All content copyright © South London Federation 2015 - 2018
Last updated May 2018

Knowledge Centre

Digital Image Projection

  Many   clubs   are   now   keen   to   show   digital   images   as   part   of   presentations   or   for   competitions.   In   this   section   we   discuss   some   of   the issues that you may face and include experience from some clubs that have already taken the plunge. You will need a data projector and a laptop computer for holding the images.

Financial

Data   projectors   cost   from   well   under   £1000   to   £1700   for   those   of   a   suitable   quality.   Spare   lamps   cost   £300   to   £400,   although   they normally   last   1000   to   2000   hours   depending   on   make.   Most   laptop   computers   are   adequate   for   this   purpose   so   a   budget   of   about   £900 should   be   adequate.   Finally,   software   costs   can   range   from   next   to   nothing   up   to   several   hundred   pounds   depending   on   what   you   wish to do. A   number   of   clubs   have   made   bids   to   the   Lottery   Fund Awards   for All.   They   provide   funding   from   £500   to   £5000   for   small   projects.   In the   London   area   (including   Bromley   and   Croydon)   they   are   looking   for   projects   that:   benefit   those   with   economic   hardship,   ethnic minorities,   the   disabled   or   help   communities   explore   and   share   their   heritage   and   London's   diverse   culture   and   traditions.   Elsewhere   in the   South   East   the   focus   is   broader   including   support   for   arts,   heritage   and   other   community   activity.   In   some   cases   your   local   Council may provide support in applying for such awards.  

Projector

Resolution:   You   should   choose   a   projector   having   a   native   resolution   of   at   least   1024   x   768   pixels   (so-called   XGA).   Lower   resolution projectors   can   sometimes   convert   from   800   x   600   pixels   (so-call   SVGA)   to   a   higher   figure,   but   such   interpolation   is   not   suitable   for good   quality   image   projection.   There   are   now   a   number   of   SXGA+   format   projectors   available   with   a   native   resolution   of   about   1400   x 1024   pixels.   Both   DLP   and   LCOS   versions   exist   (seeTechnology   below)   but   their   price   is   currently   about   £2700.   There   are   also   an increasing   number   of   widescreen   projectors   intended   for   home   cinema   purposes.   These   normally   are   a   maximum   of   720   or   768   pixels high so offer no real advantage over XGA format projectors for most photographic work. Dead   pixels:   Most   projectors   do   not   have   dead   pixels   (ones   that   are   permanently   white,   black   or   a   primary   colour),   but   manufacturers usually   state   that   they   consider   a   few   dead   pixels   to   be   acceptable.   One   club   managed   to   persuade   their   supplier   to   replace   a   projector that had a couple of dead pixels on delivery - they are not obliged to, but it might work. Technology:    There   are   two   competing   technologies   for   affordable   digital   projectors:   LCD   (Liquid   Crystal   Display)   and   DLP   (Digital Light   Processing).   With   LCD   light   is   shone   through   three   panels   for   R,   G   and   B,   and   pixels   are   turned   on   and   off   to   form   the   image. DLP   is   Texas   Instruments   technology   and   essentially   consists   of   tiny   mirrors   where   R,   G   and   B   light   is   alternately   shone   on   to   these and   reflected   on   to   the   screen.   DLP   devices   tend   to   have   higher   light   output,   but   a   few   people   can   see   "rainbow"   effects   with   them   due to the alternating R, G, B light. This is rare and is more of a problem with moving images when they are used for home cinema. LCD   image   quality   can   degrade   after   1500   or   more   hours   of   use   particularly   in   the   blue   panel   (at   least   three   years   at   10   hours   use   per week).   Competition   between   the   rival   technologies   probably   means   that   there   is   not   much   to   choose   between   them,   although   DLP   is generally lighter(weight) and possibly cheaper. Canon   have   their   own   LCoS   (Liquid   Crystal   on   Silicon)   technology   that   has   virtually   no   'barn   door'   effect   (black   around   pixels)   so produces   a   very   smooth   clean   image.   Prices   start   at   about   £2000   for   the   Canon   SX600   (1024   x   768),   compared   to   a   very   good   DLP projector (Optoma DX733) costing about £700 - April 2007 prices. See Evan Powell's article  for an excellent review of the issues. Light   Output:    A   couple   of   years   ago   the   light   output   of   projectors   was   typically   about   1000   lumens.   Now,   many   current   models produce   2000   lumens   or   even   more.   Anything   greater   than   about   1100   lumens   will   do   a   good   job   in   normal   club   surroundings   on   a   6 foot   screen.   Some   DLP   projectors   can   produce   3000   lumens   or   more   and   these   can   sometimes   be   too   bright   for   viewing   in   darkened conditions. Contrast    Ratio:    Current    projectors    claim    450:1    contrast    ratio    or    higher.    Higher    values    produce    the    best    shadow:highlight differentiation.   However,   even   though   these   projectors   are   bright,   to   see   good   photographic   detail   it   is   always   necessary   to   use   a   dark room. DLP and LCOS projectors give the best ratios - up to 2000:1 in some cases, but this is only achieved in full blackout conditions. Lens:   Data   projectors   generally   have   non-interchangeable   zoom   lenses.   To   fill   a   2   metre   screen   the   projector   will   typically   only   need   to be   about   3.5   m   away,   perhaps   about   half   the   distance   of   a   35mm   slide   projector.   Data   projectors   usually   have   keystone   correction facilities built in. Aspect   Ratio:   The   standard   aspect   ratio   is   4:3   horizontal:vertical.   Some   wide   screen   projectors   are   now   appearing   but   they   seem   to be targeted at the home cinema market. Lamp   Life:    In   most   cases   this   will   be   for   about   2000   hours.   The   projector   keeps   track   of   use   and   some   prevent   use   beyond   the   stated life.   Since   lamps   cost   about   £300   its   worth   checking   the   lamp   life   figure.   Hitachi   has   been   including   3   year   lamp   warranty   with   its projectors.   With   some   of   the   brighter   projectors   there   is   often   an   economy   mode   that   produces   plenty   of   light   for   photographic   images in darkened rooms and extends the nominal life of the lamp from perhaps 3000 hours to 5000 in some cases. Connection:    Data   projectors   are   usually   connected   to   the   laptop   using   a   15   way   analogue   VGA   cable   (blue   connector).   The   one provided   is   usually   about   a   metre   long. A   7.5   m   Extension   cable   costs   less   than   £20.   If   you   need   a   longer   distance   than   that   between laptop   and   projector   you   should   consider   a   wireless   link.   Selsdon   CC   have   a   wireless   connection   that   works   well,   although   there   is   a slight delay when images are changed. Newer   projectors   usually   come   with   a   DVI   connector   (white   connector).   This   is   the   preferred   connection   method   if   your   computer   has one of these too. Screen:    In   most   cases   existing   screens   for   slide   projection   are   fine,   but   some   beaded   screens   can   produce   Moire   patterns   with   a   data projector. Cable   Management:   Rubber   cable   covers   to   prevent   people   tripping   over   them   can   be   obtained   in   1   metre   or   3   metre   lengths.   Staples (on-line ordering look under "cable covers") are competitive. Helpful Companies:   Various people have found the following companies helpful: ProjectorPoint:   Based   at   Richmond.   Have   a   very   wide   range   and   are   very   helpful   on   the   phone.   Very   competitive   prices.   Web: www.projectorpoint.co.uk Phone: 0800 073 0833 Hocken AV: Based at Kingswood. Very helpful. Web: www.hockenav.co.uk Phone: 01737 370371 Pinnerton: Based in Woking. Very helpful. Web: www.pinnerton.co.uk Phone: 01276 488111 If   you   have   found   a   particularly   helpful   company   when   you   were   purchasing   a   digital   projector   or   related   equipment,   please   let   the   SLF know so we can add their details.  

Computer

Purpose:    It   is   worth   trying   to   anticipate   the   uses   to   which   the   equipment   will   be   put.   Some   clubs   have   been   interested   in   using   the laptop   for   Digital   Imaging   demonstrations   as   well   as   image   display   for   competitions.   A   higher   specification   computer   is   needed   in   that case.   Other   clubs   (Selsdon   CC)   have   been   keen   to   run   international   competitions   and   to   send   CDs   or   DVDs   of   the   competition, complete with judges commentary to the other clubs involved. Laptop:    Generally   laptops   are   chosen   as   they   are   more   convenient   to   transport.   Mac   or   PC   laptops   are   equally   useful   and   the   choice really depends on the preferences of club members and budget. Main   Memory:    Most   machines   these   days   have   at   least   256MB   (megabytes)   of   main   memory,   but   if   you   are   planning   to   use   it   for Photoshop demonstrations too it is best to increase it to 512MB or 1GB (gigabyte). Hard   Disk:    Images   for   competitions   will   be   relatively   small   so   disk   space   will   not   be   an   issue,   but   if   using   Photoshop   do   not   go   for   less than 40GB of hard disk space. CD/DVD:    It   is   worth   getting   an   internal   CD/DVD   writer   with   the   machine   to   allow   exchange   of   data   with   others   and   for   backing   up.   A free-standing   external   drive   (USB2)   costs   about   £150,   similar   to   the   cost   of   a   built-in   one. The   choice   depends   on   whether   the   CD/DVD drive is to be shared among several machines. Keyboard/mouse:   One   way   of   reducing   the   cabling   problems   is   to   keep   the   laptop   close   to   the   projector   and   have   a   cordless keyboard   and   mouse   so   that   the   demonstration/competition   can   be   controlled   remotely.   Standard   wireless   mice   and   keyboards   work well,   but   their   range   is   limited   to   about   5-6   feet.   "Bluetooth"   keyboards   and   mice   claim   a   range   of   up   to   about   30   feet,   but   they   are   more expensive. (Don't forget spare batteries!) Audio: Small PA systems with radio microphones are available for £200-£300. Selsdon bought theirs from Sound Dynamics Ltd. Display   Connector:    If   possible,   choose   a   machine   that   has   both   DVI   and   VGA   connectors   for   attaching   a   display   or   projector. The   DVI connector should give (slightly) better image quality.

Software

The   package   that   has   been   used   in   FSLPS   Competitions   such   as   Jack's   Jug   and   the   Vic   Smith Trophy   is   DiCentra.   It   is   costs   £35   for   a club   licence.   It   provides   facilities   for   loading   images   from   entrants   and   checking   that   they   comply   with   the   competition   rules.   Facilities are   provided   for   setting   up   the   projector   prior   to   judging.   Marks   are   accumulated   during   the   competition   and   selected   images   can   be held   back   to   be   marked   at   the   end.   The   scoresheet   can   be   displayed   at   any   stage   and   a   'Lightbox'   can   be   used   to   select   images   for awards. Some   people   use   MS   Powerpoint   for   producing   presentations,   although   it   is   relatively   expensive   if   used   just   for   that   purpose. There   are many other packages including PicturesToExe for about $30. Slide shows can also be made with Photoshop and displayed in a browser such as Internet Explorer.   

Digital Competitions

  Here are a few points about gathering and presenting images for digital competitions. Image   Size   :    Most   affordable   digital   projectors   have   a   displayable   area   of   1024   pixels   wide   by   768   pixels   high.   Some   wide   screen projectors   provide   a   wider   image   but   none   provide   more   than   768   pixels   height   (to   my   knowledge).   Let   us   suppose   we   have   a   portrait format   image   and   a   landscape   format   image,   both   with   a   2:3   (35mm)   aspect   ratio.   If   the   landscape   image   fills   the   screen   horizontally   it will   be   1024   x   682   pixels,   while   if   the   portrait   format   image   fills   the   screen   vertically   it   will   be   512   x   768   pixels.   If   you   do   the   arithmetic this   means   that   a   portrait   image   is   only   56%   of   the   area   on   screen   of   the   landscape.   If   they   were   slides,   the   two   images   would   be   the same area on screen. For   this   reason   I   advocate   that   the   maximum   dimension   (width   or   height)   of   an   image   should   be   768   pixels   with   today's   projectors.   It can   be   argued   that   you   are   losing   some   of   the   available   resolution/quality   in   the   landscape   format.   But   if   the   full   1024   pixel   width   is available for landscape format, portrait format images suffer the same problem, and are only 56% of the size. A   number   of   digital   competitions   seem   to   be   allowing   images   up   to   1024   x   768   to   be   submitted,   so   that   format   will   probably   prevail even though portrait format images are at a disadvantage. No   Interpolation:   Entries   should   be   displayed   as   submitted,   so   that   there   can   be   no   arguments   that   detail   has   been   lost   due   to interpolation   (re-sampling)   or   compression.   Files   should   be   prepared   to   a   maximum   dimension   of   768   or   to   a   maximum   size   of   1024   x 768   pixels   or   whatever   other   standard   the   organisers   choose.   (Some   software   may   put   a   1   or   two   pixel   border   around   the   image   so that needs to be considered.) Entrants   should   be   warned   that   if   they   fail   to   submit   to   the   correct   size,   jagged   edges   may   appear   (so-called   interpolation   or compression artifacts) or some of the image may be arbitrarily cropped by the software. Colour   Space:   Projectors   cannot   display   the   full   gamut   of Adobe   RGB.   Submitted   images   should   be   converted   to   sRGB   by   the   author so   that   they   can   preview   the   image   and   deal   with   any   problems   due   to   the   reduced   gamut   of   sRGB.   Entrants   should   be   advised   to   view their   images   on   a   colour   calibrated   monitor   before   submission.   Monitor   profiling   devices   are   now   easily   available   at   prices   from   £90 (e.g. Colour Confidence). File   Format:    Entries   should   be   submitted   as   JPEG   or   TIFF   files.   JPEG   files   can   be   smaller,   which   may   be   an   advantage   if   images   are being   emailed   to   the   competition   organiser,   although   even   with   uncompressed   TIFF   the   file   sizes   should   not   be   too   great.   TIFF   files should not include layers or transparency. Projector   Colour   Management:    Just   as   monitors   can   be   calibrated,   so   can   data   projectors. The   main   problem   is   that   the   calibration   is affected   by   the   ambient   conditions,   so   the   black-out   conditions   and   screen   need   to   be   in   place   before   this   is   done.   Although   a calibration   done   some   time   earlier   may   be   adequate,   it   really   should   be   done   for   the   competition   conditions.   Projector   calibration   takes up to about 20 minutes. The   Gretag   Macbeth   Eye   One   Photo   has   facilities   for   projector   calibration A   new   Color   Vision   Spyder2Pro   kit   is   available   and   includes projector   calibration.   The   Gretag   Macbeth   kit   is   expensive   but   does   printer   profiling   as   well   ad   display   and   projector   calibration   (£800). The Spyder2Pro costs about £180.   

Projector Setup

There   are   a   number   of   charts   that   may   be   useful   in   evaluating   a   projector   for   purchase   or   when   setting   up   the   projector   for   a competition. There are three sets here that you can download: Plain charts ( Download ) Colour charts ( Download ) Focus and Greyscale charts ( Download ) Black   Chart   :    By   comparing   the   blackness   of   the   projected   area   to   the   outer,   un-illuminated   parts   of   the   screen,   the   depth   of   black   can be assessed. This needs to be done in a darkened room. Grey   Chart:    This   is   good   for   identifying   colour   shifts   introduced   by   the   projector.   They   show   up   well   on   a   grey   chart   because   the human eye is very sensitive to small shifts away from neutral greys. White   Chart:   Essentially   the   equivalent   of   the   open   gate   in   slide   projectors.   It   is   useful   for   measuring   the   brightness   of   the   image.   For slide   projectors   an   open   gate   measurement   using   an   exposure   meter   should   show   50   lumens/square   foot   at   the   screen   centre.   There are   no   accepted   standards   for   digital   projectors   yet,   but   using   an   exposure   meter   at   100   ISO   pointing   to   the   centre   of   the   screen,   a reading of 1/60th at f/16 gives a similar illumination to that used for the Vic Smith competition in 2006. PAGB   Wedges:    These   give   5   steps   for   each   of   the   primary   colours   and   grey.   More   details   can   be   found   on   the   PAGB   web site(www.pagb-photography-uk.co.uk).    The    third    PAGB    report    on    Digital    Projected    Images    is    particularly    useful    and    contains information on projectors, software and competitions.   Photodisc   Chart:   This   is   a   freely   available   colour   test   chart   that   contains   many   features   including   standard   colour   and   monochrome step   wedges,   as   well   as   many   'memory'   colours   such   as   skin   tones.   The   versions   called   PDI-target   768   and   PDI-target   1024   lscape have   been   scaled   to   fit   a   standard   1024   x   768   monitor   in   portrait   and   landscape   orientation,   respectively.   Please   note   the   license   terms in the Read Me file. (The original test chart is a rather larger TIF file. It can be downloaded from the PAGB site.) Grey Wedge: This is a 21-step grey wedge. If the projector is properly set up each step should be distinct. Projector   1024   x   768   size:    If   this   is   shown   at   full   size   on   a   screen   you   should   be   able   to   see   an   alternating   yellow/black   line   around the   edge   of   the   projected   image.   Its   purpose   is   to   ensure   that   the   projector   (or   software   being   used)   does   not   lose   any   pixels   at   the edge of the image. Projector   Focus   and   Contrast:    Part   of   this   includes   a   variety   of   21-step   grey   wedges   near   the   edge   of   the   screen.   There   are   also bars at 1, 2 and 3 pixel spacing that may help with focusing and in diagnosing problems with focus at different parts of the screen .
All content copyright © South London Federation 2015 - 2017

Knowledge Centre

Digital Image Projection

  Many   clubs   are   now   keen   to   show   digital   images   as   part   of presentations   or   for   competitions.   In   this   section   we   discuss some    of    the    issues    that    you    may    face    and    include experience   from   some   clubs   that   have   already   taken   the plunge. You   will   need   a   data   projector   and   a   laptop   computer   for holding the images.

Financial

Data   projectors   cost   from   well   under   £1000   to   £1700   for those   of   a   suitable   quality.   Spare   lamps   cost   £300   to   £400, although   they   normally   last   1000   to   2000   hours   depending on    make.    Most    laptop    computers    are    adequate    for    this purpose   so   a   budget   of   about   £900   should   be   adequate. Finally,   software   costs   can   range   from   next   to   nothing   up   to several hundred pounds depending on what you wish to do. A   number   of   clubs   have   made   bids   to   the   Lottery   Fund Awards   for All.   They   provide   funding   from   £500   to   £5000   for small   projects.   In   the   London   area   (including   Bromley   and Croydon)   they   are   looking   for   projects   that:   benefit   those with   economic   hardship,   ethnic   minorities,   the   disabled   or help    communities    explore    and    share    their    heritage    and London's   diverse   culture   and   traditions.   Elsewhere   in   the South   East   the   focus   is   broader   including   support   for   arts, heritage   and   other   community   activity.   In   some   cases   your local    Council    may    provide    support    in    applying    for    such awards.  

Projector

Resolution:   You   should   choose   a   projector   having   a   native resolution   of   at   least   1024   x   768   pixels   (so-called   XGA). Lower    resolution    projectors    can    sometimes    convert    from 800   x   600   pixels   (so-call   SVGA)   to   a   higher   figure,   but   such interpolation     is     not     suitable     for     good     quality     image projection.    There    are    now    a    number    of    SXGA+    format projectors   available   with   a   native   resolution   of   about   1400   x 1024     pixels.     Both     DLP     and     LCOS     versions     exist (seeTechnology    below)    but    their    price    is    currently    about £2700.   There   are   also   an   increasing   number   of   widescreen projectors    intended    for    home    cinema    purposes.    These normally   are   a   maximum   of   720   or   768   pixels   high   so   offer no    real    advantage    over    XGA    format    projectors    for    most photographic work. Dead   pixels:   Most   projectors   do   not   have   dead   pixels   (ones that   are   permanently   white,   black   or   a   primary   colour),   but manufacturers   usually   state   that   they   consider   a   few   dead pixels   to   be   acceptable.   One   club   managed   to   persuade their   supplier   to   replace   a   projector   that   had   a   couple   of dead   pixels   on   delivery   -   they   are   not   obliged   to,   but   it   might work. Technology:     There    are    two    competing    technologies    for affordable   digital   projectors:   LCD   (Liquid   Crystal   Display) and   DLP   (Digital   Light   Processing).   With   LCD   light   is   shone through   three   panels   for   R,   G   and   B,   and   pixels   are   turned on   and   off   to   form   the   image.   DLP   is   Texas   Instruments technology   and   essentially   consists   of   tiny   mirrors   where   R, G   and   B   light   is   alternately   shone   on   to   these   and   reflected on   to   the   screen.   DLP   devices   tend   to   have   higher   light output,   but   a   few   people   can   see   "rainbow"   effects   with them   due   to   the   alternating   R,   G,   B   light.   This   is   rare   and   is more   of   a   problem   with   moving   images   when   they   are   used for home cinema. LCD   image   quality   can   degrade   after   1500   or   more   hours   of use   particularly   in   the   blue   panel   (at   least   three   years   at   10 hours    use    per    week).    Competition    between    the    rival technologies    probably    means    that    there    is    not    much    to choose     between     them,     although     DLP     is     generally lighter(weight) and possibly cheaper. Canon    have    their    own    LCoS    (Liquid    Crystal    on    Silicon) technology    that    has    virtually    no    'barn    door'    effect    (black around   pixels)   so   produces   a   very   smooth   clean   image. Prices   start   at   about   £2000   for   the   Canon   SX600   (1024   x 768),    compared    to    a    very    good    DLP    projector    (Optoma DX733) costing about £700 - April 2007 prices. See   Evan   Powell's   article      for   an   excellent   review   of   the issues. Light   Output:    A   couple   of   years   ago   the   light   output   of projectors    was    typically    about    1000    lumens.    Now,    many current    models    produce    2000    lumens    or    even    more. Anything   greater   than   about   1100   lumens   will   do   a   good   job in   normal   club   surroundings   on   a   6   foot   screen.   Some   DLP projectors   can   produce   3000   lumens   or   more   and   these   can sometimes be too bright for viewing in darkened conditions. Contrast    Ratio:    Current    projectors    claim    450:1    contrast ratio      or      higher.      Higher      values      produce      the      best shadow:highlight     differentiation.     However,     even     though these   projectors   are   bright,   to   see   good   photographic   detail it   is   always   necessary   to   use   a   dark   room.   DLP   and   LCOS projectors   give   the   best   ratios   -   up   to   2000:1   in   some   cases, but this is only achieved in full blackout conditions. Lens:   Data   projectors   generally   have   non-interchangeable zoom    lenses.   To    fill    a    2    metre    screen    the    projector    will typically   only   need   to   be   about   3.5   m   away,   perhaps   about half   the   distance   of   a   35mm   slide   projector.   Data   projectors usually have keystone correction facilities built in. Aspect      Ratio:      The      standard      aspect      ratio      is      4:3 horizontal:vertical.   Some   wide   screen   projectors   are   now appearing   but   they   seem   to   be   targeted   at   the   home   cinema market. Lamp   Life:    In   most   cases   this   will   be   for   about   2000   hours. The   projector   keeps   track   of   use   and   some   prevent   use beyond   the   stated   life.   Since   lamps   cost   about   £300   its worth    checking    the    lamp    life    figure.    Hitachi    has    been including    3    year    lamp    warranty    with    its    projectors.    With some   of   the   brighter   projectors   there   is   often   an   economy mode   that   produces   plenty   of   light   for   photographic   images in   darkened   rooms   and   extends   the   nominal   life   of   the   lamp from perhaps 3000 hours to 5000 in some cases. Connection:    Data   projectors   are   usually   connected   to   the laptop     using     a     15     way     analogue     VGA     cable     (blue connector).   The   one   provided   is   usually   about   a   metre   long. A   7.5   m   Extension   cable   costs   less   than   £20.   If   you   need   a longer   distance   than   that   between   laptop   and   projector   you should   consider   a   wireless   link.   Selsdon   CC   have   a   wireless connection   that   works   well,   although   there   is   a   slight   delay when images are changed. Newer   projectors   usually   come   with   a   DVI   connector   (white connector).   This   is   the   preferred   connection   method   if   your computer has one of these too. Screen:    In   most   cases   existing   screens   for   slide   projection are    fine,    but    some    beaded    screens    can    produce    Moire patterns with a data projector. Cable    Management:    Rubber    cable    covers    to    prevent people   tripping   over   them   can   be   obtained   in   1   metre   or   3 metre   lengths.   Staples   (on-line   ordering   look   under   "cable covers") are competitive. Helpful     Companies:      Various     people     have     found     the following companies helpful: ProjectorPoint:   Based   at   Richmond.   Have   a   very   wide range    and    are    very    helpful    on    the    phone.    Very competitive     prices.     Web:     www.projectorpoint.co.uk Phone: 0800 073 0833 Hocken   AV:   Based   at   Kingswood.   Very   helpful.   Web: www.hockenav.co.uk Phone: 01737 370371 Pinnerton:    Based    in    Woking.    Very    helpful.    Web: www.pinnerton.co.uk Phone: 01276 488111 If   you   have   found   a   particularly   helpful   company   when   you were   purchasing   a   digital   projector   or   related   equipment, please let the SLF know so we can add their details.  

Computer

Purpose:    It   is   worth   trying   to   anticipate   the   uses   to   which the   equipment   will   be   put.   Some   clubs   have   been   interested in   using   the   laptop   for   Digital   Imaging   demonstrations   as well     as     image     display     for     competitions.     A     higher specification   computer   is   needed   in   that   case.   Other   clubs (Selsdon     CC)     have     been     keen     to     run     international competitions   and   to   send   CDs   or   DVDs   of   the   competition, complete    with    judges    commentary    to    the    other    clubs involved. Laptop:    Generally   laptops   are   chosen   as   they   are   more convenient    to    transport.    Mac    or    PC    laptops    are    equally useful   and   the   choice   really   depends   on   the   preferences   of club members and budget. Main   Memory:    Most   machines   these   days   have   at   least 256MB    (megabytes)    of    main    memory,    but    if    you    are planning   to   use   it   for   Photoshop   demonstrations   too   it   is best to increase it to 512MB or 1GB (gigabyte). Hard   Disk:    Images   for   competitions   will   be   relatively   small so disk space will not be an issue, but if using Photoshop do not go for less than 40GB of hard disk space. CD/DVD:    It   is   worth   getting   an   internal   CD/DVD   writer   with the   machine   to   allow   exchange   of   data   with   others   and   for backing    up.   A    free-standing    external    drive    (USB2)    costs about   £150,   similar   to   the   cost   of   a   built-in   one.   The   choice depends    on    whether    the    CD/DVD    drive    is    to    be    shared among several machines. Keyboard/mouse:     One     way     of     reducing     the     cabling problems   is   to   keep   the   laptop   close   to   the   projector   and have     a     cordless     keyboard     and     mouse     so     that     the demonstration/competition     can     be     controlled     remotely. Standard   wireless   mice   and   keyboards   work   well,   but   their range   is   limited   to   about   5-6   feet.   "Bluetooth"   keyboards   and mice   claim   a   range   of   up   to   about   30   feet,   but   they   are   more expensive. (Don't forget spare batteries!) Audio:    Small    PA    systems    with    radio    microphones    are available   for   £200-£300.   Selsdon   bought   theirs   from   Sound Dynamics Ltd. Display   Connector:    If   possible,   choose   a   machine   that   has both   DVI   and   VGA   connectors   for   attaching   a   display   or projector.   The   DVI   connector   should   give   (slightly)   better image quality.

Software

The   package   that   has   been   used   in   FSLPS   Competitions such   as   Jack's   Jug   and   the   Vic   Smith   Trophy   is   DiCentra.   It is    costs    £35    for    a    club    licence.    It    provides    facilities    for loading   images   from   entrants   and   checking   that   they   comply with   the   competition   rules.   Facilities   are   provided   for   setting up   the   projector   prior   to   judging.   Marks   are   accumulated during   the   competition   and   selected   images   can   be   held back    to    be    marked    at    the    end.    The    scoresheet    can    be displayed   at   any   stage   and   a   'Lightbox'   can   be   used   to select images for awards. Some      people      use      MS      Powerpoint      for      producing presentations,   although   it   is   relatively   expensive   if   used   just for   that   purpose.   There   are   many   other   packages   including PicturesToExe for about $30. Slide    shows    can    also    be    made    with    Photoshop    and displayed in a browser such as Internet Explorer.   

Digital Competitions

  Here    are    a    few    points    about    gathering    and    presenting images for digital competitions. Image    Size    :     Most    affordable    digital    projectors    have    a displayable   area   of   1024   pixels   wide   by   768   pixels   high. Some   wide   screen   projectors   provide   a   wider   image   but none     provide     more     than     768     pixels     height     (to     my knowledge).    Let    us    suppose    we    have    a    portrait    format image    and    a    landscape    format    image,    both    with    a    2:3 (35mm)   aspect   ratio.   If   the   landscape   image   fills   the   screen horizontally   it   will   be   1024   x   682   pixels,   while   if   the   portrait format   image   fills   the   screen   vertically   it   will   be   512   x   768 pixels.   If   you   do   the   arithmetic   this   means   that   a   portrait image   is   only   56%   of   the   area   on   screen   of   the   landscape.   If they   were   slides,   the   two   images   would   be   the   same   area on screen. For   this   reason   I   advocate   that   the   maximum   dimension (width   or   height)   of   an   image   should   be   768   pixels   with today's    projectors.    It    can    be    argued    that    you    are    losing some   of   the   available   resolution/quality   in   the   landscape format.    But    if    the    full    1024    pixel    width    is    available    for landscape   format,   portrait   format   images   suffer   the   same problem, and are only 56% of the size. A    number    of    digital    competitions    seem    to    be    allowing images   up   to   1024   x   768   to   be   submitted,   so   that   format   will probably   prevail   even   though   portrait   format   images   are   at   a disadvantage. No     Interpolation:     Entries     should     be     displayed     as submitted, so that there can be no arguments that detail has been   lost   due   to   interpolation   (re-sampling)   or   compression. Files   should   be   prepared   to   a   maximum   dimension   of   768   or to   a   maximum   size   of   1024   x   768   pixels   or   whatever   other standard   the   organisers   choose.   (Some   software   may   put   a 1   or   two   pixel   border   around   the   image   so   that   needs   to   be considered.) Entrants   should   be   warned   that   if   they   fail   to   submit   to   the correct     size,     jagged     edges     may     appear     (so-called interpolation   or   compression   artifacts)   or   some   of   the   image may be arbitrarily cropped by the software. Colour   Space:   Projectors   cannot   display   the   full   gamut   of Adobe    RGB.    Submitted    images    should    be    converted    to sRGB   by   the   author   so   that   they   can   preview   the   image   and deal   with   any   problems   due   to   the   reduced   gamut   of   sRGB. Entrants   should   be   advised   to   view   their   images   on   a   colour calibrated    monitor    before    submission.    Monitor    profiling devices   are   now   easily   available   at   prices   from   £90   (e.g. Colour Confidence). File   Format:    Entries   should   be   submitted   as   JPEG   or   TIFF files.    JPEG    files    can    be    smaller,    which    may    be    an advantage   if   images   are   being   emailed   to   the   competition organiser,   although   even   with   uncompressed   TIFF   the   file sizes   should   not   be   too   great.   TIFF   files   should   not   include layers or transparency. Projector   Colour   Management:    Just   as   monitors   can   be calibrated,   so   can   data   projectors.   The   main   problem   is   that the   calibration   is   affected   by   the   ambient   conditions,   so   the black-out   conditions   and   screen   need   to   be   in   place   before this   is   done.   Although   a   calibration   done   some   time   earlier may    be    adequate,    it    really    should    be    done    for    the competition    conditions.    Projector    calibration    takes    up    to about 20 minutes. The    Gretag    Macbeth    Eye    One    Photo    has    facilities    for projector   calibration   A   new   Color   Vision   Spyder2Pro   kit   is available    and    includes    projector    calibration.    The    Gretag Macbeth   kit   is   expensive   but   does   printer   profiling   as   well   ad display   and   projector   calibration   (£800).   The   Spyder2Pro costs about £180.   

Projector Setup

There    are    a    number    of    charts    that    may    be    useful    in evaluating   a   projector   for   purchase   or   when   setting   up   the projector   for   a   competition.   There   are   three   sets   here   that you can download: Plain charts ( Download  ) Colour charts ( Download  ) Focus and Greyscale charts ( Download  ) Black   Chart   :    By   comparing   the   blackness   of   the   projected area   to   the   outer,   un-illuminated   parts   of   the   screen,   the depth   of   black   can   be   assessed.   This   needs   to   be   done   in   a darkened room. Grey    Chart:     This    is    good    for    identifying    colour    shifts introduced   by   the   projector.   They   show   up   well   on   a   grey chart   because   the   human   eye   is   very   sensitive   to   small shifts away from neutral greys. White   Chart:   Essentially   the   equivalent   of   the   open   gate   in slide   projectors.   It   is   useful   for   measuring   the   brightness   of the   image.   For   slide   projectors   an   open   gate   measurement using   an   exposure   meter   should   show   50   lumens/square foot   at   the   screen   centre.   There   are   no   accepted   standards for   digital   projectors   yet,   but   using   an   exposure   meter   at   100 ISO   pointing   to   the   centre   of   the   screen,   a   reading   of   1/60th at   f/16   gives   a   similar   illumination   to   that   used   for   the   Vic Smith competition in 2006. PAGB   Wedges:    These   give   5   steps   for   each   of   the   primary colours   and   grey.   More   details   can   be   found   on   the   PAGB web   site(www.pagb-photography-uk.co.uk).   The   third   PAGB report   on   Digital   Projected   Images   is   particularly   useful   and contains      information      on      projectors,      software      and competitions.   Photodisc   Chart:   This   is   a   freely   available   colour   test   chart that   contains   many   features   including   standard   colour   and monochrome    step    wedges,    as    well    as    many    'memory' colours   such   as   skin   tones.   The   versions   called   PDI-target 768   and   PDI-target   1024   lscape   have   been   scaled   to   fit   a standard    1024    x    768    monitor    in    portrait    and    landscape orientation,   respectively.   Please   note   the   license   terms   in the   Read   Me   file.   (The   original   test   chart   is   a   rather   larger TIF file. It can be downloaded from the PAGB site.) Grey   Wedge:   This   is   a   21-step   grey   wedge.   If   the   projector is properly set up each step should be distinct. Projector   1024   x   768   size:    If   this   is   shown   at   full   size   on   a screen     you     should     be     able     to     see     an     alternating yellow/black   line   around   the   edge   of   the   projected   image.   Its purpose   is   to   ensure   that   the   projector   (or   software   being used) does not lose any pixels at the edge of the image. Projector    Focus    and    Contrast:     Part    of    this    includes    a variety   of   21-step   grey   wedges   near   the   edge   of   the   screen. There   are   also   bars   at   1,   2   and   3   pixel   spacing   that   may help   with   focusing   and   in   diagnosing   problems   with   focus   at different parts of the screen .