Canon upgraded their teleconverters and has now 3 different versions of the much used 1.4x. I own a version I manufactured in 1993 and has been with me from 81N in Svalbard, in Tanzania, Kanya and South Africa to Antarctica. So it is well used! BUT can it stand against the newly arrived 1.4x III ? I have been so lucky to borrow an exemplar from Espen Bergersen http://naturgalleriet.no - loads of thanks to this fabolous photographer! So how is the performance, on my 300/2.8L IS on tripod I put the converters on not using stabilisation and with self-timer 2sec to avoid movement in the setup. To see difference in Original photo and using Lightroom 3 I present both version to compare:
1.4x I No sharpening
The physical appearence is not much different in 20 years, but the new one is a bit heavier (more glass??)
And finally a photo taken with the OLD 1.4x I in bright sunlight, exported into LR3 and the result is not bad. Should you throw away the old one? NO if you have a good exemplar, YES if you really need the latest technology and a gasket against water.