> I have come across one of these lenses, and having read that it is very
> sharp, I am considering of trading it for my current 50-135/3.5 AI-S, but I
> am worried about this "loose zoom problem".... can someone explain what is
> that all about?
>
> I would appreciate also any opinions on whether I should trade my zoom or
> not.....
Marc,
I have read that the 50-135/3.5 is also very sharp.
The 75-150 is smaller - 65x125 vs 71x133mm
The 75-150 is ligher 520 vs 700g
The 75-150 has smaller 52mm filter size compared to 62mm
The 50-135 filter does not rotate when you focus, the 75-150 does
The 75-150 focuses relatively close to 1m through the whole zoom range
and is quite good for closeups. The 50-135 only focuses to 1.3m, but it has
a macro mode at 50mm to 0.6m.
The 75-150 often has a loose zoom/focus ring, also known as zoom creep,
which means the lens zooms by itself when pointed up or down. It's
common with one-touch zooms. The 35-135 may also have this problem?
For a telephoto zoom, the 75-150 has a very small zoom range, only 2x,
which you may find limiting. The 50-135 has a 2.7x zoom range.
The 75-150 is a series-E lens so was not made to the same standard as the
AIS 35-135, although it is not bad. The later 75-150 with a chrome ring is
better of the two versions.
If want a slightly longer focal length and smaller lens, go for the 75-150,
otherwise keep your 50-135.
Roland
