Re: Zone Plate lens or aperture was Re: Pictorico for Zone Plate

 From my experience, the term "focusing your camera" is a bit overstated
with a zone plate. I put a 75mm zone plate onto the bottom (taking)
half of a cheap medium format TLR. Great fun, and a bright viewfinder
lens to compose with! I went through a lot of work to get it exactly
75mm from the film, then set up a transparent light bulb in a long dark
room, but a piece of ground glass into the camera and adjusted to that!
Perfectionist?? Who me??

Well, once the thing was in use, I discovered that changing the focus a
bit made no difference in the final print. My advice: Putting a 75mm
zone plate within 10% of 75mm and go have fun. That is about all the
"focusing" needed. I don't "focus" the camera in the field.

As for referring to the zone plate look as "artistic license", well I'm
sure it isn't for everyone. It is not sharp, period! More like a
pinhole with the "light smear" of a wide open portrait soft focus lens
added in. More interesting in color than B&W (for me).

Tom

On Feb 22, 2006, at 5:21 AM, Yves Gauvreau wrote:

> MessageMichael,
>
> from what I've read so far about these zone plate, you have to focus
> your
> camera and the resulting image is softer (fuzzyer) then with a strait
> pinhole (aperture). Lets just say beside the exposure advantage of
> these the
> rest is mostly a question of artistic licence if I can say that.
>
>
> Since you have to focus a zone plate I would have no problem calling
> it a
> lens. The usual pinhole aperture could probably be called a lens in the
> theorical sense. Infinitely this, infinitely that, 0 this 0 that, etc.
> it's
> kind of a singularity. I'm not a formalist, expert or anything else in
> these
> matters but I wouldn't trash the "pinhole lens" expression just yet.
>
> Regards
> Yves
>
>
>
> ----- Original Message -----
> From: Michael Koch-Schulte
> To: alt-photo-process-l@sask.usask.ca
> Sent: Tuesday, February 21, 2006 11:34 PM
> Subject: Re: Pictorico for Zone Plate
>
>
> If you define lens as a piece of glass no, but if you define it more
> generally as something that can cause light to concentrate or diverge
> then
> maybe yes. And yes I've been starting to design my own pinholes,
> mega-pinholes and zone-plates with the very program you mentioned. The
> idea
> came to mind when it was suggested that I use a film recorder or
> enlarger to
> create the pinhole. I thought "why not just use Pictorico"? At 5760
> DPI do
> you think edges will be much of an influence? I'll know shortly.
>
> ~m
>
> ----- Original Message -----
> From: Loris Medici
> To: alt-photo-process-l@sask.usask.ca
> Sent: Tuesday, February 21, 2006 12:02 AM
> Subject: RE: Pictorico for Zone Plate
>
>
> Lith film should be more suitable for that purpose (zone plate -
> Goggle for
> the program "Pinhole Designer"; it gives you the possibility to design
> a
> zone plate .pdf file that you can have it printed with a very high
> resolution imagesetter at a service bureau). BTW, I never heard
> anything
> such as a pinhole "lens" ;)
>
> Regards,
> Loris.
> -----Original Message-----
> From: Michael Koch-Schulte [mailto:mkochsch@shaw.ca]
> Sent: 20 Şubat 2006 Pazartesi 23:37
> To: alt-photo-process-l@sask.usask.ca
> Subject: Pictorico for Zone Plate
>
>
> Has anyone had success using Pictorico OHP to make Zone Plate or
> Pinhole
> lenses?
>
> ~m
>
Received on Wed Feb 22 09:16:19 2006