K5 multiple exposure modes
I'm just learning about this, but allow me to explain using Pg. 13 of "Photo Impressionism and the Subjective Image". This was written with film cameras in mind, but I think you'll see how it applies to how your K-5 can work.
There are two basic types of multiple exposure:
1) Repeated exposures of the same subject matter, with each exposure slightly out of register with all the others. This type tends to produce a highly impressionistic effect.
2) Repeated exposures that combine different subject matter. This type often results in an image that is highly non-represational or abstract. Since the subject matter varies from one exposure to the next, or from several exposures to several more, registration is rarely a consideration.
(Now on to exposure...)
If you have a camera that allows you to make multiple exposures on a single frame of film, you can achieve effective exposure in either of two ways. Let's assume that the film in your camera has a film speed of ISO 100.
1) You can rerate the film speed, increasing it by the number of images you want to make. For example, if you want to make 8 or 9 images on a single frame you will change the film speed setting to ISO 800. (since there is no 900 setting on your camera, for nine exposures you should also set the camera at 800. This will have minimal effect on the result).
[note: this is a film technique only. It will not work on a DSLR which would just recalibrate exposure for your new ISO]
2) Or, you can take the square root of 9, which is three, and use the function button to dial "minus three", underexposing the same amount as when you increase the film speed. This is the easier method with my cameras, and consequently the one I use. For 16 images on a single frame I dial "minus four" but sometimes I make two or three extra images if I think that reciprocity failure - the tendency of films to underexpose a little at very long or very fast shutter speeds - may be a problem.
You'll notice that 2nd option will work on the K-5. Keep in mind that when he says 8 exposures, he is not necessarily talking about 8 different subject matters. You can choose to have in registration as much as you want. The book shows one gorgeous example of a field of flowers where (for a 9 exposure multiple) he placed the camera on a tripod, and without moving it, made 4 exposures. Then he loosened the tripod head and made 5 more exposures (of the same subject) while rotating the camera slightly. The effect is as if the wind came up and moved things during a long exposure.