Panorama photos
Introduction:
- panoramic photos can be achieved by either:
- "stitching" a sequence of
photos together which is what is discussed below and is the less expensive
approach
- using a super wide angle lens - but
ideally one needs a medium or large format film or a digital sensor with
lots of pixels to capture sufficient detail.
- using a dedicated panorama format camera:
- panorama format on 35mm film
- Hasselblad XPan
- Mamiya 7 with panorama adapter kit to allow use of 35mm film
to give 24x65mm images but cumbersome and issues with film
flatness - better to just use 120 film.
- medium format film such as 6cmx9cm formats see here
- large format film such as 4"x5" and
8"x10" - although not panoramic format, these have the
greatest ability to capture detail in one shot.
- panoramic digital cameras:
- Seitz 6x17 digital (2007):
- Seitz Roundshot D3 (2007):
- some interesting information can be found on the Panasaurus web site http://www.tawbaware.com/panosaurus_review.htm
and at http://www.panoramicweb.com/
- Your photo stitching and photo editing software can correct many (but not
all) mistakes made during shooting.
- Always keep in mind that the more carefully you shoot the less work you
will have later on.
- For maximum resolution in the vertical direction (height of your
panorama), turn your camera by 90° to the portrait orientation and slowly
pan from one end of the scene to the other end to get an impression what
eventually will be on your images. When panning, keep your camera exactly
levelled at the horizon, do not tilt it up or down vertically from the
horizon line - most stitching programs cannot satisfactory handle this kind
of tilt. If you use a stitcher with vertical tilt correction (e.g.
ImageAssembler), you do not have to bother much about this issue. In this
case, tilt your camera vertically, if necessary, to catch exactly the scene
you want. Just make sure to keep the tilt angle constant for all individual
shots.
- zoom in (using only optical zoom, of course) deep enough that all objects
of interest are covered along the whole horizontal scene, but leave a small
safety margin at the top and the bottom as cropping reserve after stitching.
- After selecting the right zoom, pan several times from one end of your
scene to the other end and correct the zoom slightly, if necessary
- Unfortunately, the bigger the zoom the bigger distortion and vignetting
(gradual darkening of the image towards the outer edges), depending on the
quality of the lens. This might cause difficulties later when the images are
stitched together. If you want only small prints of your panoramic image or
if you intent to put it merely on the internet, the maximum resolution is
usually not necessary. In this case, you could use only a small zoom or no
zoom at all and cut the stitched image later generously.
- you must try to keep the vertical edge of your images as close as possible
to the exact vertical line and the elevation angle of your camera (vertical
tilt) exactly the same (at the horizon line for stitchers with no vertical
tilt correction) for all shots of the row.
- use a tripod if possible & it should have at least a levelling bubble
for adjustment of the exact horizontal orientation.
- activate exposure lock (AE lock) or set the shutter speed, aperture, and
ISO speed manually to the corresponding values to ensure using the same
exposure for all shots as this ensures that there will be no significant
brightness and coloration discrepancies between them.
- Start at the left end of the scene and take the first shot. Spot an object in the image that marks the overlapping edge. Most
stitching programs require an image-to-image overlapping between a quarter
and a half the image extension.
- If you have clouds or other slow-moving objects in your scene, try to
shoot the whole scene as quickly as possible. Otherwise, the stitching
software might get into trouble.
- Be aware that - even when using a tripod - the impact when pushing the
shutter button can still cause the image to get blurred, particularly for
long exposure times. If necessary, use the timer to shoot the image.
-
Problems with panoramic stitching:
- exposure and WB:
- it is important that each image has the same exposure and white
balance so that stitched images do not look like separate images.
- consider using manual exposure and preset white balance so these are
constant for all images in a set.
- vignetting:
- vignetting in each frame is a big problem as it is difficult to
correct exactly so that images stitched together have a smooth exposure
transition
- choose a lens/camera/aperture combination that minimises vignetting
effects and watch out for the lens shades.
- flare:
- avoid sunlight hitting the front lens as this may cause different
flare patterns on each image.
- polariser filter:
- in general, using a polariser filter tends to exaggerate unevenness in
sky brightness across a panorama so consider using a ND gradient filter
instead.
- perpective distortion:
- avoid converging lines which result from not having the camera
parallel to the subject ie. avoid tilting camera up for tall objects.
- converging lines in each image make it hard work to fix and then
stitch.
- consider avoid using very wide angle lenses and instead take more
images to cover the field of view.
- nodal point issues:
- unless you rotate the camera about the lenses nodal point (usually
where the lens diaphragm is), then you will get problems with closer
objects in the image.
- for such situations you may need an expensive especially designed
panoramic tripod head which can be adjusted for the nodal point of your
camera/lens combination.
- the nodal point:
- in general, accurate stitching relies on the camera rotating about the
lens nodal point which unfortunately is not usually the tripod socket and
varies with focal length used on the lens.
- the main point for using a panoramic head is to reduce parallax
error when shooting objects that are close to the camera.
- it is not as important for distant landscape shots.
- here are some links to info on nodal points:
- see tripods for info on tripod heads
designed to assist in single row and multi-row panoramas.
Panorama stitching software:
- Olympus Camedia Master - supplied with Olympus cameras but only images
taken in panaroma mode and recorded onto
xD memory card.
- Canon Photostitch - supplied with Canon cameras but will stitch any
jpeg, BMP, TIFF
- Adobe Photoshop Elements or C/S -
- Panorama
Factory - good automated stitcher, 30 day shareware.
- PanaVue
Image Assembler - not freeware, but provides very high
stitching accuracy and manual stitch point correction. Allows for
vertical stitching of photo rows. Stitches individual photos with
extremely size differences. Handles camera tilt in the elevation angle
(deviation from the horizontal direction) - a feature most other
stitchers do not have.
- PhotoVista
- 30 day test version.
- http://autostitch.net/ - free
demo version - fully automatic but jpegs only & not always get good
results
- Panorama
Tools based software:
- freeware but you need to do a lot of manual work, thus there are
several helper programs or interfaces to make it easier.
- can also download at http://panotools.sourceforge.net/
- PTGui:
- preferred interface tool for Alfred Molon.
- PTAssembler:
- VB6 Windows interface which supports plugins such as:
- TuFuse:
- blends images of different exposures (to create HDR
images) or different focus (to create more depth of
field)
- images should already have been stitched by another
program such as PTAssembler before invoking TuFuse
- can use RAW files if DCRaw
is installed.
- examples of workflows and capabilities: http://www.tawbaware.com/ptasmblr_help_stack_example.htm
- registered users get $20 discount on purchase of Panosaurus
tripod mount
- PTMac is a front end for
creating panoramas using Panorama Tools. PTMac is available for Mac OS X
and OS 8.6 to 9.x.
- ControlPoints
is a Windows application that allows you to select control points.
- PanoPoints is an Open
Source graphical front-end control point picker for Linux systems.
- PanoWizard is a
freeware frontend for autopano and panorama-tools.