My cunning plan that cannot possibly fail is get one good shot from the Tamy 70-300 that I can sell, then use the income to go for the Pentax.
I just love shooting in high contrast situations...
To add to my LBA misery, after I organised the Tamy, I was offered a loan of a friends SMC Pentax-F 100-300mm F4.5-5.6. I shot a couple of test shots. Not bad at all. I can keep using at long as I want.
