Sure thing Will
Simply put, the "mini35" works by capturing the projected 35mm image onto a piece of ground glass (glass that has been made opaque by grinding). This image on the ground glass is then focused on by your video camera and recorded. This retains all the properties of a 35mm image. There are of course downsides to this process: you loose some light due to the intermediate glass and, depending on the type of adapter made (which I will get to) you can sometimes pick up grain from the glass itself.
There are currently three different designs for mini35 systems.
- Static Adapter
- Oscillating Adapter
- Spinning Adapter
Each has it's own ups and downs which I will discuss.
Spinning Adapter: Works by spinning a ground CD (cheap ground glass). This makes the grain (imperfections in the glass) invisible when in motion. The downside is that it takes power, can cause audible noise, often very large, and can cause some odd "vortex" type effects due to the fact that the outside of the CD is spinning faster than the center.
Static Adapter: The simplest type. The only problem with this type of adapter is that it requires very very fine ground glass. You will see grain otherwise. No one has managed to create a grainless version yet though there is one possibility which I will discuss later.
Oscillating Adater: This is what the "real" mini35 uses. It oscillates the ground glass so that you cannot see the grain. You also don't get the vortex effect because the movement isn't predictable. Problems: takes power and can cause noise.
There is, however, an adapter version that is being developed (has been to some degree already) which is static and which has NO GRAIN. This would be the best possible solution. It relies on a wax intermediate rather than a ground glass. The trouble is making a good wax surface to use.
I'm currently building one of these wax adapters which I plan on using with my DVX. I can post results and schematics when I finish if you would like. I may even make a few to sell if it works well enough.
Static Adapter Test:
http://ideaspora.net/test_3.mov
Problems: grain and bad light transmission with some vignetting.
Spinning Frame Grab
http://www.dvdof.com/Aldu5.jpeg
Problems: some grain and some mediocre light transmission
The adapter I am working on should solve all these problems.