Dear Charlotte, beside having the scale factor in the pic, check carefully that you don't have photographic distortions. This can be easily done by having milimeter paper in the background of your pic (or something more accurate that does a similar job for small animals): lines bending near the margins of your pics will tell you that there's a distortion. This is something that can be corrected by either increasing the distance of the camera (if you've still got enough resolution) or by using a camera with a better lens.
I am sure there's plenty of publications on insects using geometric morphometrics. Issues should be pretty similar to those that you have with spiders. Good luck Andrea Dr. Andrea Cardini Lecturer in Animal Biology Museo di Paleobiologia e dell'Orto Botanico Universitá di Modena e Reggio Emilia via Università 4, 41100, Modena, Italy tel: 0039 059 2056532 fax: 0039 059 2056535 & Hull York Medical School The University of York, Heslington, York YO10 5DD, UK E-mail address: [EMAIL PROTECTED], [EMAIL PROTECTED], [EMAIL PROTECTED] http://hyms.fme.googlepages.com/drandreacardini >hi ! > >I just started a study on wolfspiders (genus Hogna), I want to measure some >morphological features (carapax,legs) but I'm also interested in >the shape from for example the carapax and the position of the eyes. I >think to use Tps. >Untill now I didn't find any related research on this topic (measuring >spiders). > >When I want to scale the pictures, do I have to take a picture of the desired >object and then from a measuring rod ? (but then I have 2 >pictures, and I will have to photoshop the rod to the first >picture..., isn't there an easier way ?) > >Thx for explaining to a fresh starter ! > >sincerely greetings > >Charlotte -- Replies will be sent to the list. For more information visit http://www.morphometrics.org
