[Brightcolours]

[quote name='ThomasD' timestamp='1298023507' post='6212']

It is in terms of light gathering of course. But comparing a 35/1.8 on DX to a 50/1.4 on FF is a huge difference in terms of DoF.

[/quote]



Not just that. f1.8 on FF is faster than on APS-C. Equivalent f-value for APS-C is 1.8 / 1.5 = 1.2.

To match the full frame f1.4, you will need on APS-C: f1.4/1.5 = f0.9333(!). Or to match the f1.8 of APS-C on FF you need: f1.8 x 1.5 = f2.7.

So, in short, equivalent are:

50mm f2.8 FF | 35mm f1.8 APS-C

50mm f1.4 FF | 35mm f0.9 APS-C

That is the REAL "in terms of light gathering". A bit bigger than stated, don't you agree (more than 1 stop)?



[quote name='ThomasD' timestamp='1298023507' post='6212']

There is no Nikon 24/1.8, or are you talking about the Sigma? I don't think I will be buying any Sigma lens again. The Nikon 24/1.4G, on the other hand is nearly as big and pricey as the 35/1.4G. At this focal length DX has no advantage over FX.

[/quote]

Correct. Other than that the 24mm designs both from Nikon and from Canon seem to be a bit better than the 35mm designs, especially regarding bokeh. But the 24mm ones are again more expensive too.

The Canon 35mm f2 is a funny small lens, but can deliver surprisingly good results. Something to keep in mind maybe?