Serious Articles on Optics and Other Stuff

I'm not sure exactly where this thread should go. I chose lenses because that is where I see the most misinformation being bandied about. The Powers-That-Be should feel free to move the tread anywhere they like.

If any of you which to get the real skinny on many technical topics--such as depth of field, ff35 equivalent focal length factor, hyperfocal distances, and tons more--I suggest you go here:

http://doug.kerr.home.​att.net/pumpkin/

URL posted with permission of site owner, Doglas A. Kerr, P.E.

Be prepared for serious articles, not fluff, and with math included. Enjoy and learn. Don't be misled by the unenlightened and just plain wrong.

I added to favorites. Thanks for posting.

Ah, so is this where you got the good stuff you posted in the 2.8 vs 4.0 DOF thread?

I'll be sure to bookmark it.

Only the truly stupid refuse to learn; only the truly selfish refuse to share.

I hope I'm neither.

Or, put another way, I try, I try. And my wife says I'm very trying.

20droger wrote in post #2440226
Only the truly stupid refuse to learn; only the truly selfish refuse to share.

I hope I'm neither.

Or, put another way, I try, I try. And my wife says I'm very trying.

control issues are especially tough on those closest to us. there is no ignore feature at home .

ed rader

Looks like a good site - thanks, and keep putting out the truth. It can be painful, but it's necessary. If someone's (mis)beliefs are shattered or bent, so be it.

I suspect the focusing screen replacement would be the same for the 20D and the 30D. I've always like split image focusing.

Edit: Welcome to POTN. It's a good site.

The focusing screen I use comes from Katz Eye Optics:

http://www.keoptics.co​m

I highly recommend it. Also, get the Optibrite treatment. It's worth it.

It took about 15 minutes for my fumble fingers to install the screen.

For bird photography, it really helps to have a split-prism focus screen. Those darn birds just love to perch in the middle of a tree, and AF always wants to focus on some branch instead of the bird. A split-prism focus and manual focusing solves the problem.