Stamps - measurement of openings and cutouts: When acquiring the images it is advisable to align areas of interest horizontally or vertically in the capture window. The software will calculate the length of a line (distance) under any odd angle using good old Pythagoras. But the result will be a fractional number with some digits behind the period. It will look pretty messy especially if you need to do more than one measurement in the same area. Also, any supporting lines need to be done under the same odd angle and that will be quite difficult.
For horizontal or vertical alignment when capturing the image you can rotate the sample (tedious), the camera, or the stage plate (easiest).
Also, you will want to align the capture image with what is seen through the eyepieces by using the ‘flip horizontal’ option of the settings menu under Misc. makes switching between eyepieces and display less confusing. But you can also do that anytime later after saving the captured image, use Image > Rotate > Flip Horizontal on the menu bar. First we need to establish the length of some feature on these images in mm or inches. A simple calculation gives us then the relationship between image pixels and mm or inches.
For better accuracy we will select a fairly large distance, the spread of the 5 circular holes on the right side of the stamp.
Here is our first image showing at top the row of 5 holes and the tips of a metric caliper. This image is only 500 pixels wide. The actual captured picture uses the full camera resolution of 2592 x 1944 pixels. Looking at it through the scope you can align the caliper tips quite precisely with the edges of the outermost holes. : The caliper reading of 15.5 mm gives us the base to convert other dimensions in this image from pixels to mm. Next we load this picture into the ScopePhoto application coming with the camera. By scaling the image a bit we have these 5 holes using nearly the whole width of the screen.
Annotations and measurements use a separate layer, the original image will not be modified. First we need to create that new layer by clicking on Layer > New on the menu bar. The defaults are in most cases ok but we should give this layer a meaningful name.
Now the draw icons on the righthand side just below the menu should be no lonher grayed out, meaning they are available.
The line button has a small dropdown option for Horizontal and Vertical Line. Just select Horizontal Line. Then locate the left most edge on the center line for the 5 holes and click the left mouse button, then move the mouse to the right. A horizintal line will appear and the length in pixels will be indicated in the center.
If on first attempt the result doesn’t look quite right you can use the UNDO funtion under Edit > Undo and start over.
After 2 or 3 attempts you will have a perfect result, 2066 pixels indicated in the line center. Dividing 2066 by the earlier measured 15.5 mm yields about 133.3 pixels per mm.
Now we have the picture calibrated and can do more measurements like hole diameter or gap between holes etc.
Using the text function on the Draw menu you can enter the dimension in mm next or below the software generated result in pixels. Next it might look better to distinguish measurement lines by color from other help lines and text. On the DRAW menu a heavy up-arrow near the screen center allows you to select an object on your measurement layer. Going to Draw > Properties allows you to change color and the endpoints to arrows for example.
The result could be similar to the image at right, turned 90° ccw to fit the page format better. You can save the original image with additional layers in .sft format only. But the Export to Image option in the File menu allows to export the sum of originial image and layers. With File > Save As you can save then in several standard file formats for images
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