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Mon, 21 Feb 2000 23:25:37 -0500 |
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Shell Creations |
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We are planning workshops at COA 2001.....hope to have photography as one of
them.
Bobbi Cordy, Chairman 2001 Shell/Space Odyssey
Art Weil wrote:
> Dear Ross;-
> You bet yer boody I'm interested in a photography session at the COA. I
> did all the photos for the Wentletrap Book. The most important thing was the
> lens; a 55mm Micro-Nicor. I used a bellows as it was more adjustable than
> "rings". I used two flashes, one a slave. I could a probably done better. But
> the law of diminishing returns set in.
> Art
>
> Ross W. Gundersen wrote:
>
> > Dear Shell Photographers:
> >
> > I have read the last series on photography with interest, since I am the
> > Photographic editor for American Conchologist. Producing good
> > photographs of shells depends upon many factors, but primarily upon what
> > type of pictures you want to produce. Price tag is also of importance
> > (35mm as well as digital).
> >
> > Lenses: Taking pictures of shells falls into the realm of macro- and
> > micro-photography. This means pushing lenses to the limits of their
> > design. Generally speaking you should use lenses that are designated as
> > "macro". This designation means that they are highly corrected lenses
> > which produce excellent quality images with the use of extension tubes.
> > Using a general lens with extension tube will produce an image which is
> > slightly blurred, with much less resolution. The drawback of most
> > digital cameras is their lens (usually low quality). Excellent lenses
> > are found only on the higher models of Nikon, Olympus, and Sony digital
> > cameras. These lenses are up to the demands of macro- and
> > micro-photography.
> >
> > Depth of Field: Depth of field is also associated with lenses. It
> > refers to the depth or thickness of an object which is in focus to our
> > eyes. To increase depth of field, or the amount of the image apparrently
> > in focus, increase the F-stop. However, as magnification increases your
> > depth of field decreases. Eventually, all of the shell will not be in
> > focus. Then multiple pictures are necessary (covered latter.
> >
> > Lighting: Adequate lighting is necessary for both resolution and color
> > rendition. Low levels of light produce grainy images of incorrect
> > color rendition. The general rule is the brighter the better for both
> > resolution and color. This becomes a necessity in macro- and micro-
> > photography when using higher F-stpos to increase your depth of field.
> > As the F-stop increases the level of light delivered to you film or CCD
> > decreases.
> >
> > Color balance or color rentition is also affected by lighting. Film
> > and CCD react to different sources of light producung different color
> > renditions. Tungste/halogen are richer in reds. Fluorescent is richer
> > in blues. Flash produces a narrow window of both reds and blues. With
> > a digital camera you are stuck with one CCD and its reaction to light
> > of different wavelengths. However, with filn you can use a film
> > produced for different sources of light (e.g tunsten). To achieve
> > proper lighting you may end up using tungsten, flourescent and flash
> > all at the same time (I do).
> >
> > Compositing: Tis term refers to assembling parts of different images
> > into one image. In extreme macro-photography and micro-photography
> > eventually magnification become so high that not all of the image is in
> > focus. Take multiple images so that all of the shell is in focus in at
> > least one of the images. To accomplish seamless compositing you have
> > to convert the image into digital format using either a flat bed
> > scanner or a slide scanner. Scan each image. Using a graphic imaging
> > program, such as Adobe Photoshop, you select the parts of the image
> > that are in focus and reassemble them into one image. Now the entire
> > shell is in focus.
> >
> > Cost: You cannot produce superb images of shells with inexpensive
> > equipment. Good quality macro lenses run from $200 - $600. Generally
> > speaking the higher the price tag, the greater the lens correction to
> > produce sharp images. Extension tubes are less expensive $50-$175.
> > Digital cameras capable of producing high resolution images are now
> > available from $800. No comment is being made here about "hidden costs".
> >
> > These comments are the tip of the iceberg and not meant to be exhaustive.
> >
> > Is anyone interested in a photographic clinic at the COA meeting in
> > Houston??
> >
> > Best, Ross
--
Jim and Bobbi Cordy
of Merritt Island, Florida.
Jim Specializes in Self-Collected
Caribbean & Florida Shells
Bobbi in Shell Creations
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