Thread subject: Diptera.info :: Photo strategy

Posted by Dima DD on 05-10-2007 20:00
#1

Tony T wrote:
4 October 2007, NB, Canada. Keys to Calliphora vicina

Just a comparison of techniques. Top photo is an image from a flatbed scanner, lower one from a digital camera. Scanner gives quite a good image but lacks the depth of field that can be obtained with a camera.

Scanning may be a good alternative technique. Many images in the "Atlas of Russian beetles" (Zoological institute RAS, SPb, here is their great coleopterological site) are taken by scanning, e.g. these very large stag-beetles. DOF depends on the scanner type (CIS-scanners has tiny DOF, CCD-scanners - large DOF) and on concrete model, too...

Posted by cosmln on 05-10-2007 20:08
#2

Dima DD wrote:
Tony T wrote:
4 October 2007, NB, Canada. Keys to Calliphora vicina

Just a comparison of techniques. Top photo is an image from a flatbed scanner, lower one from a digital camera. Scanner gives quite a good image but lacks the depth of field that can be obtained with a camera.

Scanning may be a good alternative technique. Many images in the "Atlas of Russian beetles" (Zoological institute RAS, SPb, here is their great coleopterological site) are taken by scanning, e.g. these very large stag-beetles. DOF depends on the scanner type (CIS-scanners has tiny DOF, CCD-scanners - large DOF) and on concrete model, too...


scanning is also very good for dragonflies (i used that many times)... and also for plants. this was before to have a photo camera, anywai in many case scanning is a very good alternative

Posted by Tony T on 05-10-2007 20:49
#3

conopid wrote:
Catch them, take them home, chill them in the fridge - not too long though, then photograph on a flower or leaf as quickly as possible, before they warm up and fly away.

Otherwise hunt, stalk and shoot is the best way....Pfft


You mean like your photos HERESad

Posted by crex on 05-10-2007 22:25
#4

How do you get the white background and no shadows from the lid? Maybe a bit of white paper? If you put the lid on, the fly gets smashed, wouldn't it? One should probably use as high resolution as the scanner can handle, but I still wonder what dpi you used for this particular scanning, Tony?

Posted by Tony T on 06-10-2007 00:55
#5

cosmln wrote:
scanning is also very good for dragonflies (i used that many times)... and also for plants. this was before to have a photo camera, anywai in many case scanning is a very good alternative

I agree, does an excellent job with Odonates. Also excellent for 'flat' flies such as syrphids and most tabanids, particularly Chrysops. This calliphorid has a large somewhat rounded thorax making the fly very deep and thus could not get everything in focus.

It was scanned at 3600 ppi (pixels per inch). I simply removed the scanner lid; placed 4 blocks of wood on the glass plate of the scanner and placed a sheet of white card on the blocks. The blocks are 1 cm thick. The fly, of course, was placed upside down on the glass plate of the scanner. Alternatively one could support the scanner lid about 1 cm above the glass plate using blocks