These lenses came from people who had a home in Curaçao besides their Dutch home; the equipment probably was bought in Curaçao, but the seller couldn’t confirm that. Anyway, the total set was imported in America, as both lenses and the accompanying SR-T 200 camera bore American type designations; I don’t think Celtic lenses were sold in Europe, except maybe in the UK.
This was the budget version of the MC W.Rokkor-X version with the usual cosmetic differences: a sunken instead of raised red dot and a finely ribbed focus ring instead of the Rokkor-X’s waffle-type. As far as I know the most important difference between Celtic and Rokkor(-X) lenses may be their coatings: this lens as well as a MC Celtic Macro 3.5/50mm have a golden color rendition instead of the much more neutral color balance of the corresponding Rokkor lenses. It’s well known that Minolta went to great lengths to provide equal and accurate color balance and contrast between the lenses in the Rokkor line-up. The more expensive coatings to provide that are most probably replaced by simpler and cheaper ones for the Celtic equivalents. Apart from the cosmetic differences mentioned this lens looks very similar to the Rokkor counterpart in mechanics and optics. Sharpness and contrast are very similar too.
The American equivalent of the MC Rokkor-PF 50mm 1:2 came as an unexpected and welcomed bonus. It’s one of the very few MC lenses with a plastic aperture ring; its image quality is average, even stopped down to f/8 the corners aren’t perfectly sharp.