When buying telephoto lens adapters, BEWARE that certain lenses labelled as 2x may be only around 1.4x or 1.5x , and lenses labelled as 3x may in fact be only around 1.7x or 1.8x . In order to tell...
rule 1; ALL MACRO LENSES ARE GOOD there are no bad true (=NOT the xx-yyy zoom lenses with macro function!!)macro lenses, whether nikon/sigma/... with the exception of some far away russian brands, all are...
When purchasing old and vintage cameras, one should try to avoid getting negative feedback by discussing the full story with the other party, even if it takes more than a dozen emails to rouse their interest...