Specific Video Equipment
Some diopters for capturing moving images are so specific in their use that you may never touch them. For most people getting general images is what is most important. They do not look into gathering the most specific types of shots that would require extensive film and video equipment.
For those videographers and filmmakers that absolutely must execute the specifics of their vision then they need to find video equipment that is going to do exactly what they need. The split field diopter is exactly this type of video equipment and is something that remains very specific in purpose and use.
Using the Split Field Diopter
The main purpose of a split field diopter is to capture a far away image and a close up image in the same frame. In the split field diopter you will usually find a pairing of the standard plus diopter and strait glass. Have the image focuses on a far image and half on a close up one. The glass will then be used for the far away object and the plus diopter will go for the close up one, just as a plus diopter would do in any situation. The barrier between the glass and plus diopter will be relatively out of focus.
This area has to have no object of importance as it will be impossible to make it look correct. It is best if there is essentially a blank area between the two object on the X axis. You frame the image in a long or high fashion where a close image rest on one side and a far one balances on the other.
For example, if you wanted a close up shot of a bird in the far right side of the frame and then a nearby house that is far away in the left you may use the split field diopter, as long as in between them is nothing of importance to the viewer. Because of these kinds of specifics, you have to have the camera completely steady and you have to take time composing the shot. Do not try to use the split field diopter on moving objects. Have a balanced tripod, and make sure that any other video equipment you have is up to par.