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Quick extension tube question
- Thread starter Zerimar
- Start date
Shashin
Well-known member
1. Measure the diameter of your penny (in mm). (You can save a bit of time by shooting a mm scale or ruler.)
2. Measure the number of pixels across the image of the penny is.
3. Multiply the number of pixels by the pixel pitch in mm. That will give you the image size. To convert um (mircons or micrometers) into mm, divide your number by 1,000
4. Finally, simply divide the image size by the object size. That is the linear magnification at the image plane or sensor. (BTW, if you make a print, that magnification will then change as the image is larger--that is the reason scientists use scale bars rather than describing magnification.)
2. Measure the number of pixels across the image of the penny is.
3. Multiply the number of pixels by the pixel pitch in mm. That will give you the image size. To convert um (mircons or micrometers) into mm, divide your number by 1,000
4. Finally, simply divide the image size by the object size. That is the linear magnification at the image plane or sensor. (BTW, if you make a print, that magnification will then change as the image is larger--that is the reason scientists use scale bars rather than describing magnification.)
