USE of the LOGITECH QUICKCAM PRO 9000
History of a near-failure, or a semi-success
This article is NOT written for
those with good quality photomicrography devices, already installed and working
properly. The audience I address are those with a limited budget, and
very little knowledge of the subject, who want to try, like me, to install an
inexpensive (that is to say, within their budget) but reliable option.
All approaches I found to this problem always explain, for the described camera,
an already working installation, and usually a successful one. Few people
talk about the reasons underlying the options used, and it is difficult to find
an account of why the other considered options were discarded... and which
failures were suffered. And this is, from my point of view, what we really
try to find, those who have a problem and a guide to aid us to prevent or minimize
This is a chronicle of the adventure in which I embarked, wanting to improve my
photomicrography capacities. I knew little about the theme, to begin with, and
I still have much knowledge to acquire. But I hope the data that I bring together here
is not too wrong, and can provide guidance to some other beginner who also
aims to investigate the capabilities of a webcam.
I think the article could really
seem excessive. And somewhat naive. Anyone of average intelligence
can imagine in advance the result of some of the tests I do.
But I feel that it is this visual and eyewitness testimony, which really
interests me to share.
This presentation is organized
into 3 parts. The first one explains my problem, and my preliminary researches
to decide which particular camera to test.
The second shows test samples,
with the camera for photomicrography and the results (favourable or not)
that I have achieved when working in brightfield.
The third looks at the results I
got (favorable or not) trying special techniques such as oblique illumination, dark
field illumination, episcopy, Rheinberg illumination, polarized light, and
several contrast techniques which give more or less acceptable results when
using my DC3 camera.
Unfortunately I can not provide
data on the use of this camera with phase contrast, because I do not have the
with my obsession for this article, I shall exceed the limit of patience of my readers.
But I'll never get to know this, if I do not share it.
My Current Equipment
I have a National Optical
microscope with MOTIC camera and planachromatic objectives. The DC3 camera
built into my microscope has a sensor that actually produces images of only
0.08 Mpx (320 x 240px). An internal resizing program (probably with bicubic
algorithm, or better) and delivers acceptable images of 0.3 Mpx (640 x 480px)
therefore at a size four times bigger than the original.
It is included in the head of the
microscope and cannot be removed, nor modified.
With the microscope I was given a superb
management program (Motic Image Plus 2000 v.1.3), which
allows the taking of still images, and videos from 320x240px to 30 fps (frames per second), in a
very simple exercise. It also allows image capture in rapid succession manually (I can usually
capture up to 5-6 frames per minute), or automatically. The camera is mounted in
a way that captures the best rectangle inscribed in the field visible through
An overview of the screen from the Motic
2000 v 1.3 program with the capture screen displayed. A click on the button
"Capture still image" displays a frame with an image of 640x480,
behind the screen capture (showing image of a histological section of a tadpole
4 mm long, captured though 10x objective).
The height of the computer screen is 25.5 cm with a width of 41 cm. The display
capture screen (320 x 240 px) is 98 x 68 mm. The Capture Viewer has as its main
function the electronic adjustment of the image, because the capture itself can
be simply done while viewing the subject directly through the binoculars. The
camera is parfocalizable very easily.
The microscope is equipped with 4x, 10x,
40x and 100xOI planachromatic objectives and a "pre-centered" Abbe condenser
1.25 N.A. Lighting is provided with a 12V 20W lamp that generally is somewhat insufficient for the 100x objective in oil immersion (varies
according to the subjects). Although according to the
manufacturers it has a preset Köhler illumination, the existence of a thin ground
glass diffuser filter between the lamp and the front lens of the illuminator
allows only "critical lighting", or "poor man’s Köhler" as
the best possible light style.
Eight years ago this camera was justified,
because although it was advertised as a
"research microscope" it was in fact designed as a microscope for an
advanced student of a science faculty, and at that time the VGA format was very
common on computer monitors. The reasoning that led to the design of this
microscope was apparently impeccable: the integrated camera will avoid all the
problems of adapting a consumer camera, the sensor is fully protected, and
located in the right place to record the largest rectangle inscribed in the
field of view, the camera provided the ability to monitor the microscopic
picture live on the computer screen.
This was easily parfocalizable, and,
providing the microscope with an additional output for TV, and management
software more than acceptable (that even now remains of high quality), facilitated
the observation and taking pictures in quick succession, or even short videos
while viewing directly by the eyepieces.... It wasn’t taken into account (I
think that few people currently did, and I of course did not) the fast and
explosive development of digital photography and the race towards offering more
and more megapixels (which is not finished yet) and that soon made the VGA
format obsolete. Although these models are still selling, most of the MOTIC
microscopes of this kind are currently trinoculars. MOTIC now manufactures
independent cameras: from the 1.3 Mpx Moticam 1000 (carefully reviewed by D.
Walker at MICSCAPE), to 5 Mpx professional cameras.
More megapixels (despite the table
included below, and all assertions to the contrary made repeatedly) represent
better resolved images at digital level. Anyone can verify that this is
extremely important for a good interpretation of the subject. I believe that these two images will make the
point clear enough:
Objective - two micrometer images respectively taken with the DC-3 (left) and a
SX100is Canon of 8 Mpx. The DC·3 is the complete image. Both pictures trimmed
from the originals
It is also true that every time that I
submitted to others judgement, pictures displayed at the capture size, or others
electronically enlarged; the largest (within reasonable limits of course)
always got a better appraisal. (See below for Logitech images at different
To improve the capture
size I decided to try adapting an external camera, supported on one tube of the
According to the next table, a 1.3 Mpx
camera is sufficient for the whole range of my objectives.
OF THE MINIMUM PIXELS AND REQUIRED NA (planachromatic objectives)
thought that adding a camera which produces 2 Mpx images would be enough.
Note: The calculation of this type of table depends on many factors (the NA and type of the used objectives, achromatic, planachromatic, planapochromatic), the number of photodiodes (2 or 3 e.g.) assigned to register each resolved point of the subject, sensor type (monochrome, colour and sensor type) the value of the relay lens reduction, if it is used, and also whether the photos are to be for screen use, published on the Web, or if they are to be printed, in which case there is of course an important interaction between the quality of the digital photo, the quality of the printer, and the size to which we intend to print the image.) But the important thing is that all calculations agree to allocate a higher demand in the quality of the sensor, and the number of photo diodes required, to low power objectives, with a ratio of 3 or 4 to 1 between the lower to bigger magnifications.
course I have the option between the consumer cameras and the webcams. In the
APPENDIX 1 I review very briefly my
thoughts about the use of the consumer cameras
SEARCHING FOR A CAMERA
The ease of capture and image quality, depend of course on the chosen camera. From my
particular point of view I was seeking a camera that has these 13
a. Small size and light weight to allow an easy adaptation to a binocular head
b. Sensor of good quality .*
c. Image Capture 1.3 Mpx at least, according to the table above (2, 3 or Better
4 Mpx, to be preferred)
d. High capture speed, in order to photograph moving subjects
e. Capturing blank backgrounds for correcting background dirt *
f. Monitoring of the screen image in real time *
g. Adjust lighting, color, contrast and white balance *
h. Large video frame (monitor) screen for easy composition and focus
i. Electronic capture to eliminate vibrations .*
j. Manual sequential captures, as fast as possible
k. Video capture as fast as possible
l. Ability to apply darkfield, Rheinberg, oblique illumination and polarized
m. Ability to capture stacks to use in CombineZ * or similar software
similar to these would meet these requirements:
Special cameras for photomicrography
MC 2000 2.0 Mpx
Motic MC 1000 1.3 Mpx
(The DC 3 integrated camera is only sold
in the DC3-163 digital microscope system)
Mpx U$ 499
MicroscopeNet (eBay) 1.3 Mpx U$
Mpx U$ 100
Bresser 0.3 Mpx U$
Mpx U$ 324
Webcams, better suited for
Phillips SCP1300NC 1.3
Mpx U$ 156
Philips SFP6500/00 2.0
Mpx U$ 128
Logitech Quick Cam Pro 9000 2.0
Mpx U$ 100 cost.2009
Logitech C-950 2.0
Mpx U$ 100 cost 2009
Logitech Quick Cam Pro 9000 2.0
Mpx U$ 90 (my cost)
Apart from the price of my Logitech, which is the price at which I acquired it in
Dec. 2008, the rest are prices as for December 2009, obtained from online
For all these cameras I would have to add shipping costs to Mexico that are
usually around U$ 28-30 if imported from the United States, and insurance,
because of the many risks of the transport. I do not know the price from
Europe. Usually, in Mexico, customs also collects taxes on the importation of
Until recently Philips
cameras had CCD sensors. Both Philip and Logitech cameras, according to the current
description by their manufacturers, now have CMOS sensors, although some
unscrupulous sellers advertised them as the CCD’s. Until recently the CCD was
considered unbeatable in terms of image quality. But over a couple of years
some publications insist that CMOS have achieved the same or better quality,
and that its manufacturing method allows them to have a much lower price.
See Appendix 2 about the frequently required post-processing of images APPENDIX 2
Why from the list I selected
the Logitech QuickCam Pro 9000
1 Because some leading amateur microscopists use it and
even post very acceptable videos on YouTube.
by users of this camera can be read in the Messages of the MICROSCOPE GROUP
2 Because it meets 9 and with certain conditions 10 of the 13 requirements for
the best camera. The conditions not met, or fulfilled only in a limited way,
a.Capture of images at least at 1.3 Mpx according
to the above table. According to their current operating conditions (see
below) it only captures images of 0.8 Mpx. (roughly 60% of desired)
b. High speed capture, to
photograph moving subjects. As will be seen below, 2.0 Mpx images (0.8
real) require 1 second to be recorded.
c. Ability to apply darkfield and Rheinberg techniques. The tests so far suggest that it is
possible to use oblique
illumination and polarized
light, but dark-field images
are not very good (much
3 Because it has a Zeiss Tessar lens with 5 elements.
4 Because it has a 2 Mpx sensor,
advertised as providing high quality images
5 Because it has a program that has
control of the lighting intensity, and which I thought could help to record
better images at high magnification (with limited lighting)
6 Because it is totally manageable
with the computer
7 Because the images monitor screen is
large (20 x 23 cm on my monitor)
8 Because I have the additional programs (detailed
above) necessary to process my photos and videos
9 Because it is very easy to
disassemble and only weighs 30 g
10 Because it costs me $90 and
was available in Cancun, while the European Philips are not available here, and
are more expensive.
11 Because it cost me $0.50 to fit it
to the microscope.
In fact if I had been free to choose, I would have
liked to buy a Logitech C-950 with
exactly the same specifications, but with a more flat design and more easily adjustable
to a homemade adapter.
convince me that the camera really qualifies for a trial I made some tests. The
most simple are summarized inAPPENDIX 3
ADAPTATION TO THE MICROSCOPE
task to properly adjust this camera to a microscope, is to remove the brackets that allow its attachment to the computer screen, or support it over the desktop.
These are pictures of the entire camera.
In an article by Gary
on adapting the camera to a telescope, he illustrated step by step
instructions not only to dismantle the camera, but to transform it into another to be
attached directly to a telescope .... or even a microscope, of course.
The author also describes and illustrates very effectively with the camera
itself the consequence of the inevitable removing of the Infra Red (IR) included
filter, and the need for replacement, as will be seen below.
This is the image of the camera as it was after I removed what I don’t need.
The connection to the
CPU uses a USB 2 port.
You only need to install the camera on a support that fixes it properly over
the eyepiece. This is the one I use.
This adapter was
built entirely out of cardboard and plastic putty. It's sufficiently rigid, light
weight, and fits well with the camera. If needed, slight vertical displacements
can be adjusted with small wedges of thin cardboard, which is then permanently
glued. (Or, with little additional effort, 3 screws can be installed, which can
also help to “center” the camera, though I did not find it necessary). The
camera is attached over the upper platform. For now I simply hold it with
rubber bands. These fit well, but allow easy mini-movements to focus the
objective on the exit pupil of the eyepiece. A recess into the top of the head
allows the camera to settle so that ambient light does not leak to the objective.
Whoever is more determined than I am, can glue it, using a suitable glue.
The preparation of
the adapter needed the materials below and I believe that the description of the
process is implicit. A ruler, a choice of cardboard tubes, cutting and gluing materials is
almost all that is needed.
HOW TO USE THE CAMERA
There are two methods that work with two well defined types of camera:
1 - Those with a fixed front lens, immovable, with which you can only use the
system known as "afocal", using the camera and microscope as they are,
or at most changing the camera lens. What sort of pictures can be
taken with this system?
2 - Those with
interchangeable lenses, so the front lens is unscrewed, leaving the sensor
exposed, and with which you can use the system I call "astronomical"
that only uses the microscope objective, and discards the eyepiece of the
microscope and the objective of the camera.
seen at left, the eye views through the front lens of the eyepiece
(e), the image ( i ) projected by the microscope objective in
plane of the eyepiece stop (d) and the brain recognizes the
magnified image (mi) - L, light path - t, tube of the microscope
afocal system uses only part of the sensor. The "astronomical"
system uses only part of the field of view
The Logitech can work
straight away with the afocal system, and with a little additional work (remember
the Ghonis article) as an astronomical device. But to eliminate the
camera lens is a relatively delicate task, and therefore it is almost final,
because there doesn’t exist an easy replacement method unlike the threaded
objectives of higher quality digital cameras.
The system I call "astronomical" because of its extensive use among
amateur astronomers, is one that only uses the microscope objective, and
discards the microscope eyepiece and the lens of the camera.
This was indeed the method we used for amateur
microscopy in about the 1950’s or 60’s, adding to the end of the tube of the microscope, without
eyepiece, a bellows without lens, with a cone or a hollow pyramid with
height proportional to the desired magnification, and using at the end a
sensitive element (sensitized glass plates, silver bromide paper, or 35mm film).
If the sensor is placed 25 cm from the exit pupil
the magnification of the photo corresponded exactly to the nominal magnification
of the microscope.
Attached picture: a professional Leitz instrument of the late nineteenth
century (J.E.Barnard - 1911 - pict. 38a - pg. 114)
The amateurs of the twentieth century like myself often used
cardboard cones, at the end of which was glued a wood and glass frame that we
used to make prints on sensitized paper. Instead of the usual sandwich "glass-negative-sensitive paper”, bare bromide
paper was placed in the frame and we exposed it to the light projected by the objective
of the microscope. The image was later
chemically reversed. Rigorously working in a darkroom of course.
we speak of discarding the lens of the webcam
we must make it clear that this is not a trivial action,
and that we must be ready to counteract its effects. Read the APPENDIX
Using the camera
In France the Philips webcams were used for years. (Until recently they were of
0.5 Mpx, and since a couple of years ago of 1.3 Mpx. Now they have 2.0 Mpx.
Apparently sensors previously used were CCD, but the maker's specifications indicates that now they are using CMOS sensors). Webcams
were used by adapting the method used by amateur astronomers: camera without lens, microscope without ocular.
The image generated
by the microscope objective is then projected as a cone of light, which can be
intercepted at any height after the exit from the tube of the microscope to get
the real picture. In all cases tested, the diameter of the projected cone
outside of the microscope tube is much bigger that the diagonal of the
sensor. The sensor is exceeded in great excess by the image, and the Photographic Field is a
small fraction (which can be only 5% to 7%) of the Field of View (FV)
The following circular
image represents the projected image, and the box in the middle of the field of view represents the area
captured by the sensor. Image not to scale, the rectangle is here bigger
than in reality.
of a blood vessel in a preparation of human duodenum. Fixation with formaldehyde in neutral
buffer, embedded in paraffin, cut at 8 microns thick, HE staining.
through their eyepieces the microscopist would see the complete the picture above,
the following would be an example that mimics
the part of the field that the camera would record.
This has given basis to
the absurd claim of a web site that considers possible, using common and even low
powered illuminated microscopes, by the only trick of removing the eyepiece of
the microscope and the camera lens, to get images between 5000 and 8000 optical
Of course the
resolution of the objective (in the optical sense of the term) cannot
vary. If the objective 100x, NA 1.25 with oil immersion, resolves the image when
illuminated with light of 550 nm to see as different 2 points distant only
0,02 micron, this is the maximum optical resolution achievable with any degree
of projection distance.
resolution depends on the microscope optical system (NA of the objective,
Objective magnification, Eyepiece magnification) not the size of the image.
This system is
especially attractive to those wishing to study and photograph only tiny
subjects, such as blood cells, diatoms and protozoa, for example. But it
can be really annoying for those who want to photograph such things as a
mosquito larvae. For even with a 4x normal scanning objective they must take
several pictures to cover their entire body, and then set up a mosaic. If
they tried to avoid mosaics, they should add to their equipment very low
magnification objectives, as for example a 1.6x or 2.0x (expensive of course), and require very flat and uniform lighting of the large field of view covered, which is not a very common feature in
People involved in higher invertebrates research, or histology, surely want to have greater
field of view coverage. These people are more interested in
It is based on simply
applying the camera to the eyepiece of the microscope, adjusting it properly to
the exit pupil, and to be satisfied to record the total field of view at the magnification allowed by the sensor coverage.
This is an example of an image obtained under these conditions by the Logitech
The black rectangle is actually the recorded image of the full sensor. The
central circle is the area of the sensor actually used. This effect is
usually called "vignetting".
The same image shown earlier as the Logitech registers it in "afocal
system". Reduced from the original 1600 x1200 picture
As shown, and it is
the normal situation with the webcam, and even with most consumer cameras with short
focus objectives, the virtual image visible by the camera does not cover the
sensor field. The picture obtained is the
center circle. It uses only a portion of the photoreceptors of the
sensor. Even when using a camera that normally produces images of 2 Mpx
(the size of the entire sensor), some measurements and a quick calculation shows
that the image uses barely 0.8 Mpx approximately.
Full sensor Rectangle: Image 1600 x 1200
px = 1.92 (2.0) Mpx
(without zoom): 0.8 Mpx (only 40% of
the sensor, but 10 times greater than that recorded by the DC3)
Maximum allowable cut with ratio 1:1.3:
800px x 600px = 0.48 Mpx = 24% (relation to DC3 = 0.48/0.08 = 6 times)
Cut made in scale 1:1.6 ratio: 860 x
513 = 0.44 MPx = 22% (5.5 fold increase)
Maximum square inscribed in the circle:
710 x 710 = 0.50 MPx = 25% (6.25 times higher)
Of course the ideal solution is this one.
The rectangle is the picture a dedicated photomicrographic camera takes from
the Field of View
Now the projection of
the intermediate image has a diameter coincident with the diagonal of the
camera sensor. The rectangular image is actually 2 Mpx obtained by
covering the entire sensor. The special
photomicrography cameras work that way. Webcams usually do not meet
this requirement and instead stick to the geometry of the vignetted image shown earlier as the Logitech does.
SOLUTIONS USED - Faced with this
reality microscopists have opted for some effective solutions.
Installing a telephoto lens - Using the
intermediate image size, equal to the size of the internal diaphragm of the
eyepiece of the microscope which depends on the quality of the eyepiece (my eyepieces
has a FN 18 mm) the focus of a new lens can be calculated.
To cover the sensor completely I need to replace the wide angle lens of the
Logitech which have a focus of 3.7 mm, by one of 8 or 9 mm focal length,
according to calculations that Charles Krebs kindly communicated to me. This
means that I should provide it with a telephoto lens.
There are on the Web some addresses of suppliers of suitable
lenses. (Two recommended in the Forum MICROSCOPE are: www.sunnex.com and www.optekusa.com)
The lenses themselves are not too expensive (depending on their quality of
course). You can get up one for 20 to 40 dollars.
But the amateur microscopist must understand that
these will not be Zeiss Tessars and they must
also workout for themselves how to remove the original lens of the webcam. See how you can do it in
how to adjust the new replacement lens to the camera.
The new lens does its job by reducing the image field of view so that it only
covers all the photodiodes of the sensor, thus changing the geometry to fill the field.
Some providers also
offer to calculate and build the necessary adapter to turn your webcam
into a camera similar to the so-called "Microculars”. (there are others,
but see eg. Truetex)
But that raises the price of the amendment, almost to
the price of a commercial Microcular (sometimes more) and does, from my point of view, become a completely pointless venture.
Changing the microscope eyepiece -
The second solution is to acquire and use in the microscope a SWF (super wide field)
eyepiece with FN between 22 and 23 mm, and high relief point (eyepieces for
short-sighted eye) in order to project onto the sensor a larger-diameter
circle. These eyepieces are not easy to find, and are always very
expensive. (A 15x Olympus lens with FN 22 was offered at $170 on eBay)
and hardly provides a total solution.
(see page. 3)
“I found that I needed a 15x ultra w.f. eyepiece to fill most of the field of view.
The video frame is not completely filled, but it is not bad
considering the wide angle lens of the webcam. Cavalue”
Both solutions can be
used simultaneously, of course. As in the other cases, my concern is that with
all these adjustments we are reaching the price level of a commercial camera,
which could be acquired completely prepared. Except for the pleasure of
making a homemade device, these adaptation solutions do not appear to have a
favorable cost / benefit ratio.
Finally, if you don’t buy an adapter there is the problem of preparing one at home,
to adapt the camera to the microscope. Solutions are also published on the
web. Relatively few are economic ones. The efficient Cavalue solution, for
example, not only provides a secure fixing of the camera in a working
position, but permits at any time to retrieve the same for normal use. But
the Lumicon adapter he uses, costs $50, over 50% of the price of my camera.
Others projects, based on PVC, or metal home designs, may have a favorable balance.
But involve having tools that not everyone has. Perhaps my solution is the most
economical, while being effective.
A comparative calculation is below of the cost of adapting at home
a Logitech, or purchasing a special camera for photomicrography. I limit it to
the very cheap cameras like the Micro-oculars made in China.
Camera + teleobjective + highpoint eyepiece + Lumicon adapter
90 dls 30 dls 170 dls 50 dls total with eyepiece 340 dls
without eyepiece 170 dls
Add the custom and
insurance fees if the material must be imported. Check prices for cameras
with 2.0 and 1.3 Mpx in the table above. There are 1.3 Mpx cameras between
130 and 320 dls
A summary of my
situation, after all this long analysis is:
As for many others I can’t purchase a special photomicrographic camera of
a high-class brand.
My Canon A300 can by no means be successfully adapted, mainly due to its
turn-on system which involves a difficult to operate, manually slide
protection, for its lens.
But I did buy a Logitech for $90, to undergo adaptation.
After collecting the information summarized above, and doing some experiments
with the camera, I decided to use it in afocal geometry,
for not to have to buy or import not matter what telephoto lenses, or
eyepieces, or IR filters, or adapters of any kind.
That sentences me to have a Logitech with a wasted good sensor, using only
0.8 Mpx of the actual 2Mpx available.
The cost for me was $90. 50 and just needed to build the adaptor for the binocular
tube. It was very affordable (not more than 50 dollar cents.)
To install the Logitech in these conditions was simple; it only weighs 30
g. and creates no tension on the head of the microscope.
Thus, my microscope is now equipped with the 0.08 Mpx DC3, 0.3 Mpx digitally enhanced, that is still relatively useful,
and which is managed since December with Motic Images Plus 2.0 software. It is usable with the 10x objective, but
especially with the 40X and 100xOI objectives. And the Logitech, installed on one of the
binocular head tubes, for all objectives, with 0.8 real Mpx. For occasional shots of absolutely immobile objects, I use the Canon A300, which I can manually hold over
Go to the 2nd. of 3 parts (in March 2010 issue)
In the second part I will
explore the real target of this work: the Logitech
9000 web camera as a photomicrographic
camera, especially capturing still images in brightfield.
In the third part we
will see its behavior as a photomicrographic video camera and to capture snapshots
of moving subjects, and the capabilities it has to record the results of
to acknowledge the kind assistance of D. Walker and
J-M Cavanihac, whose thoughtful suggestions allowed me to greatly improve the
presentation of this article.