This is probably the second last test (keno and 1.7EII to go)
3 images shot taken in haste this morning when Mongo’s usual friend came to join him for breakfast. You can see he displays the skills Mongo taught him from Mongo's own extensive experience about posing perfectly for police profile mugshot.
#1 - no converter - lens set down 2 stops to f8 (its sharpest setting)
#1 - 1.4EII converter - lens again set lens set down 2 stops (its sharpest setting)
#3 -16A converter - lens again set lens set down 2 stops (its sharpest setting)
You will see that there were crop differences to the original to try and get roughly the same sized images to compare.
Similarly, there were ISO differences to try and maintain a similar shutter speed. That shutter speed when adjusted for, say, a 1.6 and 1.4 magnification should have been raised to maintain parity (but was not in these tests)
Some allowance should be made for DOF with the varying magnifications. In some cases where the eye is in focus the chest is not and vise versa. There is also some movement blur due to slow shutter. Just pick the sharpest part of the bird to do your comparative assessment.
Lastly, the RAW files were converted to Tiff and then resized for posting. The only PP was a tiny amount of exactly the same sharpening was applied to all images at the resizing stage.
Mongo can honestly report back that, in real life use, the 1.4EII AND the 16A produce the same excellent results when used at the same settings. However, the 16A will add an extra ⅓ of a stop than the 1.4EII. This is insignificant in Mongo’s view. The 16A will also have a more limited use of auto focus but very usable and very handy.
The real question therefore is, why trouble yourself over a modified 16A (at about $200) when maybe a new 17EII will do just as well or better, will AF track etc and cost only $300 new ???? The answer to this longish question will become clearer after Mongo tries the 17EII which has had mixed reports. Whereas, now, Mongo can state with some certainty , that the 16A has very good to excellent reports.
Stay tuned if you are interested.