Quote Originally Posted by Christopher Walrath View Post

I differ in opinion to your assessment of medium format glass at wider apertures. As you say, and I DO agree, without side by side testing it may never be known for certain the varying degrees of effectiveness of each tool in varying mediums. However, MF glass, by and large, performs great at wider apertures, IMO, or else they would not offer MF lenses with apertures wider than an arbitrary f/8.
At the risk of waffling on perhaps I should clarify I do not criticise medium format lenses wide open, I actually have no reference point as most medium format I have seen has been said to be f8, 11 etc rather than f2.8,4.0. So my experience of seeing medium format is of being shot with smaller apertures. Knowing my need/liking of shooting wide open I am intrigued with the capability of medium format wide open compared to 35mm wide open, which is where my lack of reference ponts hinders my assesment of potential results.

Btw, having shot with lenses such as the ef200/1.8L, fd&ef300/2.8L, ef 600/4.0 and seen the results from stellar lenses such as the nikon 300/2.0 I have a reference point for 35mm capabilities though would have loved to have seen the zeiss 1000/5.6 used in anger! If vivitar produced their series 1 90 macro in an ef mount I would be near the front of the queue.

Thanks for reading the post, apologies for not being a more concise writer - more of a verbal ambler really!