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Just curious, I've seen both wide and ultra wide pop up here often in discussion. Is it a matter of preference, or is there a standard? I consider my Tokina 11-16 ultra wide (obviously) but I'm on the edge whether the short end of my 24-105mm would be considers ultra wide or not. Just a thought that popped into my head last night while shooting fireworks.
Typically (FF equivalent):
Wider than 24mm = ultrawide angle
24mm - 35mm = wide angle
36mm - ~60mm = normal
~60mm - 100mm = short telephoto
100mm - 300mm = telephoto
Longer than 300mm = super telephoto
Technically, 24mm on APS-C isn't even wide angle, it's normal (which is why I don't usually recommend 24-xx zooms as walkaround lenses for crop bodies).
I have always thought of ultra wide-angle lenses threshold as the point where distortion becomes really noticeable, which is about 24mm on a 35mm film camera. I recently learned there is a technical reason for that.
An ultra-wide angle lens is one whose focal length exceeds the short dimension of the film or digital sensor.
A 35mm film negative or full frame sensor measures 36mm x 24mm, so anything wider than 24mm is considered ultra wide-angle for that format. Likewise, Canon's APS-C sensors measure 22.3mm x 14.9mm, so anything wider than about 15mm is ultra wide-angle.
Hmmm...someone want to take a stab at the geometry of this as the focal length is perpendicular to the sensor? Also, does this fall apart at aspect ratios other than 2:3?
That's an interesting idea, but I believe it is more likely coincidence and lens design. For example, the EF 28mm f/1.8 has worse barrel distortion than the EF 14mm f/2.8L. Likewise, ultrawide zooms (16-35, 17-40) set to 20-24mm have less barrel distortion than the 24-105L at 24-28mm.Quote:
Originally Posted by Black_Dog
Since Canon USA website calls the 17-40 L an Ultra Wide Zoom, the 24-70 II L a Standard Zoom, the 14mm L an Ultra Wide Lens and the 20mm a Wide Lens I would say that it is up to your own preference since Canon itself seems to label lenses by their own preference.
Canon even put the label "Wide" on the 15mm fisheye.
For me if someone says "Ultra Wide" they are making that designation because of the distortion you get with very wide lenses and it is understood. Not because it met some magical designated lens length.
Another designation "Super Telephoto" is meaningless, except that you must have "Super" strength to carry the pile of cash that it is going to take to buy one of these lenses. Or maybe just a "Super Fat" bank account.
I agree with HDNitehawk that terms like "super telephoto" and " ultra wide-angle" are more marketing terms than scientific classifications.
However, most UWA definitions kicking around out there agree that these are lenses wider than 24mm in the 35mm format, or rectalinear lenses (i.e. not fish eye) with a diagonal angle of view of 90-degrees or wider. This is consistent with the definition I offered above.
Why 90-degrees? One source I've read says that 90-degrees is used as the magic breaking point because it is twice the angle of view of a "normal" or "standard" lens.
As I was playing the the geometry yesterday, ~21.6 mm focal length was corresponding to a 45 degree angle going into the corner of a FF sensor (right triangle perpendicular to the sensor plane). I was wondering if that came into play.
This topic reminded me of Roger Cicala/Lensrentals series on the history of lenses. Sure enough, he had one on wide angle lenses. This reminds me that the optical construction of the lenses are very different. The elements do not even look the same. So, my guess is that the designation of "wide angle" likely has more to do with the point at which lens designers historically had to use a different optical formula and lens elements, etc.
That said, Roger did offer up this definition:
"Remember in the Telephoto Lens article that the definition of a telephoto lens was a lens that was physically shorter than its focal length? The opposite holds true for reverse telephoto lenses: by definition and by design, they are all physically longer than their focal length."
I have to run measure a bunch of my lenses now ;)