From: geoff@pmafire.inel.gov (Geoff Allen)
Date: Thu, 15 Oct 92 18:20:00 GMT
Organization: Roller Coaster fanatic with no hope for a cure
Subject: Re: moonlit landscapes / stars (4x5)
Summary: 
Followup-To: 
Organization: Roller Coaster fanatic with no hope for a cure
Keywords: night, moon, stars, 4x5, view camera

franz@cs.washington.edu (Franz G. Amador) writes:
>Does anyone know a good way to pick an exposure for a moonlit
>landscape?  Seems like there ought to be a rule equivalent to "sunny
>f/16" for the full moon; the half moon ought to be one stop darker;
>etc.  I doubt my light meter will work; it reads only to EV 1 (ISO
>100).

Here are some past posts I've saved on the subject.  I have yet to try
it myself, but one of these days....

(BTW, I don't know about the brightness of a half moon.  I seem to
recall reading somewhere that it is less than half as bright as a full
moon.  But don't know for sure.)

Geoff

~~~~~~~~~~~~~~~~~~~~

From: jmacdon@cg-atla.UUCP (Jeff MacDonald)
Subject: At last, the Loony f/4 rule...
Date: 29 Nov 90 21:59:04 GMT
Organization: Agfa Compugraphic Division

After two years of brow mopping, I hereby announce the Loony f/4 rule
for taking pictures by the light of the full moon:

    Set the aperture to f/4 and open the shutter for 1/asa days.

Yes, that's right, DAYS.  This works out to be about 20.6 stops below
the Sunny f/16 rule for broad daylight.

Example: Kodachrome 25
    = f/4 for 1/25 days
    = f/4 for about 1 hour   (25 hours in a day, right?)
    = f/1.4 for about 8 minutes.

If you want the photo to look as though it were taken in daylight you
may have to compensate for reciprocity failure, otherwise reciprocity
failure will tend to cause the image to be somewhat underexposed, not
necessarily a bad thing in this case.

Example: Kodachrome 64
    = f/4 for 1/64 days
    = f/4 for about 24 minutes
    = f/1.4 for 3 minutes.

Remember:

    A. to exclude the moon itself from these pictures unless you
    want a burned out moon track across your image.

    B. to use the sunny f/16 rule if you want properly exposed
    images *of* the moon.

Whew!  I hope you guys are still interested after all this time.

-- 
Jeff MacDonald             |     [decvax|samsung|ulowell]!cg-atla!jmacdon
Agfa/Compugraphic 200-2-9F |                     jmacdon@cg-atla.agfa.com
200 Ballardvale St.  01887 |
(508) 658-0200,  ext  5406 |                 Nature abhors a trailer park


~~~~~~~~~~~~~~~~~~~~

From: chemist@techbook.com (Steve Bonds)
Subject: Re: Photographing by night with moon ?
Date: 29 Jun 91 07:28:05 GMT
Organization: TECHbooks of Beaverton Oregon - Public Access Unix

In article <12059@mirsa.inria.fr> luong@mirsa.inria.fr writes:

>I want to photography snow landscapes lit only by the moon
>(not the moon itself !). As the EV are lower than those taken 
>into account by the meters of all cameras, which exposure 
>would you suggest ? I think it counts in minutes doesn't it ?

I've done some landscape photos under moonlight.  The quality of light
was very odd, even eerie.  I used T-Max 400 and shot at 1 sec, 5 sec,
30 sec, 1 min, and 10 min.  The first two look a bit underexposed- shadow
details are lacking though the directly lit areas look OK.  The 30 sec and
1 min exposures look about the same and both show the appearance of shadow
detail, though not an awful lot.  The 10 min exposure seems like too much to
me- I lose texture in the partially overcast sky in this one.  The moon was
not quite full, but pretty close.  The overcast was thin and patchy, so it
may have varied during exposure.  (All exposures were at f/1.8.)

The Kodak book 'o' truth (Photoguide) says to use an exposure of 6 seconds at
f/2 for a landscape lit by a full moon.  For a snowscape, use 3 seconds at
f/2.  (Remember to correct for recipricocity failure!)  For close-up's and
medium-distance shots, use around 15 seconds at f/2 on ASA 400 film.  I
suspect my times are longer since the moon wasn't full and because of the
overcast.  Best to bracket.  Use the aperture to bracket if at all possible
(i.e. figure your times for an aperture besides your maximum) so you don't
have to deal with correcting more than once for recipricocity failure.

Good luck- I think you'll like the pictures you get.  Remember that if you
want the moon to be sharp, use a time less than about two seconds or so.
The earth rotates faster than you think!  (You MAY be able to get by for as
long as six seconds with a wide-angle lens.)

  -- 007



-- 
 00   00  77777 | same person, new name & address
0  0 0  0    7  +-------------------------------+-----------------------------
0  0 0  0   7   | sbonds@jarthur.claremont.edu  | chemist@techbook.com
 00   00   7    |                 "Give me FTP or give me death!"


~~~~~~~~~~~~~~~~~~~~

From: menzie@plains.NoDak.edu (Mark Menzie)
Subject: Re: Photographing by night with moon ?
Date: 29 Jun 91 08:58:52 GMT
Organization: North Dakota State University, Fargo, ND

In article <12059@mirsa.inria.fr> luong@mirsa.inria.fr writes:
>
>I want to photography snow landscapes lit only by the moon
>(not the moon itself !). As the EV are lower than those taken 
>into account by the meters of all cameras, which exposure 
>would you suggest ? I think it counts in minutes doesn't it ?

It will take some experimentation to determine "correct" exposure. I would 
start out with 8 minutes at f8 with 200asa film and bracket from there. 
Atmospheric conditions, phase of the moon, ambient light (yes, there still
will be some), snow coverage, and reciprocity failure will all play a role.

There are certainly other factors too. There was a good article on moonscape
photography in Peterson's Photographic a few years ago which gave a lot of 
good starting points....

>
>Tuan.

mark      menzie@plains


~~~~~~~~~~~~~~~~~~~~

From: lbullis@milton.u.washington.edu (Lawrence Bullis)
Subject: Re: Photographing by night with moon ?
Summary: dealing with reciprocity failure intuitively.
Date: 29 Jun 91 13:56:28 GMT
Organization: University of Washington, Seattle
Cc: lbullis@u.washington.edu

In article <12059@mirsa.inria.fr> luong@mirsa.inria.fr writes:
>
>I want to photography snow landscapes lit only by the moon
>(not the moon itself !). As the EV are lower than those taken 
>into account by the meters of all cameras, which exposure 
>would you suggest ? I think it counts in minutes doesn't it ?
>
>Tuan.


If you remember that it is very difficult to give TOO MUCH exposure,
you will probably do pretty well.  I am quoting from my own article
posted to another list:

There is a pretty easy way to think about reciprocity failure that makes
life more pleasant.  It saves one carrying one's library in a
wheelbarrow while shooting at night.  Intuition wins again.

You need to remember that the more exposure required, the hungrier film
gets for light.  What this means is that it is very easy, and usually 
disasterous, to underexpose in long exposures.  To overexpose, however,
is difficult and rarely harmful.  So, when you know you need to add 
for reciprocity, add more, then more, then more.  If you do enough of
it, it gets pretty natural.  As long as you give it enough, and then
some, you are usually just fine.  Take lunch and a book to keep you 
busy while feeding your film its evening meal of photon soup.  

[The paragraph below applies whether or not you have a meter that reads
very low light levels.  Look at the principle.]

Where your meter asks for 1/100 and you give it 1/50, you will be one
stop over.  If it says 1 second, and you give it 2, you will be about
right.  If it wants 10, you could give it a minute and be about right. 
What if you gave it two minutes?  No problem.  Half a minute? 
Underexposed for sure.  Get it?  Fifteen minutes on the meter means 
all night.  If your meter says an hour, forget it.  Talk to the 
astrophotography contingent.

Eventually, you could overexpose, of course.  But who has time?
Given a little practice, you will be amazed at how easy it is to shut
the camera off at the right time.

Check the tables.  You'll get the idea.  Then leave them home.

Remember that moonlight IS DAYLIGHT.  Of course, with color films,
reciprocity inconsistencies between the various layers will produce
color shift.  I'd recommend not worrying very much about it.  It could
be interesting.

Hope you can use this.  

Larry Bullis                 lbullis@milton.u.washington.edu
School of Art
University of Washington


~~~~~~~~~~~~~~~~~~~~

Like Larry said: Hope you can use this.

-- 
Geoff Allen          \  That's the problem with nature. Something's always
uunet!pmafire!geoff   \  stinging you or oozing mucous on you.  Let's go
geoff@pmafire.inel.gov \  watch TV. -- Calvin, speaking to Hobbes