Multiple exposure of the setting sun
You may once have seen a photo of several regularly spaced suns that
are setting over an ocean or mountain range or so, and maybe you
wondered how this is done. The technique is very simple, but you will
need a camera that can do multiple exposures. These photos require
a lot of patience, and you have to keep concentrated, but the results
are usually well worth it.
Ofcourse you can create a similar photo by digital manipulation,
but that is cheating! The one-hour dedicated, bone-chilling,
teeth-grinding session that created that stunning multi-exposure of the
moon at 4 AM in the morning surely is going to give you more of a
feeling of accomplishment and satisfaction than sitting at a computer...
... in my opinion.
What you need
With multi-exposure I mean exposing one frame and without advancing
the film, exposing another frame over the previous frame.
In general, a camera that can do double exposures can do multiple
exposures as well. If your camera cannot do multi-exposures, you cannot
try this technique. Even if you can fool your camera into doing
double exposures by winding the film advance lever with the film rewind
mechanism unlocked, as possible with the older Olympus, Pentor
and Praktica cameras, you won't be able to do a multi-exposure because
the film may move a little.
Nikon FE camera bodies do multi-exposures fine, and are not too
prohibitively expensive, although you need a lens as well. Good
Nikon lenses have the reputation of being prohibitively expensive,
unless you buy them used.
For a lens, use a short-telephoto lens like 85mm or 135mm. Wider
angle lenses make the sun's image on the film quite small, and besides,
you will need a longer time for the photo (it doesn't look very good to
have the sun start somewhere in the middle of the frame; rather let it
drift into the frame from the top). Longer telephoto lenses are an
option, but then there will be few images of the sun or moon next to
eachother on the frame.
Most importantly, you will need a solar filter if you want to do
a nice multi-sun exposure where the sun appears as a well-defined
orange ball. I highly recommend getting a visual/photographic filter
that is made for the purpose. Baader and Thousand Oaks are two
companies that distribute affordable solar filters. You need a filter
that is ND5, which has an transmission coefficient of 10-5
(i.e. 0.001 % of the light gets through). The sun will appear deep
yellow-orange through such a filter.
If there are thick cirrus clouds, you might be able to get the sun
properly exposed on the frame by using just a fast shutter speed and
no filter, but the clouds together with the sun may look strange
on the frame later, and the sun may be blurry as well.
If you do multi-exposures of the moon you don't need any filter.
You also need a sturdy tripod and cable release.
Multiple exposure of the rising moon; since the moon wasn't full, the time interval could
be shorter. Note that the atmospheric absorption near the horizon shows quite well.
The technique is quite simple, but requires patience and exact
timing. You take a series of exposures on a single frame with the
tripod and camera fixed, at regular intervals; Earth rotation makes
the sun (or moon) move across the sky. When the sun or moon has set,
or when it has moved out of the frame, you make another exposure
(without filter) of the background sky.
While you make the sun/moon exposures, the background sky will
virtually not expose the film, because of the huge brightness
difference (assuming that you will not try the technique with the moon
during the daytime). Only when you do multi-exposures of the moon during
the night, you might expect a bright star or planet that happens to be
near the moon to show up as a chain of points, also.
Most difficult is to determine the proper exposure for the sun or
moon to have it properly exposed on the frame. Also important is that
you use exactly the same exposure settings for all the exposures, even
though the sun and moon may dim appreciably when they are near the
horizon. If you were to change the exposure settings, the result would
look quite bad!
Below is a chart that lets you determine the proper exposure to
within one stop or so. Keep in mind that atmospheric scattering and
absorption can make these times drastically different, depending on
the atmospheric humidity, your altitude, and dust content of the air.
The table below is for clear conditions, with the sun or moon about
10o high in the sky.
|Sun (with ND4 filter)
|Sun (with ND5 filter)
[Exposure times for the sun and moon at about
10o to 20o degrees high in the sky, under
clear-air conditions. Note that a ND4 filter is about 3 stops
brighter than a ND5 filter.]
The background frame should be exposed according to your camera's
exposure meter (assuming it is measuring accurately); these exposure
times ofcourse vary so much that I cannot possibly give any help on
this. If you do a multi-sun exposure and the succeeding sunset is
very bright, underexpose half or one stop.
Determining the proper time interval
The sun and moon move in right ascension by approximately
15o per hour, which is 15 arc-minutes per minute. Since
both the sun and moon appear about 30 arc-minutes in diameter, and
both are near the equatorial plane of Earth, they move a distance
about equal to their own diameter in about 2 minutes. So if you
want a dense chain of suns or moons in your frame, make exposures
at about 2m 30s intervals; I recommend to start with an interval
of 4 minutes. That will give the multiple sun/moon images separated
by about their own diameter from eachother.
When doing artistic photography such as this, proper composition
The apparent track of the sun will make an angle with the horizon
that is approximately equal to 90o minus your latitude,
if you photograph the sun during the equinoxes. E.g. if you are at
latitude 35oN, the sun or moon will make an angle of about
55o with the horizon. You need to know this in order to
determine the composition properly beforehand; once you start the
exposure series you cannot adjust the camera!
The horizon intercept angle will be less if you don't photograph
during the equinoxes and may also be different if you photograph the
moon. The moon orbit makes a small angle with the ecliptic and so
the moon doesn't need to be on the equatorial plane at the time of
Have the sun or moon go into or out of the horizon slightly
off-center to the frame, if the track makes an angle with it; the
photo will have more balance.
- The technique gets very easy if your camera supports
interval-shooting. But I am not sure if there are consumer cameras
that do interval-shooting and multi-exposures simultaneously.
- When shooting during sunset/moonset, do the multi-exposures
first, and then the exposure of the background. During sunrise or
moonrise, do it the other way around, if you know exactly where it
will rise. This is because you don't want the sun or moon near
the frame when you do the longer background exposure, to avoid flares
or spurious sky glow; and you probably don't want to wait an hour or
so between the multi-exposures and the background exposure for the
sun or moon to be far enough out of the way.
Make sure there are no (sharply defined) clouds in view at any time, or the
resulting superimposed solar image will look strange.
- Keep in mind that the camera viewfinder often views only about
90% to 95% of the full frame; you need to do some exposures even when
the sun or moon is not visible in your viewfinder.
- Make sure that the tripod doesn't move. One frame will
probably have the sun or moon half over the horizon, and it is crucial
that the horizon doesn't move, otherwise the cut-off body will appear
to hover above or into the horizon.
- You cannot do multi-exposures of the moon during the daytime,
since you need a huge brightness difference between the moon and
background in order to not expose the background during the
- For multi-exposures of the moon, the background frame will show
star trails. This is unavoidable; the star trails will be shorter if
you use a faster film, since the exposure then takes shorter. Expect
to expose the background frame several minutes if you use 100 ISO and
- Use higher f-ratios such as f/5.6 or f/8 for the multi-exposure
series, if the light level permits, to get sharper detail. The
background frame may also show vignetting if you use a wide-angle lens
at low aperture numbers.
- Timing is essential! Keep a record of all exact times (writing
them as, for example, 07:21:00 and such), so you won't get confused as
to whether you forgot an exposure or not. It may seem unnecessary but
trust me, it is very easy to get confused with this if you don't keep a
log! Also, take all pictures
within a few seconds accuracy to the proper time interval, otherwise
the sun or moon will be irregularly spaced on the photo.
- Either use a dark filter such as ND4 or ND5 for the sun, or use
short exposures and no filter at all (if at all possible). Don't use a
high-transmission filter such as a +3 stops filter or so, or the photo
will have nasty reflections. Do not get confused by the various filter
designations though - some filters are (improperly?) sold as ND4, while
they have a transmission coefficient of 1/4 the incoming light, or 2
stops, not 1/10000 (about 13 to 14 stops) for the proper ND4 filter!
A true ND5 filter will appear completely dark when you attempt to look
through it, save for the sun or another extremely bright object. Most
filter designations are something like ND4x though, meaning the filter
requires exposures 4 times as long to get the same exposure as without
the filter - so watch out for the 'x' in the filter designation - these
filters are not useful for solar photography.
- For all photography that involves the sun, take great care with
your vision. Do not look directly at the unfiltered sun, not even for
a moment, and make sure the filter you use is safe for solar viewing.
- The ultimate multi-exposure of the sun is the analemma, the
figure-eight that the sun makes in the sky throughout a year if you
photograph it at exactly the same time of day once every week or two
weeks. Few people have successfully accomplished this. The
figure-eight arises from the fact that the orbit of Earth around the
sun is elliptical and the fact that the orbital plane of Earth and the
equator are not coplanar.