lol its your fault Tariq, now you have me all confused
To my eyes there is a difference in "presence" between equivalent landscape shots in large and small format, and I always attributed this to the different focal length used to get the same fov, given the same distance to subject. But I never really gave it too much thought or done any experiments, maybe my optics 101 theory is all wrong.
I'm not sure that I fully follow your discussion but perspective is independent of focal length. If you take two pictures from the same location with lenses of different focal lengths the perspective in the image will be identical. The change of perspective will only occur if you move the position of the camera.
The difference between large and small format is twofold. One is that you get higher resolution due to the larger film/sensor area (somewhat moot point for sensor though). The other is that for the equivalent framing the larger format allows you to get a more shallow DOF. Since the field of view will be larger with large format (when using the same FL) than on small format, you have to get closer to get the same framing and you will subsequently get a more shallow DOF.
denoir wrote:
Conversely if you stitch together a couple of FF frames that cover the same area as a medium format frame you'll end up with the same thing as if it was captured by a medium format camera.
No, you actually won't. The stiched image will have a spherical curvature of field due to pointing the camera in different directions for the separate parts of the final image. This is not the case with the one MF image, if the lens has a flat field.
Makten wrote:
No, you actually won't. The stiched image will have a spherical curvature of field due to pointing the camera in different directions for the separate parts of the final image. This is not the case with the one MF image, if the lens has a flat field.
Is this not correctable by most good stitching software?
Makten wrote:
No, you actually won't. The stiched image will have a spherical curvature of field due to pointing the camera in different directions for the separate parts of the final image. This is not the case with the one MF image, if the lens has a flat field.
Yes, for close ups but at larger distance it won't be much of an issue and you can solve the issue completely by using a tilt-shift lens.
I am picking nits here, but few formats have enough shift in their T/S lenses in a large enough variety of focal lengths to make it a flexible enough alternative, if the flatness of field is truly an issue.
Here's a contribution to the sensor size vs. field of view vs. 'perspective' part of this discussion. Below are three shots taken from the same viewpoint, of the same scene, with roughly identical focal length equivalents: once with a full-frame 5D2 (50mm lens), once with a 1.33 crop Leica M8 (35mm lens, approx 50mm FF equivalent), and with a Canon S90 (not sure of the crop, but a large factor: 10.7mm lens, nominally 50mm FF equivalent.)
5D2:
M8:
S90:
Obviously, they have no artistic merit, but all three are focussed on the toy dog. The dog is about a meter from the lens; the sawn-off tree is about eight meters away. All were shot at F8, although that's not an argument I want to be part of :-)
Alundeb - that was my intention, within the constraints of different aspect ratios and slightly different actual AOVs. Hopefully, conclusions can be drawn about the relationship of the near and far objects in each.
johntodd wrote:
Alundeb - that was my intention, within the constraints of different aspect ratios and slightly different actual AOVs. Hopefully, conclusions can be drawn about the relationship of the near and far objects in each.
The conclusion I draw from your comparison, is that the viewpoint is different, and thus we cannot say anything at all about near-far relationship between formats.
Tariq Gibran wrote:
Actually, this is not the case. To quote Phil Davis from my twenty five year old Photo 1 textbook:
"Contrary to a fairly common belief, lenses themselves don't affect perspective. The camera to subject distance does. From any given viewpoint, you'll get identical perspective with any lens your camera can accept."
This idea of "magnification" that both you and Spyro are suggesting (if I understand both of you correctly) is not possible because it would require that perspective change simply by changing lenses and film/digital formats WHILE STANDING AT THE SAME VIEWPOINT (PLACE). The lens used nor the format has the ability to alter the relative size of objects to one another in front of you. The only way that relationship changes is if you physically change your position....Show more →
What I am trying to say is that MF and LF compared to 35mm format is like people have said "like stepping further into the scene", similar to if you put a more telephoto lens on a 35mm format camera and then stitched to get the same AOV. This works for distant scenes but you have to worry about getting enough DOF with the more tele lens to keep foreground objects sharp as well as the background.
Maybe this is caused by the different format aspect ratios.
I doubt it is caused by the aspect ratio, although this does have a psychological effect. I suspect that what it is is simply that larger formats are often printed and shown larger, where their greater resolution can really make a difference. At web sizes there isn't much difference. Did you see Luka's stitched tree? The size of the presentation of that shot is everything. Small there isn't anything at all there, really. Large it looks great, with beautiful rendering.
Yes, I saw Luka's tree which works because this is a distant scene with no foreground object in the scene near the camera. How about this Briot classic Death Valley Raceway shot? how would you recreate this with a 35mm dslr? Notice the size of the mountains in the background. If I shot the same scene with a 28mm ( or what ever the 35mm equiv is of this MF lens, which I think is a 35mm focal length) lens on a dslr I could get the same AOV with one shot buth the distance to the mountains would increase correct and the mountains would be shorter in height, right?
wayne seltzer wrote:
Yes, I saw Luka's tree which works because this is a distant scene with no foreground object in the scene near the camera. How about this Briot classic Death Valley Raceway shot? how would you recreate this with a 35mm dslr? Notice the size of the mountains in the background. If I shot the same scene with a 28mm ( or what ever the 35mm equiv is of this MF lens, which I think is a 35mm focal length) lens on a dslr I could get the same AOV with one shot buth the distance to the mountains would increase correct and the mountains would be shorter in height, right?...Show more →
No, if you shot the same scene with a lens with the same angle of view and aspect ratio, the photo would look exactly the same as this. Same size mountains, same size everything. The rendering is the only difference. Do you have two cameras? You can convince yourself of this.
In your shot the immediate foreground is not sharp as it is out of the DOF of the lens, (what a ZE 100?) that was used in your pano stitch.If you used a T/S 100 you would get larger DOF to help with near foreground sharpness.
If I stay in the same place and use a 24mm lens and a 100mm lens on a 35mm dslr the height of the mountains in the background using the 100mm lens will be greater than the ones using the 24mm lens and will appear closer to the camera. Telephoto lenses compress scenes, right?
Show me a 35mm DSLR stitch example like this shot I linked above.
wayne seltzer wrote:
In your shot the immediate foreground is not sharp as it is out of the DOF of the lens, (what a ZE 100?) that was used in your pano stitch.If you used a T/S 100 you would get larger DOF to help with near foreground sharpness.
If I stay in the same place and use a 24mm lens and a 100mm lens on a 35mm dslr the height of the mountains in the background using the 100mm lens will be greater than the ones using the 24mm lens and will appear closer to the camera. Telephoto lenses compress scenes, right?
Show me a 35mm DSLR stitch example like this shot I linked above....Show more →
Using two different focal lengths on one camera isn't the same thing. I mean something like using an 80mm lens on medium format and a 50mm lens on 135.
In your stitching example, the mountains are larger, *in each shot*, but by the time you are done stitching and scale the two photos the same, they are the same again. Mountains are the same size.
Think about it this way: wherever you stand, the size of everything that you see is only dependent on your distance to those things. If the tree looks bigger than the mountains, it is because you are closer to the tree.
It is the same for lenses. They are only eyes, not magical devices for compressing and stretching things. Perspective depends only on where you stand. The tree cannot suddenly look smaller than the mountain just because you use a tele. Focal length is merely a cropping device.
I agree with what you are saying if the aspect ratios are the same but they are not between MF and 135.
So if the Briot shot above was taken with a 35mm focal length lens on a MFDB,which lens would use and how many stitches are needed to recreate this and if you are using a longer focal length lens, would you have enough DOF to cover the scene like this?
