blufox said:
Woah ! Hold the presses ! What is this thing doing in the everyday showoff thread ?
This deserves its own separate thread.
Congrats ! Thats one sweet lens. Wish there was something like that in the Sony lens line up.
@M-Jeri - Its a lot fatter than that 55-250mm IS lens coz its a
constant aperture lens. The 55-250mm is a variable aperture that starts at f4 but ends up at f5.6 by around 180mm. There is one full stop of light difference between the two lenses at 200mm.
If you check out the Canon 70-200mm f2.8 lens you will see that its even bigger coz it has a constant f2.8 aperture.
On the other hand, the Canon 70-300mm IS is almost as sharp as the 70-200mm f4 but is much smaller since it too has a variable f4-5.6 aperture.
Also as bluefox mentioned, it uses an internal focusing system so it will necessarily be thicker than a lens that extends during zooming.
Also the gauge 'thingy' is a distance scale for manual focusing and depth of field calculation.
So professional guys use the distance scale to set focus when using manual focusing and determine the max DOF to decide where to focus on. But on AF lenses its pretty much useless. It was used mostly in the film days where it was very much required and lenses had precise focusing rings.
Nowadays they are an afterthought and are pretty much inaccurate anyways.
I use them to check whats the minimum focus distance for my lens.
And a dedicated macro lens is NOT the only way to do macro. If you use a reverse 50mm lens you can get magnification ratios greater than the 1:1 ratio that a macro lens can give you.
@Aces - The Tamron lens is almost as sharp and the colour and build quality is almost as good as the Canon lens.
However the AF is pretty bad on that lens and people get frustrated since it hunts a lot at low light and misses focus
)
