we may talk of a four-inch brick wall 6m long and 8 feet high or any combination. But when it comes to calculations its metric all the way.

 

[R Liewenberger]

Anyone getting into photography can't figure out where the numbers come from. Actually, I think Olympus tried to fix that by using numbers from 1 to 6 in their PenF film cameras. Can't we come up with something new that would make more sense?

But it probably won't come from the US. We keep on using the archaic inches, feet, mile, oz., gallon, etc. Only two other countries besides us do't use the metric system, they are Burma ( Myanmar for the young whippersnappers! ) and Liberia. We're in good company!

Let me know what your thoughts are.......

That was used on the FT version and you needed the new lenses marked with those numbers to take advantage of it (so setting the lens on 1 when the light meter was on 1)

However those lenses also had the standard f number on the other side.





now explain to me how having number 0 on a lens is more intuitive than f/4 ?

Note that 0 on the other lenses can be 1.4/1.8/3.5/5.6 ....

BTW, why do you think the system was not used again after that ?

Interesting; this was new to me so I looked it up.

Oly called these numbers 'Through-The-Lens numbers', and they made some sense when looking through the Pen FT viewfinder (portrait oriented, btw.!), where you could see the light meter, also showing these numbers.




http://www.klassik-cameras.de/Olympus_PenF.html (German language)



0 could be translated to the least amount of light available, while the highest number represented the max. amount of light, quite intuitive, I think! Why confuse the average buyer of these little cameras with technically correct terms like f-stops when you could do it with these easily understood numbers? More light = higher number.

This light meter was obviously not coupled with the lens, so you took your reading from the viewfinder to adjust the corresponding number on the lens.

With 0 always meaning the lens at its widest aperture, the number of these 'Through-The-Lens numbers' gave away how many f-stops a lens actually had, but not if the widest aperture was e.g. 1.4 or 3.5. The lens shown above is probably a 20/3.5 or a 25/1.4 or a 38/3.5. So if a lens starts at f/4 and has 0-4 TTL-numbers, the available f-stops for this lens are f/4 (=TTL 0), f/5.6, f/8, f/11 and f/16 (= TTL 4).

Why the standard f-stop designations on the DOF scale at the rear end of the lens, hmm, I don't know. Maybe they thought if some people are more advanced amateurs and also know about the different DOF at different f-stops, better keep the old f-stops there and not confuse them unnecessarily with these new TTL-numbers?

Interesting in that context: Oly's Pen F guide to interchangeable lenses, showing the TTL numbers of the different lenses. One sentence nicely explains these TTL-numbers: "Incidentally the Through-The -Lens numbers represent aperture values established only for the Olympus Pen FT with all exposure measurement errors corrected":




http://www.klassik-cameras.de/Olympus_PenF_Lenses.html

Liewenberger

 

[Gone for Good]

.......We should have them figure out the many complex problems the world needs solved!

 

[Gone for Good]

Start working on the problem.......

 

[D Cox]

Anyone getting into photography can't figure out where the numbers come from.

And yet, we all got into photography at one point or another.

This is first day of Intro to Photography, easily mastered.

For those for whom it's too complex, you have scene modes with a choice between mountain or face.

But it probably won't come from the US. We keep on using the archaic inches, feet, mile, oz., gallon, etc.

That's because we can handle numbers besides 10

Seriously, nothing against metrics and it is sensible. But so are f-stops.

Edit: If there was any compelling drive for an alternate system, I'd use the exponent that gets you to the f-stop where the base is sqrt(2).

So 0 is for an f-stop of 1.4^0 (f/1)
1 is for f/1.4.
2 is for f/2
3 is for f/2.8
And you can go below f/1 with negative numbers:
-1 is f/.7

I don't think that makes anything any less complicated other than making it clear that 6 to 7 is one stop (instead of 11 to 16).

• Dennis
  --
  Gallery at http://kingofthebeasts.smugmug.com

I'd prefer we go to T stops. Not sure why still lenses, especially high end ones, don't use that system. I'd rather have a gauge of actual light vs fstop. Tony Northrup came up with a system based on Tstops, but linear, and based I think on total light not intensity, so that it accounted more for DOF etc than exposure. I remember thinking it just sort of substituted one problem for another, but you can see for yourself:

T stops are not needed for stills, because the transmission of modern multi-coated lenses is so good that the difference is negligible. They were needed when people were shooting movies with uncoated lenses.

Don Cox

 

[D Cox]

Lenses are metric. All millimeters as far as I know. F-Stop math was learned in elementary school. Once someone is shown what it is, it’s really easy.

The F numbers apply just the same to lenses with the focal length and aperture diameter marked in inches. They are ratios,

Some enlarger lenses are marked in exposure time ratios, with wide open as 1, then 2, 4, 8 and 16. It doesn't really help, in my experience.

 

[D Cox]

...

You don't propose any alternative?

I really don't think they are going to change anytime soon, but if the square root of 2 is too obscure, then just square it. Instead of using the focal length divided by the entrance pupil (the definition of f-number or f-stop), why not just square it and use that?

That would have the advantage that the sequence would change from 1, 1.4, 2, 2.8, 4, 5.6, 8,... to 1, 2, 4, 8, 16, 32, 64,... .

...

I actually sort of like that. Having taught photography at college level, I know from experience that a lot of beginners have trouble with f numbers. Far more than some here seem to think. I've known a good many working professionals who didn't really understand it -- they just know there's a tradeoff with shutter speed.

I can't see it happening, but with digital cameras it would not be that difficult to offer both and give the user a choice as a menu item. So not too terribly difficult if camera makers wanted to do it.

Gato

Many people do suffer from having been taught basic maths badly, so that they don't understand fractions and ratios. But you aren't doomed to stay ignorant all your life just because you had a poor teacher when you were eight.

Photography can motivate you to catch up on your learning.

Don Cox

 

[R Liewenberger]

Anyone getting into photography can't figure out where the numbers come from. Actually, I think Olympus tried to fix that by using numbers from 1 to 6 in their PenF film cameras. Can't we come up with something new that would make more sense?

But it probably won't come from the US. We keep on using the archaic inches, feet, mile, oz., gallon, etc. Only two other countries besides us do't use the metric system, they are Burma ( Myanmar for the young whippersnappers! ) and Liberia. We're in good company!

Let me know what your thoughts are.......

Well, before thinking about something new to replace 'f-stops', why not start with the biggest nonsense in Anglo-Saxon photography speak, calling an 'exposure time' a 'shutter speed' ???

There is probably nothing more confusing to a beginner in photography, when a certain duration of time, something all the world measures in seconds, fractions of seconds, hours, whatever, is suddenly called a 'speed', something usually measured in mph, km/h, meters per second and such.

I know how this nonsense came into the world, but still, it is nonsense!

Just imagine it the other way around: You ask me what average speed I was driving when I came over to your house, and my answer would be something like 'eight seconds'! :-D

Just good we never adopted this in Germany; nobody here talks about 'shutter speed', but it is and always was 'Belichtungszeit', 'exposure time'.

Like nobody cares over here if it is 'F4' or 'f/4' or 'f/stop' or 'f-stop' -- technically maybe not 100% correct, but everybody just calls it 'Blende'; 'aperture'. E.g. "I took this shot with a Belichtungszeit of 1/60 sec and Blende 8".

Liewenberger

 

[Gerry Winterbourne]

Well, before thinking about something new to replace 'f-stops', why not start with the biggest nonsense in Anglo-Saxon photography speak, calling an 'exposure time' a 'shutter speed' ???

Especially when exposure time can equally mean the time at which the exposure was made - which is shown whenever EXIF is included with photos here. It's should properly be called "exposure duration".

But, of course, there's no point in fulminating about something that has no formal definition but everyone understands the colloquial meaning.