Often we see in comparisons just how similar lenses are, but also we find out that subtle differences can have a lot of impact. So much of it is subjective, of course. I find the differences between the FD and the Rokinon to be subtle, but significant. The EF is sharp enough, but that\'s about all the positive I can say about it. Regarding bokeh, it is not even in the same class as the other two (this is where the subjectivity creeps in).
Ulrik,
If I have time, I\'ll test the bokeh at smaller apertures. Since you love the Sigmalux, I think this one is a good bet.
Empire,
Don\'t draw too many conclusions about CA simply from that cyan edge on the OOF highlights, as it isn\'t a good indicator of overall CA performance of these two lenses (as far as I can tell). Here is a separate test I did when I first got the Rokinon, which is a much better representation of the defocus CA.
Note: the FD is focused somewhere between 140mm and 150mm (on the scale) which results in both being a bit dull, whereas the Rokinon is pretty much bang on 140mm (so it is not so easy to conclude about resolution here, if you are tempted to do so )
Here, the FD has superior CA control (as I expected) but the Rokinon isn\'t that much worse. See how the reddish and greenish hues show up more along the right hand scale on the Rokinon shot. Also, the FD\'s CA seems to be more \"blended\" rather than super defined. This likely has to do with the relative lack of DoF (as both lenses are wide open). I think it is interesting that the defocus CA on the actual scales of the ruler is really well controlled in both lenses, but that the super bright, left edge of the ruler coaxes out the worse each lens has to offer. The full sun was reflecting directly off that left edge.
I think CA testing is one of the most difficult to to keep consistant, so I do not consider these results to be conclusive at all. \"Purple fringing\" can pop up out of the blue sometimes, so I need to use this lens a lot more in \"real world\" situations.
On a side note, one might notice how the Rokinon (Samyang) seemed to have better CA control than the EF 85/1.2 L II in that other test above, but worse CA control compared to the the FD 85/1.2 SSC Asph here, which says a lot about all three lenses, IMO.
