perspective vs. field of view

[Finder]

i agree with this line of thinking (and with others who have said similar)...but if this IS the case then why are folks so freaked out about the 'dreaded crop factor' ?

I am starting to think that the answer is not in the FoV. I think it is viewfinder magnification and angular size of the viewfinder image that is the cause. I know when I switch from cameras, 6x6, 6x12, 4x5, 35mm, I also prefer different focal lengths. Perhaps it is the aspect ratio, perhaps it is the image I see in the viewfinder.

The answer is certainly not about optics. It does not matter what the image circle is on a lens, it just matters how much is used. The optics are understood and that does not give you the answer. So it has to be something else.

 

[Finder]

Exactly 🙂

In the Nikkor catalog available at camera stores in Japan, Nikon uses the mathematical "perspective". No psychological stuff at all.

I have seen many Nikon catalogs in Japan. Where do the give a "mathematical perspective"? Perspective is not something you can quantify beforehand. Or are you referring to angle of view?

 

[Finder]

I find this confusion over perspective quite mystifying. It is hardly String Theory. It is really quite basic.

Can anyone rank these images in order of the strength of the perspective?

 

[jonmanjiro]

I have seen many Nikon catalogs in Japan. Where do the give a "mathematical perspective"? Perspective is not something you can quantify beforehand. Or are you referring to angle of view?

There's example photos for both perspective and angle of view on page 24 of the Nikkor catalog dated 30th July 2009. Nikon's been using these examples since I can remember.

 

[Finder]

Thanks. I did not understand what you meant.

 

[FrankS]

For what it's worth, here's my understanding of perspective:

Perspective describes the relative size of visual elements, at different distances to the camera, in an image.

Perspective only changes when the camera moves closer or farther from the subject, thus changing the relative distances between camera to foreground subject and camera to background elements.

This is seen in the series with the surfboards in the post above. The camera is moved farther from the surfboard when longer lenses are attached to keep the surfboard the same size in the frame.

Enlarging a photo does not change the perspective in that photo. So, when taken from the same camera position, the perspective in an image taken with a 100mm lens and the enlarged central section of a 35mm shot will exhibit the same perspective.

This is how I learned perspective.

 

[Finder]

For what it's worth, here's my understanding of perspective:

Perspective describes the relative size of visual elements, at different distances to the camera, in an image.

Perspective only changes when the camera moves closer or farther from the subject, thus changing the relative distances between camera to foreground subject and camera to background elements.

This is seen in the series with the surfboards in the post above. The camera is moved farther from the surfboard when longer lenses are attached to keep the surfboard the same size in the frame.

Enlarging a photo does not change the perspective in that photo. So, when taken from the same camera position, the perspective in an image taken with a 100mm lens and the enlarged central section of a 35mm shot will exhibit the same perspective.

This is how I learned perspective.

OK, Frank. Got a question. Would the perspective look different if the camera distance had not changed? The examples I posted clearly show the uncropped image having greater perspective, yet both are from the same position.

Also, try my three image test. Rank the images based on the strength of their perspective.

I am not trying to pick a fight, but I cannot understand how people cannot see perspective. This is a mystery to me.

 

[FrankS]

Again, this is as I understand it:

If the camera position does not change, and you enlarge the central portion of the shot done with wider lens so that the subject is the same size on the print, the perspective would be the same as the shot, from the same position, of a longer lens.

I think that the only reason we are disagreeing, is because you are talking about uncropped images from wide and tele lenses. I'm saying that if the central portion of the wide shot is enlarged so that subject sizes are the same, the perspective will be the same. My procedure is more relevant to Joe's initial question, because he's talking about a cropped sensor.

I would agree with you that when comparing uncropped images, the wide angle lens produces, over the entire image, a more foreshortened (wide angle) perspective than a longer lens. But Joe was asking about the effects in a cropped sensor camera, which has the same consequence as enlarging the central portion that I was talking about.

 

[Jeicob]

(M.C. Escher: Tower Of Babel)

... angered God who interrupted the construction by causing among them a previously unknown confusion of languages ...

 

[Roger Hicks]

For what it's worth, here's my understanding of perspective:

Perspective describes the relative size of visual elements, at different distances to the camera, in an image.

Dear Frank,

That's one kind of perspective. There are several others, including scale, overlap, aerial and texture. Oh: and architectural, which also includes 'battering' columns.

Cheers,

R.

 

[Finder]

Again, this is as I understand it:

If the camera position does not change, and you enlarge the central portion of the shot done with wider lens so that the subject is the same size on the print, the perspective would be the same as the shot, from the same position, of a longer lens.

But if you crop a picture taken with a wider lens to make it look like a picture taken with a longer lens, you simply have two pictures that look the same. So why would the crop look different from the long focal length picture? I don't think anyone is disputing that relative image size is a function of object distance. But that is not the comparison.

We are talking about perspective, the illusion of depth in an image. What if you compare the full-frame wide with the full-frame telephoto. You don't think the wide shot would give a greater apparent depth?

Why does no one want to take my three image challenge? Can't people see perspective?

 

[jonmanjiro]

Dear Frank,

That's one kind of perspective. There are several others, including scale, overlap, aerial and texture. Oh: and architectural, which also includes 'battering' columns.

Cheers,

R.

Yup, linear perspective. The type of perspective the Nikkor catalog photos show 😉

 

[ferider]

It's a language thing, the same term used by different people with different definitions.

If the camera position does not change, and you enlarge the central portion of the shot done with wider lens so that the subject is the same size on the print, the perspective would be the same as the shot, from the same position, of a longer lens.
:
I'm saying that if the central portion of the wide shot is enlarged so that subject sizes are the same, the perspective will be the same. My procedure is more relevant to Joe's initial question, because he's talking about a cropped sensor..
: : :
Perspective describes the relative size of visual elements, at different distances to the camera, in an image.

That's how I think about it, too, Frank. And so did Ansel, there is a nice example in one of his books (a studio shot) with the caption saying exactly the same.

A good way to think about cropping is this: a crop factor of 1.5 is equivalent to the use of a 1.5x tele-converter. Loss of speed, change of FOV, DOF, etc.

Roland.

 

[FrankS]

If there are different types of perspective, let's agree which one we are debating: let's call it linear perspective which is what is illustrated in the Nikon lens brochure in the post above, and which I believe Joe is asking about.

Finder is talking about comparing uncropped images taken with different focal lengths, I'm talking about enlarging the central portion of the wide lens image so that it is the same size as the longer lens image, which is what happens in a crop sensor camera.

I believe that we are both correct in describing our different situations.

 

[Finder]

It's a language thing, the same term used by different people with different definitions.



That's how I think about it, too, Frank. And so did Ansel, there is a nice example in one of his books (a studio shot) which exactly says the same.

Roland.

Yes. The example is just showing one aspect of perspective. And therein lies the problem, people are using an incomplete definition.

How about taking my three image test? Which image do you think has the strongest and weakest perspective?

 

[Finder]

If there are different types of perspective, let's agree which one we are debating: let's call it linear perspective which is what is illustrated in the Nikon lens brochure in the post above, and which I believe Joe is asking about.

Finder is talking about comparing uncropped images taken with different focal lengths, I'm talking about enlarging the central portion of the wide lens image so that it is the same size as the longer lens image, which is what happens in a crop sensor camera.

I believe that we are both correct in describing our different situations.

Fair enough.

Here is back alley's original post:

would i be correct in saying that a 35mm lens on a cropped sensor camera (say a 1.53 crop) would still have a 35mm perspective but a 53mm fov?

I read that as a 35mm lens on a 35mm camera having the same perspective as a 35mm lens on a smaller format. The perspective in that case would be different assuming he is displaying the entire frame from each camera--there was nothing to suggest he was cropping.

(However, given Joe's later clarification of his problem, that does not appear to be the question.)

 

[jonmanjiro]

How about taking my three image test? Which image do you think has the strongest and weakest perspective?

You mean which image has the least/most perspective distortion?

 

[Finder]

You mean which image has the least/most perspective distortion?

No. Exactly what I mean. Which has the stronger and weaker perspective. Perspective is the apparent depth in the image.

 

[back alley]

so, how about those yankees?

 

[Finder]

so, how about those yankees?

Who's on first?