[Leica] TTL Flash, pros and cons

[Herbert & Lee Kanner <kanner@acm.org>]

I am interested in getting some opinions on TTL flash.  I am 
considering buying the Metz (Leica) unit.  But, is it worth the 
price?  I already have a little Vivitar 225 which has a guide number 
of 132 ft. for ISO 400 and automatic flash for that film of f 5.6 and 
f 11.

I don't know the guide number of the little Leica unit.  I can think 
of three advantages it could have: 1) Because it allows all f stops 
to be used, it makes fill flash practical despite the limitation on 
shutter speed; 2) by the same token, by shooting at f 2, one can have 
a quicker quenching of the flash, making it less obtrusive in candid 
situations (is this really noticeable?); and 3)   by making use of a 
wide open lens possible, it permits differential focusing.
- -- 
Herbert Kanner
kanner@acm.org
650-326-8204