At some unknown future date I hope to attempt to decode the protocol 
used by the top family of Minolta flashes which are used by the two 
Minolta digital SLRs (5D, 7D) and the preceding family of prosumer 
cameras (7, 7i, 7Hi, A1, A2, A200) plus the later Maxxum/Dynax film 
cameras.

 These flashes include the

    2500(D)
    3600(HS)D
    5600(HS)D

Same language is spoken by two macro ring flashes.
There are a few 3rd party flashes which also do this.

All share the common feature of being far far far more expensive than 
one would expect for their capabilities. Also, the top flashes get 
dearer with flash capacity rather than with features. Other non 
compliant flashes of similar overall capabilities cost far less.

While I think this project may have commercial worth, it would be a 
satisfying project in its own right if time was available. Publishing 
the spec would make one several powerful enemies and many many 
individually less powerful friends. Obviously some 3rd parties have 
done this and they now sell flashes using the information. There is a 
significant after market for such flashes and all the new Sony Alpha 
cameras can use them.

What I envisaged was an adaptor that talked the talk and allowed much 
simpler cheaper "thyristor" flashes to implement the core functions. 
While the 3600/5600 do a number of things that would take some effort 
to emulate, many users would be everlastingly grateful for an adaptor 
at a moderate price which simply allowed them to use a basic external 
flash on a 5D/7D/Alpha and get normal results. Users are currently 
held to ransom by this lack of capability.

If anyone is interested in the *possibility* of cooperating on such a 
project in future please advise. Whether it ever happens is to be 
seen.



        Russell 

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist