My new flying rule - bring camera

No, I mean in MegaPixels.

"Jim Macklin" wrote in news:POzWg.1483
$XX2.194@dukeread04:

About 1 minute of angle if there is good light and contrast.
"Judah" wrote in message
. ..
| What is the resolution of the human eye, anyway?

"Bob Chilcoat" wrote in
news
Having my camera with me the day I landed on 4R at EWR in the Archer
nearly caused a bad day. On short final approaching the numbers, I
couldn't resist snapping a pic of that runway disappearing into the
perspective. I grabbed the camera off the right seat, flipped off the
lens cap and got a great shot through the prop:
http://www.geocities.com/viewptmd/EWR4RShortFinal.JPG. Unfortunately,
the camera strap got tangled up in the yoke. I had approval to land
long, which was a good thing because after finally getting the strap
free, I realized I had ballooned up 100 feet or so. Fly the airplane!
The tower didn't say anything, and I set it down right where I had
originally wanted to, but it could have been bad, and/or embarrassing.


Nah. They probably didn't know what to expect... When do you think was the
last time they saw an Archer land?

"Judah" wrote in message
. ..
No, I mean in MegaPixels.

That depends on both your estimate of angular resolution as well as your
estimate of the high-resolution field of view. Both vary considerably.

As an example, let's say that for the purpose of your question, we consider
only the field of view attributable to the fovea (the part of the eye that
has only cones, and no rods...this is considered the limit of
"high-resolution" vision...you can see a much wider field of view than this,
but without nearly the same detail as in the center of your vision). A
quick Google search turns up estimates of foveal field of view between 4
degrees and 15 degrees. So already we have quite a discrepancy of
estimates.

If we accept the 1 minute of angle estimate for angular resolution, that
gives us between 240 and 900 units of vision across the field of view. Call
those the equivalent of pixels, and assume a perfectly circular visual
reception, and you get between 45K and 636K "pixels". So in megapixels,
that's between 0.045 and 0.636.

That said, this is a pretty simplistic analysis of the equivalent in
megapixels of human vision. Human vision is different than digital vision
in a variety of ways, and a direct mapping such as shown above is leaving
out a lot of other factors that may affect total effective resolution. But
at the very least, this gives you a ballpark minimum starting point.

Also keep in mind that a digital camera may or may not have a lens capable
of resolving in perfect detail the total resolution available on the image
detector (usually a CCD). So you may have an 8MP camera, but when you look
at an image zoomed on a computer screen at a
one-display-pixel-per-image-pixel ratio, you may find a variety of artifacts
in the digital image.

So basically, human vision may be better than the theoretically calculated
resolution, while a digital camera may have less than the theoretically
calculated resolution. It's really hard to compare in a true
apples-to-apples way.

Pete

Google
Clarkvision Photography - Resolution of the Human Eye At any
one moment, you actually do not perceive that many pixels,
but your eye moves around the scene to see all the detail
you want. But the human eye ...
http://www.clarkvision.com/imagedeta...esolution.html -
12k - Cached - Similar pages


Visual Acuity and Digital Images It turns out that the human
eye only has a certain number of light detectors in it. ...
However, in digital images, the pixels or dots are square.
....
www.blaha.net/Main%20Visual%20Acuity.htm - 53k -
Cached - Similar pages


[DOC] http://clarkvision File Format: Microsoft Word - View
as HTML
The Human eye is able to function in bright sunlight
and view faint starlight, ... Visual acuity is defined as
1/a where a is the response in x/arc-minute. ...
http://www.nhn.ou.edu/~johnson/Educa...Range-2005.doc
- Similar pages


TECHNOLOGY CORNER ACUITY IN PRACTICE. A single human eye
sees roughly a 140-degree field ... Now, let's calculate the
distance between scanning line centers and pixel centers ...
http://www.tvtechnology.com/features...features.shtml
- 25k - Cached - Similar pages


Visual Acuity in Sensory Substitution for the Blind In
measuring the visual acuity of normal human vision, the eyes
move around ... with a typical horizontal resolution of 176
pixels for the PC camera input, ...
www.seeingwithsound.com/acuity.htm - Similar pages


HDTV displays: How good do they need to be? Thus, screens
don't have lines any more, only rows or columns of pixels.
.... The human visual acuity is 20/20 at any distance if the
height of the ...
broadcastengineering.com/hdtv-displays/ - 67k -
Cached - Similar pages


"Judah" wrote in message
. ..
| No, I mean in MegaPixels.
|
| "Jim Macklin" wrote
in news:POzWg.1483
| $XX2.194@dukeread04:
|
| About 1 minute of angle if there is good light and
contrast.
| "Judah" wrote in message
| . ..
| | What is the resolution of the human eye, anyway?

"Peter Duniho" wrote in
:

"Judah" wrote in message
. ..
No, I mean in MegaPixels.

That depends on both your estimate of angular resolution as well as your
estimate of the high-resolution field of view. Both vary considerably.

snip

Call those the equivalent of pixels, and assume a perfectly circular
visual reception, and you get between 45K and 636K "pixels". So in
megapixels, that's between 0.045 and 0.636.

snip

So basically, human vision may be better than the theoretically
calculated resolution, while a digital camera may have less than the
theoretically calculated resolution. It's really hard to compare in a
true apples-to-apples way.

So what you're basically saying is that my idea of plugging a BlueTooth
interface into one's cereberal cortex is impractical until we first come up
with a way to upgrade the eyes to a higher megapixel rating... I guess that
makes some sense - I can't really tell the difference between a 1 MP image
and an 8MP image...

yep - I've been kind of dumb these past few fall flights. Today
was yet another absolutely perfect flying day (today's flight is
the reason I own an airplane). I'm still kicking myself for
not having my camera.

After trashing two Canon Elph cameras (by keeping them in my pocket all
the time, and fouling the auto-focus lens with pocket lint), I
purchased a little velcro belt pouch for it. I wear it like a cell
phone, and the camera is with me at all times.

My kids think I look like a geek (and I do), but I've always got the
camera along, and never "miss the moment"...
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

On Mon, 09 Oct 2006 12:16:48 GMT, B A R R Y
wrote:
Yesterday morning , there was a 100 ft thick layer of ground fog over
the CT River valley, with unlimited ceilings to either side. Buildings
and towers were poking through a smooth, white blanket!

I was also sans-camera... 8^(

Years ago I was flying up the Jersey shore over a fog bank. Passing
Atlantic CIty, the only building visible above the could was the top
of the Playboy Club casino... all you could see was the rabbit... and
of course, no camera.

My favorite missed picture, though, was when PPGing at Fantasy of
Flight a few years back. A hot air balloon was just landing at the
field, and for one brief moment I could see the balloon, its perfect
inverted reflection in glass smooth water of a pond... the scene
perfectly bisected by the triple tail of the museum's Constellation.

Barry, ya gotta drop by at Griswold one of these days, yesterday was
jumpin' there. Mini-flyin on 10/29...

-Dana

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"Ron Lee" wrote in message
...
This was taken last month on a breakfast flight to Leadville CO. No
camera...no pics.

http://home.pcisys.net/~ronlee/RV6A/...Sep06Small.jpg

That is a great pic! You got a link for a high resolution version?

Just curious, but what reference points on the planes do the wingmen use for
lining up on lead? Root trailing edge to roll bar?
--
Jim in NC

"Judah" wrote in message
. ..
So what you're basically saying is that my idea of plugging a BlueTooth
interface into one's cereberal cortex is impractical until we first come
up
with a way to upgrade the eyes to a higher megapixel rating...

No, not at all. If you come up with a 100% safe means to do that, I'll be
one of the first customers, especially if you include a "last 5 minutes"
video loop buffer. Resolution is not always the most important aspect of
photography.

So, get to work!

"Morgans" wrote:

Just curious, but what reference points on the planes do the wingmen use for
lining up on lead? Root trailing edge to roll bar?
--
Jim in NC


Link sent via email. I don't know what the reference points are. My
formation flying is very limited. Maybe someone else can answer that
question.

Ron Lee