[Brightcolours]

 

  Oh and Klaus/BC/Airydiscus.......how about a "simple for idiots" explanation on interpreting resolution charts...... please?

Uhmm... Simple (as far as I understand it then):

 



You see a grid, horizontally going from 0 to ~21..5 mm.

That represents the 135 format film/sensor, from center (0) to corner:

film = 36x24mm. Diagonal is 36^2 + 24^2 = 1872. square root from 1872 = ~43mm. Half the diagonal is then ~ 21.5mm.

 

Vertical represents the performance. 1 is when separation between black and white lines used to measure the lens is perfect, 0 represents no separation at all, just an even grey mess.

 

10 lines per mm (line pairs (b + w) per mm) is used to measure contrast, 30 lines per mm to measure sharpness, basically.

The solid lines are "Radial" or "sagittal" lines, they go parallel with the radius. The dotted lines are "Meridian" or "tangential" lines, they go at right angles to the radius.

 

We can see that this lens is pretty sharp, especially if this is from measuring wide open. We also can see that the lens is pretty contrasty.

 

When the sagittal and meridian measurement lines are close together, that shows pretty good performance with certain aberrations/distortions like astigmatism, and also shows the lens probably having smooth bokeh.

In this case, the lines are pretty close together, so we can expect pretty good bokeh (which the sample images concur).

 

We also can see that the lens performs better at the center than at the corners, but when we compare this MTF chart with those of other lenses, we can also conclude that the corner performance is pretty good for this lens.