(OT?) video card

[Nervous Nick]

Hey all. At the lab where I work we have a Nikon D50 camera attached
to a stereo microscope which we use for taking photos of human and
animal tissue. We have found it extremely difficult to focus and
compose through the microscope itself, so we would like to be able to
link the D50 to the adjacent computer for real-time viewing to
facilitate focusing and composition.

So I am pretty sure what we need is a video card to which we can
attach the RCA plugs from the camera. We need nothing fancy, as this
is going to be the sole use of the video card.

The computer is a Dell Precision 530 running XP Professional, with 1
gig of RAM and a Xeon 2.8 gig CPU, so I think this is more than enough
to support what I need, but I know very little about such hardware.
Any and all advice in this matter would be quite welcome.

Thanks very much!

 

[=?iso-8859-1?Q?M=E5ns_Rullg=E5rd?=]

Hey all. At the lab where I work we have a Nikon D50 camera attached
to a stereo microscope which we use for taking photos of human and
animal tissue. We have found it extremely difficult to focus and
compose through the microscope itself, so we would like to be able to
link the D50 to the adjacent computer for real-time viewing to
facilitate focusing and composition.

So I am pretty sure what we need is a video card to which we can
attach the RCA plugs from the camera. We need nothing fancy, as this
is going to be the sole use of the video card.

This won't work. Just like other DSLRs, the D50 doesn't provide a
live preview. Even it did have live preview, the resolution of the
composite signal is not anywhere near good enough for focusing.

 

[Bill Funk]

Hey all. At the lab where I work we have a Nikon D50 camera attached
to a stereo microscope which we use for taking photos of human and
animal tissue. We have found it extremely difficult to focus and
compose through the microscope itself, so we would like to be able to
link the D50 to the adjacent computer for real-time viewing to
facilitate focusing and composition.

So I am pretty sure what we need is a video card to which we can
attach the RCA plugs from the camera. We need nothing fancy, as this
is going to be the sole use of the video card.

The computer is a Dell Precision 530 running XP Professional, with 1
gig of RAM and a Xeon 2.8 gig CPU, so I think this is more than enough
to support what I need, but I know very little about such hardware.
Any and all advice in this matter would be quite welcome.

Thanks very much!

The D50, like most DSLRs, does not have a live preview that you can
connect with cables to a viewer of any sort. So the idea of a video
card with RCA inputs won't do you any good for focusing, unless you
wan to download the images after they've been shot so you can adjust
focus then; but that would be pretty hit-or-miss.

--
The Dixie Chicks won the Grammy
for Best Country Album on Sunday
even though they are boycotted
by country radio stations. You
can tell the vote was held in
Hollywood. The other nominees
for best country were Cuba,
Switzerland and Vietnam.

 

[Nervous Nick]

The D50, like most DSLRs, does not have a live preview that you can
connect with cables to a viewer of any sort. So the idea of a video
card with RCA inputs won't do you any good for focusing, unless you
wan to download the images after they've been shot so you can adjust
focus then; but that would be pretty hit-or-miss.

I guess I wasn't very clear. I suppose the question should have been,
if we were to have the camera in *video* mode, would this be feasible;
i.e., could we view in real time in video mode, then switch to still
mode to take the actual photos, or would what you two gents said still
apply? Or would the resolution still be shite in the video mode?

Thanks much for your feedback.

Nicko

 

[Daniel Silevitch]

This won't work. Just like other DSLRs, the D50 doesn't provide a
live preview. Even it did have live preview, the resolution of the
composite signal is not anywhere near good enough for focusing.

Agreed on the former, but not the latter. I used to work in a lab where
we could focus our scopes based on the video feed off a Nikon Coolpix
990, which was hooked up to a video monitor (not a computer). It was
actually easier to focus the microscope using the video screen than by
looking through the eyepieces, especially when we were using the
high-mag objectives (we were typically looking at thin wires ~300 nm in
diameter; you couldn't resolve any details with the optical scope, but
you could certainly see and focus on the wires).

For acquiring stills, we took pictures with the camera and then used a
card reader to bring them onto the computer. For video, we used
the live preview and either a VCR or a firewire-based video digitizer
thingy. This was 5 or 6 years ago, so I'm sure the particular model we
used is long obsolete.

-dms

 

[Cgiorgio]

I guess I wasn't very clear. I suppose the question should have been,
if we were to have the camera in *video* mode, would this be feasible;
i.e., could we view in real time in video mode, then switch to still
mode to take the actual photos, or would what you two gents said still
apply? Or would the resolution still be shite in the video mode?

Thanks much for your feedback.

Nicko

Wish you good luck in finding "video mode" on a Nikon D50!

As in other DSLR's the sensor is not built for video read out and is only
powered after the shutter button is pressed. While nearly all compact
digital cams do provide a video feature, that is not true for DSLR's. For
autofocus they use a separate sensor system much like advanced film SLR's.
The only DSLR which provides live preview that I know is the Olympus E-330
and that is using a second image sensor mounted in the viewfinder optical
path.

Some gadgets that have their own image sensor and can be mounted to the eye
piece of a DSLR are available that allow live preview on a LED screen, but I
am not aware of any of those providing an external Video output signal.

 

[=?iso-8859-1?Q?M=E5ns_Rullg=E5rd?=]

Agreed on the former, but not the latter. I used to work in a lab where
we could focus our scopes based on the video feed off a Nikon Coolpix
990, which was hooked up to a video monitor (not a computer). It was
actually easier to focus the microscope using the video screen than by
looking through the eyepieces, especially when we were using the
high-mag objectives (we were typically looking at thin wires ~300 nm in
diameter; you couldn't resolve any details with the optical scope, but
you could certainly see and focus on the wires).

The composite output has a resolution of no more than 720x480 pixels.
If the sensor resolution is 5M pixels, the blur will be about 4x4
pixels before showing up on the video output. You can't argue with
facts.

 

[Daniel Silevitch]

The composite output has a resolution of no more than 720x480 pixels.
If the sensor resolution is 5M pixels, the blur will be about 4x4
pixels before showing up on the video output. You can't argue with
facts.

Well, the Coolpix is a 2 or 3 MP camera (I forget which), so it's more
like 2x2. I'm speaking from direct experience on one particular
microscopy system, that it was easier to do precise focusing on a 13"
video monitor than it was using the eyepiece.[1] And, as I said, we were
looking at objects with dimensions comparable to the wavelength of
visible light, using objects with very little depth of field, so good
focusing matters.

For serious imaging, we used an electron microscope, but we could do a
pretty reasonable job with just optical stuff.

-dms

[1] And yes, before you ask, it was a pretty good microscope. One of
Nikon's reflected-light scopes.

 

[tomm42]

Hey all. At the lab where I work we have a Nikon D50 camera attached
to a stereo microscope which we use for taking photos of human and
animal tissue. We have found it extremely difficult to focus and
compose through the microscope itself, so we would like to be able to
link the D50 to the adjacent computer for real-time viewing to
facilitate focusing and composition.

So I am pretty sure what we need is a video card to which we can
attach the RCA plugs from the camera. We need nothing fancy, as this
is going to be the sole use of the video card.

The computer is a Dell Precision 530 running XP Professional, with 1
gig of RAM and a Xeon 2.8 gig CPU, so I think this is more than enough
to support what I need, but I know very little about such hardware.
Any and all advice in this matter would be quite welcome.

Thanks very much!

OK a couple of basics, where is your camera, on an eyepiece or on a
dedicated port? Do you have an eyepiece with a reticle? If not get
one, your camera won't be parfocal without it. I looked at our D70s
and there is a miniplug for video on the side, this can go directly
into a monitor. Get Nikon Camera Control Pro so you can grab full res
images from the camera.
We use an ophthalmic biomicroscope (slitlamp) for photography all the
time. It isn't hard but you need to set it up right. Our camera is on
a dedicated port we focus the microscope via eyepices with reticles.
We have it set so we know what is in focus for us is in focus on the
camera i.e. parfocality.

Tom

 

[Bill Funk]

I guess I wasn't very clear. I suppose the question should have been,
if we were to have the camera in *video* mode, would this be feasible;
i.e., could we view in real time in video mode, then switch to still
mode to take the actual photos, or would what you two gents said still
apply? Or would the resolution still be shite in the video mode?

Thanks much for your feedback.

Nicko

Sorry, no DSLR has a video mode, either.

--
Anna Nicole Smith's family and
friends converged on the late
model's seaside mansion in the
Bahamas on Monday. It's chaotic.
Hundreds of people are waiting
outside the mansion's security
gate, and that's just the line
for the paternity test.

 

[tomm42]

Sorry, no DSLR has a video mode, either.

--
Anna Nicole Smith's family and
friends converged on the late
model's seaside mansion in the
Bahamas on Monday. It's chaotic.
Hundreds of people are waiting
outside the mansion's security
gate, and that's just the line
for the paternity test.

The only thing you can do with video with a DSLR, is see the image you
have just taken on a screen larger than the LCD. Was valuable with
some microscope shot I was doing since all I had the the video image
and what was written on the card, this was with a Fuji S1 with a
pitiful LCD.

Tom

 

[Floyd L. Davidson]

The only thing you can do with video with a DSLR, is see the image you
have just taken on a screen larger than the LCD. Was valuable with
some microscope shot I was doing since all I had the the video image
and what was written on the card, this was with a Fuji S1 with a
pitiful LCD.

I've never done photography through a microscope, but that
sounds to be a *very* useful configuration. Because each setup
is relatively unique, viewing immediate results via a video
connection to the camera allows each image to be previewed
critically, which simply cannot be done with an on camera LCD.

The other option is of course to download each image to a
computer for previewing. That would not be quite as fast/smooth
as a video connection, but could be configured to also provide
relatively quick previewing. If the downloading is done with a
cabled connection to the camera, it may even have some other
advantages because at least with some cameras it is also
possible to control the camera from the computer, which may
provide other benefits.