1889 sovereign coin from Sydney. S Mint-Mark. | Copper coin found in Ruhuna,
Lanka.
Small Grains. |
10X 400 dpi 20.MMx15.MM | |
60X 2400 dpi 3.3MMx2.5MM | |
200X 8000 dpi 1.0MMx0.75MM |
This Mint mark (9 pixels/dots height) at 300 dpi is not resolved and
barely resolved at 600 dpi.
The QX3+ seems to have been optimized for best performance at 60X.
Getting Optical 2400 dpi image of even a small 3MM region at 60X
is IMHO clearly worth what I paid for it.
The Intel QX3+ Play Microscope was discontinued on March 29th, 2002 and now on sale as Digital Blue QX3 for about US$40 including S&H in USA. It connects via a USB port to a PC. Has even a Linux driver. The coin can be illuminated from above. The Toy is a great gift for kids and provides versatile software to do many types of image capture.
Intel FAQ
says The microscope uses a CMOS CIF sensor, which is
ideal for use in a microscope that focuses on a small image area. CIF
resolution is 352x288 pixels, but the microscope software only uses a
central region of interest (ROI) of the image - 320x240 pixels to be
exact. The image is interpolated to 512x384 pixel resolution for
display in the microscope software's Live View window.
The 10X image is equivalent to a 400 dpi scan at 150%
The 8000 dpi at 200X is probably limited by the cheap optics. The depth of focus is poor and the surface of coin and high-relief of design was not the sharpest at same focus setting.
The mounting is clearly that of a Toy and is the worst part of the device. It is difficult to do any fine focusing or move/slide/rotate the platform. But this can probably easily be resolved by mounting the electronics which is independent on a better platform.
Overall it has good electronics, OK optics and toy mount. I have read of persons who replaced both the optics and mount to get a good low cost digital microscope.
Scanners clearly have the advantage of an unlimited field of view. I will be greatfull to anyone who E-mails me .jpg images of same or similar Mint-Marks from other image capture devices like very high optical-resolution scanners, digital cameras with Macro capabilities to be able to do a comparison of resolution, focus and price.
List of Numismatic and other sites with images from QX3
Links to other more expensive but higher quality USB Microscopes