OK FP, - I'll try and keep it short and sweet unless asked to expand,
Firstly a good lens is one where you can't tell, apart from DoF, whether it's wide open or f8 and you like the sharpness, (or softness), and you like the "bokeh" (OOF areas).
About the nearest you'll get to that, in the affordable sort, is a second-hand current spec 90f2.8 Elmarit. - sharp and contrasty all over, - the 135 is even better.
Now to the 75f1.4,
Wide open - it's hard to focus !, - twice as hard as a noctilux wide open, and four times as hard as a 50f2 wide open ! - the DoF at 10 feet is razor thin.
Wide open, if you imagine a 10x8 print, and put coffee mugs in the corners, those areas are at least a stop under exposed, due to vignetting. - a mathematically unavoidable phenomenon.
The middle is sharp and contrasty, but smooth and creamy OOF areas.
At F2 and below, you can't tell it's not a Summicron, except that objects in the pic are 50% bigger.
It's big and heavy, bigger and heavier than a noctilux, but beautifully balanced, - you can use it all day if you've had your porridge, (back alley joe are you listening)
It's incredibly fantastic because it's f1.4 - 400asa film is not good enough for this lens, - but 100asa in low light is what it's made for.
BTW, a noctilux is a stop faster but it'll vignette nearly 3 stops in the corners, and you'll have to get a lot closer, (DoF problems again)
The 75f1.4 is a whole stop faster than the 75f2, which can be mission critical on 100asa in low light.
It's nearly 2 stops faster than the VC, so you'd probably have to use 1600asa in low light with that one !
Hmmm...... I'll stop there for now........ Quick edit on last sentence
Regards John C.
