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PulsGuide-- Why it works

So what's the big deal about pulsing?

The big deal is designing the reticle illumination to complement how the eye works. Red light of course, to preserve night vision. Pulsing to keep the eye from going blank because the eye, the retina, is more than just billions of light sensors converting photons into electical signals to send on to the brain for processing. If the retina merely converted photons to electrons, it would require an optic nerve an inch across! So something must happen in the retina itself , the retina processes the image to extract the most important information and sends that to the brain. So what is the most important thing your retinas see?Well, put your self into an eat-or-be-eaten state of mind. If your sitting in the jungle, what is the most important thing in the environment that your retinas need to tell your brain about? Is it the tiger sneaking up on you, or the bush sitting next to you? How does your retinas tell the two apart?Tigers move and bushes don't. It is that motion, that change in the image on your retinas, that retinas extract and send on to the brain. Intensity and hue are secondary, and can be filled in later. As you can see in the following eye chart.

So how does the retina process information? Doesn't that take Neurons? Brains? Yes, and that's exactly what the retina is, an approachable part of the brain (ref: John E. Dowling " The Retina an Approachable Part of the Brain", 1987, ISBN 0-674-76680-6). The retina is a mesh of neurons and photoreceptors, wired and programed to extract change from the image on the retina.
Indeed this is one part of the brain that we do know pretty well how it works. We know how it works so well, how the retina extracts motion, edges, contrast, that scientists have built it in silicon (Ref: Carver Mead, "Silicon Retinas"). To illustrate this, Try out the next two eye charts.
If intensity and hue were more important than change in the image (contrast in this case) then the ring would not look brighter on one side than the other. Edges are important too. To give an example of how important edges are, think why should a pencil sketch -- line drawing-- of someone's face be recognizable as a face? After all it's just lines! But those lines are the edges of the facial features. A line sketch simplifies things down the same way the retina does. To the basic important features your brain is designed to make sense of... edges! Which leads to the next eye chart.
This chart is sorta neat. Stare long enough and the fuzzy edged circle goes to gray. If you could keep your eyes completely still (notice how hard it is to keep them still the longer you stare), then even the sharp edged circle will grey out. Fortunately your eyes won't let you. They constantly jitter just a little bit to keep sharp edges detectable by the retina's processing. Which brings us back to why PulsGuide works.

The longer and harder you stare at a guide star hiding behind a constantly illuminated crosshair, the more you try to keep your eye from jittering, the worse you'll do because its completely contrary to how your retina works. PulsGuide, by blinking the crosshair introduces change in the image, PulsGuide works with your retinas to keep your vision at maximum sensitivity. As a result you can work with fainter guide stars, guide more comfortably, get better astrophotographs.

PulsGuide WORKS!

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