Originally posted by Jed
Nikon doesn't need to come up with DO... it's already silently doing so while Canon are as usual milking the marketing for all it's worth. The AF-S II 400/2.8 is almost a full kilogram lighter than the Canon equivalent.
If you look at Canon's only DO offering properly, there really isn't much of a weight saving at all, although there may well be a size saving (I haven't seen one in real life so I can't tell).
I have to concur and the Kwanon website shows an interesting 'version' of optical theory too regarding the DO. I notice that they have managed to completely exclude ED and ASP elements from their optical overview an occurence that a cynic might infer is because they don't want to scupper sales of their 400/2.8.
According to the Kwanon website:
EF 400mm f/4 DO IS USM
Min foc dist: 11.5 feet
Size: 5.0x9.2 inches - (127mm x 233.68mm)
Weight: 4.3 lbs - 1.83 kg
Assuming this lens is a good performer then hats off to Canon for producing a reasonably fast light 400mm lens and credit where credit's due.
As we well know Nikon don't have an equivalent lens in their current lineup, however the old 400/3.5 AIS is still in production and lo and behold;
Nikkor IF-ED f/3.5 AIS
Min focus dist: 15 feet
Size: 134mm x 296mm (5.27 x 11.65 inches)
Weight: 2.8kg (6.5 pounds)
It should of course be realised that comparing these two lenses is somewhat unfair, the Nikon design is manual focus and housed in a full metal body. The design and construction is essentially the same as the first AI version released back in 1976. However for an old design that's 1/3 stop faster and not much larger one does have to wonder about advances in recent years.
Of course there's no equivalent to the Canon 400/4 DO in the Nikon AF lineup, however if Nikon were to produce a 400/4 AFS it would probably weigh a bit more than the 300/4 and an informed guess would be around 50% heavier based on the extra lens diameter (100mm vs 77mm ) and extra body size etc taking the weight up from 1.45 to around 2kg which is within 100 gr of the kwanon.
As the saying goes, the gulliable will rush to part with their money like lemmings rushing towards the cliff.... :devil: