View Full Version : gl2 "shallow focus"


Seth Richter
December 17th, 2003, 11:26 AM
I was wonder how to extend the focal length without paying for it royally. I know there is a wide angle adapter, which would change the length, but, not by much.. Anyone have any ideas?

Ken Tanaka
December 17th, 2003, 11:41 AM
Your question is confusing.

It's titled "shallow focus", which is a depth-of-field matter. But then you ask about changing the "focal length", which is often a matter concerning a lens' telephoto properties. Then you ask about a wide-angle adapter.

Can you clarify what you want to accomplish? Do you want to get a wider field of view or do you want to see birds' eyebrows from 1000 yards?

Seth Richter
December 17th, 2003, 11:44 AM
Sorry I meant "Shallow DOF"

Ken Tanaka
December 17th, 2003, 11:54 AM
OK. Please do a Search on DOF, as this has been discussed literally hundreds of times. We have a very large body of typing on the subject. Jeff Donald has also written an extensive article here (http://www.dvinfo.net/articles/optics/dofskinny.php) on the subject.

Bottom line: With 1/4' ccds you're very limited. Back-up, zoom-in, open your iris as wide as possible. That's the story. Has nothing to do with adapters.

Seth Richter
December 17th, 2003, 12:02 PM
Thanks,

I have been trying to research it, but, after a few hours of trying to find any telephoto-type lenses that were cheep for the gl2, I decided to try and cut the middle man.