I've always thought that shutters were composed of two vertical curtains that moved along the sensor in order to expose it (at least for most DSLRs). Recently I've bought a Pentax K1000 that surprisingly its curtains move horizontally instead in a vertical motion.
So, this raised a couple of questions:
- What's the difference between those systems?
- Is there any advantage in the vertical system over the horizontal system?
- How does this affect very high speed photography?
- Does a DSLR with a horizontal shutter exist?