Re: [pinhole-discussion] focusing zoneplates

2002-01-04 Thread G.Penate
--- Gordon J. Holtslander hol...@duke.usask.ca wrote: I'm going to try making some zoneplates. I've read about that zoneplates require focussing. None of my cameras pinhole cameras can focus. Is zoneplate focusing necessary in all cases? Is focusing needed only for subjects that are

Re: [pinhole-discussion] focusing zoneplates

2002-01-04 Thread George L Smyth
--- Gordon J. Holtslander hol...@duke.usask.ca wrote: I'm going to try making some zoneplates. I've read about that zoneplates require focussing. None of my cameras pinhole cameras can focus. Is zoneplate focusing necessary in all cases? Is focusing needed only for subjects that are close

[pinhole-discussion] focusing zoneplates

2002-01-03 Thread Gordon J. Holtslander
I'm going to try making some zoneplates. I've read about that zoneplates require focussing. None of my cameras pinhole cameras can focus. Is zoneplate focusing necessary in all cases? Is focusing needed only for subjects that are close to the camera? Does it matter whether a positive or