<p>James, This is an issue that I have just recently resolved to my satisfaction. First let me say that the Mark 1 lens is awesome! I am now the proud owner of 2 of them. I tested my first one head to head with a Mark 2 and two 1.4's. Categorically the Mark 1 is sharper than the 2 1.4 lenses from wide open through to F5.6. The 1.4's start to catch up around F4.0 but still do not render as good an image as the Mark 1. I can email these images if anyone is disinclined to believe me. The second Mark 1 that I recently purchased came with what appears to be the OE ES-65 hood with it. However, it does not mount on the lenses, which leads me to believe that is why they are few and far between. It seems to have a 54 mm thread on it. A 52-54 step ring is available as a very special order from online camera retailers. However, I found an ES-62 hood which is almost as deep as the OE hood that doesn't fit. The ES-62 was designed for the Mark 2 50 mm. It screws in perfectly to the filter mount and does not vignette on my Full Frame 5D. Depending upon how much room you have in your bag will determine which way you go. A step ring and rubber collapsible hood is also a good option if space is limited.(cheap too) The plastic ES-62 does not turn around for storage purposes. Can anyone tell me if the ES-65 III does? Also I'd like to know if any of the older guys reading this who purchased the Mark 1 new had the same mounting problems as I have? I hope this is helpful. </p>
