Should I get this 50mm f/1.8 MK-I?

[vvizard]

I owned the 50mm f/1.4 USM previous, but sold it due to economical issues. Now a guy near where I live is selling a used 50mm f/1.8 MK-I, and if I recall correctly, the MK-I is the one with metal mount, isn't it? Should I buy it now, since I need a small lens with good aperture, or should I go with the 50mm f/1.4 USM again? In my current possition, I can afford a new f/1.4 without much worries, but is it worth the difference? Since I've never tried a non-USM lens, and don't know how much difference 1.8 and 1.4 is, I'm asking you for advice..

[skyphix]

The MK1 is with the metal mount. I paid 140 dollars US for a Mk1 and EOS650 (Film SLR) a few months ago. From what I've heard, the 1.4 is worth the difference over the Mk2 because of the USM alone, but I dont know about any build quality differences between the 1.4 the Mk1... Ive never held a Mk2 to know if the build quality differs from the Mk2 to the Mk1 other than the metal mount and the 1.4 is supposed to be considerably better than the Mk2.

[KevC]

I believe the optical quality between the MKI and MKII are the same. You're paying for the build quality, the metal mount, and the distance scale.

For me, that's not worth it.

I'd either stick with the 1.8 Mk2 (super cheap!) or move up to the 1.4, depending on how much you use that focal length. I'd get the 1.4 for the buttery smooth bokeh :)