I did not choose this target at random! This is to my knowledge the only objective that covers the range 8 to 16, opening 4.5 is not really a problem with modern housings. I use it on a EOS70D landscape and it's great! Best of all, the sharpness is extraordinary and chromatic abberation is invisible after treatment in DXO. Only downside (for which I did not put 5 *) impossible to use filters on this goal ....