I am very glad that we had no lens discussion here. There was something to learn for me here.
If you want to know, there was the 24-105, the ef 50 1.8 and the zeiss tessi 45mm in between them. There was some image shake involved in the first Tessar shot. I did not care too much as all the pictures were only taken to start the discussion.
Here are some full size samples with these lenses, I prepared them for this thread but found there was no need to post them (until now). Dont look at them to close, no real test shots.
While we're on the subject, here's a stereogram shot with a pair of 5D's and Zeis 100 Makro-Planars. It's a crop of about 1/3 of the frame and I got my exposure wrong. Still, cross your eyes so that you see three images, then concentrate on the middle one. Keep trying for a few seconds and let your eyes relax. Now that's what I call the 3D effect.
The further the image is from your eyes, the less cross-eyed you need to go. The main thing is to overlap the two middle pictures accurately when you go cross-eyed. At that stage all 4 of the pictures look blurred. Overlap the middle two so they map perfectly onto each other. It can help to lean your head slightly from one side to the other so that your eye horizon is level with the images' horizon. Once you have the pictures overlapped so you see a row of three, concenctrate entirely on the middle one. Gradually as you relax your eyes will hunt for focus. Don't look around, look only at the middle of the three images. When it happens you'll know.
With practice you can do it instantly at any distance, and for prolonged periods without any ill-effects.
You will notice that the 3D is actually too strong. That's because I couldn't get the lens axes as close together as a pair of human eyes; the 5D's prism is too big. This is what people look like to E.T..
I think the subject, the composition, colors, the DOF, the blur effect, etc, all play an important role in dictating if an image is “flat” or if there is a 3D look to the picture.
Macro photography sometimes provides impressive 3D look because of composition, the image quality provided by the lens, the DOF, the subject, and the colors. Here are some examples I felt had a 3D look to them. The last one is not a macro or close to it, but it might provide a certain depth to it.
I still think it is the level of detail (micro contrast ?) With the butterfly notice how the ridges along the wings stand out making a 3d effect (ignoring the background which helps). Likewise for the strawberries the sparkle on the berries help (without the background to help). You could crop the picture to just the front row and seeing the ridges in teh white brick and sparkle/gap in the berries still make it 3dish (this is helped by the subtle changes in the berries colour as they flow up and down the vallies of the berries)
Because it's worth it, I'll try to explain the method again.
Look at the end of your nose. While looking at the end of your nose, notice that the background fields from your eyes no longer overlap properly. You can see two of everything in the background.
As a result, the two images become four. You might want to approach the pictures until the two nearer the middle of your field of view perfectly overlap. I mean the left image of the right pair, and the right image of the left pair. If you can get those two to overlap exactly and hold your eyes there, you are nearly done. It may help to wobble your head from side to side so that the overlap is perfect, and then just concentrate on the middle overlapping pictures without moving your eyes. Practice holding it there so that there is one middle composite picture, and a fainter one on either side, i.e. 3 instead of 4 images.
Once you can hold the pictures there, as a panel of three, and you concentrate on the middle picture, your eyes will gradually relax and start to hunt for focus. Then it happens, zap. Perfect veridical 3D. Don't look away from that middle panel of the three, as you will lose it straight away. Just get used to it at first, then you can start to look around the frame and maintain the illusion.
Some people find it easy, others never manage it. A friend of mine tried for half an hour before it happened. Then he loved it. It's like riding a bike. It's certainly easier than that magic eye crap, and only about half as pointless.
Richard, Thank you for the efforts. And it is very embarrassing for me to tell you that I still can't do it. I think I could see the Magi Eye crap But this one is tougher.
Micro-contrast is the only way to achieve 3D look on images. Lens with high micro-contrast were achieved by controlling higher level of lens aberrations.
Pondria wrote:
Richard, Thank you for the efforts. And it is very embarrassing for me to tell you that I still can't do it. I think I could see the Magi Eye crap But this one is tougher.
What should be the distance to the screen from the eyes ?