These are the histograms of the unadjusted output of the various converters as displayed by Photoshop. I have added a red marker at the midtone point for easy reference. Note that the 'ideal' placement of the midtone value is not necessarily in the middle (128), but slightly above the midpoint, perhaps in the 130 to 140 range. Observations and Notes

• C1 renders images approximately 1/3 stop brighter than RIC or ARC. In my opinion, the proper exposure here is f8 for C1, f7.1 for RIC and ARC, although it is difficult to determine the 'proper' exposure for a test shot such as this.
• RIC shows extreme shadow compression, particularly in underexposed shots. C1 shows the best shadow expansion with ARC somewhere in between.
• The two darkest tonalities show unusual spread in the ARC conversion. Preliminary investigation with an eyedropper indicates that this is due to noise. Both the RIC and C1 conversions show a somewhat lesser spread in the high tones of the f9 shot. Since both converters show the same effect I'm attributing it to sloppy procedure or video refresh issues at this point.