Landscape Question

[Jackie Schuknecht]

Since we are doing landscapes, I thought this might be an appropriate question to post here.
I have been doing a bit of reading and I was wondering about using longer lenses for landscape. At what mm length do you start getting compression and why would you want it. Around 100, 200, 300??? Would you use it with distant mountains in the BG or something. Does the compression make the picture look odd. Probably pretty basic questions for a lot of people, but I don't know the answers. Maybe someone can fill me in.
Thanks.

[Roman Kurywczak]

Hi Jackie,
Aaaah.....that depends.......a lot of this depends on distance to subject......compression is not a bad thing....if the subject is distant and I often use my long lenses.....for subjects I can't normally reach with the 28-135.....or the 17-40. If I get into the whole Hyperfocal distance chart......we'd be asleep in 30 seconds.....(although it's not a bad thing to look into...Google it).......if my FG is close and I want max DOF....the long lenses weren't designed for this. I especially like the long lenses for silhouettes in the morning or evenings....this helps isolate things better.....when detail isn't as important. Don't get too hung up on what lens you use.....just use the appropriate lens for the composition. If you really want the tech info on this.....ask Roger Clark....our newest mod in the digital workflow forum. He has the tech answers for sure!

[Roger Clark]

Since we are doing landscapes, I thought this might be an appropriate question to post here.
I have been doing a bit of reading and I was wondering about using longer lenses for landscape. At what mm length do you start getting compression and why would you want it. Around 100, 200, 300??? Would you use it with distant mountains in the BG or something. Does the compression make the picture look odd. Probably pretty basic questions for a lot of people, but I don't know the answers. Maybe someone can fill me in.
Thanks.

Jackie,

There is no reason you can't use a longer lens for landscapes. In 35mm format, probably my most use focal length is about 70 mm. I've used 300 mm on a 4x5 a lot (equivalent to about 75 mm on 35mm). I would say use whatever focal length gives the framing you want. The big problem with using longer focal length is that it gets harder to get close things in focus as well as the distant ones. You can check depth of field with:
http://www.dofmaster.com/dofjs.html

If a "normal" lens on 35 mm is 50 mm, it takes a considerably longer focal length to see compression, I would say perhaps 200 mm and longer. Here is an example that I think makes a dramatic effect: full moon rising with 700 mm on a 1.3x crop body:
http://www.clarkvision.com/galleries...586.b-800.html

I do like the compression effect, but there are limited situations where you can use it. But when you can, go for it!

[Jeffrey Sipress]

Do it! I use long lenses for landscapes on every outing lately. My most well received image from Africa is a critterscape made with a 700mm focal length and a full frame dslr.

For the record, there is no such thing as telephoto lens 'compression' effect. It is simply the perspective of objects in the scene due to the great camera to subject distance. A long lens simply provides a narrow field of view. Using a long lens typically puts the camera far from the subject, hence the confusion and improper use of terms.

[Roger Clark]

For the record, there is no such thing as telephoto lens 'compression' effect. It is simply the perspective of objects in the scene due to the great camera to subject distance. A long lens simply provides a narrow field of view. Using a long lens typically puts the camera far from the subject, hence the confusion and improper use of terms.

Jeffrey,
I agree to a degree. If you had infinite resolution, you could take a 28mm image and enlarge it to that 700mm view and get the same proportion of subjects, thus the same perspective. But in reality, you don't have that kind of resolution, so the telephoto does give a different feel to the image, thus the long used "compression" terminology. It is really a magnification effect. Here are two examples:

Telephoto image of a sunset at (390 mm, in 35 mm equivalent):
http://www.clarkvision.com/galleries...2540a-600.html

Wide angle of a sunset (about 40 mm equivalent focal length):
http://www.clarkvision.com/galleries...3372b-600.html

Because the wide angle image shows subjects that are closer to the camera , it changes the impression of the view, even though the perspective of the subjects are not different even if the image was with a telephoto from the same spot.

In the wide angle image, distant subjects appear small relative to near subjects. In the telephoto shot, the proportions are the same, so perspective is the same, but many of the close foreground subjects are lost and the distant subjects are magnified. It is the magnification that gives the impression of the compression.

So in summary, perspective does not change with focal length, but magnification does, and that is what is meant by "compression."

[Jackie Schuknecht]

Thanks for the responses everyone. It has cleared a lot up for me. Will try some with the longer lenses.

[Jeffrey Sipress]

Magnification is a perceived concept, and a layman's term for the fact that an object consumes a larger portion of the frame (from using a narrower field of view). It's the same as zooming in and then cropping on a computer or enlarger. The only thing changing is the image quality (resolution, if you go by numbers).

I've set up experiments to prove all of this. Using a 4x5 and a polaroid back, I shot a porch scene that included a chair, flowerpot and some other things. Using lenses from 90mm to about 300 mm, I adjusted the camera to subject distance to achieve the same compositional borders for each exposure with four different focal length lenses. The images were similar, but the differences in the relationships between the objects themselves, and their relation to the background was astonishing. Image quality was equal in all. I wish I still had those little prints to scan and show here.

[Roger Clark]

Magnification is a perceived concept, and a layman's term for the fact that an object consumes a larger portion of the frame (from using a narrower field of view).

Jeffry.
I disagree. Optical magnification is a real quantity.
E.g.: http://en.wikipedia.org/wiki/Magnification
and not a layman's term at all. You will find it defined in any decent optics book. You should also be familiar with macro photography where magnification is cited as real object size to size in the focal plane. It is the same thing with any lens and any subject.

It's the same as zooming in and then cropping on a computer or enlarger. The only thing changing is the image quality (resolution, if you go by numbers).

As you note, optical magnification is not actually the same as magnifying post image acquisition. That is really a sampling issue and an optical system resolution difference. Even with infinite sampling, the resolution between a small aperture lens and a large aperture lens is basic physics and is the major factor in the difference in recorded detail in photographic images.

I've set up experiments to prove all of this. Using a 4x5 and a polaroid back, I shot a porch scene that included a chair, flowerpot and some other things. Using lenses from 90mm to about 300 mm, I adjusted the camera to subject distance to achieve the same compositional borders for each exposure with four different focal length lenses.

And there is the key statement that proves you did a different experiment: you changed the camera to subject distance. That is a perspective change.

The images were similar, but the differences in the relationships between the objects themselves, and their relation to the background was astonishing. Image quality was equal in all. I wish I still had those little prints to scan and show here.

And that is because of the perspective change. What we were talking about was keeping the camera in the same spot, so no perspective change, and only changing magnification (i.e. lens focal length). Two different things.

Roger