Stop this crop factor / equivalent focal length nonsense
Jul 30, 2019 21:58:28 #
AlfredU wrote:
Well said. I haven't visited this site for about a month now. I think I'll make it two months before I try again. I know I will get nasty remarks for saying that. Hoping for more humility and civility on this site and in America in general.
Jul 30, 2019 22:18:07 #
I'm a new member and I'm excited to join this forum.
I totally agree. Even as many of us are quite familiar with converting between full frame and cropped frame, when we get into smaller sensors and especially smartphone cameras with the many different sensor sizes, most of us would not know the equivalency. This was done successfully with aperture - we don't talk about absolute size of the aperture (iris), we speak of f-stops which is a constant ratio of focal length to entrance pupil ( in effect, aperture) which represents the same effect on exposure regardless of what focal length one is using. The same could be done for representing how wide or long a lens is on a particular sensor size and angle of view is the logical choice.
I totally agree. Even as many of us are quite familiar with converting between full frame and cropped frame, when we get into smaller sensors and especially smartphone cameras with the many different sensor sizes, most of us would not know the equivalency. This was done successfully with aperture - we don't talk about absolute size of the aperture (iris), we speak of f-stops which is a constant ratio of focal length to entrance pupil ( in effect, aperture) which represents the same effect on exposure regardless of what focal length one is using. The same could be done for representing how wide or long a lens is on a particular sensor size and angle of view is the logical choice.
Jul 30, 2019 22:30:15 #
cjcampos wrote:
I'm a new member and I'm excited to join this foru... (show quote)
Welcome to the forum cj and thank you for your breath of common sense. Of course, being a newby here, you haven't depleted your supply of brain cells - yet!!
Jul 30, 2019 22:33:10 #
cjcampos wrote:
The same could be done for representing how wide or long a lens is on a particular sensor size and angle of view is the logical choice.
So lets assume you know the AOV of each lens and sensor combination you own and its written on them. As an example, you have just purchased an 18 to 86 degree AOV lens for your camera.
Now you are out in the field with it and want to take an image of a 6ft human and for him to fill 3/4 of the frame height.
Has knowing its AOV (or in this case its variable AOV) helped you?
Sure you can feed these figures into an AP as you can if knowing the FL and Crop size but by the time you have done that your 6ft human of interest has disappeared
Jul 30, 2019 22:33:49 #
Jul 30, 2019 22:37:12 #
Grahame wrote:
So lets assume you know the AOV of each lens and s... (show quote)
I don’t use these numbers in the field. In your example, I would zoom my lens to frame the scene well, press the shutter button ..... and then perhaps look to see what zoom setting I’d used.
Jul 30, 2019 22:59:08 #
Learning how a lens "behaves" and how position affects perspective is one of the basic tools of any photographer. If you don't understand the effects of the angle of view and how you have to frame and change position to get the image you want, you really can't translate your vision to the photo. Many of us older shooters learned this in full frame terms, and it's still a standard shortcut and means of thinking. I know exactly what to expect from a "35mm equivalent" or "300mm equivalent" but there's really no inherent advantage to thinking in those terms.
Certainly Angle of View (AoV) is an equally acceptable, even perhaps preferable, shorthand, but that ain't the way I learned it. Perhaps the next generation will learn this new shorthand and start thinking in those terms, but I agree with repleo that it's unlikely as long as manufacturers keep using the older terminology to please us old farts.
Andy
Certainly Angle of View (AoV) is an equally acceptable, even perhaps preferable, shorthand, but that ain't the way I learned it. Perhaps the next generation will learn this new shorthand and start thinking in those terms, but I agree with repleo that it's unlikely as long as manufacturers keep using the older terminology to please us old farts.
Andy
Jul 30, 2019 23:00:43 #
rehess wrote:
I don’t use these numbers in the field. In your example, I would zoom my lens to frame the scene well, press the shutter button ..... and then perhaps look to see what zoom setting I’d used.
Exactly, this is why I wonder what "added value" anyone would get by knowing that their lens is a 20 deg AOV rather than its FL denoted in mm.
Jul 30, 2019 23:06:36 #
Grahame wrote:
Fully agree !
If you cant master by physical use in a very short time which of your lenses to use on whatever camera you own for the subject and framing you want there's little chance you are going to get any value whatsoever from something being given a different naming.
If you cant master by physical use in a very short time which of your lenses to use on whatever camera you own for the subject and framing you want there's little chance you are going to get any value whatsoever from something being given a different naming.
Jul 30, 2019 23:07:21 #
Grahame wrote:
Exactly, this is why I wonder what "added value" anyone would get by knowing that their lens is a 20 deg AOV rather than its FL denoted in mm.
But if a photographer had learned what to expect of a lens based on AoV, they'd have exactly the same experience I do when I decide that a 28mm equivalent is what I need. A rose is a rose is a rose, no matter what you call it.
Andy
Jul 30, 2019 23:12:55 #
Notorious T.O.D. wrote:
Doesn’t a square sensor crop the circular image from the lens too... Isn’t a square just a special type of rectangle...
Yes but it would obviate the need to flip the camera 90 deg for portrait...and no need for vertical grips or awkward contortions...it was a side note ... something bugging me since the moon landing Hassy's. Especially with today's high MP sensors we can crop with abandon.
Jul 30, 2019 23:15:16 #
There would be no portrait or landscape in square world😎
chrisg-optical wrote:
Yes but it would obviate the need to flip the camera 90 deg for portrait...and no need for vertical grips or awkward contortions...it was a side note ... something bugging me since the moon landing Hassy's. Especially with today's high MP sensors we can crop with abandon.
Jul 30, 2019 23:38:36 #
AndyH wrote:
But if a photographer had learned what to expect of a lens based on AoV, they'd have exactly the same experience I do when I decide that a 28mm equivalent is what I need. A rose is a rose is a rose, no matter what you call it.
Andy
Andy
I suppose that is just the same way that many of us think in that if we have a 28mm FL its equivalent to a certain AOV.
Personally, it would not bother me if AOV was used instead of FL in mm's because as an engineer angles are instantly recognised but to many now they will be meaningless.
Jul 30, 2019 23:42:09 #
Jul 31, 2019 00:16:08 #
AndyH wrote:
But if a photographer had learned what to expect of a lens based on AoV, they'd have exactly the same experience I do when I decide that a 28mm equivalent is what I need. A rose is a rose is a rose, no matter what you call it.
Andy
Andy
But most of us already know what to expect of focal lengths. That’s how lenses are designated. There’s no way you’re ever gonna see lens manufacturers designating lenses by AoV.
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