There are currently several third party lenses for :43: but I get the feeling there is something missing. Something in the spirit of the Sigma 19mm/33mm primes, which combine above average performance and IQ with very modest prices. Sigma just introduced a 17-70mm zoom lens for DSLRs, a version of which would perhaps be quite welcome in a :43: version. There is also Tamron which announced they have :43: under development but nothing solid yet. What do you think?