Why do they say the 50mm lens is a like a human eye? (continued)

jrtrent said:

aman74 said:

Is the link at the bottom of your OP the original discussion? If not, would be nice to have a link. Always fun when random topics appear with reference to some mythical discussion that some of us aren't privy to.

Click to expand...

Sorry, that problem never crossed my ming. Here's a link to the original discussion:
http://forums.dpreview.com/forums/read.asp?forum=1018&message=35049839

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No problem, thanks I think I found it linked earlier in this thread. Hadn't read through the whole thing yet.

Looks like that was quite the discussion. I was going to comment, but I don't want to clog this thread with more bickering. I have to tell myself not to engage in such things.

I'll just say that I thought most people at this point in time knew that telephoto lenses don't flatten a thing.

Oh, and I like 50mm lenses and whether they are similar to our vision or not is of little interest to me really. There was a post in the other thread where someone was talking about how the 50 feels "real", etc. That's fine if that's the photographers thoughts and approach, but I always get a kick out of it when people don't seem to embrace photography as an abstract art form. The reference Ansel Adams as pure when he knew this as well as anyone and said as much. Also, his darkroom work in today's equivalent would be considered seriously heavy PP.

Sorry, went on a bit of a tangent.

Carry on...

http://forums.dpreview.com/forums/read.asp?forum=1018&message=35090614
--
Frank
Please check out my galleries here
and http://www.pbase.com/fjlsolys

jrtrent said:

Nice link. That's a striking example of using camera position to create dramatically different perspective effects while changing focal lengths to maintain consistent framing of the young lady in the foreground.

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It's the best link yet. Wonder why he posted it? It is exactly the opposite of what he's been saying all along. Go figure.
--
Frank
Please check out my galleries here
and http://www.pbase.com/fjlsolys

Frank LoPriore said:

http://forums.dpreview.com/forums/read.asp?forum=1018&message=35090614
--
Frank
Please check out my galleries here
and http://www.pbase.com/fjlsolys

Click to expand...

Not sure your point Frank. Weren't you on the side of "tele lenses causes compression" ?

It's a fallacy and that post shows nothing to make anyone feel any different. If you don't change the cameras position in relationship to the girl to account for focal length and then you cropped the image taken with the wider angle lens it would match the image taken with the longer focal length.

The rumors of my demolishment have been greatly exaggerated.
--
Frank
Please check out my galleries here
and http://www.pbase.com/fjlsolys

It's actually more like 43 or 45mm focal length in the 35mm camera system that is most like the perspective of the human eye. The human eye may have a wider FOV, but it's the perspective that 43 or 45mm provides that will give us, when cropped, the save perspective as our eyes. Our eyes see wider then 43 or 45mm, but we cannot focus on the wider regions. We have to move our eyes to "see" well that are outside of the 43 or 45mm FOV perspective.

Frank LoPriore said:

jrtrent wrote:

It's the best link yet. Wonder why he posted it? It is exactly the opposite of what he's been saying all along. Go figure.

Click to expand...

I don't think it's the opposite at all; he's maintained all along that it's camera position and not focal length that determines perspective. I happen to think focal length has an effect also, but I think I understand better now the position some (such as info333 and Barrie Davis) have taken with respect to the idea that perspective is a function of position, while framing (through focal length, cropping, stitching) is simply the decision of which elements you want to capture, at that distance/perspective, in the picture.

RedFox88 said:

It's actually more like 43 or 45mm focal length in the 35mm camera system that is most like the perspective of the human eye. The human eye may have a wider FOV, but it's the perspective that 43 or 45mm provides that will give us, when cropped, the save perspective as our eyes. Our eyes see wider then 43 or 45mm, but we cannot focus on the wider regions. We have to move our eyes to "see" well that are outside of the 43 or 45mm FOV perspective.

Click to expand...

We have to move our eyes to see even within that field.

Take my previous suggestion, of viewing a 10 x 8 inch print from a distance of about 12 inches. Two things are obvious, firstly that the 10 x 8 inch print doesn't cover our entire field of view. Secondly, when viewing the details of the print, our eyes will scan over it, briefly pausing on particular points of interest. Our brain will merge these separate small details to give the impression that we are seeing the whole thing in detail.

Regards,
Peter

aman74 said:

There was a post in the other thread where someone was talking about how the 50 feels "real", etc. That's fine if that's the photographers thoughts and approach, but I always get a kick out of it when people don't seem to embrace photography as an abstract art form. The reference Ansel Adams as pure when he knew this as well as anyone and said as much. Also, his darkroom work in today's equivalent would be considered seriously heavy PP.

Click to expand...

That may well have been me. I don't embrace photography as art at all (at least not my own), but as an aid to remember things (and as fun toys to play with!). And you're right about Ansel Adams, of course. He often wrote about using photographic tools to capture, not reality, but the vision in his mind's eye.

aman74 said:

Frank LoPriore said:

http://forums.dpreview.com/forums/read.asp?forum=1018&message=35090614
--
Frank
Please check out my galleries here
and http://www.pbase.com/fjlsolys

Click to expand...

Not sure your point Frank. Weren't you on the side of "tele lenses causes compression" ?

It's a fallacy and that post shows nothing to make anyone feel any different. If you don't change the cameras position in relationship to the girl to account for focal length and then you cropped the image taken with the wider angle lens it would match the image taken with the longer focal length.

Click to expand...

Actually, I'm the one who originally said tele lenses cause compression. Not sure why you don't think those two pictures demonstrate that? The author even describes the picture taken with the tele as "perspective compression". No mention that I can see about moving and cropping. Both subjects appear to be the same size
but there is quite a difference in the apparent distance to the background.
--
Frank
Please check out my galleries here
and http://www.pbase.com/fjlsolys

Frank LoPriore said:

aman74 said:

Frank LoPriore said:

http://forums.dpreview.com/forums/read.asp?forum=1018&message=35090614
--
Frank
Please check out my galleries here
and http://www.pbase.com/fjlsolys

Click to expand...

Not sure your point Frank. Weren't you on the side of "tele lenses causes compression" ?

It's a fallacy and that post shows nothing to make anyone feel any different. If you don't change the cameras position in relationship to the girl to account for focal length and then you cropped the image taken with the wider angle lens it would match the image taken with the longer focal length.

Click to expand...

Actually, I'm the one who originally said tele lenses cause compression. Not sure why you don't think those two pictures demonstrate that? The author even describes the picture taken with the tele as "perspective compression". No mention that I can see about moving and cropping. Both subjects appear to be the same size
but there is quite a difference in the apparent distance to the background.
--
Frank
Please check out my galleries here
and http://www.pbase.com/fjlsolys

Click to expand...

The opening line states: " Due to a close viewpoint... " and " Due to a distant viewpoint... ". Those two phrases clearly describe the fact that the camera position is moved between the two shots.

Regards,
Peter

jrtrent said:

jrtrent said:

jrtrent wrote:

It's the best link yet. Wonder why he posted it? It is exactly the opposite of what he's been saying all along. Go figure.

Click to expand...

I don't think it's the opposite at all; he's maintained all along that it's camera position and not focal length that determines perspective. I happen to think focal length has an effect also, but I think I understand better now the position some (such as info333 and Barrie Davis) have taken with respect to the idea that perspective is a function of position, while framing (through focal length, cropping, stitching) is simply the decision of which elements you want to capture, at that distance/perspective, in the picture.

Click to expand...

I would have easily accepted that camera position and focal length have an effect on perspective. I never maintained otherwise. That was not the position that he and Barrie took. They maintained there was no connection between focal length and perspective at all.
--
Frank
Please check out my galleries here
and http://www.pbase.com/fjlsolys

sherwoodpete said:

The opening line states: " Due to a close viewpoint... " and " Due to a distant viewpoint... ". Those two phrases clearly describe the fact that the camera position is moved between the two shots.

Regards,
Peter

Click to expand...

He could also have meant a tele gives a close viewpoint and a wide angle a distant one. I don't know for sure, but neither do you. He specifically states a tele lens compresses/ flattens perspective, no specific mention of changing camera position. This is an instructional site. I doubt he would not mention changing camera position when changing focal lengths. But even if you are correct and he did move back for the tele shot, can you explain the very apparent difference in the size of the buildings
--
Frank
Please check out my galleries here
and http://www.pbase.com/fjlsolys

sherwoodpete said:

RedFox88 said:

It's actually more like 43 or 45mm focal length in the 35mm camera system that is most like the perspective of the human eye. The human eye may have a wider FOV, but it's the perspective that 43 or 45mm provides that will give us, when cropped, the save perspective as our eyes. Our eyes see wider then 43 or 45mm, but we cannot focus on the wider regions. We have to move our eyes to "see" well that are outside of the 43 or 45mm FOV perspective.

Click to expand...

We have to move our eyes to see even within that field.

Take my previous suggestion, of viewing a 10 x 8 inch print from a distance of about 12 inches. Two things are obvious, firstly that the 10 x 8 inch print doesn't cover our entire field of view. Secondly, when viewing the details of the print, our eyes will scan over it, briefly pausing on particular points of interest. Our brain will merge these separate small details to give the impression that we are seeing the whole thing in detail.

Regards,
Peter

Click to expand...

Peter, I can't say that Redfox is wrong, but I agree with you. Some would even have to "scan" this reply box to read it left to right.
--
Frank
Please check out my galleries here
and http://www.pbase.com/fjlsolys

Frank LoPriore said:

sherwoodpete said:

The opening line states: " Due to a close viewpoint... " and " Due to a distant viewpoint... ". Those two phrases clearly describe the fact that the camera position is moved between the two shots.

Regards,
Peter

Click to expand...

He could also have meant a tele gives a close viewpoint and a wide angle a distant one. I don't know for sure, but neither do you. He specifically states a tele lens compresses/ flattens perspective, no specific mention of changing camera position. This is an instructional site. I doubt he would not mention changing camera position when changing focal lengths. But even if you are correct and he did move back for the tele shot, can you explain the very apparent difference in the size of the buildings
--
Frank
Please check out my galleries here
and http://www.pbase.com/fjlsolys

Click to expand...

I didn't realize people were actually debating whether tele lenses cause compression. As someone who shoots wildlife with an 800mm lens, and also takes shots of the same scenes with a 24mm lens, the answer is obvious on every shot.

Of course they do.

Dave

Chato said:

Frank LoPriore said:

sherwoodpete said:

The opening line states: " Due to a close viewpoint... " and " Due to a distant viewpoint... ". Those two phrases clearly describe the fact that the camera position is moved between the two shots.

Regards,
Peter

Click to expand...

He could also have meant a tele gives a close viewpoint and a wide angle a distant one. I don't know for sure, but neither do you. He specifically states a tele lens compresses/ flattens perspective, no specific mention of changing camera position. This is an instructional site. I doubt he would not mention changing camera position when changing focal lengths. But even if you are correct and he did move back for the tele shot, can you explain the very apparent difference in the size of the buildings
--
Frank
Please check out my galleries here
and http://www.pbase.com/fjlsolys

Click to expand...

I didn't realize people were actually debating whether tele lenses cause compression. As someone who shoots wildlife with an 800mm lens, and also takes shots of the same scenes with a 24mm lens, the answer is obvious on every shot.

Of course they do.

Dave

Click to expand...

Thanks for the input, Dave. I admittedly don't have the experience to use your example. I imagine changing camera position would be problematic for you in that situation.
--
Frank
Please check out my galleries here
and http://www.pbase.com/fjlsolys

Frank LoPriore said:

sherwoodpete said:

The opening line states: " Due to a close viewpoint... " and " Due to a distant viewpoint... ". Those two phrases clearly describe the fact that the camera position is moved between the two shots.

Regards,
Peter

Click to expand...

He could also have meant a tele gives a close viewpoint and a wide angle a distant one. I don't know for sure, but neither do you. He specifically states a tele lens compresses/ flattens perspective, no specific mention of changing camera position. This is an instructional site. I doubt he would not mention changing camera position when changing focal lengths.

Click to expand...

Well, the pictures speak for themselves:



Look for example at the point where the woman's legs meet the background. In one case the background is a sandy beach, in the other it is the sea itself.
That change in relative position can only be due to a change in camera position.

Or consider the blue sky and cloud next to her shoulder. In the other shot it has been replaced by part of a building. Again that indicates a change of camera position.

Frank LoPriore said:

But even if you are correct and he did move back for the tele shot, can you explain the very apparent difference in the size of the buildings

Click to expand...

I'll try. The shot on the left was taken with a wide-angle lens, meaning that the buildings are small. The second shot was taken with a telephoto lens, and the buildings are larger as a consequence.

But that's only part of the story. In order to include the human subject in the frame at the original size, the camera was moved back by a few feet.

Let's put some rough figures to this. Say the first shot was taken from about 6 feet away with a 35mm focal length. Then the second shot could have been taken from about 24 feet using a 140 mm focal length.

Changing the focal length and shooting distance like this will preserve the scale of the human subject.

But what about the distant buildings? Well, the shooting distance will have changed from 2000 feet to 2018 feet, which will have an insignificant effect in making the buildings appear smaller, so the dominant effect is the extra magnification due to the change of focal length.

(all figures are my estimates, for purposes of illustration only).

Regards,
Peter

Before this thread goes south again, allow me to explain my position fully. I have never stated that camera position does not effect perspective. Of course it does. But given the same camera position, focal length also effects perspective. To say, as some do, that focal length has no effect on perspective is incorrect.

--
Frank
Please check out my galleries here
and http://www.pbase.com/fjlsolys

Chato said:

Frank LoPriore said:

sherwoodpete said:

The opening line states: " Due to a close viewpoint... " and " Due to a distant viewpoint... ". Those two phrases clearly describe the fact that the camera position is moved between the two shots.

Regards,
Peter

Click to expand...

He could also have meant a tele gives a close viewpoint and a wide angle a distant one. I don't know for sure, but neither do you. He specifically states a tele lens compresses/ flattens perspective, no specific mention of changing camera position. This is an instructional site. I doubt he would not mention changing camera position when changing focal lengths. But even if you are correct and he did move back for the tele shot, can you explain the very apparent difference in the size of the buildings
--
Frank
Please check out my galleries here
and http://www.pbase.com/fjlsolys

Click to expand...

I didn't realize people were actually debating whether tele lenses cause compression. As someone who shoots wildlife with an 800mm lens, and also takes shots of the same scenes with a 24mm lens, the answer is obvious on every shot.

Of course they do.

Dave

Click to expand...

Take the shot with a wide angle lens and then crop and the relationship between the subject and it's background will be the same as if you had used a long tele. Tele lenses cause no flattening, compressing, etc....

http://books.google.com/books?id=wiaciWKK2xEC&lpg=PA62&dq=perspective%20compression&pg=PA62#v=onepage&q=perspective%20compression&f=false

Quote:

"The human eye has a fixed focal length and a fixed field of vision. Apparent perspective in the viewfinder can be altered by changing the focal length of the lens together with the distance of the camera from the subject. "

Note that here it is mentioned that two things are changed:

• focal length
• distance of camera from subject

There are those who say that only one of these factors is important - in some cases the first, in others the second, but I think it is fair to include both together as a more complete description of what is happening.

Regards,
Peter