The pinhole in the "What's This" No. 360 reminded me of this tip.

Metal content: Reading a mike, the markings on a small drill bit, or a
phone number printed on a tool supplier's business card......when you
haven't got your reading glasses with you......and nobody is around to
ask for help.

Use a "hand made" pinhole lens.

Cup your hand slightly and cross your thumb over your index finger. Roll
and squeeze your thumb sideways until you can see light coming through a
little opening (about .015" diameter) between your thumb and the place
where your forefinger joins your hand.

Freeze your fingers in that position, bring your hand up to your eye and
peer through that "pinhole". Put the thing you need to read about two
inches in front of your hand and alter that distance until it's in focus.

Presto! Not much depth of field or angle of view, but if you only need
to read a few characters it's much better than nothing.

I've always wondered how many millennia ago some poor bugger with
deteriorating eyesight discovered that trick, using nothing other than
the hand G-d gave him.

Jeff
--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."

Jeff Wisnia writes:

Use a "hand made" pinhole lens.

Damn! That's clever! Thanks! :-)

-tih
--
Don't ascribe to stupidity what can be adequately explained by ignorance.

Jeff Wisnia wrote:
The pinhole in the "What's This" No. 360 reminded me of this tip.

Metal content: Reading a mike, the markings on a small drill bit, or a
phone number printed on a tool supplier's business card......when you
haven't got your reading glasses with you......and nobody is around to
ask for help.

Use a "hand made" pinhole lens.

Cup your hand slightly and cross your thumb over your index finger. Roll
and squeeze your thumb sideways until you can see light coming through a
little opening (about .015" diameter) between your thumb and the place
where your forefinger joins your hand.

Freeze your fingers in that position, bring your hand up to your eye and
peer through that "pinhole". Put the thing you need to read about two
inches in front of your hand and alter that distance until it's in focus.

Presto! Not much depth of field or angle of view, but if you only need
to read a few characters it's much better than nothing.

I've always wondered how many millennia ago some poor bugger with
deteriorating eyesight discovered that trick, using nothing other than
the hand G-d gave him.

I've been doing it all my life.

I'm not sure whether the effect is that of a pinhole
lens or a stopped-down aperture.

Jim Stewart writes:

I'm not sure whether the effect is that of a pinhole
lens or a stopped-down aperture.

It's both: you get magnification because of the lens effect, and you
get sharpness because of the depth of field of the small aperture.

-tih
--
Don't ascribe to stupidity what can be adequately explained by ignorance.

Jeff Wisnia wrote:

Use a "hand made" pinhole lens.

Have to write this down that I dont forget. 8-

Nick
--
WDR Fernsehen:
"Ein Computer arbeitet so lange Befehle ab,
bis keine mehr vorhanden sind."
Muss ich die dann irgendwie nachfüllen?

"Jeff Wisnia" wrote: (clip) Not much depth of field or angle of view,
(clip)
^^^^^^^^^^^^^^
Thanks, Jeff. This is a good idea that is so old that I had forgotten it.
I just tried it on some small type, and was able to read it at a distance of
only about 3", with my glasses OFF. Any closer and my hand got in the way
of the paper. BTW, I believe the depth of field is practically
unlimited--that's one of the characteristics of a lens at small aperture, or
a pin-hole. What IS limited is the amount of light, so you need to have
good illumination.

this is how I read my clock radio in the middle of the night, when I don't
want to wake up enough to put on my glasses...

"Jeff Wisnia" wrote in message
...
The pinhole in the "What's This" No. 360 reminded me of this tip.

Metal content: Reading a mike, the markings on a small drill bit, or a
phone number printed on a tool supplier's business card......when you
haven't got your reading glasses with you......and nobody is around to ask
for help.

Use a "hand made" pinhole lens.

Cup your hand slightly and cross your thumb over your index finger. Roll
and squeeze your thumb sideways until you can see light coming through a
little opening (about .015" diameter) between your thumb and the place
where your forefinger joins your hand.

Freeze your fingers in that position, bring your hand up to your eye and
peer through that "pinhole". Put the thing you need to read about two
inches in front of your hand and alter that distance until it's in focus.

Presto! Not much depth of field or angle of view, but if you only need to
read a few characters it's much better than nothing.

I've always wondered how many millennia ago some poor bugger with
deteriorating eyesight discovered that trick, using nothing other than the
hand G-d gave him.

Jeff
--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."

"Jeff Wisnia" wrote in message
...
The pinhole in the "What's This" No. 360 reminded me of this tip.

Metal content: Reading a mike, the markings on a small drill bit, or a
phone number printed on a tool supplier's business card......when you
haven't got your reading glasses with you......and nobody is around to ask
for help.

Use a "hand made" pinhole lens.

Cup your hand slightly and cross your thumb over your index finger. Roll
and squeeze your thumb sideways until you can see light coming through a
little opening (about .015" diameter) between your thumb and the place
where your forefinger joins your hand.

Freeze your fingers in that position, bring your hand up to your eye and
peer through that "pinhole". Put the thing you need to read about two
inches in front of your hand and alter that distance until it's in focus.

Presto! Not much depth of field or angle of view, but if you only need to
read a few characters it's much better than nothing.

I've always wondered how many millennia ago some poor bugger with
deteriorating eyesight discovered that trick, using nothing other than the
hand G-d gave him.

Jeff
--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."

Jeff's getting old, Jeff's getting old, na-na-na-naaa-naa-na!

Please post more geriatric tricks as I curse the *******s that print stuff
smaller and smaller and with grey ink on slightly lighter grey paper...Mom
told me I'd go blind.

OBTW, you're using a small aperature as the pin-hole effect produces an
image upside-down.

The pinhole in the "What's This" No. 360 reminded me of this tip.

Metal content: Reading a mike, the markings on a small drill bit, or a
phone number printed on a tool supplier's business card......when you
haven't got your reading glasses with you......and nobody is around to
ask for help.

Use a "hand made" pinhole lens.

Cup your hand slightly and cross your thumb over your index finger. Roll
and squeeze your thumb sideways until you can see light coming through a
little opening (about .015" diameter) between your thumb and the place
where your forefinger joins your hand.

But, but, but how do you hold and read the dial calipers to get the
015"????? :-) Ken.

Freeze your fingers in that position, bring your hand up to your eye and
peer through that "pinhole". Put the thing you need to read about two
inches in front of your hand and alter that distance until it's in focus.

Presto! Not much depth of field or angle of view, but if you only need
to read a few characters it's much better than nothing.

I've always wondered how many millennia ago some poor bugger with
deteriorating eyesight discovered that trick, using nothing other than
the hand G-d gave him.

Jeff
--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."

On Thu, 26 May 2005 22:52:43 GMT, "Tom Gardner"
wrote:



OBTW, you're using a small aperature as the pin-hole effect produces an
image upside-down.

It's both.

A pinhole can form an image like a lens, but unlike a lens it doesn't
have a focal distance. It'll form an image at any distance, larger
and dimmer for greater distances from the image plane.

A lens, including the one in your eye, forms an image by converging
various rays coming from each part of an object into a corresponding
part of the image plane or retina. The pinhole eliminates all but a
very few rays from each part of the object, so no convergence is
necessary. Therefore, the eye's lens doesn't have to focus, and
aberrations have no effect.

"Tom Gardner" wrote: (clip) OBTW, you're using a small aperature as the
pin-hole effect produces an image upside-down.
^^^^^^^^^^^^^
So does a lens, even the one in your eye, with or without the pinhole/small
aperture.

Tom Gardner wrote:



Jeff's getting old, Jeff's getting old, na-na-na-naaa-naa-na!

Chronologically perhaps, but never emotionally. I may get old, but I'll
never "grow up". Mom made it to 94 and dad to 87, and with today's
medical improvements, he probably would have lived even longer. Neither
of them really "lost it" until just a few days before they met their
maker. So, I may not have brains on my side, but I lucked out on the
longevity genes.

I'm happy that spent a major part of my life living in the USA through
what I truly believe were some of its finest years. It's hard for me to
accept that our four kids will have to struggle to stay afloat given the
slippery moral slope our nation has headed down.

Maybe it's just because the media is more pervasive and less courteous
about exposing the seamier side of people all around us, but I can't
remember things in the 50s and 60s being as ugly as they are now, with
fiscal corruption almost everywhere, kids uder 15 murdering each other
with firearms, and pornography so rampant today it no longer has the
sweetness of forbidden fruit....just to name a few.

I'll stop now.


Please post more geriatric tricks as I curse the *******s that print stuff
smaller and smaller and with grey ink on slightly lighter grey paper

The only other "trick" I can think of is one I developed myself to
combat my obviously deteriorating short term memory. If SWMBO phones up
and says, "Please pick up a quart of milk on the way home." I swap my
wris****ch onto the "wrong" wrist at that moment. Seems to work like
stink for me, I keep remembering that task every time I go to check the
time.

as I curse the *******s that print stuff
smaller and smaller and with grey ink on slightly lighter grey paper

Do you think that lawyers might have something to do with that? Seems to
me like they are also into writing stuff using language "intended to
supress information".

...Mom told me I'd go blind.

You should have been quieter. She probably heard you....singing, "I've
got the whole world in my hands".


OBTW, you're using a small aperature as the pin-hole effect produces an
image upside-down.


Thanks, I never stop learning..

--
Jeffry Wisnia

(W1BSV + Brass Rat '57 EE)

"Truth exists; only falsehood has to be invented."

"Jeff Wisnia" wrote in message
...

Tom Gardner wrote:
...Mom told me I'd go blind.

You should have been quieter. She probably heard you....singing, "I've got
the whole world in my hands".

--
Jeffry Wisnia


The whole office had a good belly laugh! Thanks!!!

Jeff, this also helps if you have cataracts, at least it's a crutch
until you have a lens replacement. ...Been there, done that! :-)

Harry C.

Tom Ivar Helbekkmo wrote:
Jim Stewart writes:

I'm not sure whether the effect is that of a pinhole
lens or a stopped-down aperture.

It's both: you get magnification because of the lens effect, and you
get sharpness because of the depth of field of the small aperture.

Do you want to explain that in english? Looks like magic to me. ;-)

-- Mark

On Thu, 26 May 2005 14:49:16 -0400, Jeff Wisnia wrote:


Use a "hand made" pinhole lens.

I wonder if this is why people squint at hard-to-see objects.