5D MKIII and focusing with f8 ....
Not the best day in the field. The plan was to test the 5D MkIII and the AF with some birds in flight....but for whatever reason they all decided to stay on the ground and only took off in the evening when the light was to poor for the job.
To make things worse they were foraging as far away from us as possible....I had the 500mm + the Canon 1.4 attached and as I detected y old Tamron 1.4 x in the bag I attached it as well. I honestly didn't expect anything worth to mention with this combination and was rather surprised when I detected that the combination 500mm/4.0 IS + 1,4 Canon MkII + Tamron 1,4 ( in this order) even allowed AF with all the focusing points available for the combination with a single 1.4 converter. As usual the Tamron didn't transmit the loss of 1 stop so the pictures had to be underexposed by 1 stop and it doesn't show up in the exif .... not at all.
The Quality is not really what I call brilliant but for web- usage or small prints it will work. Will I use it? Yes but certainly only when I am reach limited and when the 7D is not in the bag otherwise I would stick to the 7D with the 500mm + the 1,4 from Canon.
I uploaded a zoomify picture (you can zoom in to 100% but it takes some time until the picture is showing up ) http://www.hofmann-photography.de/CURLEW_ZOOM/GH5D0065.html
With the second converter attached the background gets this less pleasant look some zoom shows as well. The picture was taken with the lens stopped down 1 stop and exposure time of 1/320