Lenses make all the difference to your picture. Talking about lenses in the four presentations I wrote for the Digital Photo and Imaging Show at the International Centre makes me realize this more acutely than ever.
And the most important thing, of course, is aperture. A lens needs a large aperture, meaning, as I am sure you all know, a low minimum “f-number”.Like f/2.8 for a quality zoom.
Many people today tried out the various lenses money can buy:
One reason you need fast lenses is the low-light ability of these lenses.
Let me say here now: there is (almost) never enough light.
Let me illustrate what I mean.
With an f/2.8 lens I can get a picture like this at 800 ISO and 1/100th second:
If I had had an f/5.6 lens, that would have been either 3200 ISO, or 1/30th second – both of which would have spoiled the image.
f/1.8, on the other hand, in this type of light today gave me as fast a shutter speed as 1/320th second for some shots, which is enough to show dancers blur-free as they lift off the floor:
And there really is little alternative. If I have to shoot faraway moving objects in low light, therefore (like animals at dusk), I can only do three things other than go to a lower “F-number”:
- Add light.
- Tell the subject not to move.
- Shoot at very high ISO values.
So if I feel wealthy, I might want to buy this, a Sigma 200-500mm f/2.8 lens.
Beautiful. Here it is one more time:
(Of course I also shot those images with a fast lens: a 50mm f/1.2 lens set to f/1.8).
One last picture – again, f/2.8 at 1/100th and 800 ISO.
I could not have done this any other way without getting too much grain, or too much motion blur.
More about this tomorrow at the show: I present Portrait Lenses at 11:45 and unless I am mistaken, 1:45 is Travel Lenses.