From: faust@bagels.enet.dec.com (Stephen R Faust)
Subject: Re: Illuminated buildings, advice required.
Organization: Digital Equipment Corporation
Date: 24 JUL 92 10:27:31 EDT


In article <1992Jul23.140916.27901@gdr.bath.ac.uk>, mapres@gdr.bath.ac.uk (R E Slade) writes:
> 
>|>  I have been asked to take photographs of a church (here in England) which
>|>is being specially lit up by floodlight.  I only have one chance at this
>|>so I want to make sure that I get it right!
> 
>|>  My camera is a Canon EOS 1000FN with 35-105mm f4.5-5.6 lens.  Perhaps someone
>|>else has taken similar photos with this camera and could give me some advice as
>|>to films, reciprocity failure, exposure compensation etc.

Here is something that I entered before. It is a table of average nighttime
scenes, and their exposure values. Recip is built in, and bracketing will take
care of the differences between different types of film. 2 seconds at f5.6 or
its equivalent will get you in the ball park, and bracketing will take you home.

Nighttime Exposures Guidelines
   Most city scenes, streets lit by  street  lamps, cityscapes, buildings lit
   by flood light, etc, are all fairly  consistent  as  far  as light levels.
   They may be off by a stop or  two,  and  the  barcketing will take care of
   that, and give you  a  few  choices.  Bracket whenever possible by about 1
   stop each side (items marked  (bracket) below denote when the light levels
   vary widely, and bracketing of around  2-3  stops  is required).  Here are
   some examples for fairly common light situations for ISO 100 film.

    	Cityscape/Night			        f11, 1 min
    	Cityscape/sunrise-set		        f11, 8 sec
        Cityscape/twilight                      f11, 1/2
    	Buildings lit by floodlights	        f5.6, 2 sec
    	Bldg fire/bonfire/lg campfire           f2.8, 1/30
    	Subj lit by fire (about 5' from fire)   f2.8, 1/4
    	Street scene by street light (dim)      f2.8, 2 sec (bracket)
        Bright street scene by street light     f2.8, 1/15
    	Moon lit landscape		        f5.6, 4 minutes (bracket)
        Moon, full (crecent use +2)             f11, 1/125
        Average office interior lighting        f2.8, 1/30
        Average household interior              f2.8, 1/4
        Subj, close to household lights (3')    f2.8, 1/15
        Neon signs                              f5.6, 1/15
        Fairgrounds/amusement park/circus       f2.8, 1/15 
        Theatre/plays/drama                     f2.8, 1/30 (bracket)
        Typical museums                         f2.8, 1/4
        Hospitals/industrial bldgs              f2.8, 1/30
        Fireworks displays against dark sky     f8 @ any duration up to 2 min
        Indoor sports/basketball/hockey/etc     f2.8, 1/30
        Outdoor sports (well lit)               f2.8, 1/30
        Outdoor sports (average lit to dim)     f2.8, 1/4 (bracket)
        Store windows/displays (average)        f4, 1/15
        Subject lit by candelight               f2.8, 1/2
        Churches, interiors                     
                daylight through stained glass  f4, 1/4
                interior lighting by electric   f2.8, 1/2

Sunny 16 Variations    

    Here are some variations to the sunny 16 rule under different conditions.
    They are listed as a exposure compensatition value from the nromal  1/ISO
    at f16.  These are for frontal sunlit conditions.    Additionally,  apply
    the  correction listed under 'lighting correction' when not using frontal
    light. 

      Sunny 16 variations           Lighting correction
        Bright sun      0               Backlit subject         +1-1/2 to +2
        Hazy sun        +1              Sidelight Subject       +1/2 to +1
        Light clouds    +2               (-1/2 under hazy conditions, -0
        Overcast        +3               under overcast or shade conditions)
        Heavy rain      +4
        Dense Shade     +6


Reciprocity Failure Guidelines    

    On reciprocity failure, you can use some guidelines as far as the
    exposure compenstation is concerned. This numbers are an average of the
    recip compensation of some of the more popular slide and negative film.
    You can use this as a guide for non-critical work. Bracket on the plus
    side up to about a full stop, and these numbers should work fine for
    you. For ctitical work, you need to check the film recommendations for
    exposure and color correction filter pak info.

    Exposure time	Slide Film	Negative Film	B&W (with devel comp)
    	1s		+1/2 stop	+1 stop		+1 stop, +10% devel cut
    	10s		+1-1/2		+2 		+2, +20% devel cut
    	100s		+2-1/2		+2		+3, +30% devel cut
    	

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Stephen R Faust                                         faust@bagels.dec.com
Digital Equipment Corp.                            faust@bagels.enet.dec.com
Networks and Communications                                   (508) 486-7433
Littleton, MA
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