USE of the LOGITECH QUICKCAM PRO 9000
History of a near-failure, or a semi-success
CONSUMER CAMERAS AND PHOTOMICROGRAPY
Many microscopists commonly use very successfully "consumer cameras” (Nikon, Olympus, Sony, etc) without direct screen monitoring capacity, or USB connection to computer (except for downloading images). Microscopists generally focus with the electronic viewfinder or LCD preview panel of the camera, for that a camera with large display is needed, or, as in the great installation of Charles Krebs, they parfocalize the camera so that the image can be captured while observing directly with the binocular microscope. The valuable technical guidelines, methods, and results, of Krebs MUST be read at
An image provided by Charles Krebs of his impeccable facilities
Those who read his articles would be divided into two groups:
1) those who can acquire the necessary equipment (high quality optics for their microscopes, cameras with the desired sensor size, with adequate number of photodiodes to produce images of a high number of pixels, relay lenses carefully calculated, and professional adaptors, etc.) which can therefore effectively use the quality of their facilities in their photomicrographs, and ...
2) those that do not, and who, forced by the circumstances, must try to adapt their cameras, to their personal microscopes, with the sensor size and pixel size they have, to obtain the best possible images.
Of course it is only for the latter that these lines are written.
In my case, I wish to maintain the advantages of the Motic DC-3, although surpassing the capture size limitations. It is clear that my choice of camera will depend, fundamentally, on whether it is commandable by the computer.
If you want to monitor the image on the screen, making there a first adjustment, and capture it with a click of the "mouse", but to also have the option to easily capture video of moving subjects, this limits the choices to webcams, or ... to certain Canon cameras. (A70, A75, ...., A520, A540, A620, etc) that have included software ( "Remote Capture") for monitoring on-screen, mouse capture, and image download to your computer via a USB-2 port. With their 10 Mpx pictures and easy connection to a computer, the A620 Camera has won the prestige of being recommended by Zeiss as a good photomicrography camera.
Note: Currently, software is offered online for "remote capture" (PSRemote, eg.) which can be adapted to various other cameras. But I have not seen any microscopist who describes its use. The remote capture eliminates any mechanical maneuver for shutter release of the camera and thus avoids most of the vibrations that affect the quality of the image. (the program costs $95.oo)
The Canon Powershot A70 and A540 are used by Howard Webb, in his contributions to MICSCAPE. The Canon S50 (which also allows remote capture) is used by Michel Verolet from the French forum MIKROSCOPIA, who has obtained remarkable rotifer pictures using it on the eyepiece. His images are available in the Encyclopedia of the Forum, after a simple registration. Thanks to their kindness many of his images can also be seen in MICSCAPE, by reviewing the following works
Post processing of the images.
I do not extend the discussion nor add illustrations on this subject because my information differs only in details with those provided by D. Walker to whose article I refer again, and whose magnificent illustration describes the program in detail.
I own these, with which I perform the following functions:
g. To trim in various proportions
(ACDSee, Photoshop, PhotoPaint)
o. Editing videos. Extraction of selected frames (Avidemux)
DOES THE LOGITECH 9000 HAVE THE DESIRED QUALITY?
The Logitech as a webcam, or as a normal camera (1.3, 2.0, 3.0, 4.0, 8.0 Mpx).
The following is a preliminary test I made to decide whether the camera complied with the manufacturers promises of image quality. There are some comments on this subject posted to the net, but none very critical, because almost all refer to the normal use as a webcam for live video, a task for which their behavior is outstanding.
The pictures were taken by successively graduating the camera for each reported capture size. Then I cut a "manageable" rectangle of a similar area from each image to be compared here.
Removing the camera lens also means eliminating the infrared filter it has
Logitech 9000 - Image with the IR filter in position. Logitech 9000 - Image once the IR filter removed
Without other facilities the webcam does not record what photographers really know as infrared photographs. To achieve this (something that rarely interests the photomicrograph amateur) it is necessary to filter the remaining visible light, which amateurs get using one or more color filters prepared with completely veiled color negatives. If some one is interested, methods and results can be viewed at the following website: http://www.hoagieshouse.com/IR/ with two fine examples (pictures of a Lake) at the end of the article.
To counteract the effect of the removal of IR filter there are only two solutions:
1) reinstall an IR filter in the light path. Probably
the best place to put it is over the front lens of the illuminator. The
filter is expensive. If you have an old 35 mm slide projector, these have a
large IR filtering glass, built-in to prevent burning the slides with the lamp heat. Place
the filter over the lamp, at the foot of the microscope.
Although the choice depends a little on the used microscope and camera, more useful modern LEDs, are the 3W, lambertians, with 50-60 ° aperture of the cone of light, which work on 1.5A, and consume 10V. A well-known, widely used mark is Lumiled.
They emit enough heat and need to be mounted on heat sinks generally especially built and ventilated if possible, and connected to a voltage regulator independent of the microscope system.
There are commercially available microscopes equipped in the factory with LEDs.
also requires the possession of some tools, good eyesight, and sufficient manual skills.
One example of a complete installation on a Swift microscope, with an extensive discussion of the LED's characteristics and operation can be found in http://www.microscopy-uk.org.uk/mag/artmay04/iwled.html
Comments to the author,
, are welcomed.
Published in the February 2010 edition of Micscape.
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