35 vs 50 vs 24

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I'm surprised you guys are not aware of this basic pronciple.

 

I'm going to explain it differently.

 

Let's say you shoot a scene with a 24mm lens on a 24x36 sensor. The lens is a wide angle with the corresponding exaggerated subject to background perspective.

 

Now crop the image to an equivalent of let's say 2x3mm sensor. Now that's a substantial crop, but just to explain my point. The 24mm lens is now equivalent to a 300mm lens on 24x36, with the corresponding flattened subject to background perspective.

 

The opposite is true. You take the same lens and you shoot with it on a 40x50mm sensor, and the 24mm provided the image circle can cover the format becomes an ultra wide angle with much more exaggerated perspective.

 

Elementary stuff.

Do try that elementary stuff. Your position determines the perspective, i.e. the relative sizes of things in your frame. Your focal length determines the field of view, i.e. how much of the world in front of the lens is caught within the frame.

[edwardkaraa]

Do try that elementary stuff. Your position determines the perspective, i.e. the relative sizes of things in your frame. Your focal length determines the field of view, i.e. how much of the world in front of the lens is caught within the frame.

 

Position determines perspective, that is correct. I don't see why it contradicts what I'm saying.

[edwardkaraa]

I suppose the confusion arises because in order to get the same amount in the frame with a long lens and a wide angle, you have to change your position relative to the subject (step, walk, catch a bus, depending on the focal lengths in question) and that shift, not the focal length itself, then alters the perspective. The focal length generally influences your position relative to the subject though, which is why the photos do often end up looking different, and causing the confusion.

 

Those photos with huge moons in the background taken with telephoto lenses absolutely can be replicated with a wide angle lens but you'd have to make such a drastic crop of the wa lens image that the quality would suffer substantially if not irredeemably,  and that, aside from convenience and safety considerations is why lenses of different focal lengths are necessary.

Absolutely. Thank you Peter!

[Jeff S]

Position determines perspective, that is correct. I don't see why it contradicts what I'm saying.

 

 Your quote...  "Now crop the image to an equivalent of let's say 2x3mm sensor. Now that's a substantial crop, but just to explain my point. The 24mm lens is now equivalent to a 300mm lens on 24x36, with the corresponding flattened subject to background perspective."   

 

Wrong.

 

Jeff

 

[Jeff S]

Or, to put it another way.  Take any photo.  Now cut out a section (you've just cropped it).  You haven't changed a thing in terms of perspective.....you just have a smaller field of view (and the same focal length).

 

Jeff

[edwardkaraa]

 Your quote...  "Now crop the image to an equivalent of let's say 2x3mm sensor. Now that's a substantial crop, but just to explain my point. The 24mm lens is now equivalent to a 300mm lens on 24x36, with the corresponding flattened subject to background perspective."   

 

Wrong.

 

Jeff

 

Read what Peter wrote above.

[edwardkaraa]

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Or, to put it another way.  Take any photo.  Now cut out a section (you've just cropped it).  You haven't changed a thing in terms of perspective.....you just have a smaller field of view (and the same focal length).

 

Jeff

But that's what I'm saying.

[Jeff S]

No, it isn't.  Peter wrote that the photographer needs to change position....you didn't.

 

Jeff

[edwardkaraa]

No, it isn't.  Peter wrote that the photographer needs to change position....you didn't.

 

Jeff

Read the comment about the huge moons. You are not changing position.

 

I think you're confused because in the link you provided, the crop is in the extreme corner, which suffers from distortion. The crop should be in the exact center.

[Ernstk]

Or, to put it another way.  Take any photo.  Now cut out a section (you've just cropped it).  You haven't changed a thing in terms of perspective.....you just have a smaller field of view (and the same focal length).

 

Jeff

That's the point that I was arguing with. But we now seem to be arguing at cross purposes.

 

The consensus seems to be, if you don't change your camera position and you shoot with a 24mm lens or a 240mm lens, the perspective between objects in the photo will be the same, 'tho the field of view will be very different.

 

Ernst

[edwardkaraa]

That's the point that I was arguing with. But we now seem to be arguing at cross purposes.

 

The consensus seems to be, if you don't change your camera position and you shoot with a 24mm lens or a 240mm lens, the perspective between objects in the photo will be the same, 'tho the field of view will be very different.

 

Ernst

I agree with that.

[Jeff S]

Read the comment about the huge moons. You are not changing position.

 

I think you're confused because in the link you provided, the crop is in the extreme corner, which suffers from distortion. The crop should be in the exact center.

 

I'm not the least bit confused...you are.  The moon comment doesn't change the principle involving the terms 'focal length', 'field of view' or 'perspective'.

 

Jeff

[Jeff S]

I agree with that.

Ha.  The last paragraph is verbatim from my various posts.  But not yours (where you incorrectly use the term perspective....post 24.

 

Jeff

[edwardkaraa]

I'm not the least bit confused...you are.  The moon comment doesn't change the principle involving the terms 'focal length', 'field of view' or 'perspective'.

 

Jeff

It doesn't matter. Have it your way and be happy.

[edwardkaraa]

Ha.  The last paragraph is verbatim from my various posts.  But not yours (where you incorrectly use the term perspective....post 24.

 

Jeff

I'm talking about telephoto compression since the beginning. Read my post carefully.

[Jeff S]

Except when you use the term perspective instead of compression.....and talk about near/far (background/foreground) relationships. 

 

Jeff

[edwardkaraa]

Except when you use the term perspective instead of compression.....and talk about near/far (background/foreground) relationships. 

 

Jeff

 

Hmmm, it's not the wrong use of the word, though I now understand the point you're making. Perspective depends on the position, but the end effect photographically depends on which part of the frame you decide to isolate.

[Jeff S]

Perspective has technical underpinnings, i.e., the relationship between near and far objects.  That doesn't change anywhere in the frame....it is what it is.....which is why cropping doesn't matter; it merely changes the field of view (and not even the focal length as your words sometimes imply).

 

Jeff

[edwardkaraa]

Perspective has technical underpinnings, i.e., the relationship between near and far objects.  That doesn't change anywhere in the frame....it is what it is.....which is why cropping doesn't matter; it merely changes the field of view (and not even the focal length as your words sometimes imply).

 

Jeff

I think the problem is you're misrepresenting what I'm saying, because I agree with the above, and never claimed the contrary.

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Hallo,

Look here: Leica M

[Jeff S]

No misrepresentation, just sloppy wording on your part (as well as your statements that incorrectly cited flaws in my wording/reasoning).  I already gave you an example, which you never rebutted.  I'm done.

 

Jeff