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Sigma Sd Quattro, applications for Palaeontology

Sigma Sd Quattro macrophotography fossil photography

The image quality of the Sigma SD Quattro has been a real surprise for me. I tried it in a professional context and the camera revealed as an excellent tool for palaeontological documentation. I explain here how and why.


 
 
Usually a scientific paper reports not only photos but also interpretative drawings of those character that aren't readily evident from photos such as some bone outlines/articulations and other features.
 
These drawings may be done by putting a "Camera Lucida"  on the microscope. With this tool the optical path is partially splitted and one can see a paper sheet superimposed to the specimen via a mirror reflection (the stuff is more complicated, this is just to give an idea). In this way one can draw what is under the microscope. It is a necessary step in many cases but it is a slow procedure, lines are somewhat flickering and borders of the framed area suffer heavy distortion, thus one can draw only the central portion of what he sees.
Obviously the institution that holds the specimen must have the stereo microscope and the camera lucida, since bring they are not that easy to carry around.
 

 

Immagine Allegata: camera lucida.jpg

 

A Stereo microscope with Camera Lucida (the arrow points at the mirror).

 

Today this method can be in part replaced by adding a layer over a photo in Photoshop and drawing on it with a graphic tablet. To increase precision, one must draw at 200-300 or even 400% of the image size.  However I wrote that this method can only replace in part the work with Camera Lucida, because the quality of the photo can compromise results, if is blurred, there are shadows that obscure details, sharpness is not adequate or there is lack of contrast between the fossil and the rock. In such cases one must see the specimen again first hand in order to avoid misinterpretations leading to wrong reconstructions.
 Seriously, I never meant that one can make reconstructions with photos without carefully looking at real specimens, this is foolish, I am just saying that good  photos may help to reduce the frequency of direct observations.
And the better is the photo, the lesser the need to check the specimen.
 
As an example  this article I took the forearm of a Cretaceous marine turtle
 
 
 

Immagine Allegata: tartaruga2a.jpg

 

the limb section is about ten centimeter long.

 

 

 

Immagine Allegata: limbcropbone.jpg

 

 

This is a 100% crop, but to make the drawing I enlarged the image up to 300% and all elements were still easily readable.

 

To give you an idea of how the final interpretative drawing may look like, I printed the outline drawing and added manually the shading and the with Photoshop I added just some lettering (for a real illustration most bones should have been  labelled)
 

Immagine Allegata: tartaruga2dr.jpg

 

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