28 Feb
2005
28 Feb
'05
12:03 p.m.
Recent discussion about photographing machines prompted this one.
Has anyone got any useful tips for photographing (with a digital camera)
running machines such that whatever's on the screen is captured with
some kind of decent quality?
I've been playing around with all the manual settings on my camera and
just experimenting (using any kind of auto mode results in banding on
the computer's display, and of course use of flash is no use for a shot
of a glass screen). So far results have been mixed though...
Any useful hints much appreciated!
cheers
Jules
28 Feb
28 Feb
12:08 p.m.
And thusly Jules Richardson spake:
Recent discussion about photographing machines prompted this one.
Has anyone got any useful tips for photographing (with a digital camera)
running machines such that whatever's on the screen is captured with
some kind of decent quality?
I've been playing around with all the manual settings on my camera and
just experimenting (using any kind of auto mode results in banding on
the computer's display, and of course use of flash is no use for a shot
of a glass screen). So far results have been mixed though...
Any useful hints much appreciated!
cheers
Jules
This is what I remember from reading old computer magazines... The room
must be dark, with the only light coming from your monitor. You also need
you camera on a tripod because you need to have the shutter stay open for
a longer period of time.
Cheers,
Bryan Pope
12:37 p.m.
On Mon, 28 Feb 2005, Bryan Pope wrote:
This is what I remember from reading old computer
magazines... The room
must be dark, with the only light coming from your monitor. You also need
you camera on a tripod because you need to have the shutter stay open for
a longer period of time.
I took some shots with the room light with a torchiere style light
(pointing at the ceiling), and the camera on a tripod with a manual
shutter release. I'm happy with that setup.
Mike Loewen mloewen at cpumagic.scol.pa.us
The Dixie Lion Jazz Band http://ripsaw.cac.psu.edu/dixie.html
The B9 Robot Builders Club B9-0014 http://ripsaw.cac.psu.edu/~mloewen/B9/
Old Technology http://ripsaw.cac.psu.edu/~mloewen/Oldtech/
2:02 p.m.
On Mon, 28 Feb 2005, Bryan Pope wrote:
> I've been playing around with all the manual
settings on my camera and
> just experimenting (using any kind of auto mode results in banding on
> the computer's display, and of course use of flash is no use for a shot
> of a glass screen). So far results have been mixed though...
With chemical photography:
When I had some artwork professionally photographed, to catch all
the indicators etc the photographer did multiple-exposures, as
suggested here. "Static" display equiv.
The stuff was operating, and illuminated and photographed
normally, then again with lights-out, longer exposure, enhanced
the light-generating parts. He did a number of exposures, I picked
out the ones that looked best (slides).
That way also you don't get color reciprocity failure; with really
long low-light exposures, the dyes in the color film don't all
react at the same rate, so the colors get all muddy.
Don't use a "one hour" developer under any circumstances, pro
developers don't charge much more, take a few days, and do
excellent work.
"One hour" places work by literally turning up the heat on the
development process, which ruins grain. I suspect they don't
change chemicals as often and I can tell you, my pro photos look
great after 10 years while the "one hour" photos look like crap at
10 years. It really makes a huge difference.
Pretty much all "brand" film these days is pretty good, its all in
the development, even with a relatively crappy camera.
I've noticed my low-light digital photos look muddy too, I don't
know what's goin on there, maybe someone here does.
2:51 p.m.
>>>> "Tom" == Tom Jennings
<tomj at wps.com> writes:
Tom> I've noticed my low-light digital photos look muddy too, I don't
Tom> know what's goin on there, maybe someone here does.
That's noise in the sensor. Photoshop may be able to help a bit with
that. Cooling the sensor helps too, but that's probably not practical
for a camera. (It's how astronomers use CCD sensors, I believe. Some
vague memory says that liquid nitrogen works really well here. It
certainly did in an image intensifier demo I saw at the local
astronomy club 30 years ago.)
paul
12:22 p.m.
Flash is a big no - no...
I find taking a 45-60 degree angled shot usually gets a good photo.
For straight on shots, the best is if you have a camera with a night
shot feature no-flash, it keeps the iris open longer and you can usually
get a very good photo.
Curt
Jules Richardson wrote:
Recent discussion about photographing machines prompted
this one.
Has anyone got any useful tips for photographing (with a digital camera)
running machines such that whatever's on the screen is captured with
some kind of decent quality?
I've been playing around with all the manual settings on my camera and
just experimenting (using any kind of auto mode results in banding on
the computer's display, and of course use of flash is no use for a shot
of a glass screen). So far results have been mixed though...
Any useful hints much appreciated!
cheers
Jules
12:55 p.m.
[Curt responding to Jules Richardson]
> I've been playing around with all the manual
settings on my camera
> and just experimenting (using any kind of auto mode results in
> banding on the computer's display, and of course use of flash is no
> use for a shot of a glass screen).
Sounds to me as though you want a long exposure, which means either low
light or a slow film; since the screen is self-luminant, low light is
not a good way to handle it in this case. But...
> (with a digital camera)
Yeah, if your camera doesn't have settings equivalent to exposure time
and film speed, it sounds to me like a case of Don't Do That, Then.
Not that that's teribly helpful.
For straight on shots, the best is if you have a
camera with a night
shot feature no-flash, it keeps the iris open longer and you can
usually get a very good photo.
Iris? This is a digital camera; they often (usually?) don't actually
have an iris.
I suspect you may have to put the camera on a tripod (or equivalent
means of keeping it fixed) and take something like a dozen pictures and
then digitally average them, to get the equivalent of a long exposure
with a slow film.
/~\ The ASCII der Mouse
\ / Ribbon Campaign
X Against HTML mouse at rodents.montreal.qc.ca
/ \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B
2:06 p.m.
This is already a pretty wordy discussion, but anyway...
Watch for reflections in the screen.
If you can see a reflection with the display off, there will
be some overlaid image effects with the display on.
Careful control of surrounding light levels can lower the
effect while still allowing photography of the rest of the machine.
The video* signal is strobing at something like 30-80 hz.
The camera's shutter speed should be slower than at least 1
frame of the screen. I use 1/20th second for noncritical work.
Those are the big 2 factors. Flash should be off for those reasons.
If you have autofocus=off, autoexposure=off controls, use them too.
* flames off plz
John A.
2:34 p.m.
On Mon, 2005-02-28 at 12:55 -0500, der Mouse wrote:
FWIW if I stick the camera into manual mode I do have total control over
shutter speed (1/2000th sec to 15 secs) and aperture (f2.0 to f8.0) so I
should be able to do something reasonable there.
I don't know if I should be playing around with manual focus or not too;
depends whether the auto-focus tries to focus on the front of the
display tube or the actual text I suppose - trial and error time.
Just thought I'd pick on list wisdom to save me going back and forth
between the place downstairs where I can take photos, and upstairs where
the PC is that I can download images to :-) (LCD displays obviously
being too small to tell how good a detailed shot is going to turn out. I
can probably zoom/pan around the image on the camera, but I haven't
worked out how yet :)
Under Linux, I don't think there's any way I can pull metadata off the
camera along with images - so if I take lots of shots under a trial and
error approach, I have to note down what settings I was using for which
shot which is getting to be a pain in the butt!
ta for all the pointers,
Jules
> (with a
digital camera)
Yeah, if your camera doesn't have settings equivalent to exposure time
and film speed, it sounds to me like a case of Don't Do That, Then.
Not that that's teribly helpful. 
3:26 p.m.
Under Linux, I don't think there's any way I
can pull metadata off the
camera along with images - so if I take lots of shots under a trial and
error approach, I have to note down what settings I was using for which
shot which is getting to be a pain in the butt!
I am using Nikon 995 and I download the images to linux directly (via
USB). The model supports the kind of flash storage protocal, and I can
mount it directly as a local directory. I heard that many new cameras
could be mounted too.
vax, 9000
ta for all the pointers,
Jules
4 p.m.
On Mon, 2005-02-28 at 15:26 -0500, 9000 VAX wrote:
Good point. I don't think Gphoto (at least the version I have) works
with my camera (a Canon G5) in PTP mode - which is what I believe would
be needed for it to copy all the extra metadata stuff as well as
images... but you're probably right, and it probably appears under the
filesystem somewhere which might do the job.
I've just been playing around and had a lot of luck with trying the
suggestion of taking two seperate images then combining them in software
- the monitor taken on automatic and the screen done on manual (0.4
secs / f8.0, along with re-evaluating the white balance). Problem
solved, I think :)
cheers to all
Jules
Under Linux, I
don't think there's any way I can pull metadata off the
camera along with images - so if I take lots of shots under a trial and
error approach, I have to note down what settings I was using for which
shot which is getting to be a pain in the butt!
I am using Nikon 995 and I download the images to linux directly (via
USB). The model supports the kind of flash storage protocal, and I can
mount it directly as a local directory. I heard that many new cameras
could be mounted too.
5:10 p.m.
>>>> "Jules" == Jules Richardson
<julesrichardsonuk at yahoo.co.uk> writes:
Jules> On Mon, 2005-02-28 at 15:26 -0500, 9000 VAX wrote:
> > Under Linux, I don't think there's
any way I can pull metadata
> off the > camera along with images - so if I take lots of shots
> under a trial and > error approach, I have to note down what
> settings I was using for which > shot which is getting to be a
> pain in the butt!
>
> I am using Nikon 995 and I download the images to linux directly
> (via USB). The model supports the kind of flash storage protocal,
> and I can mount it directly as a local directory. I heard that
> many new cameras could be mounted too.
Jules> Good point. I don't think Gphoto (at least the version I have)
Jules> works with my camera (a Canon G5) in PTP mode - which is what
Jules> I believe would be needed for it to copy all the extra
Jules> metadata stuff as well as images... but you're probably
Jules> right, and it probably appears under the filesystem somewhere
Jules> which might do the job.
Something about this sounds odd.
The metadata is right in the JPG files. At least it is on my Nikon
880. There's nothing else on the file system (which is a plain old
FAT filesystem).
Yes, you can read it via USB. I've had no luck at all with that on
Linux, but I didn't try very hard. The main reason is that, on a
laptop, it's easier and faster just to plug in the CompactFlash card
using a $10 PCMCIA adapter, and read directly from there. It shows up
in Linux as a disk, you just read it.
paul
1 Mar
1 Mar
6:19 a.m.
"Jules" == Jules Richardson
<julesrichardsonuk at yahoo.co.uk> writes:
>> > Under Linux, I don't think there's any way I can pull metadata
>> off the > camera along with images - so if I take lots of shots
>> under a trial and > error approach, I have to note down what
>> settings I was using for which > shot which is getting to be a
>> pain in the butt!
Have you looked at 'exiftool'?
NAME
exiftool - print meta information from image files
SYNOPSIS
exiftool [OPTIONS] [-TAG or --TAG ...] FILE ...
DESCRIPTION
Prints information for specified tags from listed files. -TAG specifies the
name of a tag to extract, or --TAG to ignore. FILE may be an image file
name, a directory name, or - for the standard input. Currently recognized
file types are JPG, TIFF, GIF, THM, CRW, CR2, NEF and DNG.
I have it on my RedHat laptop; it was able to return wads of info from
pictures taken with my Olympus D10, including shutter speed and
aperture, which is what I expect you are after.
-ethan
10:51 a.m.
On Mon, 2005-02-28 at 17:10 -0500, Paul Koning wrote:
<snippage>
>>>> "Jules" == Jules Richardson <julesrichardsonuk at
yahoo.co.uk> writes:
Jules> On Mon, 2005-02-28 at 15:26 -0500, 9000 VAX wrote:
> > Under Linux, I don't think
there's any way I can pull metadata
> off the > camera along with images - so if I take lots of shots
Jules> metadata stuff as well as images... but
you're probably
Jules> right, and it probably appears under the filesystem somewhere
Jules> which might do the job.
Something about this sounds odd.
The metadata is right in the JPG files. At least it is on my Nikon
880. There's nothing else on the file system (which is a plain old
FAT filesystem).
Yup. FWIW, you can even dump the data out under Linux w/ a command
called 'exif' (Source here, if your distro is package challenged:
http://sourceforge.net/projects/libexif )
FWIW, Below is a dump of the data my Canon A80 saves (and I suspect most
modern digital camera's do similarly) To keep it from being further off
topic, the picture (not that its attached) was of a SGI Crimson CPU
board.
And I agree, its easier to just rip the memory card out, stick it in a
USB reader, and mount it up than to try and get the camera to "talk"
directly.
David
$ exif img_0310.jpg
EXIF tags in 'img_0310.jpg' ('Intel' byte order):
--------------------+----------------------------------------------------------
Tag |Value
--------------------+----------------------------------------------------------
Manufacturer |Canon
Model |Canon PowerShot A80
Orientation |top - left
x-Resolution |180/1
y-Resolution |180/1
Resolution Unit |Inch
Date and Time |2004:01:22 21:59:25
YCbCr Positioning |centered
Compression |JPEG compression
x-Resolution |180/1
y-Resolution |180/1
Resolution Unit |Inch
Exposure Time |1/59 sec.
FNumber |f/2.8
Exif Version |Exif Version 2.2
Date and Time (origi|2004:01:22 21:59:25
Date and Time (digit|2004:01:22 21:59:25
ComponentsConfigurat|Y Cb Cr -
Compressed Bits per |5/1
Shutter speed |189/32 sec. (APEX: 7)
Aperture |f/2.8
Exposure Bias |0.0
MaxApertureValue |95/32
Metering Mode |Pattern
Flash |Flash fired, auto mode, red-eye reduction mode.
Focal Length |7.8 mm
Maker Note |878 bytes unknown data
User Comment |
FlashPixVersion |FlashPix Version 1.0
Color Space |sRGB
PixelXDimension |2272
PixelYDimension |1704
Focal Plane x-Resolu|2272000/280
Focal Plane y-Resolu|1704000/210
Focal Plane Resoluti|Inch
Sensing Method |One-chip color area sensor
File Source |DSC
Custom Rendered |Normal process
Exposure Mode |Auto exposure
White Balance |Auto white balance
Digital Zoom Ratio |2272/2272
Scene Capture Type |Standard
InteroperabilityInde|R98
InteroperabilityVers|
RelatedImageWidth |2272
RelatedImageLength |1704
--------------------+----------------------------------------------------------
EXIF data contains a thumbnail (5219 bytes).
28 Feb
28 Feb
5:17 p.m.
ANY light sources other than the display will be deleterious to the image
of the display.
You should use a relatively small aperture, to give lots of depth of
focus, since a convex display is opposite the concave field of focus.
You should use an exposure that is long enough to include multiple frames,
otherwise, lack of synchronization will give you bands. OR, you could tap
into the video circuitry an use the VBI plus a short delay to synchronize.
Does anybody have a good collection of Rainbow magazine?
There was a mediocre article in it (all the really GOOD stuff about
flat field lenses, etc. got edited out)
--
Grumpy Ol' Fred cisin at xenosoft.com
10:28 p.m.
On Mon, 28 Feb 2005, Fred Cisin wrote:
Does anybody have a good collection of Rainbow
magazine?
I do.
There was a mediocre article in it (all the really
GOOD stuff about
flat field lenses, etc. got edited out)
...and?
--
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
[ Old computing resources for business || Buy/Sell/Trade Vintage Computers ]
[ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]
1 Mar
1 Mar
6:29 p.m.
ANY light sources other than the display will be deleterious to the image
of the display.
You should use a relatively small aperture, to give lots of depth of
focus, since a convex display is opposite the concave field of focus.
Minor correction. You mean 'depth of field' here. 'Depth of focus'
relates to the possible error in positioning the image (film) plane, not
the subject.
You should use an exposure that is long enough to
include multiple frames,
One good thing is that a small aperture and long exposure go together,
and here you need both of them :-)
otherwise, lack of synchronization will give you
bands. OR, you could tap
into the video circuitry an use the VBI plus a short delay to synchronize.
Good luck!. I've yet to find a digital camera that triggers when you
think it will. There's often an unknown (and suprisingly long) delay
between closing the 'shutter release' contact and actually captruing the
image.
-tony
9:04 p.m.
Unlike film, you can'y simply open the shutter and integrate the
image over time arbitrarily. CCDs are extremely noisy; silver
nitrate (etc) it's at atomic scale.
11:22 p.m.
On Tue, 1 Mar 2005 18:04:54 -0800 (PST), Tom Jennings <tomj at wps.com> wrote:
Unlike film, you can'y simply open the shutter and
integrate the
image over time arbitrarily. CCDs are extremely noisy; silver
nitrate (etc) it's at atomic scale.
I routinely have to manually (GIMP) remove noisy pixels from my 30+
second night shots. It's a hazard with long exposure CCD shots.
My Olympus D-10 (4MP) has about 20-30 pixels that *scream* to full
blue, red, or white intensity from long exposure times. Nothing to do
but mute each one down later.
-ethan
28 Feb
28 Feb
5:35 p.m.
On Mon, 28 Feb 2005 21:00:13 +0000, Jules Richardson
<julesrichardsonuk at yahoo.co.uk> wrote:
On Mon, 2005-02-28 at 15:26 -0500, 9000 VAX wrote:
Good point. I don't think Gphoto (at least the version I have) works
with my camera (a Canon G5) in PTP mode - which is what I believe would
be needed for it to copy all the extra metadata stuff as well as
images... but you're probably right, and it probably appears under the
filesystem somewhere which might do the job.
I have to do this manually, with root privilege,
"/sbin/modprobe usb-storage; mount -t vfat /dev/sda1 /mnt/camera;"
It works on RH and fedora.
cheers,
vax, 9000
Under
Linux, I don't think there's any way I can pull metadata off the
camera along with images - so if I take lots of shots under a trial and
error approach, I have to note down what settings I was using for which
shot which is getting to be a pain in the butt!
I am using Nikon 995 and I download the images to linux directly (via
USB). The model supports the kind of flash storage protocal, and I can
mount it directly as a local directory. I heard that many new cameras
could be mounted too.
I've just been playing around and had a lot of luck with trying the
suggestion of taking two seperate images then combining them in software
- the monitor taken on automatic and the screen done on manual (0.4
secs / f8.0, along with re-evaluating the white balance). Problem
solved, I think :)
cheers to all
Jules
1 Mar
1 Mar
5:12 p.m.
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
On 28 Feb 2005, at 19:34, Jules Richardson wrote:
Under Linux, I don't think there's any way I
can pull metadata off the
camera along with images - so if I take lots of shots under a trial and
error approach, I have to note down what settings I was using for which
shot which is getting to be a pain in the butt!
Normally this information is stored as EXIF data which is actually
embedded inside the JPEG image. I cannot remember the name of the
specific program that reads them but it is a standard format so google
should be able to throw something up.
- --
Chris Blackburn
E-Mail: cblackburn36NOSPAM at softhome.net
E-Mail: cblackburn36 at NOSPAMgmail.com
PGP Public Key: http://makeashorterlink.com/?C2AF31929
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28 Feb
28 Feb
1:56 p.m.
Hi,
julesrichardsonuk said:
Recent discussion about photographing machines prompted this one.
Has anyone got any useful tips for photographing (with a digital camera)
running machines such that whatever's on the screen is captured with
some kind of decent quality?
I've been playing around with all the manual settings on my camera and
just experimenting (using any kind of auto mode results in banding on
the computer's display, and of course use of flash is no use for a shot
of a glass screen). So far results have been mixed though...
Long exposures a neccesary, several display frames worth if possible.
I usually use a tripod and shutter speeds of about 1/8 sec with a
film camera. Standing the camera on something and shooting with the
self-timer (to avoid shaking the camera with your hand) will work.
Assuming you want to show the equipment in the same shot as the display,
if you can manually meter with your camera - or a seperate meter - adjust
the lighting in the room so that the exposure metered from the computer
or monitor case is about the same or a little less than the exposure reading
from the display. You might need to fill the screen
with a screenfull of
characters, such as capital em, if it's a text display, in
order to get a
good reading of the brightness of the characters. Meter close up to the
display for this. I cheat and use a proper spot-meter, but not everyone
has one :-) Unfortunately digital cameras don't give you much in the
way of metering options (unless you spend oodles of money!).
Judging the light levels by eye is not *too* difficult, but will take
a bit of practise.
Any lighting should be well off the camera axis, of course, to avoid
reflections and a polaroid filter is a godsend.
--
Cheers,
Stan Barr stanb at dial.pipex.com
The future was never like this!
5:58 p.m.
Recent discussion about photographing machines prompted this one.
Has anyone got any useful tips for photographing (with a digital camera)
running machines such that whatever's on the screen is captured with
some kind of decent quality?
I can't comment on digital cameras, I've never used one. But I guess the
problems of using a film camera are much the same.
There are basically 2 problems. Reflections in the screen and the fact
that the image is scanned, it's not all there at once.
The best way to eliminate reflections is to put the camera at an angle
(and off to one side) and correct the perspctive with a swinging back.
Problem is that no digital camera that I've seen has a swinging back
(actually, few modern film cameras do either, but...)
You might be able to correct the perspective by manipulating the digital
image o na computer. I've never tried this.
The second problem is easier to get round. You need a relatively long
exposure time -- I normally say at least twice the refresh time of the
display. 1/8 of a second should be fine. Set the aperture to give the
right exposer, use a neutral density filter if your lens won't stop down
far enough. With a digital camera you should be able to do some test
exposures and fiddle the aperture setting until it comes out right.
If you want to get both the machine and the image in the same picture, I
would suggest taking 2 exposures. One of the screen image (in a darkened
room), the other of the machine (turned off?) under normal lighting.
Maybe you can combine the resulting digital images on a computer (I'd do
it by multiple exposure on the same film, but...)
Obviously you should put the camera on a solid tripod, and don't use
flash at all.
-tony
7064
days inactive
7065
days old
22 comments
16 participants
participants (16)
-
allain＠panix.com -
ard＠p850ug1.demon.co.uk -
bpope＠wordstock.com -
cblackburn36＠softhome.net -
cisin＠xenosoft.com -
curt＠atarimuseum.com -
dholland＠woh.rr.com -
ethan.dicks＠gmail.com -
julesrichardsonuk＠yahoo.co.uk -
mloewen＠cpumagic.scol.pa.us -
mouse＠Rodents.Montreal.QC.CA -
pkoning＠equallogic.com -
stanb＠dial.pipex.com -
tomj＠wps.com -
vax9000＠gmail.com -
vcf＠siconic.com