Date: Wed, 14 Apr 2010 22:06:53

Author: Dan Bernoulli

Subject: Re: Digital Pinhole Camera

Post:

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My web cam has been sitting on my desk for two days now just waiting for me=
to try it out. I am thinking an issue besides the brightness is the small =
size of the ccd. It is on the order of +/-0.5 cm. So any shake at all would=
be amplified considerably. Also=2C because of the small size the ccd may n=
eed to be closer to the pinhole meaning the pinhole would need to be smalle=
r? If I remember=2C Hecht in his optics book says a 0.5 mm hole works well =
at about 40 cm. That would be a pretty narrow field of view for objects any=
significant distance away. Guess I should figure out the geometry but the =
easiest proof is probably simply to try things. And bright can't hurt. In p=
laying the other night using a piece of aluminum foil with a crude hole I d=
id get some bright spots from our dining room chandelier. Nothing that look=
ed like an image but it suggested there might be hope. I will work hard to =
find some time to play a little tomorrow.

Dan Beeker



> From: bnorwood@umd.edu
> To: tap-l@lists.ncsu.edu
> Date: Mon=2C 12 Apr 2010 13:14:02 -0400
> Subject: Re: [tap-l] Digital Pinhole Camera
>=20
> OK guys=2C this will be our opportunity to photograph the sun - - careful=
ly. Bill N
>=20
> -----Original Message-----
> From: tap-l-owner@lists.ncsu.edu [mailto:tap-l-owner@lists.ncsu.edu] On B=
ehalf Of Jerry DiMarco
> Sent: Monday=2C April 12=2C 2010 12:17 PM
> To: tap-l@lists.ncsu.edu
> Subject: Re: [tap-l] Digital Pinhole Camera
>=20
> From what I've read and heard=2C if you use a webcam for
> astrophotography you must stack a succession of photos (integrate) to get=
a
> bright enough image. I suspect something similar will have to be done to
> use a webcam with a pinhole aperture...
>=20
> =
Jerry
>=20
>=20
> At 4/9/2010 08:43 PM=2C you wrote:
> >Web cams are commonly used in astrophotography. Lots of good info if one
> >searches using the term. For best results the lens is removed and the cc=
d
> >is placed in/near the focal plane of the telescope. Webcams seem to have
> >better software on the pc side. Webcam software for Macs is abysmal.
> >Problems are most webcams are now so specialized everything is automatic
> >and basic parameters such as exposure time are generally inaccessible to
> >the user. But many have good sensitivity=2C some on the order of 1 lux o=
r
> >less. I have a webcam I pulled the lens on to use in a scope but didn't
> >work well because of the poor Mac drivers. Don't know why it wouldn't wo=
rk
> >for a pinhole camera. I'll play with mine and see what kind of results I
> >can get.
> >
> >Dan Beeker
>=20
>=20
> <><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
>=20
> Jerry DiMarco
> Manager of Lecture Demonstrations and Instructional Labs
> Montana State Univ.=2C Physics Dept.
> Bozeman=2C MT
>=20
> Our Motto: "Find your inner demo."
>=20
>=20
>=20
=20
_________________________________________________________________
The New Busy is not the too busy. Combine all your e-mail accounts with Hot=
mail.
http://www.windowslive.com/campaign/thenewbusy?tile=3Dmultiaccount&ocid=3DP=
ID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_4=

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My web cam has been sitting on my desk for two days now just waiting for me=
to try it out. I am thinking an issue besides the brightness is the small =
size of the ccd. It is on the order of +/-0.5 cm. So any shake at all would=
be amplified considerably. Also=2C because of the small size the ccd may n=
eed to be closer to the pinhole meaning the pinhole would need to be smalle=
r? If I remember=2C Hecht in his optics book says a 0.5 mm hole works well =
at about 40 cm. That would be a pretty narrow field of view for objects any=
significant distance away. Guess I should figure out the geometry but the =
easiest proof is probably simply to try things. And bright can't hurt. In p=
laying the other night using a piece of aluminum foil with a crude hole I d=
id get some bright spots from our dining room chandelier. Nothing that look=
ed like an image but it suggested there might be hope. I will work hard to =
find some time to play a little tomorrow.Dan Beeker=
>=3B From: bnorwood@umd.edu>=3B To: tap-l@lists.ncsu.edu>=3B =
Date: Mon=2C 12 Apr 2010 13:14:02 -0400>=3B Subject: Re: [tap-l] Digi=
tal Pinhole Camera>=3B >=3B OK guys=2C this will be our opportu=
nity to photograph the sun - - carefully. Bill N>=3B >=3B -----=
Original Message----->=3B From: tap-l-owner@lists.ncsu.edu [mailto:ta=
p-l-owner@lists.ncsu.edu] On Behalf Of Jerry DiMarco>=3B Sent: Monday=
=2C April 12=2C 2010 12:17 PM>=3B To: tap-l@lists.ncsu.edu>=3B =
Subject: Re: [tap-l] Digital Pinhole Camera>=3B >=3B From=
what I've read and heard=2C if you use a webcam for>=3B astrophotogr=
aphy you must stack a succession of photos (integrate) to get a>=3B b=
right enough image. I suspect something similar will have to be done to>=3B use a webcam with a pinhole aperture...>=3B >=3B =
=
Jerry>=3B >=3B >=3B At 4/9/2010 08:=
43 PM=2C you wrote:>=3B >=3BWeb cams are commonly used in astrophot=
ography. Lots of good info if one>=3B >=3Bsearches using the term. =
For best results the lens is removed and the ccd>=3B >=3Bis placed =
in/near the focal plane of the telescope. Webcams seem to have>=3B &g=
t=3Bbetter software on the pc side. Webcam software for Macs is abysmal.>=3B >=3BProblems are most webcams are now so specialized everything i=
s automatic>=3B >=3Band basic parameters such as exposure time are =
generally inaccessible to>=3B >=3Bthe user. But many have good sens=
itivity=2C some on the order of 1 lux or>=3B >=3Bless. I have a web=
cam I pulled the lens on to use in a scope but didn't>=3B >=3Bwork =
well because of the poor Mac drivers. Don't know why it wouldn't work&g=
t=3B >=3Bfor a pinhole camera. I'll play with mine and see what kind of r=
esults I>=3B >=3Bcan get.>=3B >=3B>=3B >=3BDan Beek=
er>=3B >=3B >=3B <=3B>=3B<=3B>=3B<=3B>=3B<=
=3B>=3B<=3B>=3B<=3B>=3B<=3B>=3B<=3B>=3B<=3B>=3B<=3B=
>=3B<=3B>=3B<=3B>=3B<=3B>=3B<=3B>=3B<=3B>=3B<=3B>=
=3B<=3B>=3B<=3B>=3B<=3B>=3B<=3B>=3B<=3B>=3B<=3B>=3B=
<=3B>=3B<=3B>=3B<=3B>=3B<=3B>=3B<=3B>=3B<=3B>=3B<=
=3B>=3B>=3B >=3B Jerry DiMarco>=3B Manager of Lectu=
re Demonstrations and Instructional Labs>=3B Montana State Univ.=2C=
Physics Dept.>=3B Bozeman=2C MT>=3B >=3B Our Motto: "F=
ind your inner demo.">=3B >=3B >=3B The New Busy is not the too busy. Combine all your e-mail accounts w=
ith Hotmail. Get busy.
=

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From tap-l-owner@lists.ncsu.edu Thu Apr 15 02:33:04 2010

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