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Stereo photography with the Pentax Optio - Peter walks you through stereo photography with the new Pentax Optio RS.
Stereo photography has been around since the Victorian times, but now Pentax have brought the feature into the digital age on their Optio RS cameras, but anyone can have a go. All will be revealed.
Words and pictures Peter Bargh
Theres an unusual feature lurking on the latest Pentax Optio RS digital cameras a 3D mode that delivers stereo pictures. It may be a unique feature on a digital camera, but those who know a bit about the history of Pentax will no doubt remember the Stereo Adaptor and Viewer that have been sold for years for use on Pentax SLR cameras.
The Pentax Stereo Adaptor and true stereo cameras, such as the new Vivitar 3D cam, take two pictures at the same time making 3D photograph almost effortless.
The new digital Optios record one picture on one half of the file and then you take a second picture by moving the camera slightly left or right to recreate the stereo lens effect. The camera displays the first on the left and the composition of the new one appears on the right. A grid is provided so that you can ensure perfect alignment.
The skill is knowing how far to move to ensure a good result. The instruction book suggests you divide the camera to subject distance to determine the distance to move. So if your subject was one meter away you would move the camera 2.5cm. Get it right and the subject will leap out at you. Make a mistake and the view youll see will be like the one you have when looking through damaged binoculars.
A tripod will come in handy to ensure each picture is at the same height. All you have to do then is move it left or right to get the second shot. If you can get hold of a macro arm you could use this sideways to get very precise alignment. A Benbo tripod will also offer this adjustment if you use the centre column set horizontally.
Special camera not essential
If youd like to have a go at 3D photography and are feeling annoyed that you don't have one of the new Pentax Optio digital cameras, dont despair. While the 3D mode makes life easy, equally good results can be achieved with a little extra effort from your camera too.
The same principle applies. Take two pictures from slightly different position and then place the two pictures side by side. This can be done with a film based camera by mounting the two photos on card, but it helps if you can scan in the photos and use an image-editing program to arrange and resize the photos so they can be viewed using a stereo viewer.
The digital pair
Open a pair of photos in your image-editing program. Then select one and double the width of the canvas. Most editing programs have this option and show a nine square grid of the canvas area. If you increase the size without changing the grid the canvas will expand outwards from the middle.
In our case we want to expand out only to the right so we click in the left hand centre square of the grid. Enter a value that's twice what's already indicated for the width and leave the height. Click OK. This will produce a larger file with your original picture on the left and a space on the right for the second one.
Now click on the second picture and copy it (Ctrl+C). Go back to the expanded picture and paste (Ctrl+V) the second photo will appear in the middle. Click on it with the move tool and drag it to the right so it fills the blank area of the canvas. Make sure that the new image butts fully up to the original and that the subject is at the same height. If not move the second image up or down until everything aligns horizontally.
When you are happy flatten the image. The next stage is to make the photograph the right size so it can be viewed. Most stereo viewers are designed to view either 5in or 6in wide prints. Go to the image resize option making sure Constrain proportions and Resample are ticked and change the width to 5in or 6 and set the resolution to 240ppi. Then print out using your inkjet printer. If you choose 5in, you can place three shots on a sheet of A4 paper to save costs. Use the extend canvas technique explained above.
You need a 3D viewer, unless you want to use the novel way of viewing the print cross eyed. It works! Hold the print at arms length, cross your eyes and focus on the middle one of the three images that appear. This will have the 3D depth. Its a bit of a strain though so a viewer would be better. The one here costs 20 and is made by Loreo. The Vivitar 3D Cam comes with a viewer in the kit.
Subject matter counts
This shot worked really well because the three sculptures were each at different distances and they leap out when viewed with the Loreo viewer.