How to create a 180º Visual Tours
Below we can see a series of eight ( 8 ) picture were taken to create a 180 º Picture of a master bedroom. Here the photographer was standing
in a corner of the room as he pan the camera from left to right taking overlapping
pictures.
All you have to do is the same take a series of overlapping pictures organize them by folder ( example; folder name - master bedroom, with 8
picture inside) compress the folder and email it to us. Contact us for more information
The
Final Picture ( click here to view the final 180º Virtual Tour )
Shooting the pictures
How many pictures?
Each picture
should overlap with the next by up to 50% (or at least somewhere between 30 and
50%) depending in the camera. But please note that providing you overlap each
picture with the next, it doesn't matter exactly how much overlap you use,
and the amount of overlap can be different between each pair of pictures.
So, you can just guess 50% overlap and that will be fine. If you think you will
need 10 pictures but you take 9 or 11, it doesn't matter! We suggest to take the in vertical or portrait position as shown above.
Note: more
overlap means it is easier to blend lighting/color differences (if you make a
mistake with exposure/color temperature or the light changes anyway). A larger
overlap also makes it generally easier to edit out moving subjects (vehicles,
people, etc).
Depth of field
Generally
panoramic pictures capture a scene rather than a moment. In other words most
panoramic pictures are of places rather than of people or events as such, therefore
you will probably want to aim for a crisp picture that captures the entire
scene through to the horizon. To do this you want to set a very large depth of
field so that everything in shot is in crisp focus, by focusing on the hyper-focal
distance.
When
determining the depth of field you need, remember that when shooting indoors
you do not need to focus further than the walls of the room and therefore you
are likely to be able to widen the aperture and consequently reduce the
exposure time.
Avoid altering
the depth of field because to do this you will need to alter focus, and when
you alter focus you subtly change the field of view of your lens. Most software
cannot cope with a mixture of lenses being used for a panoramic sequence - they
assume the same lens was used throughout, or more
specifically that the lens was used with exactly the same settings (including
focus).
So in
conclusion, you need to:
·
decide whether you want
everything in focus (large depth of field)
·
make sure that if you use these settings that they are sufficient
for every frame of the sequence. In other words, if one of the pictures
features something very close to the camera, which you want in focus, then you
should set up a large depth of field for all pictures.
Shooting panoramas hand-held without a
tripod
To get good
results without using a tripod, make sure you stand in one spot and as you turn
to take each picture keep the camera close to your body, i.e. close to
the point of rotation. Don't move from the spot you are standing on between
shots. Don't learn forwards or backwards between shots, but try to stay still
and steady.
What you are
trying to do is to emulate the tripod - keep the camera steady and level, and
rotate it around a single point. All of these things help you to produce a good
set of pictures from which to create a panorama.
*Optional only, for a more professional
look ____________________________________________________________
White balance (digital cameras only)
Some digital
cameras can correct color casts caused by lighting. (For example both
incandescent and fluorescent lighting can cause a yellow cast across your
photos.) Be careful when using the 'automatic' white balance setting if your
digital camera has one.
The reason
for this is that if the scene contains a mixture of lights, your camera may
switch white balance setting half way through the shoot and you will then have
problems stitching the pictures because the colors will look different.
Instead, decide for yourself which is best and manually set the white balance.
If you can't decide, shoot the scene several times using different settings for
the whole set of images.
Contrast/Brightness: Exposure
That leaves
just one thing to play with. Exposure. You might have
a scene in which everything is well lit in which case you can probably set an
exposure for every frame. However you will quite often come
across situations where the lighting changes. Lighting problems can
perhaps be generalized as:
·
areas of strong shadow in a
scene where there is also strong light
·
light directly at the camera
in part of the scene
The first of
these is more likely. I find it useful to spin my camera around the scene while
holding the shutter button halfway (which on my camera causes it to focus and
meter the scene). I can then instantly see whether there is going to be a
problem because the camera will show me in the viewfinder the exposure it
thinks is appropriate for each image. If the exposure changes dramatically I
will have a problem: if I let the camera judge exposure, it will ensure each
picture is as good as it can be. But that means any two adjacent images could
differ greatly in lighting conditions so that a shadow in one is barely visible
in another. That will confuse the stitching application. Exactly this happened
with the Woodland scene. The first 10 pictures from that set are shown below.
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No. |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
Note the
dramatic change in contrast between frame numbers 2 and 3, and the slightly
less dramatic change between numbers 4 and 5. Different stitching programs cope
with contrast change in different ways: some will offer to automatically adjust
color and contrast between each of the pictures,
others use a wide blend area to soften the transition.
I allow the
exposure to change by no more than two increments between frames (e.g.
if one shot was taken at 1/30sec then the next one should be no less than
1/60sec and no more than 1/15sec). If a scene contains a mixture of brighter
areas and darker areas, I will meter correctly for an intermediate position,
and then slightly over expose the dark areas (to make them lighter) and
slightly under expose the light areas (to make them darker). You can see
exactly this in the set of images used for Trinity Hall, shown below.
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4 |
6 |
4 |
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2 |
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6 |
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Small
exposure time changes in a pan sequence |
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Most cameras
will tell you as you take a picture whether they think you are correctly
focused and whether they think you are correctly exposing the scene. I have
also shown above what the camera metering system made of each shot - whether it
thought the shot was under or over exposed. Note that the shots that did not
include windows were therefore darker and the camera thought they were under
exposed. Those facing windows with light streaming in confused the camera so it
throught they were over exposed. Had I gone with full
automatic exposure there is a good change the pictures facing windows would
become sillouettes.
You can
alter the exposure if your camera has manual controls, or allows you to set the
exposure manually. If it does not, you might be able to:
·
set the exposure on a
mid-lightness frame and use AE-lock to lock the exposure, then all subsequent
shots will use these same settings
·
adjust the exposure by under
or over-exposing by adding f-stops, normally from -2 to +2 stops
Using flash or additional lighting
If the scene
you are shooting is not very well lit, your camera may prompt you to use flash.
My advice is that you avoid ever using a flash gun in or attached to you camera
or tripod. There are a couple of reasons for this:
·
flash guns have a limited range and a limited field of coverage which
is why if you use a wide angle lens the flash is normally disabled. Also in
some cameras there is a risk that the built in flash will be partly blocked by
the lens itself so you would end up with the shadow of the lens in the picture!
·
flash gives strong shadows,
which then won't line up when you stitch images together because the light
(from the flash) is moving as you rotate the camera
We recommend
you either:
·
Use a large reflector and
point the flash gun at the reflector - this will give more diffuse light and
more even lighting
·
Alternatively, if you are
shooting in a room with pale walls, use a wall as a reflector/diffuser, by
pointing the flash at the wall behind you (but beware that you might end up
with a faint shadow of the camera/tripod if you use a wide angle lens)
·
If you are shooting indoors,
turn on all the lights to enhance the lighting (but beware that this might give
uneven lighting, unwanted shadows and a yellow cast from tungsten bulbs)
·
Use additional freestanding
lights (spots or flash guns with reflectors) and be careful about moving them
about while shooting so as to avoid changing the direction of any shadows which
would cause stitching problems later
·
Use a longer exposure and
vary it if necessary (see above) - this is what I do most of the time!
If in doubt, shoot twice
An added
complication is if there is a view through the window that you want to capture
(let's assume there is). So, not only do you need to ensure you take a picture
which properly captures the room, but you want to get a good view of what is
outside too. The answer is to simply take two (or more) pictures of this part
of the panoramic sequence. Force the camera to meter the scene based on the
foreground only (most SLR's allow this, if you can't do this then point your
camera at somewhere else in the room with similar lighting conditions but
without light directly at the camera and meter there). Use that meter reading
to take one picture of the window. Now take another and allow the camera to
meter the scene to take account of the light. So you have two images of the
same part of the room.