Thanks for the post and giving us some of your extensive lens design and MTF knowledge.
Can you compare the distortion of the new 21ZF with the 14-24 Nikon and the 18ZF?
From test shots with the 18, it seemed to have alot more distortion than the 14-24 at 18.
Also, can you suggest a couple of good books on lens design and MTF graph reading?
Thanks!
Still saving up for the Coastal Optics 60mm lens. Hate to see what Shirozina might do if he got his hands on one of those!
Hi Wayne:
I don't have any data for the Nikon zoom. The 18ZF looks very similar to the 21ZF, although the 21ZF might be a tiny bit better. Both should be a little better than the Contax 21/2.8, but neither one has the ideal distortion curve shape.
As far as books go, I've always liked Warren Smith's "Modern Lens Design". However, I've never seen any book that really does a great job of discussing MTF curves. And no book I'm aware of has ever discussed what a good distortion curve should look like and why. This is something I first picked up from discussions with Ellis Betensky (of Vivitar Series 1 fame) nearly 20 years ago, and I suspect the Zeiss designers haven't quite figured it out yet.
If you look at the MTF closely, you will see that the ZF 21 is way better than the ZF 18 in all Zones A, B and C. The ZF 18 is already an excellent performer, so the 21 must be truly exceptional.
brianc1959 wrote:
Hi Wayne:
I don't have any data for the Nikon zoom. The 18ZF looks very similar to the 21ZF, although the 21ZF might be a tiny bit better. Both should be a little better than the Contax 21/2.8, but neither one has the ideal distortion curve shape.
As far as books go, I've always liked Warren Smith's "Modern Lens Design". However, I've never seen any book that really does a great job of discussing MTF curves. And no book I'm aware of has ever discussed what a good distortion curve should look like and why. This is something I first picked up from discussions with Ellis Betensky (of Vivitar Series 1 fame) nearly 20 years ago, and I suspect the Zeiss designers haven't quite figured it out yet. ...Show more →
Ed Sawyer wrote:
Paul, glad you liked realultimatepower. ;-) That is some funny stuff.
I'll look for the megacar.com site, probably available from the wayback machine @ archive.org I'd think.
-Ed
I've tried it, but maybe you'll have better luck.
Basically it was the ultimate gratuitous Flash site for a company in Germany that does custom installs of computer/networking systems into expensive cars like Benz, etc.
The best part the cheesy voice clips for all the rollover menus. It sounded just like the "movie preview" guy (deep, rumbling voice).
"Welcommmme"
"Photos"
"Videos"
"Specifications"
Any time I was depressed, I'd just hit megacar.com:
(see this video for an example of the "movie guy" voice: )
