[bronger]

I own this lens: http://www.opticallimits.com/sony_nex/72...ex?start=1

 

At 210mm and f/6.3, it has a resolution of 2536 lw/ph.

 

Now, have a look at this one: http://www.opticallimits.com/nikon--nikk...os?start=1

 

At 200mm and f/5.6, it has a resolution of 2670 lw/ph.

 

My question is whether one can compare these figures if the crop factor of the sensors used is the same.  In particular, does one have to take the sensor resolution into account?

 

[dave9t5]

The FAQ and Lens Review section states that the absolute numbers cannot be compared across systems.

 

However, I believe you can make a relative comparison by the height of the bars within the 5 sectors that say "Excellent/VeryGood/...".

 

[JJ_SO]

The Sigma was adapted to a Nikon DX (D7000, 16 MP, AA filter) while the NEX7 has 50% more pixels and more modern sensor. It's not directly comparable, I'd say.

 

The Sigma delivers a far better resolution in the borders at f/5.6 (2155 to 1581) - never look only at the center resolution, no lens should be weak in the center. A difference of only 100 lw/ph is hardly noticeable. Nearly 600 lw/ph are a big difference.

 

And, of course, 2 ⅓ stops faster DO make a difference, too.

[Brightcolours]

Like Dave points out, look at the bar heights within the graph lines, not the numbers. That gives you more or less a good idea of how lenses compare. The Sigma lens outperforms that Sony lens by quite a margin.