Are Imperial Measurements outdated?

[David Kuhn]

Assuming the definition of 'precise' is the ability to represent some physical metric (length for instance) with minimum measurement error... then Imperial is every bit as precise as metric. 1 millionth of an inch is as precise as 25.4 nm. What the metric system really is is more usable across a wider range of values. Imperial peters out at inches, metric has words for really short lengths (nanometers, pico meters, etc..). Mutiplying and dividing by 1000 to change unit's is easier than 12ths, thirds, and fractions of an inch (ignoring the more esoteric length measures that are rarely used anymore... the only use of 'cubit' I've ever seen was a Bill Cosby comedy bit).

 

[ericyoung]

Assuming the definition of 'precise' is the ability to represent some physical metric (length for instance) with minimum measurement error... then Imperial is every bit as precise as metric. 1 millionth of an inch is as precise as 25.4 nm. What the metric system really is is more usable across a wider range of values. Imperial peters out at inches, metric has words for really short lengths (nanometers, pico meters, etc..). Mutiplying and dividing by 1000 to change unit's is easier than 12ths, thirds, and fractions of an inch (ignoring the more esoteric length measures that are rarely used anymore... the only use of 'cubit' I've ever seen was a Bill Cosby comedy bit).

Both Jeff and yourself are of course correct with your definitions of "precise". In practice, it also depends on the measuring tools being used.

In the context of length, with the tape or steel engineering measures I've used in the UK which are marked in metres, cm, mm and/or yards, ft, in and usually only as small as 1/16in along the whole length, then the metric markings allow the smallest measurement error along the whole length of the tool, and so metric is my default unit system for more precision in the typical situations I would use those measuring tools.

When estimating distance, especially in the context of focus pulling, Imperial feet and inches are far easier to visualise than metric, at least for me.
I think it's because for focus pulling, metres are too big a unit, while cm and mm are too small. Feet and inches are a better fit for lens markings and estimating the more typical focus pulling distances.

 

[Jeff Kilgroe]

Where the metric system carries all of its advantage is the uniform naming and consistent base-10 manipulation across all named dimensions. It is no more or less precise, the power is in its uniform simplicity and logical progression of units.

We see a lot of comparisons between the two trying to denounce fractions as opposed to decimal units, however that's just plain silly. They are one in the same, only a different representation of each. Imperial measurement historically carries more fractional labeling as it's very easy to reference 1/2, 1/4, 1/8, 1/16 and 1/32. And Metric precision was never much better than any of those standard fractions before the advent of calculators and computers, just as today, working with Imperial measurements, decimal precision is normal.

 

[Dave Blackham]

Metric is logical and easy to use, I live in a metric country.

However I think I recall our own BSF and BSW threads being stronger than metric near equivalent, ever try drinking a pint of beer which seems to be a perfect measure of beer to drink, half a litre or 1 litre of beer just isn't the same. As mentioned in the thread focus pullers don't ever seem to like using metric lenses or not the ones I know.

 

[Björn Benckert]

The one that always gets me is the 50mm lens with focus marked in ft and in.

Graeme

I don't understand what lens are you referring to? Do you mean the 1.9685 inch lens or the 0.164042 foot lens?

 

[David Kuhn]

I still use Imperial for things like woodworking and larger (travel)... but at work where I'm often working in very small units it's all metric. mm/um/nm are a LOT more convenient than thou/tenth/millionth.

I still use Imperial for weight though, and temperature... for me there's no benefit to switching.