I have the EF50 / 1.4 now on my EOS40D in use for nearly two years - and it's become the most widely used lens from my collection. Usage is - obvious because of the 80mm-Entsprechnung to APS-C - mostly portrait, especially in difficult lighting conditions.
Specifications are probably not as interesting as anywhere nachlesbar. Only I find the weight is worth a mention: with 190g very light and by the short length a great lens to have it always with you.
The optical performance even at full aperture perfectly acceptable, though not - for PixelPeeper - super sharp. In Aperture 1.4, it is quite a bit soft. I use it therefore usually stopped down to F2 and only if the exposure time actually due, at F1.4-1.6. The optimum is rapidly reached at about F3.5-F4 and only for stays of F-numbers at the 13 back (easy!) From.
The performance, however. Also of the resolution of the sensor depends or of its Pixel Pitch The "softness" in OB will make more noticeable than on a 20D, 30D or 5D (I) to a 60D or 7D.
My "Pro" s:
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++ Image quality
+++ Bokeh
++ Lightweight
++ Workmanship
My "counterpoint" s:
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- Zoom ring could be a bit softer and more precise run at MF
- Scattered light sensitive, Lens Hood, therefore, duty
My Conclusion:
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Much lens for a good price. Even if the basic structure of this lens is virtually unchanged since FD-hours (if you take the Micro USM instead micromotor apart), is a lens whose focal length should be in every collection.
Alternatives? Sure, there are some. For example. the EF50 / 1.2L Canon, but the beats with more than 1,200 impact. Despite slightly better color and good OB-performance certainly not affordable for everyone. Inexpensive is because the EF50 / 1.8 Canon to have a rule for under 100 and thus extremely low, if you can live at the workmanship with micromotor and minor degradation. SIGMA 50 / 1.4 - to which I do not say anything ... my experience anyway did not lead to a purchase. At best fixed focal length to 35mm are to APS-C nor alternatives if you just want to get some more on the image - here the 35/2 for the small and the 35 / 1.4L for thicker wallet.
My recommendation to EF50 / 1.4 USM: Buy if you want to do portraits in low light. Buy even if you - like me - will change someday APS-C to KB - then the 50 is more versatile for 'real' 50s and the applications.
