[NHCOLL-L:5486] Re: Colour of thin section images

[Laura Nightengale]

Please send any replies to the list.
Thanks!
Laura

At 06:37 AM 6/9/2011, Christian Baars wrote:
>
>Hi,
>
>we are having slight issues with the colours of images captured 
>using a digital camera from a petrological microscope. The colours 
>on images of petrological thin sections are never quite like those 
>seen through the eye pieces. This can be adjusted using Photoshop 
>but if taking a large series of images this can be quite laborous; 
>it would be better to capture the correct colours in the first place.
>
>Capturing images from stereomicroscopes we use a colour chart to 
>calibrate the camera and to do a white balance prior to taking 
>photos. With a petrological microscope this is obviously not 
>possible, but I am wondering whether the principle may be.
>
>Does anyone use a thin section with a standard material that appears 
>to be white under the petrological microscope (plain polarized 
>light)? Using simply a clear glass slide is not an option as we 
>would just be calibrating the camera against the colour of the light 
>from the lamp which is not necessarily white. Instead, we are 
>looking for a material that we can use to make up a standard thin 
>section for setting up a white balance.
>
>Any ideas would be gratefully appreciated.
>
>Kind regards
>Christian
>
>
>
>
>Dr Christian Baars
>Department of Geology
>National Museum Wales
>Cathays Park
>Cardiff CF10 3NP
>UK
>Telephone: 0044 (0)29 2057 3352
>
>


Laura H. Nightengale
Head of Collections
Texas Archeological Research Laboratory
The University of Texas at Austin
1 University Station R7500
Austin, TX 78712-0714

512-475-6853
http://www.utexas.edu/research/tarl/
http://www.texasbeyondhistory.net/  
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