I haven't checked my local store recently, but here in the US, Ace Hardware lists a Duracell 28L and a Duracell 28A online. The A (Alkaline) version highlights "Medical" but admits to photo uses also. It shows as $6.49. The 28L is a lithium version that is $10-something. Last year I bought a PX28A in my local Ace for $5.79 as I recall. The A versions seem to be fine in my Canon A-1 and Bronica SQ-A -- in fact Bronica recommended against the lithiums for the SQ-A as being too variable in specs.