Here is a complete guide to major variations of the "true" Exaktas, i.e., ones made by Ihagee in Dresden. In particular, the RTL 1000 is not shown here, as it is an entirely different camera, constructionally having nothing common with the others here.

There were eight "true" Exakta models altogether, with minor variations. These are shown by number in the second row, as per my star notation.

In addition to the major camera specifications the table also shows some of the most visible external appearance features (front plate, logo).

A more detailed (although less readable) listing of all models and their variations can be found by clicking here, while annotated pictures of all major models are shown in my Exakta Gallery.

The table spans the period of 34 years (1936-1970). Interestingly enough, we can see that none of the features listed here changed more than twice in that time. That's a remarkable stability; some explain it with the technical excellence of the original design (and the intentional persistence of the system), while others — by stubbornness and unwillingness of Ihagee to innovate. I think it was the mix of both.

To make the table more interesting, I have marked all features of the initial release (Kine Exakta) in green, and all features of the final one (VX 1000) in yellow. (The VX 500 is a special case, as it was a cheaper, simplified version of the latter.)

Other distinguishing features as marked in the table:

1. The first 1936 version of Kine Exakta had a round magnifier, while all others — rectangular. It was protected with a metal cover in Exakta II.
2. Only the IIb did not have a finder release switch (placed on the front plate above the lens).
3. The shortest of "long" times was 1/10s in the Kine Exakta Version 1, changed to 1/5s in Version 5, and then to 1/8s in the IIb.
4. Kine Exakta Version 4/5 and Exakta II Version 1 had a third contact hole.
5. The models from IIa to VX 1000 had three concentric sockets; others (including the VX 500) — two. This is a minor difference; the third socket was intended for fast-burning flashbulbs.
6. The front plate design was slightly changed in the VX 1000 and VX 500.
7. Actually, a rare version (A&R 3.2) of Exakta Varex/V has a detachable back, but very few of these exist. I yet have to see one.

When trying to distinguish between "early" and "mature" (whatever that means) Exaktas, some collectors and users draw a line as early as at the Varex/V model (interchangeable finders), while others — only at the VX 1000 (returning mirror). This is largely a matter of agreement; I like to assume that the first "mature" model is the VX A&R Version 4 (standard flash sockets). You may have a look at the table and draw your own line anywhere you like.