Chazs
28th of December 2004 (Tue), 23:50
A different thread earlier mentioned using a DSLR as a pinhole camera. I experimented with it tonight and came up with some interesting results.
http://members.isp01.net/snevetsc/photos/pinhole.jpg
Photo 1: hole too large (about 1/8 inch): 2 second exposure
Photo 2: hole the size of a small nail: 5 second exposure
Photo 3: hole using a sewing needle through tinfoil: 15 second exposure.
Photo 4: same as (3)
So, I got to thinking... what focal length lens gives the same field of view as the pinhole? Would it be the 50mm "normal" lens, or would I need to use about a 32 mm because of the 1.6-"whatever"-factor.
Photo 5: 50mm lens gives the SAME field of view as the pinhole. Hmmm?
Photo 6: 30mm shows a much wider field of view.
One last thing the pinhole showed me was an EXTREME amount of dust and bad pixels. Over this holiday break I've taken about 30 to 40 pictures a day and haven't noticed anything too unusual. However, the pinhole pictures revealed numerous bad pixels and an over-population of dust bunnies. Time to clean the sensor and take note of bad pixels.
100% crop of a typical region:
http://members.isp01.net/snevetsc/photos/dust.jpg
CHUCK
http://members.isp01.net/snevetsc/photos/pinhole.jpg
Photo 1: hole too large (about 1/8 inch): 2 second exposure
Photo 2: hole the size of a small nail: 5 second exposure
Photo 3: hole using a sewing needle through tinfoil: 15 second exposure.
Photo 4: same as (3)
So, I got to thinking... what focal length lens gives the same field of view as the pinhole? Would it be the 50mm "normal" lens, or would I need to use about a 32 mm because of the 1.6-"whatever"-factor.
Photo 5: 50mm lens gives the SAME field of view as the pinhole. Hmmm?
Photo 6: 30mm shows a much wider field of view.
One last thing the pinhole showed me was an EXTREME amount of dust and bad pixels. Over this holiday break I've taken about 30 to 40 pictures a day and haven't noticed anything too unusual. However, the pinhole pictures revealed numerous bad pixels and an over-population of dust bunnies. Time to clean the sensor and take note of bad pixels.
100% crop of a typical region:
http://members.isp01.net/snevetsc/photos/dust.jpg
CHUCK