woodyspedden wrote:
[ I think the most compelling issue is that none of us have been able to articulate what causes the 3D effect. But when you see it, you know it is there
I've maintained all along that 3D effect is from depth cues and from textural detail. This image very clearly has both.
This is an outstanding example of what is trying to be demonstrated here with regard to 3D. I think the most compelling issue is that none of us have been able to articulate what causes the 3D effect. But when you see it, you know it is there
Amen to that. That's what has made this thread so fascinating. The effect is something so visceral, and yet it continues to resist analysis. It reminds me of a quote: "Water is two parts hydrogen and one part oxygen. But there is also a third thing that makes it water, and nobody knows what that is."
I used my recently acquired 200/f1.8 in battle for the first time yesterday. It has great 3D, unbelievable sharpness at f1.8, and interstingly to me it does that trick of making light cling to edges like no other lens I have ever seen (camera jpeg, iso 800, f1.8):
I am sure the strange edge effects are caused by the very large entrance pupil of the lens. One side of the lens is seeing darkness, while the other, due to parallax, isn't. Hence the strange impression that the light is bending around the edge of the object. Surely that is something that can help with 3D. In extreme cases is cuts the subject out from the background, but presumably in less extreme cases it only does so subliminally. When you think about it, every edge, in every picture, must be doing this to some extent, all the time. In this case the sharp black edge is clearly more sharply focussed than the cloth it outlines, which suggests that it may be the result of interference rather than resolved detail.
How's this one? This is shot on 8x10 with a Wollensak Voltas convertible lens built in 1919. I'd converted it to the 500mm focal length, which means I was using it as a single element uncoated lens. Absolutely wild bokeh -- a very old school look.
Do you use lightroom ?
I found that lightroom sometimes adds strange halos like this.
Do the conversion in Capture one and they are gone.
No. This is an in-camera jpeg. The edge outline is an optical effect. I first noticed this effect when using a Hasselblad 80mm at close range wide open about 20 years ago. Some lenses are prone to doing this, notably Zeiss. It is my belief that the human eye does this as well, but you will only notice it once you start to look for it. If you hold up a pencil against varied light and look carefully at the edge you may well notice bright lights eating into the edge of the pencil, or a dark halo clinging to it. Give it a try. It is real.
Looks like chromatic abberation due to highcontrastbleed.
However what I meant was that I found (I think) a bug in Lightroom, when I develop a high res version there sometimes is on the right side of the picture a chroma delay problem but only on the right.
DrPablo wrote:
How's this one? This is shot on 8x10 with a Wollensak Voltas convertible lens built in 1919. I'd converted it to the 500mm focal length, which means I was using it as a single element uncoated lens. Absolutely wild bokeh -- a very old school look.
brainiac wrote:
No. This is an in-camera jpeg. The edge outline is an optical effect. I first noticed this effect when using a Hasselblad 80mm at close range wide open about 20 years ago. Some lenses are prone to doing this, notably Zeiss. It is my belief that the human eye does this as well, but you will only notice it once you start to look for it. If you hold up a pencil against varied light and look carefully at the edge you may well notice bright lights eating into the edge of the pencil, or a dark halo clinging to it. Give it a try. It is real....Show more →
That s all very well but look at the faces or the tie, the dimensionaly is there despite the absence of the edge outline
Edited by Andi Dietrich on Jun 03, 2007 at 10:24 PM GMT (Reason: english)
maybe those show in print, but I don't see much '3d' in most of the shots posted here (granted web images are probably bottom of the barrel as far as the best method to view images). i find all my images look much better in print :-)
My own personally feeling, I think "the look" ("3d", what have you) is probably just as much (probably more) a function of how you shoot/process the image (composition, lighting, aperture, how you process/print the image), than it is a function of the lens/medium.
@Doorhoof
Yes, they are calibrated weekly at work :-) (nice to have tech guys who do that!!)
Foxbat, that's probably true, some folks may sense more 3d in some images than other folks do. Or maybe because I actually work in 3d every day at work, when I hear "3d" I don't think the same thing yall do. I would probably describe what yall are describing 3d, as "the look" of a particular lens?
That s all very well but look at the faces or the tie, the dimensionaly is there despite the absence of the edge outline
What I am suggesting is that the dimensionality (eek!) IS the edge outlining effect. Light superposes, that's why you can't distinguish the edge outlines. It's happening all over the image, but it is only in these extreme instances that you see the peculiar reflectance of tangential surfaces. I am wondering if 3D-looking lenses do this edging trick more.
To be honest with the naked eye I never see this kind of abberation.
It really looks like chromatic abberation or chroma delay.
But I don't want to argue of course.
but look at the white of the shirt you see a blue ghostly vague line which is in my book chromatic abberation.
The dark edge on the gray suit is something that I did not yet see on my shots, not even on 1:1 viewing, expect for in lightroom were it's a more glass like halo by the way.
Frank, love the interiors. In picture 1, how did you get the doorhof?
To be honest with the naked eye I never see this kind of abberation.
It really looks like chromatic abberation or chroma delay.
In low light hold an envelope at your closest focussing distance and focus on the edge. If there are lights or dark/light vertical transitions behind the envelope you should be able to see the bokeh creeping along the edge. Just as a pinhole focusses light in all directions, so an edge focusses it in one direction. The bokeh kind of breaks down and a sharper halo is formed around the edge of the object. Tangential surfaces/edges reflect and diffuse to varying degrees. From a distance even quite rough surfaces can become mirror-like. All surfaces and edges do this. It is a real optical effect, not an aberration.
