There is a 90mm leaf shutter version separate to the usual 90mm f2.8 lens. From what accounts I have read the optical performance is not that far removed, but the leaf shutter mechanism makes the LS version heavier — is weight a consideration for you? This (90) lens has fewer operational idiosyncracies than the 165mm LS (e.g. mirror lock-up can be used with the 90mm LS but not the 165mm LS — whether or not you can justify using MLU with leaf shutter mode engaged is entirely up to you rather than speculative feedback). I have the 165mm LS and it is quite heavy but it is very sharp and crisp on Velvia 50 at 12x16 enlargements. I would definitely not besmirch it on the basis of a handful of negative or marginal comments on this forum or elsewhere, especially from only occasional users with limited experience; I use mine quite often in situ, as I said earlier, in the landscape context and it has saved quite a few situations where I found myself too distant from the subject. The 90mm f2.8 lens inclusion is a 'bridge' between the 55mm and 165mm, again, just right for a great many situations and I have no plans to add to this kit (this is enough weight to carry around, thanks!
)