Anywhere from $650 to $30000, depending on the kind of round.
Tall? My CD's are round with a diameter of 120mm and 1mm thick.
120mm = 0.00012km
Measure from the installation screws horizontally and vertically. Round to the nearest 10mm. Most common sizes are 80mm and 120mm.
A magnification of 40 times is needed to achieve a 120mm image of a 3mm object. This is calculated by dividing the desired image size (120mm) by the original object size (3mm). So, a magnification factor of 40x would enlarge the 3mm object to 120mm.
80mm x 120mm equates to 3.15 inches x 4.72 inches.
4.72440945
120mm precisely xxx
120mm
120 million
130mm
Answer120mm = 0.12m
if you can see it, you're in range.