Originally posted by Pitzik Sono indeciso. Per la mia k10D e K-5 meglio il vecchio 50mm f1,4 FA o il nuovo SDM 55mm f1,4 ? Quale ha il miglior IQ ? Grazie
Both seems to have similar IQ, even in corner when used on cropped bodies (all Pentax DSLR).
Here is a comparison, though as per the link, 55m is slightly better in corners.
Pentax DA55 and FA50 - a comparison
If you are okay with MF, you may want to consider Nokton 58mm too which is considered sharper of the lot by some users - I do not have any personal experience though.