Defining a "normal focal length"/"normal AoV" and "absolute zoom"

Started Apr 17, 2012 | Discussions thread
Barrie Davis
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Re: Defining a "normal focal length"/"normal AoV" and "absol
In reply to dark goob, Apr 21, 2012

dark goob wrote:

Barrie Davis wrote:
I agree that Absolute Zoom figures would not be useful during shooting itself.

However I think we are getting a bit away from the point.

The point is to make the act of shopping for a camera or lens easier.

Lets say you're looking at the latest line of Canon Elph and Nikon Coolpix cameras. They all say "4x" zoom or "5x" zoom etc. You could have two cameras with a "5x" zoom and the average person will think that means they have the same range. But they might not. It's deceptive marketing.

It isn't deliberate deception... it's just a lack of understanding.

So, what is needed is better understanding of the significance of focal lengths in describing angle of view. That's all.

What I propose is that the cameras say what their Absolute Zoom range is, as opposed to showing a relative zoom figure that makes comparing cameras to each other an act of frustration.

Hmmm... Well, I propose that trying to take an acknowledged FAILED concept ("X" factors) and trying to polish them up with an additional layer of complexity...

... is to move yet further away from understanding focal lengths and their effect on framing a subject.

For instance the box would say "0.8x - 4.2x Absolute Zoom range." And then you would know what that meant, because it would translate to real-world distances quite easily.

(Note: You have a decimal fraction factor in there... not everybody will realise that means smaller .)

Remember, "X" factors were spawned in an attempt to "simplify" things for people who were (assumed to be) incapable of understanding what focal lengths meant in terms of a camera's shooting capabilities. But they failed because they were meaningless WITHOUT an understanding of the focal length realities that lay underneath....

.... only it was worse than that, because people had a natural expectation that this "technical appearing" "x" factor had to mean something real, even 'though it didn't. What mislead them was that it looked legitimate, when it wasn't.

It's not a perfect concept, but it would be a better than having to google up the actual angle of view range for a given camera, a stat that is typically buried pretty far down the stat sheet.

What you are proposing just adds a complicated legitimatising gloss to a concept that was ill-begotten in the first place.

And I will argue that 135-format figures are not a substitute. They are useless these days. They only add to the confusion, because at best they only give some people a vague idea of how a lens performs -- meanwhile most people have no idea what they mean.

If you really think "most people" know what 28mm-equivalent means, I'm perfectly willing to go out on a the streets and canvass people. I'll bet you $1,000 that most people have no idea what it means.

So what? Anybody sufficiently interested to make a camera purchase will see what a 28mm equivalent "gets in" as soon as they look through a camera.... or maybe they WONT because they don't even get to look at what "real" or "equivalent" focal length they happen to be using because they are too busy actually framing up a subject and taking a picture.

My contention is that it would be a lot easier to explain the concept of Absolute Zoom to those individuals than it would be to explain what 28mm-equivalent is supposed to mean and why.

Yes. We know you have a pet idea. Fine. It just isn't needed. And what's needed even LESS is a NEW need to describe the difference between Absolute and Relative "X" factors.... thanks very much!

I have to stand there and explain cameras to people all day long. Something like Absolute Zoom would make my life easier. Much easier. It would make shopping for cameras and selling them easier.

What's to stop you trying? Give it a shot! See how you get on..... (shrugs) You can show your commitment by working out all the Absolute "X" factors for yourself and writing a list... and updating it for all the new models as they appear.

As stated, I don't believe it would help. You will just be miring yourself deeper in stuff people have a hard time getting a grip on as it is. You are referring to three layers of complexity, instead of just two, when it should never have been allowed to expand to more than one.

And, let me remind you that it was a marketing decision to make things easier that led to the invention of spurious "X" factors that created this mess in the first place....

Whether or not Absolute Zoom gets based on the diagonal equivalency or the horizontal equivalency is rather academic. But if we can at least agree that there needs to be some objective standard like Absolute Zoom, that isn't tied to what has become a professional camera format that almost no one uses anymore, then that would be wonderful.

Look, I'm sorry to disappoint you, but we already have an objective standard.... focal lengths relative to image diagonal. There isn't a need for yours, just as there isn't a need for the "X" factors it is a development of.

However, I have had enough of this topic, having discussed it in more detail than it was worth.
I'm moving on now.
All the best to you.
Message ends.
--
Regards,
Baz

"Ahh... But the thing is, they were not just ORDINARY time travellers!"

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