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               Frequently Asked Questions: NSSDC Photo Gallery

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This FAQ is not intended to answer general questions about NASA photos or
information about solar system bodies. These FAQs (for the sci.space
newsgroups on usenet) are available at Ohio State University.
URL: http://www.cis.ohio-state.edu/hypertext/faq/usenet/space/top.html
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Contents

   * Can I use the images from NSSDC's Photo Gallery or do I need to obtain
     permission from somebody first?
   * I'd like to get a copy of these images as a photo product. How?
   * Why are all of the "full-resolution" images on the Photo Gallery in
     JPEG format rather than GIF?
   * Do you have these images available via FTP as well?
   * Where can I find images of (insert whatever)?

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  1. Can I use the images from NSSDC's Photo Gallery or do I need to obtain
     permission from somebody first?

     All of the images presented on NSSDC's Photo Gallery are in the public
     domain. As such, they may be used for any purpose. NSSDC does ask,
     however, that you acknowledge NASA and the NSSDC as the supplier of the
     data. In addition, where the source of the image (by project or as a
     specific person) is credited in the text, you should also acknowledge
     that, too.

     In addition, NASA further requires that NASA images cannot be used to
     imply endorsement by NASA.

  2. I'd like to get a copy of these images as a photo product. How?

     Many of the images in the Photo Gallery can be obtained from NSSDC
     either as a hardcopy photograph, transparency, or 35 mm slide. The
     photographs which can be so obtained have photo numbers (usually NASA
     press release, or PR, numbers) next to them. To order such photos, send
     an e-mail to our user support office at request@nssdca.gsfc.nasa.gov or
     phone at (301)286-6695. You should have the photo number of the images
     you want and the name of the mission for each photo.

     NSSDC does charge for photographic materials on a cost-recovery basis.
     The current cost of different photographic reproductions is available
     in NSSDC's Photo Price List.

     Some of the images are not available as a photo product at this time.
     Others are available on CD-ROM. These can generally be identified by
     the lack of a NASA PR number. Images from the Hubble Space Telescope
     which are identified with both a Space Telescope number (e.g.,
     STScI-PRC-96-30) and a NASA HQ number (e.g., 96-H-634) are available
     from NSSDC. Ones with only a STScI number are not currently available
     from NSSDC.

  3. Why are all of the "full-resolution" images on the Photo Gallery in
     JPEG format rather than GIF?

     The choice of JPEG format over GIF for the larger images was made for
     two different reasons. The first is a matter of size. In most cases,
     the JPEG images are smaller. In order to reduce the load on both our
     server machine as well as on the network and users machine, it was felt
     that using JPEG compression was a reasonable alternative. It preserves
     most of the original image, but minimizes the file sizes.

     The second consideration was one of color depth. Although most imagers
     on spacecraft in use today still have only a depth of 256 levels (gray
     scale), the color images which are on the photo gallery are often
     combinations of three such filters. Thus, even though the original
     single-filter images are only 8-bit (and therefore appropriate for the
     lossless GIF compression), the resultant color images are actually
     24-bit. Since GIF compression gets rid of this additional color
     information, but JPEG does not, it was felt that the loss of color
     depth was much more severe than the loss due to using the JPEG
     compression.

  4. Do you have these images available via FTP as well?

     Yes! We finally have our images available via FTP as well as via the
     WWW for those browsers (shame on them!) which don't support saving the
     image. You can FTP to: nssdc.gsfc.nasa.gov and set default to
     pub/photo_gallery/ to see what is there. At this time, both the
     captions and the images are available. If you prefer to exercise the
     link right now, try:
     URL: ftp://nssdc.gsfc.nasa.gov/pub/photo_gallery/

  5. Where can I find images of (insert whatever)?

     There are a number of reasons you might not have found what you're
     looking for in the NSSDC Photo Gallery. First, the image(s) may not yet
     be available. Second, the image(s) may be available, but not (at least
     yet) from NSSDC. Third, it may be something which no one has suggested
     be put up. Lastly, it may be outside the province of NSSDC's
     responsibilities. In all cases, feel free to send your feedback and
     we'll try and address your concerns. However, you might also try first
     looking through the other sites to which the Photo Gallery provides
     links. The list is not a comprehensive listing of all sources of
     images, but covers most of the areas we are asked about most
     frequently.

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Other NSSDC FAQs of potential interest

[*] The NSSDC Planetary FAQ Page
[*] The NSSDC CD-ROM FAQ Page
[*] The NSSDC Earth FAQ Page
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                 [ Home] [ | Photo Gallery] [ | Feedback ]
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If you have questions about the images on NSSDC's Photo Gallery, please
first consult our Frequently Asked Questions page. Other questions and
comments may be submitted using the feedback button on each page.
                        [NSSDC logo] Author/curator:
        Dr. Edwin V. Bell, II, ed.bell@gsfc.nasa.gov, +1-301-286-1187
 NSSDC, Mail Code 633, NASA/Goddard Space Flight Center, Greenbelt, MD 20771
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            NASA Official: J. H. King, king@nssdca.gsfc.nasa.gov

                          Version 2.1, 29 June 1995
                     Last Updated: 23 June 1997, EVB II