Cautionary notes:  If you are using these images to make measurements on images of devices -

Different users have a way of changing the microscope software settings - sometimes in ways that distort the saved images.  The calibration images on this page should only be used if you used the same software settings used for these images. Under the Capture Properties icon, Still Image tab:  4CIF (704x576) image size (also landscape orientation and 24-bit color). The key point is that the image size be set to 4CIF (704x576) in the Capture Properites menu.  If it is not set this way the horizontal and vertical scale factors will not be the same on a given image, thus the image will be distorted.
Hardware changes may also have occurred, and are harder to correct.  For example, someone may have disturbed the mechanical adjustment of the height of the digital camera above the optical column of the microscope, which probably will impact the scale factor of images.  You would basically have to obtain new images of the calibration reticles to account for such changes.
Make sure you are viewing or printing the your images and the images of the calibration slides at the same scale.  Don’t let your software mess up your scale calibration.
Measurements made off of captured images will probably not be as accurate as by directly measuring using an eyepiece reticule.  Keep the following in mind when estimating the uncertainties for your measurements using these calibration images.
*	The camera has finite pixel size and pitch.  The pixelization that this causes can distort the scale on the calibration slides and on your image.  (This is particularly evident in distortion of the smallest divisions of the image of the 1 mm/full reticle scale with the 2.3x objective.)
*	The microscope camera software allows the images to be saved in either jpeg or bitmap formats.  Neither of these formats produced saved files that were as clear as the original images.  I tried several options.  The bitmap images looked worse than the jpeg images and had much larger file size.  The software defaults to a quality setting of 75 for the jpeg format.  Lower settings give worse saved images.  Higher settings (I tried the maximum) produced much larger file size without significant noticeable improvement in the image quality.  (Assessed by distortion of the pitch of the 1 mm/full reticle scale with the 2.3x objective.)
*	The screen you are viewing the images on or the printer you are printing them with has its own tolerances and introduces additional error.

Images of two different calibration slides were captured using three or four of the five objectives.  The image quality of the 10 mm/div slide (emulsion pattern) was too poor to be useful with the 100x objective.  The spacing for the marks on the 100 mm/div slide exceeded the field of view for the 100x objective.

Image dimensions may be set to a variety of standard sizes, or to a custom size.

Standard image dimension settings include: 

Note that the CIF settings have an aspect ration of 1.222 (e.g. 704/576), while the other settings have an aspect ration of 1.333.  If you saved your images using one of the settings with an aspect ratio of 1.333 (e.g. 640x480) the horizontal axis of your image will be stretched out by a factor of 1.333/1.222 = 1.09 relative to the vertical axis.  Similarly, if you were to use a custom image size with an aspect ratio different from 1.222 the saved images will be distorted.  For example, a custom image size of 1200x800 has an aspect ratio of 1.5, so the horizontal axis will be stretched out by a factor of 1.5/1.222 = 1.23 relative to the vertical axis.

The available orientation selections are landscape and portrait.  All of these calibration images have been obtained in landscape orientation.

The available image type selections are 24-bit color, 256 color and black and white.  24-bit color was used for these calibration images.

Selection Table

	The calibration images under this column were taken in August 2004.	The calibration images in this column were taken in April 2004.
3.2x objective	1 mm/full reticle	100 mm/div
5x objective	1 mm/full reticle	100 mm/div
20x objective	10 mm/div	100 mm/div
50x objective	10 mm/div

August 2004 - 3.2x objective 1 mm/full reticle | Selection Table The length of the full scale is 1 mm.  The numbered divisions are 100 mm apart.  The smallest divisions are 10 mm apart.  Note how the pixelization has caused some of the lines to appear almost double.  Note that the pattern of almost doubled lines is periodic (determined by the relationship between the pitch of the pixels in the camera and the pitch of the image focused onto the imaging chip in the camera).

April 2004 - 3.2x objective 100 mm/div | Selection Table Since the lines on this scale have significant width be sure to use the same edge on each line (e.g. use the right edge on each line) when measuring.

August 2004 - 5x objective 1 mm/full reticle | Selection Table The length of the full scale is 1 mm.  The numbered divisions are 100 mm apart.  The smallest divisions are 10 mm apart.  Note how the pixelization has caused some of the lines to broaden.  Note that the pattern of broadened lines is periodic (determined by the relationship between the pitch of the pixels in the camera and the pitch of the image focused onto the imaging chip in the camera).

April 2004 - 5x objective 100 mm/div | Selection Table Since the lines on this scale have significant width be sure to use the same edge on each line (e.g. use the right edge on each line) when measuring.

August 2004 - 20x objective 10 mm/div | Selection Table The numbered divisions are 100 mm apart.  The smallest divisions are 10 mm apart.

April 2004 - 20x objective 100 mm/div | Selection Table Since the lines on this scale have significant width be sure to use the same edge on each line (e.g. use the right edge on each line) when measuring.

August 2004 - 50x objective 10 mm/div | Selection Table Since the lines on this scale have significant width be sure to use the same edge on each line (e.g. use the right edge on each line) when measuring.