Here it is, with the lens wide open (no aperture plates installed). At a guess, I reckon this makes it an f/2.7 or f/2.8 lens.
Here it is at f/8
And here it is at f/16; I had to boost the ISO to 400 here because the AF280T simply didn't have the power to do the job at that aperture and 200 ISO.
Shots with all the plates sequentially installed are on my Flickr; the f/11 shot is notably darker because the 280T was already struggling, but by the time I noticed this (I'd already reshot the markedly underexposed f/16 shot), I'd packed the lens away and was too tired to dig it out and reshoot.