Challenge: How Small Can You See

Started Oct 5, 2012 | Discussions thread
ForumParentFirstPreviousNextNext unread
Flat view
Stephen Barrett
Regular MemberPosts: 456Gear list
Like?
Challenge: How Small Can You See
Oct 5, 2012

The challenge:
1) Find a macro target with a very small repeating pattern, either in nature (e.g. evenly-spaced hairs on a leaf or bug) or "home-made" from inexpensive parts.
2) Take a Macro-photograph of your target, together with a millimetre scale or ruler; blow the picture up so that you can count how many times the pattern repeats per millimetre.
3) Post your picture or crop or both, tell us what it is, camera & settings, and your claim for highest cycles/mm     [or 1000 / (cycles/mm) gives you microns].  IQ and contrast are not concerns, just whatever you can definitely distinguish on at least a portion of the target.)
4) Highest number of cycles per millimetre wins the prize, which is the glory of winning.
5) I volunteer to be the judge, but others are free to disagree with my rulings.  Winners to be announced November 1, 2012.    (There may be winners in different categories, such as "single-lens"  "lens with attachment".)
Here is my entry, which shouldn't be too hard to beat:

Light-bulb filament from a Noma 4-Watt night light.

Photo Details:
Light-bulb filament from a Noma 4-Watt night light.
Taken with SX30, Macro, F/2.7, L-Format (4320 x 3240); target touching the lens.
Filament mounted on graph-paper with 1-mm square divisions; backlit with sunlight.
My claim:
The filament is helically wound with 40 coils per mm (or 1000/40 = 25 microns separation) so try to find something that repeats more than 40 times per mm (i.e. with a separation smaller than 25 microns).
Article:
If you are interested, I wrote an article about "My Search for an Inexpensive Macro Test Target":
http://www.dpreview.com/articles/5039116594/my-search-for-an-inexpensive-macro-test-target

 Stephen Barrett's gear list:Stephen Barrett's gear list
Canon PowerShot SX30 IS +3 more
ForumParentFirstPreviousNextNext unread
Flat view
Post (hide subjects)Posted by
ForumParentFirstPreviousNextNext unread
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark post MMy threads
Color scheme? Blue / Yellow