Adding extra depth to conventional stereo.

tony brown wrote:

uuglypher wrote:

tony brown wrote:

Here's a re-work of the first image pair, again with lower image the original conventional stereo and top one is the rework.

Hi, Tony,

Here’s my take when comparing the three steps:

conventional S3D, your first re-work, and the latest rework) I see each as composed of two regions: the foreground and middle ground ending at the near side of our view of the water, and background all beyond that.:

your first rework produced an apparent precipitous drop-off of background water level beyond the middle ground, while in your latest re-work the drop-off seems less severe- less precipitous.

The delineation between middleground and background does, however, remain distinct.

How does that jibe with your intent?

Best regards,

Dave

Hi Dave,

What you observe is what I have tried to reduce. BTW I searched for 'bizonal perspective' without sucess but can imagine what it is.

I started stereo only a year and a half ago and used B&W film in 1950s cameras to make images whuch were mostly landscapes and old architecture. Finding the conventional spacing could not distinguish depth much beyond 15 yards, I then used Cha-Cha technique with perhaps 1 to 2 metres separation between captures. The depth continued as far as I required into the image but the foregrounds were irreconcilable. Not only that but I couldn't have animals, birds or moving people because of the interval between exposures.

Thus I assembled two Fujifilm XP60 cameras on a bar with the lenses ~100mm apart and was able to download images and recharge their batteries without removing the cameras from their mountings. Using 'finger synch' I was able to get exposures to within about 1/4 second and often better which allowed more motion. However, the depth at distance was gone again.

So I use the Fuji pair to take a conventional stereo and now follow with ONE additional capture, usually to the right, at 1 to 2 meters as before, to capture background depth separation. Thus I produce two stereo images with the left image common to both pictures and the right two are both used to create stereos with the common left one.

These are assembled as Photoshop layers, lined up in Anaglyph mode (by switching off the RED channels in both right hand images) to get matching lateral displacements at the horizontal joining area and the right hand, wide image masked to avoid interfering with the foreground. The mask can be quite unsharp and the viewer's eye does most of the work. I attempt to get the lateral displacement of the wide (rear) view the same as that at the rear of the front (foreground) view as it is at the joining area. That can be achieved by moving the rear view horizontally with respect to the left hand image which remains as it was captured without masking or alteration.

Having got the positioning right as above, I then restore the RED channels, switched off to display the Anaglyph for working, and then move the layers to display the full colour, Side by Side or Xeyed versions you see. I enjoyed Anaglyphs when only taking B&W images but feel so much improvement with SxS in colour using Loreo hand held prismatic viewers. Colour Anaglyphs, as in the reworked image containing the red car, require use of DuBois treatment by which time the end result is far from the real life 'as you see it' 3D image.

I assume 'bizonal perspective' is a draughtmanship involving combining just such two images with different perspectives? Any link to same would be appreciated to give me a superficial insight.

It is a moot point whether my Tri-shot process adds extra depth to conventional stereo or enables rational foregrounds to be added to hyperstereos to provide scale and avoid the 'model village effect'. The price to pay is some visual discontinuity at the join which must be balanced with the extra depth information provided.

Hi, Tony,

I ought start by making clear that my interest in 3D is not via “stereo photography” but by means of 2D-to-3D conversion using disproportionate geometric transformation of a copy of an original 2D image (the left eye image) and transforming the copy to b3come the right eye image.

That said, I did read through your explanatory disquisition, then realized I’d better get a cup of coffee and give it another, more contemplative, read! Which I did, and I’m beginning to get the gist of it.

Basically, I think you and I are both less than totally happy with the results of traditional S3D photography. My major problem with it is the early extinction of rendition of the 3rd dimension leaving a 2D background looking like a painted stage backdrop.

For the past 8-10 years I’ve been working on techniques of 2D-to-3D conversion. By the way, “Bizonal Perspective” is a technique of differentially transforming the sky above the horizon and the terrain below the horizon so that when counterposed at the horizon, the result serves as the right eye image of the 3D image pair. But this brief summary was by way of explaining why I have little experience with the “two simultaneous image” sort of 3D imagery and why you won’t (yet) be able to find “bizonal perspective” in a literature search.

Here is an example of the technique as applied to a 2D image I made In AZ some years ago.

Anyway, You are in the right place to get lotsa help with S3D photography. I hope you will find help from those far more experienced in traditional “stereo” photography than I am.

Now, I’m back to another read of your explanation of your problem.

Best regards

Dave