Sensor Aspect Ratio

[Manfred M]

In terms of scientific measurements then I agree that metric is easier to deal with but it is very hard to visualise in the real world.

Robin - Let's agree to disagree on that one. I was (un?)fortunate to grow up at a time when Canada went through the process of changing from the Imperial system over to Metric (or more properly SI (Systeme Internationale) measurements.

So units of measure like pounds, bushels, pecks, quarts, gallons (US and British), miles, etc, etc. are something I grew up with as a child and well into my teens. All through my primary school career we had one system and by the time I got to university we were firmly using both systems because much of industry was still slowly converting, even though Canada phased the metric system in through much of the 1970s; in fact I was in the last graduating class in mechanical engineering at the university where both systems were taught. All of the following years worked exclusively in SI. The dual system training worked out well for me as when I graduated and got out into industry, the I certainly found that working in British engineering units was still the norm. Instead of measuring energy in MJ we were using the abbreviation Mk BTU; this was really illogical because we were using both the Roman numeral M (1000) and the metric kilo (also 1000) in the same time, yet M (for mega - 1 million) was used in other places. That really drove home why going metric made a lot of sense, as mixing units was just asking for a conversion error somewhere.

So, can I visualize a foot / meter or pound / kg; yes, just as easily as I know how cold -18°C / 0°F feel, and I don't mind buying fuel for my car in gallons (be they US or Imperial) or litres. Driving in mph or km / hr isn't particularly challenging either (even if the car's speedometer is in the "wrong" unit of measure for the country. But I must confess there is one conversion that I never really caught on to when putting air into my car or bike tires; there for some reason my mind still works in psi rather than kPa, even though I have made the conversion to metric regarding atmospheric pressure measurements.

Bottom line is you can get used to either, but it does take a fair bit of time (really at least a full generation) to make the switch between systems. And frankly, we still are 100% there; if I step into the kitchen, I still see measuring cups that show both ml and oz and measuring spoons in teaspoons and tablespoons and recipes calling for items in pounds and ounces, rather than in grams and kilos. Both of my daughters, who were only educated in SI in the school system seem to have no problems following either American or English recipes when they are running around the kitchen, learning how to cook.

[Letrow]

I think sensors are the root of the problem, which is probably why this thread started with them.

They confuse me. Not on a 35mm camera or a full frame one. There it is easy: 35mm is what it is. But on my compact the zoomlens is a 5.1-15.3mm. That is pretty wide as far as I knew when I started with it, but as it turned out I had to multiply those numbers by a certain factor based on my sensor size.
I know from various sources that bigger is better in sensorland, but even small sensors can develop (old fashioned photo speak) into something big nowadays, which confuses me even more. Is bigger still better?
According to my wife it doesn't matter, she likes all my photos, especially if the family or dogs are in them. Sensor size is a by-product for her. For me it does matter though. Sure, I like the family and the dogs just as much, but I concentrate (sometimes only) on those tiny, tiny things that come out of the sensor and I say the bigger the sensor, the better the pixels.

Ah well, as long as sensible folks use their meters and kilos, the world will stay a better place. The rest will slowly disappear, I am sure of it, just like the dinosaurs did.

[Inkanyezi]

Years ago, my GF used to pour scorn on people who wrote 1/10" circuit board pitches as 2.54mm much as we, in our turn, would question the sanity of a 1.968503973" focal length prime lens.

But the 1.968503973" is simply insane. The 50 mm lens isn't 50.000000000 mm. In fact most measurements indicate about 51 mm for 50 mm lenses, with odd ones ranging from about 48 to 53 mm. And 51 mm is not so far from 50.8 mm. Most lenses have rounded off numbers, even those with somewhat odder numbers than 50. So in most real life respects, 50 mm equals 2". The tele lenses for 8 mm movie were mostly 1" and 1½". the former 25 mm and the latter 38 mm, although sometimes there were 37,5 mm lenses, even though 38 is closer to 1½". There surely is a variation in real focal length regarding lenses as well.

[Mito]

But the 1.968503973" is simply insane.

Not insane at all. What is insane is the marketing man who decided to reduce manufacturing costs after the first 2" lens was produced.

[AB26]

Hi Guys,

I think we have missed the point of Dave’s original post. The question is why should there be different aspect ratios. Does it make sense to have 4:3, 16:9, 3:2 and many others.
Is there perhaps a ratio that is more cost effective than others.

Why not standardize on a specific aspect ratio and keep improving on it? Why change aspect ratios? Is there any logic having so many different aspect ratios?

[Letrow]

Hi Guys,

I think we have missed the point of Dave’s original post. The question is why should there be different aspect ratios. Does it make sense to have 4:3, 16:9, 3:2 and many others.
Is there perhaps a ratio that is more cost effective than others.

Why not standardize on a specific aspect ratio and keep improving on it? Why change aspect ratios? Is there any logic having so many different aspect ratios?

It is a good question, but it will have more than one answer I think, due to different tastes.

I have always used 3:2, unless one of my older digital cameras forced me otherwise (mostly 4:3 I think). I like the look of 3:2 or just used to it I guess, so in PP, even when I crop, I try to stay close to that aspect ratio.

The other ratios have less appeal to me somehow, so I am fine with them not being on my camera (I know the D800 has some extra options, so the user will be able to try out a bit more).
There are photos that force me to crop to a square, but I always struggle with that, because the subject can only be in the middle. I like it when a photo forces me to move my eyes around a bit.

[pnodrog]

The meter (metre) used to be a chunk of metal in Paris, but it's probably something much more absurd now, like wavelengths of a phaser set to stun, especially as the original chunk of metal was a bit inaccurate, IIRC. (I resisted the temptation to visit the nist.gov site, honest :-)

Did I do good?

Years ago, my GF used to pour scorn on people who wrote 1/10" circuit board pitches as 2.54mm much as we, in our turn, would question the sanity of a 1.968503973" focal length prime lens.

O.K. for old fashioned layout with Bishop Graphic transfers and tapes but as soon as CAD tools for PCB design were available a lot of people in advanced sophisticated metric countries immediately switched to 2.54mm with glee but it is nice to be able to switch from one to another at the press of a key.

[xpatUSA]

O.K. for old fashioned layout with Bishop Graphic transfers and tapes but as soon as CAD tools for PCB design were available a lot of people in advanced sophisticated metric countries immediately switched to 2.54mm with glee but it is nice to be able to switch from one to another at the press of a key.

Yes, exactly what she used to do (in UK) - on Mylar, or something, and on top of a lightbox - those were the days! Then came CAD and weird phrases like "net list" and such. Multi-layer boards made their appearance about then, IIRC.