Jumper Stacks

Jody Melanson · Post by **Jody Melanson** » Fri Jul 31, 2009 5:47 pm

Between 16-29 images in each stack. Stereogram included for those of you that can view them.

Canon 1DMK2N + 3 Tubes + Sigma 150 + reversed Canon 50/1.8 + Canon EX380 flash + 2 Sigma DG 500 Super flashes.

rjlittlefield · Post by **rjlittlefield** » Fri Jul 31, 2009 6:19 pm

Jody, the single frames are lovely, but the "stereo" is a complete bust. Dead flat. In what's posted at this moment, there's no difference at all between the two sides except for your signature and what looks like one pixel of retouching in the center of one big eye. What gives?

--Rik

ChrisR · Post by **ChrisR** » Fri Jul 31, 2009 7:55 pm

A mixup I think. By putting the single pic to the right of one of the lower ones, I get a small 3D effect.
The pairs of hairs to the left of the knee and left eye just show a difference visible on the singles.

rjlittlefield · Post by **rjlittlefield** » Fri Jul 31, 2009 8:39 pm

ChrisR wrote:A mixup I think. By putting the single pic to the right of one of the lower ones, I get a small 3D effect.

Yeah, that would do it. If I scale the single pic to match the flat pair, and swap it in as a new left-eye view, then the result shows pretty good depth.

It's an odd mistake, though, certainly one that I've never seen before. Jody doesn't drop by very often. I'll try sending him an email so he knows.

--Rik

ChrisR · Post by **ChrisR** » Sat Aug 01, 2009 7:46 am

That's odd, I tried it on the right and it worked .

I'm not too surprised, sometimes I type an entire word sdrawkcab, read it through, and don't see anything wrong.

I just made an RL pair above an LR pair. Upper and lower pairs lock at the same time, and both look 3D. Apart from the size of the sig, identical.

This could explain a few things

rjlittlefield · Post by **rjlittlefield** » Sat Aug 01, 2009 9:56 am

ChrisR wrote:That's odd, I tried it on the right and it worked .

The single pic is a "left-eye view", meaning it's the view that's intended to be seen by the left eye.

But when you're laying up for crossed-eye viewing, the left-eye view goes on the right side of the pair, so what you had and what I said were both right...uh, correct.

The crossed-eye layout gets confusing to talk about -- sort of the same problem as does "left leg" mean the critter's left, or mine?

I just made an RL pair above an LR pair. Upper and lower pairs lock at the same time, and both look 3D. Apart from the size of the sig, identical.

If I understand you correctly, "identical" means that you're not seeing a difference between the left-right and right-left arrangements.

That's not uncommon, but it's not correct, either. When the views are swapped, the depth-from-stereo cue gets inverted -- what should be closest is farthest and vice versa. But there are always a bunch of other cues about what is closest, like cues from shading and occlusion and prior knowledge. The other cues are usually stronger, so your brain forms an impression that has the correct (non-inverted) geometry. At the same time, your brain tags the image as "3-D" because of the disparities, even though the disparities are inverted!

To help sort this out, get yourself a copy of StereoPhoto Maker. Write your new stereo pair to a file and load it into StereoPhoto Maker. Put your cursor over the black/red button with the tooltip that says "Swap Left/Right". Lock up the pair so you see a 3-D image. Then click the button a few times, slowly. What you'll see is that in one orientation the stereo looks good, while in the other orientation it looks a little odd in some obscure way.

If you carefully analyze the case that looks odd, you'll gradually figure out about the inversion, but it takes a surprising amount of study even after years of practice. At least it does for me.

This could explain a few things

Hope this helps.

--Rik

Jody Melanson · Post by **Jody Melanson** » Sun Aug 02, 2009 2:05 pm

rjlittlefield wrote:Jody, the single frames are lovely, but the "stereo" is a complete bust. Dead flat. In what's posted at this moment, there's no difference at all between the two sides except for your signature and what looks like one pixel of retouching in the center of one big eye. What gives?

--Rik

Sorry for the "complete bust" Rik. I fixed it. Was a long day I guess.

On a side note, I just started using Zerene Stacker, very cool.

rjlittlefield · Post by **rjlittlefield** » Sun Aug 02, 2009 3:47 pm

Yep, the stereo works great now. And we got a good discussion from the initial version, so everything came out wonderful!

I'm glad to hear you're enjoying Zerene Stacker. There's some new capability coming out in a few days that may strike your fancy too.

--Rik