From: Lensbaby News
Date: 2009-05-28
Subject: Lensbaby May Newsletter
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Lensbaby News: Nature, Motion, and Flare
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LENSBABY EDUCATION
UNDERSTANDING PINHOLE AND ZONE PLATE
Our new pinhole/zone plate optic alternative has been greeted with a lot of enthusiasm…and a little confusion.

We hope to illuminate the strange science of light bending behind these two classic photography techniques, and then continue the conversation on our forum.

PINHOLE

In pinhole photography, a tiny hole known as a pinhole is used in place of a lens.

It takes longer to gather enough light to create an image through a tiny hole than through a regular lens, so pinhole cameras require much longer exposure times. Lensbaby’s pinhole is roughly equivalent to an aperture of f/177.

Pinhole photography is defined by high contrast, low resolving power and almost infinite depth of field.

Check out Lensbaby’s pinhole gallery.

ZONE PLATE

A zone plate is a set of alternating opaque and transparent concentric rings which diffract the light passing through them.
Pinhole (above) and zone plate (below). Both images by

LisaSmithStudios.com

Below left: Close up image of a zone plate. Each ring has exactly the same

total area. Lensbaby’s zone plate is equivalent to a aperture of f/19.

In a zone plate, diffraction occurs when light bends around the edges of the opaque rings, which results in the relative sharpness of the image.

The zone plate’s transparent rings also allow a great deal of undiffracted light to reach the image plane. This causes the distinct glowing highlights characteristic of zone plate images.

Thus, zone plate images can be described as having sharpness overlaid with softness. Check out Lensbaby’s zone plate gallery.
Do you have follow-up questions? A degree in physics? Awesome pinhole or zone plate images to display? Visit us on the forum.
PINHOLE TIPS
Don’t try to focus your pinhole — with pinhole’s infinite depth of field, focusing is unnecessary. You can alter your pinhole’s field of view by twisting the Composer’s barrel focusing ring.

Clean your sensor — larger apertures blur the dust on your sensor, making it invisible. Shooting with a pinhole will reveal all that dust.

Pinhole requires slow shutter speeds, so use a tripod.

Average shutter speeds for pinhole photos shot at ISO 400 (results may vary):

Bright outdoor light: 1 second
Overcast outdoors: 4 seconds
Indoors, well lit: 25-30 seconds
Indoors, dim: 30+ seconds

For best results, choose high contrast subjects

You won’t be able to see anything through your camera’s viewfinder unless you point a pinhole at a bright light. Try switching to a zone plate to compose your shot and then switch back to pinhole to make your image.

Have fun with the long exposure and show a little selective movement. See Richard’s photo below for inspiration.



Pinhole photo by Richard Born


Zone plate self portrait by Keri Friedman


ZONE PLATE TIPS

The zone plate has a minimal ability to focus, with a depth of field roughly comparable to that of a regular lens with an f/22 aperture.

You can handhold your camera when shooting with zone plate in bright light, but use a tripod when the sky is overcast.

Average shutter speeds for zone plate photos shot at ISO 400 (results may vary):

Bright outdoor light: 1/30 of a second
Overcast outdoors: 2 seconds
Indoors, well lit: 4 seconds
Indoors, dim: 10 seconds

For best results, choose high contrast subjects.

Zone plate is great for night photography because bright light sources become halos of concentric rings. This phenomenon is visible in Keri’s self-portrait above and the detail to the right.


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© 2009 Lensbaby
516 SE Morrison Street - Suite M4, Portland, OR 97214
Zone Plate Image