I eventually got around to combining my basic digital camera and a stereo
microscope.
As a test i decided to try capturing the crack in a known bad video head as
a good test of
resolution, focus and exposure for a small black ceramic surface.
http://www.diversed.fsnet.co.uk/vcr_head.htm
The crack is just visible by eye through the microscope, but not in the
lower of the 2 pics, vertically at the narrowest central
point of the black horizontal section that is in focus, a secondary small
horizontal crack at that same point
is visible in the pic just to the top right of this necked central area.
Assuming it is not a problem with lack of resolution , only 2Mp, any tips
for such demanding situation ?
The camera is in place of one of the eyepieces removed and a pre-focus torch
bulb shone down the other eyepiece to get the illumination level up, as well
as some overall illumination. I broke into the camera to be able to wire in
a remote switch for "shutter release" to avoid camera shake. There is some
manual exposure control on the camera but I've not tried that option as yet,
relying on auto exposure.

Incidently for the electronics bods I assume there is no filler /fudge for
such a cracked head.
I seem to remember the wire for such heads has to be gold and not copper to
be ductile enough to form such coils, is that still the case?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs
http://home.graffiti.net/diverse:graffiti.net/

"N Cook" wrote in message
...
I eventually got around to combining my basic digital camera and a stereo
microscope.
As a test i decided to try capturing the crack in a known bad video head
as
a good test of
resolution, focus and exposure for a small black ceramic surface.
http://www.diversed.fsnet.co.uk/vcr_head.htm
The crack is just visible by eye through the microscope, but not in the
lower of the 2 pics, vertically at the narrowest central
point of the black horizontal section that is in focus, a secondary small
horizontal crack at that same point
is visible in the pic just to the top right of this necked central area.
Assuming it is not a problem with lack of resolution , only 2Mp, any tips
for such demanding situation ?
The camera is in place of one of the eyepieces removed and a pre-focus
torch
bulb shone down the other eyepiece to get the illumination level up, as
well
as some overall illumination. I broke into the camera to be able to wire
in
a remote switch for "shutter release" to avoid camera shake. There is some
manual exposure control on the camera but I've not tried that option as
yet,
relying on auto exposure.
...

Most cameras have a self timer that can be used to reduce camera shake. In
most recent cameras the time can be adjusted. Also many SLRs have a feature
that lifts the mirror a half-second or so before the shutter opens which
also helps withi camera shake.

N Cook wrote:
I eventually got around to combining my basic digital camera and a stereo
microscope.
As a test i decided to try capturing the crack in a known bad video head as
a good test of
resolution, focus and exposure for a small black ceramic surface.
http://www.diversed.fsnet.co.uk/vcr_head.htm
The crack is just visible by eye through the microscope, but not in the
lower of the 2 pics, vertically at the narrowest central
point of the black horizontal section that is in focus, a secondary small
horizontal crack at that same point
is visible in the pic just to the top right of this necked central area.
Assuming it is not a problem with lack of resolution , only 2Mp, any tips
for such demanding situation ?
The camera is in place of one of the eyepieces removed and a pre-focus torch
bulb shone down the other eyepiece to get the illumination level up, as well
as some overall illumination. I broke into the camera to be able to wire in
a remote switch for "shutter release" to avoid camera shake. There is some
manual exposure control on the camera but I've not tried that option as yet,
relying on auto exposure.

Incidently for the electronics bods I assume there is no filler /fudge for
such a cracked head.
I seem to remember the wire for such heads has to be gold and not copper to
be ductile enough to form such coils, is that still the case?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs
http://home.graffiti.net/diverse:graffiti.net/




Did you use your optical zoom at all or did you just crop a wide angle
image?
I've tried a similar thing to you except that I used a maccano
construction to support the camera but left the eyepiece in place. The
point of an eyepiece in a microscope is to make the tiny hole of light
right at the end of the body tube larger but keep focus so try it with
it on.

"bren[at]gillatt.org" wrote in message
...
N Cook wrote:
I eventually got around to combining my basic digital camera and a
stereo
microscope.
As a test i decided to try capturing the crack in a known bad video head
as
a good test of
resolution, focus and exposure for a small black ceramic surface.
http://www.diversed.fsnet.co.uk/vcr_head.htm
The crack is just visible by eye through the microscope, but not in the
lower of the 2 pics, vertically at the narrowest central
point of the black horizontal section that is in focus, a secondary
small
horizontal crack at that same point
is visible in the pic just to the top right of this necked central area.
Assuming it is not a problem with lack of resolution , only 2Mp, any
tips
for such demanding situation ?
The camera is in place of one of the eyepieces removed and a pre-focus
torch
bulb shone down the other eyepiece to get the illumination level up, as
well
as some overall illumination. I broke into the camera to be able to wire
in
a remote switch for "shutter release" to avoid camera shake. There is
some
manual exposure control on the camera but I've not tried that option as
yet,
relying on auto exposure.

Incidently for the electronics bods I assume there is no filler /fudge
for
such a cracked head.
I seem to remember the wire for such heads has to be gold and not copper
to
be ductile enough to form such coils, is that still the case?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs
http://home.graffiti.net/diverse:graffiti.net/




Did you use your optical zoom at all or did you just crop a wide angle
image?
I've tried a similar thing to you except that I used a maccano
construction to support the camera but left the eyepiece in place. The
point of an eyepiece in a microscope is to make the tiny hole of light
right at the end of the body tube larger but keep focus so try it with
it on.

I could not get an image on the camera viewscreen without removing an
eyepiece,
i never bother with optical zoom and no mechanical zoom as rock bottom
camera
, so no qualms about getting inside it to add remote switch option.

This is the write up that will appear on my otherwise electronics tips file
http://www.divdev.fsnet.co.uk/tips2.htm
when I get around to ftp'ing it

Macrophotography with microscope and basic digital camera

Modified the camera for remote trigger/shutter release ( see
repair4.htm file) to avoid camera shake.
I started with an ancient Watson Barnet stereo viewing
microscope, with x5 double objective and 2 x10 eyepieces.
Unscrewed one of the eyepieces and fixed over it a 35 mm film
storage pot, with base cut off. Padded out with rubber
pulley tyres. Did the same with padding out the boss of the
camera lens at the othe rend. Fixed the camera to the microscope so it
could not be knocked off.
For dark subjects shine a pre-focus torch bulb through the
other lens system. Put this bulb on a draughtsman's bendable curve or
one of those silly pig's tail drinking straws with deformed
concertina section so will take up any XYZ position.
I found the camera image was a circle diameter 3/4 of the smaller axis of
the frame.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/