Re: Pentax's sudden infatuation with ED glass.

[Joseph Tainter]

"I too would be interested in a comparison of the 20-35 vs 16-45 at 
equiv. focal lengths. I've been considering finally selling my beloved 
FA 20-35 f/4 AL, and would replace it with the 16-45mm f/4 AL ED lens. I 
would hope for at least as good performance out of the 16-45, 
particularly since it is tailor made for the *ist-D(s) cameras, wheras 
the 20-35 was tailored for 35mm format."

On film, the FA 20-35 was my favorite lens. I cannot bring myself to 
part with it.

When I got the DA 16-45, I went out and tested it in general use against 
the FA 20-35. I made a few prints at 7 x 10 inches on my Epson 870. The 
results from both lenses at that degree of enlargement were identical to 
my eyes. This result is what first sold me on the DA 16-45.

More recently I tested them both at 20 mm., ISO 200, on a tripod, 
shooting a mud brick wall about 1 yard away. I posted the results a few 
weeks ago. Here it is again:

"At f4 the FA lens is better all over. At f5.6 the FA is better in the 
center, but the DA is better at the edges and in the corners. F8 gives 
the same result, except that the center difference is quite slight."

I have to go to actual pixels to see this difference. For practical use, 
the two lenses seem to give equivalent results.

Joe