[Coral-List] Photoquadrat

[Kevin Kohler]

Ron,

CPCe is not particularly sensitive to exact camera specifications. The 
image being analyzed just has to have sufficient resolution to identify the 
features you are interested in, which would include all newer cameras. If 
you are using the area measurement portion of CPCe, you would want to 
decrease as much as possible the amount of lens distortion (pincushion or 
barrel)  in the image in order to obtain accurate image scaling and area 
traces.

-Kevin

t 09:29 7/1/2009 +0800, you wrote:
>Project Seahorse Foundation for Marine Conservation
>30 June 2009
>
>Methodological Question about Photoquadrats for "Coral List"
>
>The benthic survey component of our coral reef long-term monitoring program
>has (again) presented us with some tricky methodological issues, and were
>hoping to consult with this community for advice on how to resolve them. We
>are a small marine conservation NGO conducting research on marine protected
>areas in the central Philippines, with a small team of marine biologists.
>
>Some background: we piloted a photoquadrat ("PQ") method in 2007 to replace
>our older line-intercept method. At each survey site, this PQ method uses 10
>haphazardly laid 25 m transects, with photos taken every 1 m along the
>transect. We plan to conduct PQ once a year at these sites, all of which are
>shallow (~3-4 m depth) with some turbidity.
>
>Basically, our current digital camera (Sony DSC-P10 Cybershot, 5.0
>megapixels, purchased in 2003) has been malfunctioning and we need to
>replace it. We are very concerned that if we simply bought a new camera
>(with new wide-angle lens etc.) that the photodata we have already gathered
>using this old camera would not be comparable with the newer photodata with
>whatever new camera equipment we decide to purchase. Our current wide angle
>lens is the "MPK-P9 wide version 16 mm/F5.6." We use CPCE to process the
>images.
>
>Are photoquadrat methods using this image-processing software sensitive to
>the exact specifications of particular cameras? Or is the software and
>analysis of this kind of data robust to all kinds of equipment? What kind of
>considerations do we need to keep in mind when making this decision? Would
>it be ok if just replace our camera with a new set of camera that are of
>different specs on the camera that we are using?
>
>We would appreciate any advice this community can offer. Thanks!
>_______________________________________________
>Coral-List mailing list
>Coral-List at coral.aoml.noaa.gov
>http://coral.aoml.noaa.gov/mailman/listinfo/coral-list

----------------------------------------------------
Kevin E. Kohler <kevin at nova.edu>
Director of Computing Services
National Coral Reef Institute (<http://www.nova.edu/ncri>www.nova.edu/ncri)
Nova Southeastern University Oceanographic Center 
(<http://www.nova.edu/ocean>www.nova.edu/ocean)
8000 North Ocean Drive  Dania Beach, Florida  33004
Ph:  954.262.3641    Fax: 954.262.4158