Karen Nakamura wrote:
> Photodo and most other MTF measurements are flawed when you try to > compare a f/2.8 lens against an f/4 or f/5.6 lens. They test the > lenses wide open and in that case, of course the f/2.8 lens at f/2.8 > will have more problems than an f/4 lens at f/4. First off Photodo tests are not flawed. They use Hasselblad MTF equipment, among the finest in the world. These are bench tests that are also used by the manufacturer, so to say they are flawed means that Canon's method of development is also flawed. The reason they test wide open is that too is a criteria for testing lenses when they create them. Some will be better than others. > If you compare an f/2.8 lens at f/4 against an f/4 lens at f/4, > you'll see the difference. Even at f/8 which is the point at which > lenses tend to approach each other, the L is superior to the IS at > all focal lengths. Karen , I am surprised you are saying this. This is absolutely not true! I have used L lenses, Nikkor, Leica, etc. This is not true in all cases and I speak from experience. I wrote the equipment review column in Professional Photographer Magazine from 1994 to 2002 so I can tell you about nearly every lens made. Take a look at the alleged flawed Photodo tests. Compare the 35mm F1.4L to the cheap 35mm F2. At F8 they yield identical resolution. The reason you buy a fast lens is for the wide aperture, that is why you pay the price for L glass as it provides a better image at a faster aperture that does not always translate to better at every aperture. > Anyway, it seems like you're speaking from zero personal experience > (except "friends" and "pros") so there's really no point in > discussing this any further. Because at f/2.8, the L lens is much > superior to the IS. :-) Furthermore, the IS lens suffers from almost > twice as much distortion than the L lens. At the wide lens, the IS > has more than twice the distortion. Note that the new 24-70 has even > less distortion. j * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
