|
Search this group's discussions
|
HOw to Measure The Pinhole Using Scanner
|
hi guys!, i heard you can measure youre pinhole in your cam using a scanner but i dont know what method? or software involve? any ideas? Thanks!
Posted at 3:12AM, 19 November 2007 PDT
(permalink)
|
|
The simplest way is to put your pinhole on the flatbed scanner with a ruler or something of known size as close to the hole as possible. Scan as a normal image (not transparency), then zoom in and compare to the scale on the ruler. It isn't perfect, but will get you close enough.
Posted 55 months ago.
(permalink)
|
|
If you know the scan resolution, you can count pixels across the diameter of your pinhole. For example, you could scan the pinhole at 600 dpi, then blow up the result until you can count pixels. If the pinhole is 12 pixels wide, then the diameter is 12/600 inches (reduces to 1/50" or 0.02").
I would urge you to not place too much importance on the exact pinhole size. Just get it close to whatever is recommended by Mr Pinhole or one of the other online calculators and it will be good enough. Whether you know the exact size or not, experimentation will be required to get the exposure right. I use the scanner to evaluate the pinhole for roundness and crisp edges more than to measure exact size.
Posted 55 months ago.
(permalink)
|
Would you like to comment?
Sign up for a free account, or sign in (if you're already a member).
|
|
Pinhole Photography /
Discuss
Feed – Subscribe to Pinhole Photography discussion threads
