classic near IR photography requires detection of the 700-900nm
range of IR
photography of infra-red region of the light spectrum allows:
unusual landscape photos with false color or unusual
graveyard shots - grass will go almost white leaving
the tombstone floating in an eerie space, similarly for standing
derelict buildings covered in creepers - again the
contrast of stone and vegetation. See Pete Schermerhorn's excellent article on castles in Ireland.
people on the beach - sky and skin, water reflecting
nudes in a landscape - skin and vegetation and/or sky
haze reduction - only reduces blue haze, but try it
hot houses - vegetation
people with sunglasses - it is sometimes possible to
see the eyes behind seemingly opaque sunglasses.
visualise the elements in the photograph by the way
that they reflect infrared light.
blues, browns, dark greens in shadow will all appear
dark in the final print. Reds, whites, greens in sunlight will appear
light in the final print.
the eye is drawn initially to areas of high contrast
in a photograph, so frame the elements to lead the viewer into the
scene from the high contrast starting point.
try using strong graphical shapes with high contrast
to lead the viewer into the photograph and place important elements
using the rule of thirds.
finally, every so often throw the rules out and do
something just because it feels right or because you want to experiment
portrait photography, esp. to minimise skin complexion
problems such as acne.
skin looks bleached and may show veins
eyes are dark, brooding & dramatic
- most nebulae have strong emissions in the infrared H-alpha band
there is more infrared light around when there is bright
sunlight. This doesn't mean you should avoid using IR film in other
conditions but that the effects are stronger when the sun is out.
largest amount of IR: the hours just after sunrise and before
sunset (due to the angle of the sunlight through the atmosphere), the
effect is most dramatic (i.e deep black sky) when photographing with
the sun behind the camera.
an electronic or bulb flash will increase the amount of IR as
well as visible light.
Electronic flash guns and flash bulbs emit plenty of
infrared light together with visible light. This means that you can use
fill-in flash and flash alone for shooting in infrared. You will need
to calibrate your flash for the infrared film of choice through test
The use of flash allows an interesting possibility - you
can use a filter over the flash to reduce or eliminate the visible
light output and take infrared photos in the dark without any apparent
light. This means that you can take photos without out disturbing your
subject or alerting them to the fact that a photo has been taken. If
there is no ambient light then an infrared filter over the flash gun is
all that is required. If there is ambient light then a filter will also
be required over the lens as most infrared film is sensitive to some
thermal radiation will not be recorded by infrared film;
infrared films are not sensitive to a long enough wavelength to show
such things as heat patterns, however, IR can be used to photograph
self-luminant objects as cool as 250 degrees C.
creating a IR-pass filter for an electronic flash:
A cheap and cheerful way of making a flash filter is by using
two strips of unexposed but developed E6 film as an approximation to a
Wratten 87 (for more info. contact: Andrew
Davidhazy). Be careful on the frequency of flash use.
It appears that one thickness of E6 film is roughly the
equivalent of an 87 filter but with a broader spectral response and
with some 1% transmission valleys at 500 and 600 nm. Its transmission
starts to drop from 1% at 700 nm to about 95% at 800 nm. Two
thicknesses of D max E6 are basically visually opaque with transmission
starting at 720 nm and dropping quite rapidly to 90% or so at 850 nm.
Basically the two sheets of E6 simply do not have a cutoff as
steep as the Wratten filters nor is the maximum transmittance of light
as good. But they are serviceable, particularly for placing over a
flashgun where the expensive thin gel Wratten filters tend to fry and
There is another option for the DIY fanatics - paint your own
filters and bulbs. The formula for the infrared paint requires a range
of chemicals, some of which have to be purchased in bulk. This could be
an expensive exercise, however the formula and instructions on
concocting the brew are in this article.
whether using IR film or a digital camera, you need a IR filter
which allows IR light but blocks most or all visible light if you want
to get IR effect.
the degree of IR effect is higher as the cutoff frequency
increases, but the filter also becomes darker so composition through it
may be impossible to visualise, necessitating that composition is
performed PRIOR to adding the filter UNLESS you have a live preview
digital camera that is sensitive to IR (ie. does not have an IR
blocking filter as most have).
as infrared filters get very expensive above 58mm and in most SLR
cameras are too dark to compose, consider hand held square IR filters
such as Cokin 007 (#89B), Heliopan RG715 and Infrarex IR filter set of
red (RG1), dark red (RG2) and black (RG3) but note that the RG3 is of
no use on the Rollei IR 820/400 IR film but may be of use on some
look through red filters:
general notes regarding use of these filters:
for most digital and film work, the IR effect will be
minimal unless using Kodak HIE film or Konica IR750 film.
Hoya 25A (Wratten #25):
min. wavelength 580nm - actually a red filter
Wratten #29 (B&W #91):
min. wavelength 600nm - dark red filter, only needs 3
f-stop increase in exposure, OK for portraits and Kodak HIE film
Wratten #70 :
min. wavelength 640nm
less pronounced than & lose the light-coloured trees
effect as with Hoya R72 but only need exposure increase of 7 f-stops
which may allow hand-held photos with some digital cameras
B&W 092 (89B, RG695, Cokin IR007):
dark red filter is for black and white infrared films and
filters at light below approximately 650nm. It allows pictures of a
pure red image while making good use of the relatively low sensitivity
of infrared films. Filter factor is approx. 20-40
good IR for Kodak HIE and Konica 750 film
not really deep enough for digital IR
general notes regarding use of these filters:
for most uses, you will not be able to compose through
the filter as it is too opaque and thus you need to compose first then
place the filter on, unless:
using it on a digital camera with live preview with
good IR sensitivity
using it on a rangefinder or twin lens reflex film
install the filter in front of the film or sensor but
behind the SLR mirror so it doesn't block your viewfinder image.
exposures will be longer as the minimum wavelength
increases and may become very long if exceeds the film or sensors
Konica 750 film has minimal sensitivity at > 800nm
=> best to use R72 or lighter filters;
Kodak HIE film has minimal sensitivity at > 940nm
Kodak TMax 400 has minimal sensitivity at > 680nm
Rollei IR has minimal sensitivity at > 820nm
peak at 700nm;
min. wavelength 700nm; 50% by 720nm and 85% by 750nm;
probably the best IR filter for general use
works well on digital cameras as long as subject is not
moving and you use a tripod, although you may have difficulty composing
even with live preview digitals, although in bright sunlight, can use
Olympus models with their live boost ON and a f/2.0 lens.
composition impossible with unmodified Nikon, Canon dSLRs
gives good IR effect with all IR films and is usually the
most affordable filter, but still gets expensive in sizes > 67mm.
works on Canon 1DMIII for IR (ISO 400, f/5.6, 25sec for
the IR blocking filter on the Canon 5DMII is too strong
and gives NO IR effect with this filter but just acts as a ~26 stop
neutral density filter! - ISO 3200, f/4, 30sec in bright sunlight but
no Wood's effect
peak at 760nm;
Wratten #87 (Heliopan 5780):
min. wavelength 740nm, cuts off all visible light but
then can't see image to compose with so limited use
Unlike the 092 infrared filter, it makes pure
infrared photographs possible without the visible red component. Its
transmission only begins to exceed 1% at 800 nm, rising to 88 % at 900
nm, and remains that high far beyond the upper limit of sensitization
covered by infrared films. In the scientific field, materials research
and forensics, the limitation to a strictly infrared range is often
important. The filter factor is very dependent on the illumination and
on the characteristics of the film.
IR film has an emulsion that is sensitised to respond to a wider
range of light and radiant energy than standard film, allowing it to
record not only visible light, but also the near infra-red end of the
in contrast, normal "panchromatic" B&W films record only to
about 700nm & eyes are sensitive from ~400 to 760nm
it is a B&W film that is used for creative purposes as images
will show a sharp shift in tonal values, esp. in bright sunny weather
when objects transmit & reflect a lot of infrared light such as
healthy foliage, which then record almost white & luminous. In
contrast, open blue skies & bodies of water that reflect little IR,
are printed very dark which can create stunning contrasts with clouds.
Portraits can be interesting as it causes skin tones to look bleached,
may expose veins, whereas eyes look dark & brooding, allowing a
dramatic or spooky or more magical effect.
IR film also cuts through haze in distant landscapes & can
also be used at night in the dark if there is a IR lightsource.
the most sensitive (to 900nm, peak 750-840nm) &
provides the most spectacular results
low sensitivity to green; fine grain & very sharp;
no anti-halation layer & must be loaded in total
the dimpled pressure plate of Olympus OM cameras is only
a problem with 87 or deeper filters, and only on bright scenes.
good IR effects even with Wratten 25:
bracket exposures, Kodak
recommends starting with the following settings with a Wratten 25
for bright to hazy sunlight or electronic
use 50-100ISO metered without the Wratten 25
filter in place, or,
1/125th f/11 for distant objects (f/16
without a filter)
1/60th f/8 for nearby objects
for tungsten lighting, effective ISO increases by
1 to 1.5 stops.
add 0.5-1 stop for R72 filter (?use ISO 50),and 1-2
stops for #88A filter (?use ISO 25) and ~2-3 stops for Hoya RM90 filter
(?use ISO 12);
relatively expensive and unfortunately not available in
although gives the best Woods IR effect, it tends to lose
highlight detail in high contrast scenes more than the other films, and
is much more grainy (the other films have similar grain to Kodak TMax
Unfortunately Kodak is discontinuing
manufacture of this unique film in Dec 2007, so Kodak HIE will be no
more - see link
slower, very fine grain; sens. to 820nm peak at 750nm;
not sensitive to green;
easy to handle as has an anti-halation layer & can be
loaded in subdued light
lovely tonal rendition with Wratten 25 (effective ISO ~6)
but needs 89B (effective ISO = 3-8) for best IR effects;
use ISO 3 with Hoya R72 filter and ISO 1.5 with #88A
stocks only produced once a year around April.
maybe available in 120 film size;
spectral curves have two peaks:
360-510nm with peak at 440nm;
650-800nm with peak at 750nm;
Ilford SFX 200:
not a true IR film, and the least sensitive of the four,
only to 740nm (peak 720nm); easy to handle as has an anti-halation
layer & can be loaded in subdued light
large grained, great for dramatic high-contrast effects
only; latitude +1 to -1 stops
need Wratten 89B or Ilford's own SFX filter to give good
Kodak Ektachrome color IR film:
has 3 layers:
THUS, film can be scanned and processed as cyan -
(yellow + magenta) and used for similar effect to Kodak HIE with 89B
without need for an IR filter!
precautions using IR film:
most must be loaded into camera in complete darkness as its
lack of anti-halation layer which normally prevents flare from bright
lights, in addition to giving the film its wonderful glowiness in the
highlights, makes it extremely sensitive to fogging by stray light.
must be loaded into a IR-safe processing tank (eg. Paterson
tank) in complete darkness
should be stored in its original container in the fridge or
freezer until ready to use then defrosted to room temperature before
opening to avoid condensation
must be stored lower than 55degF if possible as high temps
will cause fogging - ie. a cool place => NOT in the car!
to keep out visible light which would take away its effects,
must use a red filter such as Hoya 25A (Wratten 25) - can use a deeper
filter such as Hoya R72 (Wratten 89B) but this appears opaque and one
can not focus or compose through it, and thus it must be applied just
prior to taking the photo.
there is no ISO rating like normal films, so have to bracket
exposures +/- 2 stops in 1 stop increments, try using the following for
Kodak HIE film with Hoya 25A filter:
bright sunshine in warm summer conditions: set ISO to 400
& use TTL meter as a starting point
cooler but bright sunny days in spring/autumn: set ISO to
cooler, overcast day: set ISO 100
IR focuses slightly closer than visible light which
is an issue with simple lenses and achromatic lenses but not a real
problem on apochromatic lenses or pure mirror lenses.
on many SLR lenses, there is a red marker to indicate IR
it usually is not a problem if there is sufficient depth
of field such as when using a wide angle lens for a landscape.
beware that stopping down a lens to create depth of field
may make things worse as the diffraction limits are much worse for IR
and thus you need to use a larger aperture to avoid this (eg. f/8 is
normally the smallest aperture on prosumer digitals due to diffraction
issues, for IR, you may need to settle with f/5.6 or 6.3 being the
processing IR film:
home processing Kodak HIE:
standard developer such as Kodak D-76 or Ilford ID11
using stock solution
11 minutes at 20degC in a small Paterson tank, agitating
continuously for the 1st 30 secs, and then once every minute (5
this is followed by a brief stop bath of 30sec then a fix
of 2-4 minutes
wash the film for 15-20min at temp. within 5deg of
printing IR film:
make a contact strip and look for frames where black of scene
matches the black of the film base with a density roughly equivalent to
remember to allow highlight areas to glow & sparkle
dense HIE negatives show a rapid increase in grain and
reduced tonal separation and will interpret ghostly, grainy &
filter thread to allow infrared filter eg. Hoya R72
(although you can handhold it if desperate)
a way of composing the image:
optical viewfinder (non-TTL) may be best as one can
actually see, or,
live preview LCD screen - although may still be
difficult to see image
ie. NOT a digital SLR unless it does have live LCD
screen or live AV out to an external LCD.
preferably a mode that removes the usual IR-blocking
filter eg. Sony nightmode style, or at least a camera known to be
reasonably sensitive to IR
a sturdy tripod - most exposures will be 1-5 secs at
least unless the IR-blocking filter has been removed.
ability to save in RAW mode to get the best results,
although TIFF is OK, although big - use jpeg as last resort as the
substantial image processing will lead to excessive artefacts.
image processing software such as Photoshop
most digital cameras have a CCD sensitive to near IR light up to
~1100nm, but also have a special IR-blocking filter in front of the CCD
as the IR light would otherwise degrade the image, thus sensitivity
ranges are usually:
normal digital cameras with IR & UV blocking filter:
400nm to 750nm
normal digital camera with IR & UV blocking filter
removed: 280nm to 1200nm, but because CCD sensitivity is reduced at the
extremes, the practical range is approximately 325nm to 1100nm.
the best time to shoot IR is either in the late morning or early
evening. When the sun is directly overhead, it is hard to get good
contrast between IR sensitive objects and the sky.
ideally, the live preview on your camera will display
sufficient detail with your IR filter on so that you can manually focus
if your camera will not focus with your IR filter in place,
then consider using a old manual focus lens with IR marker, then
without the IR filter focus then adjust focus to the IR marker then
replace the IR filter.
IR-pass filters which must be used:
as with film cameras, for daytime use, still need to use a
filter to block normal visible light.
see above under filters;
digital cameras have the advantage that their auto-exposure
& auto-focus should still work BUT be aware that the camera will
try to adjust exposure so that average of all 3 RGB channels is
correctly exposed, BUT THIS IS NOT WHAT WE WANT as the main channel we
are interested in, the red channel will be grossly over-exposed, so you
need to set exposure compensation perhaps to -1 to 2 EV. You will not
be able to rely on the camera's histogram either unless it shows the 3
RGB channels rather than the resulting jpeg image histogram. Thus your
exposure will need a bit of trial and error comparing your red channel
results with your camera exposure compensation setting.
ideally one should shoot in RAW mode, then in Photoshop,
select the red channel and convert to monochrome then adjust the levels
to improve the contrast.
some cameras allow in-camera generation of monochrome images
by selecting Black and White option but this will use all 3 RGB
channels which is not what we want.
color IR images:
colour IR is not easy to achieve on cameras with high IR
blockade, while they are possible on the Sony F7x7 with a R72 filter,
the Sony F828 appears to give better colour IR is one uses a deep red
29 filter instead.
try setting WB to manual and metering with filter on for
interesting colour effects - sepia-like
or, take 2 identical photos, 1 with the filter and 1 without
the filter but exposed normally but at same aperture to ensure
consistent depth of field
post-processing method 1:
selecting the color image, selecting the entire image
(ctl-A), clicking on the "Channels" tab and selecting the green channel
and copying this (ctl-C), selecting the blue channel and pasting
(ctl-V). Repeat the process to copy the red channel into the green
channel. Select the IR image, select the entire image, copy the red
channel, return to the color picture and paste it into the red channel.
this may produce "crazy" colors
post-processing method 2:
Take the color image and convert it into "Lab Color"
mode. Take the IR red channel and copy into the "Lightness" channel.
This creates color images that "pop" very well and have very dramatic
post-processing a Sony green nightshot image with R72 filter
open hue/saturation and set green saturation to minus
then change master to: hue = +124 and saturation =
+50 to 60
use Gaussian blur of 3-5 pixels radius on background
copy layer to reduce noise
change background copy layer to layer method "colour"
use auto-levels on background layer
open hue/saturation on background layer & set red
saturation to minus 100%
flatten the layers
post-processing via Daniella
("zylen)" method using a Dimage 7:
take a good photograph with good subject, white balance
to tungsten, color saturation to -3 or -2 and contrast to -2.
copy the layer and apply auto-level. Adjust the slider to
adjust the result. Once the result is ok, merge them.
copy the layer again, then adjustment, channel mixer and
swap the blue and red channel. Keep the unswapped image underneath. You
can add a layer mask and blend the swapped and unswapped image, and
reveal or hide part of the swapped image that you want or don't want.
create a new layer and use "color" mode for the blend.
Then use the color that you want and spray the area to tint the area
that you want to correct.
some cameras allow you to remove the IR blocking filter, but
as this allows one to take "see-through" photos through dark clothing,
the manufacturers such as Sony prevent this from being used in daylight
Sony nightshot mode:
Nightshot IR pictures are taken by setting the dial on
the cam to Auto and the Nightshot switch to "Nightshot". The aperture
will be forced to open all the way up (F2 to F2.4), and fastest shutter
speed will be limited 1/60th sec with a 7*7 or 1/30th with a V1 or 828.
You will most likely need one or more ND filters to darken the scene
plus your IR filter, as the pictures will be overexposed otherwise. In
nightshot, the IR hot mirror is removed from in front of the CCD, and
the camera will be very sensitive to IR light. These pictures can be
taken handheld, and come out looking green.
Another good thing to have when shooting in Nightshot is
a donut cover for the IR emitters. These are the two little holes that
are around the lens near the top. If you don't cover these, you will
get a round circular reflection near the top of your pictures from the
IR light reflecting off of your filter. You can make a donut out of
cardboard and cut the outside diameter by using my lens cover, and the
inside diameter adjusted until it was just outside of the lens. Pop the
donut on and then stick your IR filter on over the top. (not required
on the F828).
may need to set EV from 0 to -2 and ISO to lowest setting
(64-100) - DON'T use auto-ISO!
R72 stacked with neutral density filters +/-
polariser filter to give correct exposure:
to select the level of ND filter, keep going up
to a higher level of ND until the shutter speed just drops below the
1/60th second or 1/30th second maximum (depending on the camera model).
Otherwise the photo will be overexposed. Remember to stay near the
maximum shutter speed, especially for hand held shots.
bright sunny days require an ND8X filter (3
stops). This is the usual filter.
on dim days, or for photos in shade use an ND4X
(2 stops), or perhaps even an ND2X (1 stop).
the number of stops is additive, and a polarizer
is equivalent to an ND4X (2 stops).
also, don’t forget the possibilities of a
graduated ND filter for shots with extreme dynamic range.
cuts visible light by ~99.75% - so visible light
exposure needs to increase 500x - thus a normal visible light photo
taken at 1/500th sec requires 1sec using this filter.
even though it cuts the visible spectrum way
down, the infrared sensitivity of the camera in NightShot mode is way
up. The IR light makes pictures, and the visible light is almost
completely drained from the shot. But not absolutely completely.
Blue sky still has some faint color. Bright neon
signs can show color, too.
a true IR filter such as R72 gives a cleaner IR
result but more vignetting as it needs stacked NDs.
if you shoot with "Daylight" WB, your pictures come out
with a Reddish tint. With "Indoor", you will get a purplish tint. If
you use the "Manual WB" button. This will make the foliage green and
the sky reddish.
in Nightshot mode, the camera’s metering pattern is
other features that still work when in Nightshot mode:
modified cameras have limited use for daytime photography
without additional filters.
digital SLR modifications:
sells modified new Canon, Nikon, Olympus and Panasonic Micro Four
Thirds digital SLR cameras with the IR blocking filter removed,
in addition they sell pop-in filters that users can insert in front of
the sensor such as a IDAS filter to reduce light pollution for
astrophotography, or a "type I H alpha filter" for nebulae photography.
used without any filters, daylight exposures are
some 2 stops greater than an unmodded camera but you will not be able
to colour balance
by purchasing additional screw-on or pop-in
filters such as:
Hoya R72 screw on: IR photos - require ~0.5
stops more exposure than unmodded camera without R72 - ie. short
exposures of 1/640th sec are possible, but you cannot compose through
Hutech type UV + IR block pop-in filter - as
for unmodded camera but with some extended IR range & good colour
Hutech IDAS LPR pop-in filter - light
pollution filter for astrophotography but can be used in daylight with
exposures ~ 0.5 stops less than unmodded camera, while colour balancing
NB. the pop-in filters sit behind the lens and thus
help to protect the sensor from dust, while obviating the need for
larger, more expensive filters for the lens, but cannot be used with
EF-S lens as these protrude into the body too much and would hit the
IR can almost totally eliminate many complexion problems—even
acne pockmarks—as long as your subject is evenly frontlit. Infrared
film, when exposed through a red filter and printed high-key (in other
words, light) on a contrasty black-and-white enlarging paper (as in the
portrait, left), will reproduce Caucasian skin tones in creamy, almost
ghostly whites. Pimples and other surface imperfections simply
A black-and-white film that's sensitive to visible light plus the
750–840nm wavelengths of infrared radiation, HIE is easier to learn to
use and, at $12 per 36-exposure roll, is a fraction of the cost of
Adobe Photoshop. The film is very grainy, especially when overexposed,
so meter carefully and don't plan on making wall-spanning enlargements.
The lighter and more contrasty you print it, the less objectionable the
grain becomes. Unless you have a darkroom, you'll probably need a
custom lab for the film processing and printing.
Correctly exposing infrared film isn't your only challenge.
Because camera lenses don't focus infrared radiation in the same plane
as visible light, for maximum sharpness, first focus normally, then
shift focus slightly toward infinity. Many lenses indicate the degree
of shift with a tiny index mark on the focusing scale. One last
thought: You'll need to use a deep red Wratten #25 filter to block red
(i.e., blemish-colored) light from reaching and overexposing the film.
Test infrared film under your shooting conditions to explore its
idiosyncrasies. You may need several test shoots, altering the
lighting, exposure, and printing.
Infrared film responds differently depending on the light source.
Whenever you change lighting, retest.
While the effects are not as dramatic, try Ilford's near-infrared
film, SFX 200. It's easier to use and less expensive than HIE.
If the complexion problem is minor, any black-and-white film (or
monochrome mode in digital) shot through a red filter may mask the skin
Some 35mm SLRs' film advance systems use film-fogging infrared
light beams. Check your camera manual.
Various Photoshop post-processing
techniques for digital IR photos:
2. Select [Green] From the dropdown menu, adjust the [saturation] to
3. Select [Master] From the dropdown menu,
4. Adjust [saturation] to +50 & adjust [Hue] to +120
5. [image]->[Adjustment]->then [Brightness/Contrast]
6. Adjust Contrast to +15
7. Finally, do the [Auto Level]
using Nightshot mode on a 707. IIRC, the filters were Hoya
r72, ND8 and polarizer. Post processing is seat of the pants type.
Generally, with IR, I use PSP's Hue/Saturation/Light filter to
desaturate, then apply contrast filter. I frequently then use PSP's
Clarify filter, which is a special contrast filter, sometimes applying
it twice. Then I use unsharp mask and apply a color tone using HSL.
When the images come out of your camera, they will have a
dark green cast.
1. Go to Image / Adjustments / Levels to boost brightness/darkness (use
right most and left most sliders).
2. The go to Image / Adjustments / Channel Mixer, check Monochrome,
then use the specific RGB channels to boost certain characteristics of
3. Then do Image / Adjustments / Auto Contrast to add more punch. Or
adjust Contrast to you liking using curves or other technique.
For the colorized IR shots below, I used the following method:
1. Image / Adjustments / Levels.
2. Image / Adjustments / Hue/Saturation.
3. Select Green From the dropdown menu, adjust the Saturation to -100.
4. Select Master From the dropdown menu.
5. Adjust Saturation to +50 & adjust Hue to +130 (for blue effect)
or -60 (for red effect), or customize to taste.
6. Adjust Contrast (optional).
7. Finally, do the [Auto Level].
In PS copy the IR and paste it as a second layer on top of
the color version.
Level the IR layer to become close to B&W.
Set the blending mode to luminosity.
thermography uses special infra-red cameras to image &
measure radiant heat from objects
a body radiates heat in various frequencies of e-m radiation,
and its peak frequency becomes higher in proportion to the
temperature of the body and can be calculated from Wien's
peak wavelength radiated in microns = 2897.2/(temperature
cameras typically measure temperature ranges of minus 20deg C to
300 deg C with resolution of 0.1degC, although some will measure up to
900degC or more.
whereas digital cameras usually only detect 0.4 to 1 micron
wavelengths, thermal cameras that detect heat use a different sensor
technology (Microbolometer Uncooled Focal Plane Array (MUFPA)) and fall
into two main groups:
mid IR (MIR) - detect 4-6 micron
far IR (FIR) - detect 8-14 micron
can show areas of a house where heat is being lost or the
different skin temperatures on a person
most only have resolution of 320x240 pixels
US law means that these cameras cannot be sold to non-US citizens