Yes, you can still view stereo photographs without a stereoscope, although the experience may be different.
Here are two methods:
- The parallel view
You need to relax your eyes, as if watching something far away. Then hold a stereo image pair in front of your eyes. Each of the images need to be seen with one eye. They will then merge into 3D.
Especially for short-sighted persons will like this technique when taking off their glasses.
- The cross eye view
This basically means squinting. The two pictures of your stereo pair need to be switched. You then need to focus with your right eye onto the image on the left and vice versa.
Please note that OCZKO STEREO publishes stereo pairs only in parallel mode.
While a stereoscope provides the most comfortable and immersive way to view stereo photographs, these alternative methods can still offer a glimpse into the fascinating world of stereoscopy.
Have a look at this Tutorial.
Here is another one.