Originally posted by Uluru I think many of the DA lenses are misunderstood by people. They are optimised optically for digital photography, and Pentax did release APS-C only DSLRs so far. However, many of the DA lenses do cover the 35mm image frame quite well, with little to zero vignetting.
As I said in other forum, FF or thereabouts is a great way to further utilise current DA lenses, and it gets even better with a 1.2x or 1.3x image crop sensor (like top of the line Canons).
A new body won't render DA lenses unusable, just the opposite.
I'd like to know which lenses will work because it's my understanding that when used on FF sensors
a) all zoom lenses in their top of the line DA* will be usable due to vignetting
b) all wide zoom lenses in their DA line will be unusable due to vignetting
c) all wide primes will be unusable due to vignetting
If this is the case, that would leave about 5 DA/DA* lenses that are fully compatible plus the 7 FF lenses, for a grand total of about 12. Take into account the considerable number of either downright duplicate lenses or similar models between both lines and you end up with less than 8-9 unique lenses to chose from.
If I'm going to switch to a FF system and my workhorse lenses become useless, then either I stick to what I have until it dies, or start over at great expense.
The smart thing to do before introducing a FF system is to load up the lens lineup with full frame compatible models, particularly replacements of the current DA* zooms, the wide angle zooms, and wide angle primes.