Super 8mm camera technology greatly standardized what was previously a great problem in regular 8mm technology - namely registration of the image on the film. Regular 8mm cameras (and projectors) varied greatly in how they pulled (or pushed) the film into position and also on how they kept the film against the aperture hole. Super 8mm standardized all this by putting the pressure plate in the fim cartridge and leaving the film plane on the camera relatively simple in design. In fact, all Super 8mm cameras have the exact same pressure plate/film gate/claw mechanism. Open them up and they will all have the very same plate, aperture hole, and two screws/bolts/rivets holding it all together. Simplicity at its finest.
In super 8mm technology, the film cartridge provides the pressure plate for
the film in all cameras using Kodak's 50-foot cartridge design. The Fuji single
8mm format is slightly different, being superior in registration and having
the pressure plate built directly into the camera. All Super 8mm film (essentially)
is in 50 foot "Kodapak" cartridges (to use the original term coined by Kodak), with the minor exception of double Super 8mm film.
All that remained to be innovated by the various manufaturers (in terms of
the Kodak Super 8mm cartridge cameras) were four major areas: the claw rate;
the shutter; the optics, and the light metering system.
To cover the last item first, the light meters in Super 8mm cameras came in three
varieties: TTL (through-the-lens), separate metering from the lens (non-TTL),
and separate but still TTL (Beaulieu style).
The vast majority of cameras came equiped with the TTL, behind-the-lens metering
system. This is an accepted and perfectly good method of determining the correct
exposure of any given scene. The only drawback is that the portion of light
hitting the meter does not reach the film. The lens, then, becomes slightly
inefficient since it is not passing all of the light to the film. Also, the
lens can be fooled at extreme telephoto settings when recording bright or dark
objects if your scene requires exposure consistency. Of course, the zoom lens
also helps to act as a spot metering sytem!
The totally separate meter is usally found on extra low light ("XL" = "Extra Light") cameras where 100 percent of the light gathering ability of the lens is used for exposure of the film. The Kodak camera used in the background of this webpage is a perfect example. Similary, the Eumig Nautica employs this light metering system. The negative aspect here is that a change in the focal length does not usually cause any change in exposure - the light meter is still reading the overall scene. So be careful with this style of meter.
The last style is found (to my knowledge) only on the Beaulieu camera models. These cameras have the unique ability to pass 100 percent of all gathered light to the film while still offering complete though-the-lens, TTL, metering. It does this by using a guillotine shutter that has a mirror surfaced. The mirror reflects the lens subject to the viewfinder/light meter. Then, when it moves out of the way, it allows all light to pass to the film. It does this at any speed from 2-54 (or more) frames per second! The drawback is that the image will flicker while you are shooting and the light meter may read a fraction more open during this time. Worse, the meter may bounce to the rythmn of the flickering light. So, it is a good idea to meter the scene with the camera first, lock the aperture with the manual setting, then run the camera.
As you can see, all three styles offer advantages and disadvantages.
Now, the claw. Here you will find there is differing circuitry controlling the rate at which the claw moves. Pretty basic, but there are variations. Early models, like some of those from Sankyo and Kodak, had entirely gear driven mechanisms with very little in the way of electronics. Later models and makes (i.e. Canon 1014 Electronics) started using circuit boards to great success. Made to ensure exact speeds of operation, oftentimes offering "sync" control from a regulator like a crystal unit. The key here was to ensure accurate timing between exposures. My preference is the later, electronically-driven shutters.
Next, the shutter. The word shutter in Super 8mm terms is a rather fancy word for a piece of circular plastic cut out to the specified degrees in fixed shutter cameras (usually 150 - 230). It is designed to rotate on a gear and thereby let the light through at specific intervals. The shutter is tied to the same mechanism controlling the claw rate. Generally, it looks like a pie with a big portion missing (the amount missing is how fast or big the shutter degree measurement is). As mentioned in other areas, the smaller shutter (i.e. 150 degrees) provides sharper images but is not good in low light situations. The big shutters (ie. 220 degrees) offer excellent light gathering capabilities but tend to give softer images on fast moving subjects. In my experience, I would recommend getting the biggest shutter you can afford since more often than not you will be shooting Kodachrome 40 film in poor light. Some cameras like the last Canon models (814, 1014) and Beaulieu offer variable shutters. On the Beaulieu, the shutter can be varied from 150 degrees to complete closure ("0" degrees), thereby offering perfect fades without a chenge in depth of field like an aperture fade would give.
Finally, the optics is where some variations can really start to pay off. Coatings and precision of manufacture are the determining players. Of course, makes like Nikon, Canon, Nizo, (Schneider), Bauer (Schneider), Leicina (Leitz) offer incredible sharpness, color , and contrast. But again, if the shutter is relatively narrow, you may get suprisingly sharp images from even the basic Kodak models! Some cameras to avoid include Vivitar (Kobena), Argus, Keystone, older GAF cameras, and Agfa. Of course, exceptions to the rules exist. Also some cheaper cameras will be necessary for specific situations that pose a clear and present danger to your camera!
Lenses are compared similarly as they are in still format camera terms so without going in to depth here, let's just say that often you will be able to tell the quality of a lens by simply looking at the condition of the coatings and claritiy of the optics. I have found the Eumig Nautica and Bauer XL305 to offer outstanding sharpness and contrast. Same too with the Leicina. In fact, you can see this simply when looking through the viewfinder. Then again, the Kodak M2 and M12 have given me excellent results on bright sunny days. So too has my old Sankyo XL255 Macro on close subjects such as flowers and small critters. So whether you are using the wonderful Schneider or Angenieux lens or simply the plastic lens fitted on your Kodak "Our Gang" XL camera, you may be pleasantly surprised at the results.
Before I leave this subject completely, try to find a camera that does not require separate "button" batteries for the light meter. Many times the batteries are difficult to obtain or require some sort of compensation in exposure. For instance, the PX-14 (2.7 volts) battery is nearly impossible to obtain. The PX-13 (1.35 volts) is still around in some areas but in a non-mercury version. The "625" (1.5 volts) can often, though not always, be used interchangeably with the PX-13. Many times, I have found a perfectly working camera with a blown light meter. There must be some relation to the fact it uses separate batteries? So, stick with cameras that require only "AA's" and you will be better off for it.
Now that you have the discovered some basics lessons, you can use this knowledge to be more proficient in you next Super 8mm camera purchase.
One last point. What I have come to find is that the price paid for a camera (or any consumer good, really) seems, for many people, to add some subjective "I feel good" factor to the purchase. Higher prices usually make someone feel better about their purchase vis-a-vis a lesser price for the same product. Be careful with this tendency. Be cheap and spend your money on film and processing! I found some of my best cameras for under $20!