Monday, May 9, 2011

Relief Carvings

I just added some images of relief carvings that I have hanging around in my home. Go to the Relief Carvings page to see more like this.

Saturday, May 7, 2011

Taking 3D Stereo Pairs

How to Take
for 3D viewing

            A set of “stereo pair pictures” consists of two NEARLY identical photos. One will represent the RIGHT eye view and the other will represent the LEFT eye view. Because these two photos are not taken simultaneously the subject matter should be stationary. Landscapes and still life subjects work best.

            When taking the two photos there are only a few things to take into consideration. There are basically 2 types of viewing techniques. They are convergent and divergent. Convergent is also know as cross eye viewing and divergent is where you will need to focus your eyes out beyond the photos.

            1. First consideration is how far are you from the nearest object in the field of view. This distance will dictate the distance between the vantage points for taking the two photos. For instance; if the nearest object is within 10 feet then the distance between the two vantage points should only be about 3-1/4 inches. (The distance between your eyes) The further away the nearest object is, the further you can move left or right for the second photo. I have actually moved up to 25 feet for a distant scenery view. (This is called a hyper stereo pair).

            2. Taking the first photo: Frame the picture the way that you want it. For most of my first photos I stand square to the subject. Then I shift my weight to my right foot. I then take the first photo. It will represent the right eye view.

When you take the first photo take special note of certain elements in the camera frame.

                        A. The left and right edges of the image.
                        B. The top and bottom image lines
                             relative to the line of the camera frame.
                        C. The very center object.

            3.Taking the second photo: Move RIGHT or LEFT an amount you think is right for the distance to the subject. For most of my photos that means shifting my weight from my right foot to my left foot.

Before taking the second photo be sure to re-establish the first image as identical as possible. Check the left and right boarders as well as the top and bottom image lines and the very center object. The most important of these elements are the center object and the top or bottom image lines relative to the camera frame. When you are satisfied with the framing go ahead and take the second picture. Now you have a stereo pair.

Getting the pictures ready for viewing

The first step is to review the two photos and determine which eye each photo represents. Here is how you do that. Examine the photo to locate two elements close together, one that is in the foreground and one that is in the background. In the example below those elements are the hump on the back of the bison and the tree. If the background element is to the right of the foreground element then the gap between the two will be larger for the photo that represents the right eye view. If the background element is to the left of the foreground element then the gap between the two will be larger for the photo that represents the left eye view.
The second step is to decide if the presentation is to be for convergent or divergent viewing. The sample here is presented for convergent viewing. (see the previous posting for how to view 3D stereo pairs).

 Right Eye View                                   Left Eye View

An interest in taking 3D Stereo Pairs will
increase your environmental awareness.