photographing corms on grids

Tue, 29 Jan 2013 12:39:59 PST
Jim mentions photographing corms on grids. What he does not mention is that I made a whole lot of mistakes before finally learning how to do those right! (I dont post the mistake photos.) Several PBS members have given me advice on this, including David Pilling and Mary Sue Ittner who saw some of my early attempts. To help others avoid the pitfalls:

Graph paper is available online to print, such as from:

for the 1 cm grid (despite the filename, this really is 1 cm or 10 mm grid)
However, when you print it, be sure to say scale 100% and after it prints, measure it with a ruler. I photographed a whole shipment before realizing my printer had "helped me fit the image to the paper".  Ugh.
Sometimes I include a marked ruler alongside the grid.

Getting a good exposure of dark corms or seeds on a white background can be tricky. Load the photos off the camera onto your computer and inspect them before planting the corms. How many times I have planted the corms (or bulbs) only to later realize the photos had problems.  Too late!

Things to look out for: 
White balance, so the colors are closer to realistic. 
Shadows (it helps to make a tent of white fabric to disperse the light.) 
Focus and close-up enough to show fine texture of the corm. 
Get a view of both the top and bottom; some species have characteristic shapes to their bases. 
Include several corms in the photo to show the range of variation; I got that tip from an old moldy library book on botanical illustration. 

Labeling. I photograph a printed or written label before each different species so when I sort the photos by time the label appears first. Then I use that to rename the photo files. I used to write the photo number in a notebook with its id but discovered I was too impatient. Wherever possible, I use "inherent labeling", with the id included in the photo or series of photos. 

And finally, to close the circle on this thread, identity verification makes the photo more valuable as a reference. I learned not to post photos of corms on the wiki until after they have bloomed and been verified.

If you enter "grid" in the PBS wiki search box you get 165 results. Only about 10 of those are mine.

- Gastil

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