|
Photographing
Your Models
Part Two
By Robert
Pounds
Robert Pounds is a journalist, director, cinematographer and has written
several articles for photo journals. His many interests include model ship photography.
Robert presents a detailed examination of this subject, following the introduction to the basics of model photography previously
presented on HyperScale. His perspective of model ships does not lessen the relevance of
this article to other forms of model photography.
Copyright for this article remains with the author, Robert Pounds. This article is
provided for personal information or research only. All other usage, including
republication in model club newsletters, etc, requires express approval of the author
People who build models - be they in wood, plastic, or for that matter card and paper -
sooner or later want to share the results of their labours with friends and fellow
modellers. Short of being able to look at the model itself, photographs are, of course,
the perfect way to do this. Photographs are also sometimes required by modellers to
illustrate articles, construction guides or catalogues.
Yet some modellers find their photo results disappointing. They may not be sure what is
wrong, or if they do recognise the fault, are uncertain of how to fix the problem for next
time. Like modelmaking, photography requires a certain level of skill to produce good
results. And, like modelmaking, these skills can be learned. But some basic instruction is
needed if skills are to be developed. This article sets out to looks at some of the
factors that need to be considered when photographing, in this case, ship models. The
basic principles, however, are common to a wide variety of photographic situations, and I
am sure the reader will readily adapt the basic to her or her own purposes.
For nearly 20 years I was a documentary film director/cinematographer and as a sideline
wrote technical articles for several photo journals around the world, including some in
the US. I trust the article will not be too technical for non-photographers, but at the
same time will be of interest to those who have more than a basic knowledge of
photography. There is no special magic involved, but it is assumed for the purposes of the
later technical examples that the camera being used is a 35mm single lens reflex. It does
not matter much if the camera is fully automatic or totally manual in how its exposure
settings are achieved, but you will see that in some instances it is better to be able to
over-ride the fully auto features. If you are unsure of what your camera can do, dig out
the manual.
The article is broken into three parts: light
and lighting, films and their
characteristics, and the optics of close-ups.
I apologise for referring mostly to Kodak products, but it is theirs that I generally use
and am most familiar with. It is also assumed in the section on colour of light that
colour photographs or slides are the intended result. If the finished product is to be
black and white, then the necessity for correct colour temperature matching of light
sources and film is eliminated.
Light is the basis of all photography, and the quantity and type of light that you send
down the front of your camera lens is directly related to the quality of your final image.
Without going into the physics too much, light, as part of the electro-magnetic spectrum,
covers a ‘band’. Perhaps you’ll recall a high school science experiment in
which a prism was used to split sunlight into a range of colours The explanation was that
each of these colours was at a different frequency and thus the rays were bent at slightly
different angles by the prism. All of the colours in the spectrum are present in any kind
of light, but the proportions depend on the type of light source.
The quality of light is measured by its ‘colour temperature’. Daylight, for
example, is rated at 5400 degrees Kelvin. This is the kind of light that would be emitted
by a theoretical perfect black body heated to that temperature. ‘Daylight’
colour temperature light, as provided by the sun, is true only for the period between
about two hours after sunrise to about two hours before sunset. Film manufacturers such as
Kodak will advise that for the most faithful image quality, in respect of colours,
photographs using ‘DAYLIGHT BALANCED’ film should be taken during this period.
So pictures of Mum, the kids and the dog are best taken then for the most accurate colour.
It also partially explains why the colours in some photographs taken in the shade
don’t look quite right.
Outside the two hours margin, the colour temperature of daylight is cooler, resulting in a
redder light quality. Portraits taken during this time will show a more ruddier complexion
to the skin. If accurate colour rendition is required, the light may be measured with a
special light meter called, as you might expect, a colour temperature meter. From there
calculations can be made to determine the necessary colour compensating filters that are
to be put on the front of thelens. Let me say now that we are now in the realm of
(usually) the professional scientific photographer where absolutely accurate colour is
required under the existing light conditions. Ship modellers, being basically a sensible
breed, have enough nous to simply not try to take colour images when the colour
temperature of the light is beyond the range for which their the film was designed.
The most common artificial light source for photography is the photoflood lamp.
Photofloods are designed to put out a cooler light than daylight. As you
look at it, it is decidedly yellow in character, and for the technically minded it is
rated at 3200 degrees Kelvin. If you photograph a model - ship or female - using daylight
balanced film under this light, the results will be reds that are very saturated, whites
that look yellow and blues that are dull and lifeless. Compared with the same image taken
on TUNGSTEN BALANCED film, the latter is infinitely superior.
So the solution is one of two things: somehow convert the light from the
photofloods to daylight; or use tungsten balanced film stock when using photofloods.
The first can be achieved by putting a filter in the front of the camera lens to modify
the light reaching the film to the equivalent of daylight or by placing a gel in front of
the light source to convert the light reaching the subject to daylight equivalent.
Correction filters to suit most popular camera sizes are readily available, although your
camera store may have to order one in. In Kodak’s nomenclature, the filter you need
is a 80A. It is blue in colour, and for exposure compensation usually requires an extra
1.5 stops (a factor of x3) to be added. In layman’s terms, the filter will reduce the
amount of light reaching the film, so allowance has to be made for it by either using a
slower shutter speed or by opening up the aperture a bit more. Cameras that read the
exposure through the lens will automatically compensate for it.
An alternative is to put a colour gel in front of the lamp. Professional lighting units
such as those made by Lowell have a gel frame into which the filter material can be
fitted. However, as long as the filter material is in front of the lamp (and not touching
it) the result is the same - light, equal in daylight in colour temperature terms, at the
subject. As one might expect, the gel material is also called 80A. I’ve always used
the material made by Rosco.
As an aside, most film makers work the other way round. Kodak’s Eastmancolor motion
picture film is balanced for tungsten light right from the start. When using it in
daylight, we put an orange-looking filter (called an 85B) in front of the lens to convert
the light entering it to the equivalent of tungsten colour temperature. A range of other
special filters and gels enable the film maker to cope with light from fluorescent tubes,
etc. I recall one production where I put large sheets of green gels over a glass wall in
an office to convert daylight to fluorescent equivalent, other filters on the tungsten
fill lights to do likewise, and then a filter on the camera to convert all that back to
tungsten equivalent.
Using tungsten balanced film with tungsten lights is the simplest solution. However,
tungsten rated film is not always readily available, and sometimes even then only on
special order of a substantial amount.
So, unless you can get gel for the lights, you’ll need to use the blue correction
filter with daylight rated film stock to achieve correct colour balance.
There may be some who’ll say ‘what’s the difference: putting filters on the
lights or camera- you’re still going to reduce the amount of light available?’
I am a firm believer that the less I put on the front of the lens, the better. The optical
quality of gels doesn’t matter very much: but that of filters on the front of the
lens does.
Other might say, "But the photo lab can make colour corrections in printing".
While it can be done quite successfully, it is at best a ‘rescue’ rather than a
planned solution: far better to get the image as close to correct at the start than
depending on massive correction in the lab.
Before moving onto light placement, a few quick comments about ‘making do’ with
high wattage tungsten filament bulbs that look like photoflood lamps. Some have a mirror
back to them and a translucent front surface; others are designed for all-weather use in,
say, lamp fittings outdoors. SOME will give a light output similar or very close to
properly manufactured photoflood lamps - I’ve used the former quite successfully, but
only reliable way to be sure if they will suit your purpose is to try them out. I suspect
that for almost all your photography work they will do, but if you require extremely
accurate colour rendition, then stay with ‘real’ photofloods.
Getting the light quality right is only part of the issue. It is how the lights are placed
that sets the mood of the photograph.
In any lighting equation there are four components: Key light, fill light, back light and
background light. Each of these contributes to the final image - even if sometimes one of
the components of the equation is ‘nil’ or ‘not present’.
The best way to discuss each of these elements is to set up a hypothetical photo session.
--------------------Background---------------------
X Background light (set up high - but may be on one side)
X Back light
00000 Subject
X Key light
O Camera
X Fill light
In the above set-up, the key light is set about 30 to 45 degrees off the
camera to subject axis. This light, as the name implies, is the main light source and
should fall on the principal facet of the object being photographed. In portraiture terms,
if the model is sitting three-quarters on to the camera, this light falls on the front of
the face.
The key light also sets the basic exposure.
Adjust the key light’s position until the main shadows fall where you want (or do not
want) them to fall. Something to watch might be the position of the shadow from the
foremast in relation to the mainmast or, perhaps, the position and size of the shadows of
the deck fittings. Does a shadow fall from a deckhouse onto an area that you particularly
want to feature?
The fill light is used to reduce the depth of shadows produced by the key light. If the
fill is placed in the same relative position as the key light, but on the opposite side,
the result is a very flat light. Unless flat lighting is required for some technical
reason, it is far better to have some shadow tone to introduce a sense of texture and
depth. Too deep a shadow and the detail on the fill side is lost. Simply move the fill
light back and forth until the shadows look about right. Use your camera’s exposure
meter to help judge the lighting ratios. Place a Kodak Grey Card (more about this device
later) at the subject but facing directly at the camera. Take a reading with only the key
light switched on. Move the camera in closer temporarily, if you have to, to get an
accurate reading. Now do the same with only the fill light. A two-stop difference will
give you a good result. A two-stop difference is a ratio of 4-1 lighting (and fairly
natural looking). Photos intended for publication should err on the flatter lighting side
rather than the contrasty side, so a one or one and half stop difference may be
sufficient.
Both the key and fill should be placed higher than the camera (the key is emulating the
sun, remember) although the fill can be a little lower than the key if that helps reduce
shadows on items such as overhanging details, eg, the underside of lifeboats on a model.
The background light, as the name implies, lights the background. For ship models, it is
probably a good idea to shoot them on a cyclorama. This is a clever-dick name for what is
essentially a background that drops down and curves into and becomes the base on which the
model stands. It provides a seamless transition from background to foreground. It may be
of any colour but white or a very pale grey would be the most suitable. The background
light should illuminate only the background, and none of the model. Its intensity should
be adjusted so that it provides a balance between the main and fill lights. It is much
easier to do than describe: the background light should not be so bright so that it
overpowers the other lighting. It
needs not be as high a wattage as, say, the key light. An old roller blind makes a good
cyclorama, provided the surface is not glossy. It has the advantage also of being easy to
store.
Sometimes, there is no background light, especially when the effect desired is a deep
black behind the model and the back light is used to highlight the model.
The back light is one of the most useful lights of all. Used properly, it will put a
‘snap’ in your images that will make people sit up and take notice. Used wrongly
it will produce extremely disappointing results because the halo effect it provides
becomes too overpowering.
One of the other names by which the back light is known is the ‘rim light’ and I
guess that’s as good a description of what you are trying to achieve with it. This
light, usually restricted down by folding flaps on the lamp fitting (called ‘barn
doors’) or a tubular snoot, aims to put just a hint of light across the back of the
most prominent features of the subject. In portraiture, the light is used to gently kiss
the back of the top of the head and the shoulders. It has the effect of making the subject
stand out from the background. For a model ship, the danger would be to have this light
too bright, thus making the rigging seem to glow rather than having the merest hint of
light on the top edge of the lines and spars. The back light is placed high, on the
opposite side to the key light. Almost certainly you’ll need to limit the coverage of
the light with a sheet of card or something similar. You want the light to spill across
the back of the model but not be visible at the camera to prevent flare in the camera
lens.
Having said all that, my own preference now would be to place a softening filter (called a
scrim) in front of the key, fill and (possibly) background lights. This is a translucent
material, and looks like tracing paper. Again, the popular professional product is made by
Rosco. The scrim takes away the harshness of direct lighting. The same effect can be
achieved by bouncing the light from a white painted reflector or umbrella. Soft, gentle
lighting should be your aim rather than a hard spotlight effect.
The light set-up I have described is not meant to be definitive, but a basis on which to
start and experiment. For example, as a special effect to highlight the detail of some
stern carving, you might reduce amount of fill light right back so that there is more
contrast between the key and fill, and thus the shadows reveal the fine detail.
One other point comes to mind: if you are shooting colour, don't be tempted to adjust the
lights using a dimmer or rheostat. The colour temperature of the light put out by the
photolamps will change with the brightness, defeating the whole purpose of the exercise.
Sometimes a very pale yellow gel is used on the backlight to help make the separation of
the planes more apparent, this is especially so if you are using a light blue background.
I have not discussed flash at all as I believe that unless you have fairly sophisticated
equipment, including bounced flash heads and built-in set-up lights, or have a standard
fixed set-up, the results are too unpredictable for producing quality images. In any case
flash, for this kind of work, invariably needs some sort of scrim or reflector head to
soften the light.
What film stock do I use? Film manufacturers have made huge advances in recent years in
what their film materials will do. Older modellers may well remember the original
Kodachrome slide film. It had a speed rating of 10 ASA (or ISO, as it is increasingly
being called). Now there is a professional grade Kodachrome rated at 200 ISO. Early colour
print films were 100 ASA or slower, now 400 ISO is commonly regarded as the norm and
recently I have been experimenting with a very wide latitude film that has a nomial rating
of 800 ISO.
The ISO (or ASA) rating is a measure of the ‘speed’ of the film. The higher the
number, the less light it needs to produce a correctly exposed image.
Choice of film stock should be made on the basis of the proposed end use. While it is now
not as critical as it once was, generally photographs intended for reproduction in
magazines and journals should be shot on slide film; images intended for enlargement and
framing should be taken on negative stock.
Though things may have changed recently, the sharpest film available to the average
consumer is Kodachrome rated at 25 ISO. Nothing comes near it for crispness of image.
Negative films have undergone rapid advances and in the end there is very little to pick
between them. While it is true that a 400 ISO film will exhibit more grain size than, say,
one of 100 ISO, in practical terms for enlargements up to 10 inches by 8 inches the
differences are likely only to be apparent under critical analysis. I compromise by using
a 200 ISO readily available consumer neg film for most of my stuff, but on occasions I use
a professional grade negative 400 ISO stock (which costs a lot more than the general
consumer product) for things where I need a bit more speed.
One of the problems with closeup photography is that you never seem to have enough light.
You are always working, so it seems, at the extremes of your lens aperture, shutter speeds
and film latitude. Film latitude is the amount that you can be under or over in your
exposure and still produce an acceptable result. Negative films have a wider latitude than
slide films. Typically, you could be out by two stops either side of correct exposure with
a negative film and still have an acceptable (note - acceptable) result, while much more
than 1/2 of a stop either way with slide film and the result will be an over- or
under-exposed image. Obviously, the aim is to always have correctly exposed images.
Added to the ship model photographer’s problems is depth of field. Depth of field is
the zone of acceptable focus in an image either side of the point of sharp focus. (Do not
confuse the term ‘depth of field’ with ‘depth of focus’- they are two
different things.) For example, while your lens may be set to be in focus at 10 feet, in
fact, at a particular aperture, the zone of acceptable focus - the depth of field - may be
from eight feet to fifteen. This zone is not absolute - somthing is not in focus at one
point and an inch further on, out of focus. Depth of field is calculated according to some
assumptions about the size of the final image, but the scale provided by the manufacturer
on the lens barrel is good enough for most purposes. Depth of field is related to
aperture: the wider the aperture (the smaller the f/number) the less the depth of field.
Thus in an extreme case, in a very tight close-up, with a lens wide open, the depth of
field on, say, a binnacle mounting on a model might be less than 1/16 inch in front and
behind. Closing down the aperture will give increased depth of field, but the exposure
time will have to be lengthened to compensate for less light being allowed through to the
film.
In the end, especially when using extension tubes between the camera body and the lens, it
may be possible to run out of marked shutter speeds before reaching the minimum aperture.
As some may be aware, camera shutters and apertures work on an interrelation that says, in
effect, for the same exposure, if you decrease the aperture, you must increase the shutter
speed. Thus, if you have an exposure of, say, 1/125 sec at f/8, for the same exposure at
1/250 sec, you must adjust the aperture to f/5.6. Automatic cameras make this adjustment
for you - some camera programs let you decide on whether the fixed element is to be the
shutter and thus vary the aperture for you, or vice versa.
But this linear arrangement falls down when very long (and very short, for that matter)
exposures are encountered. Once you get down to exposures longer than about one second,
the film emulsion no longer acts in the same way. This is called a reciprocity failure
effect. Without going into a long technical discussion on this, corrections have to be
applied when very long exposures are being used.
For an article for US Professional Photographer magazine, I produced two images of the
Sydney Opera House at night. The exposure meter indicated 8 seconds at f/4, but the
resulting image was very dark - at least three stops underexposed. The same subject taken
at 64 seconds at f/4 on the same film was correctly exposed.
For a rule of thumb, if the exposure should be 2 seconds, use 4; for 4 seconds use 16, and
for 8 seconds, use 32. Results will vary according to film stock - not all react the same,
so either make tests first or shoot a set of images using different lengths of time. This
is called ‘bracketing’ and ensures that among the half dozen or so photos you
take at least one will correctly exposed. Note that with colour stocks there may be some
shift in colour rendition, and the use of colour compensating filters is recommended by
the film maufacturers. Most film manufacturers provide reciprocity failure effect data for
their films, though you may have to get this from the technical information section of the
relevant head office..
Thus for a closeup on a ship model where deep depth of field was wanted (and so the camera
is set for f/16 or f/22, the exposure, depending on the light, might be quite long. I once
shot an extreme close up of some diamonds that, because of the limited light that could be
used, required an exposure, including allowing for reciprocity failure effect, of more
than 15 minutes. Add to that a couple of retakes and a few shots at different exposures to
take care of any miscalculations and there went the best part of a morning.
I referred earlier to Kodak’s Grey Card. This is wonderful piece of equipment and,
for the serious photographer who has work done by various photo laboratories, it is a
boon. The card, about the size of a standard sheet of paper, is coloured grey. It is a
very specific grey, reflecting 18 per cent of the light that reaches it. All photographic
exposures are calculated on the basis that the average subject has about an 18 per cent
reflectance. The grey is also a dead neutral colour and thus any colour shifts that occur
because of a mis-match with lighting or processing can be corrected in the printing
stages. The way to use the card is to take one photo with the card in the main subject
area and then another AT THE SAME EXPOSURE SETTINGS with the card removed. The lab will
read the processed frame containing the card through a densitometer and calculate any
necessary corrections before it prints the main image. The cards are quite inexpensive and
it is well worth while getting into the habit of using them. Publishers often appreciate
the grey card image when submitting photos for publication as the film separators can
balance their equipment more easily by working from the card. A company called Macbeth
also produces a similar card, but it includes standard reference colour patches as well.
The Macbeth card or Kodak’s own colour patch cards are also useful for determining
the amount and direction of any colour shift caused by mismatches in film and light colour
temperature or reciprocity failure effect.
There are several ways photographers can get close to their subjects. Clearly, a purpose
designed macro lens is the best solution, but even then there may be times when just a bit
more is required. Sometimes a long focal length lens (telephoto) focused right down to its
minimum will do, but the compromise is that depth of field may be quite small.
With many standard lenses (45 mm or 50 mm focal length) the minimum focussing distance may
not be sufficient to frame as closely as desired. Some sort of supplementary system is
required.
Traditionally, this has been achieved by adding an extension bellows or rings between the
camera body and the lens. The major draw-back, however, is that exposure times are
considerably lengthened because the film has been displaced further back from the lens.
Some automatic cameras can make the exposure compensations, but for extreme
closeups, it
may be necessary to switch across to manual mode to take care of reciprocity failure
effects. Bellows and rings, especially for the modern autofocus cameras, can be quite
expensive.
Most modellers seem, however, to only require to get in moderately close. A framing area
of about three by four inches seems common. Few seem to need to get in so close as to
cover just the area of a postage stamp.
From my own experience, it seems that most modellers are after, for example, the broad
detail of the fittings on the foredeck, not the screw heads on the winches.
An expensive way to get in closer is to use diopter lenses which screw onto the front of
the camera lens, rather like a filter. They require no exposure compensation, and with the
taking lens set at a modest aperture (say, two stops down from wide open or smaller)
provide good image quality. Of course, you can stop right down to the maxium f number on
your lens. Diopter lenses are available in a range of ‘powers’ from 1 to 6.
Usually they are sold in a set of three, made up of 1, 2 and 3 diopters. The lenses may be
ganged together for increased power, but always put the most powerful (highest number)
next to the camera lens. It is not usually recommended to gang more than two diopter
lenses together, but by all means try 3, 2 and 1 together and see what kind of result you
get. As a guide, No 3 and No 2 diopter lenses used together should allow you to focus down
to about 6 inches.
Diopter lenses are not expensive, but like most things, you get the quality you pay for.
Another way to get in close is to obtain a reversing ring to mount the lens backward on
the camera body. Try also putting your telephoto lens backwards onto your standard lens.
You may have to make up the adapter ring yourself by using two old filter mounts (remove
the glass carefully) glued together.
For owners of older cameras whose lenses simply screwed into the camera body and had no
electronic or mechanical contacts to make, simply unscrewing the lens a fraction may
provide all the extra lens-to-film plane distance needed to get in that little bit closer
to the subject.
In summary, however, it is the quality of light and its placement that has the most effect
on your images. I would far prefer to work with lower rated lamps that I could control
than multi-kilowatt heads whose light beam could start a grass fire at fifty feet.
Quantity can be compensated for (such as through corrections for reciprocity failure
effect) but quality - light at the right colour temperature for the film stock you are
using - coupled with techniques to give adequate depth of field for the task at hand will
always produce outstanding images. It it goes without saying that for close-up work a
tripod and cable release are virtually essential to keep the camera steady during
exposures. There has (unfortunately) been a trend recently to do away with a cable release
socket on some cameras. If you are shooting using a slow, timed shutter speed, you can
eliminate any shake introduced from your hand touching the camera by triggering theshutter
via the self timer mechanism.
Go to Part One of "Photographing Your Models"
Text Copyright © 13 June, 1998 by Robert Pounds
Page created on Monday 30 June, 1998
This page last updated on 18 May, 2001
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