Before leaving for Indonesia tomorrow I was able to do a quick comparison between my new addition WACP-C and adapted 8-15 the photos of which I made back in spring. Disclaimer is that WACP samples were done with the strobe at ISO100 while for 8-15 I was using video light at higher ISO and so the results might not 100% comparable. Will reshoot when I have time.

First the costs and weights of both systems (8-15 quoted at used price level):

Both systems are kind of neutral-ish buoyant in this configuration:

The following screenshots have this system: first Fit view followed by 300% comp view with rectangle at left upper corner showing the part of the frame compared.

As I stated earlier I picked up samples which showed good focus for 8-15 as weaker light and also shutter speed without flash sometimes produced unfocused images. But these I think were sharp in the center and so let's get on with these.

8-15 TC2x in 140mm dome 55mm+35.5mm N100/120 vs WACP-C both F11:

... and 8-15 TC2x 55+35.5 in 180mm dome vs. WACP-C 28mm:

And finally 8-15 TC2x 55+35.5 in 140mm at 30mm vs WACP-C at 60mm

I am very happy with performance of WACP-C especially at 60mm as this is what I would be using for smaller subjects and crop heavily on 50Mpix image.

I will leave conclusions to yourselves :-). For me I realized that 180 degrees view is not as important as the DOF and native AF lens performance which doesn't mean I am going to sell 8-15 combo - yet. Cheers :-)

I think not exactly apples to apples comparison, this tests out the sharpness but does not consider the barrel distortion which tends to pull the subject forward in the frame in comparison to the edges. This effect becomes increasingly less obvious as you zoom in. @Alex_Mustard has chimed in when I have been comparing fields of view between fisheyes and other lenses with this observation on a number of occasions

Counting squares in the centre crop looks like the image scale is 1.16x for the WACP at 60 over the 8-15 @ 30mm which could be handy for some marginal objects but with MP available I think hardly noticeable in details captured. Interestingly my calculations say almost the same thing 1.16 vs 1.17 image scale factor.

To me the 8-15/2x combo has sharpness advantage in the corners at least at the wide end (just really looking at the 140mm - the 180mm as expected is a little worse).

just a side note - the pad was not photographed from the same distance for presented scenarios so the number of squares in crops and their size is meaningless in comparisons. the purpose of this comp was sharpness and rendering, perhaps CA, - not distortions or magnifications.

Edited 1 hour ago1 hr by RomiK