BUILDING A DIGITAL SLIDESHOW
--------------------------
John Pazmino
NYSkies Astronomy Inc
nyskies@nyskies.org
www.nyskies.org
2009 December 26
Introduction
----------
At the NYSkies Astronomy Seminars, talks at other astronomy clubs,
and presentations at conferences, I am commonly asked about my
slideshows. In years before about 2005 there were built from chemofilm
pictures -- color slides -- and assembled into a rotary tray for
projection. Since the mid 20-thous my slideshows are built from
computer images, which is by now almost the only way to offer shows.
While i do not take myself to be the master of slideshow
presenters, I am credited for giving talks that are highly welcomed,
with requests for a repeat in a future occasion. With my own shift to
digital photography and computer graphics, I find that my slide shows
are vastly more specific for the audience to hand and I have orders
greater selection of prime pictures for them.
Yet, and this surprises many in the audience, it is indefinitely
easier for the lay person to compile a good slideshow with computer
images than it ever was with chemophotography.
Slideshows
--------
I deal here pura mente with slideshows, a sequential display of
still images, like those of the optical-mechanical slide projector. I
leave out use of audio and video or interactive techniques here. In
spite of the increasing availability and ease of these more advanced
techniques, overwhelmingly as at yearend 2009 an astronomy slideshow
is a series of still pictures.
In the modern means of building slideshows, a slide is just an
other computer picture. It doesn't HAVE to hold a picture. It can be a
video or audio file. I just as yet didn't need to include such extra
bells & whistles in my talks. They are static pictures thru and thru.
When the slideshow file is played, you index from slide to slide
by a keypress at the computer, similar to working a film-based slide
projector. If you prefer, the host can detail an agent to work the
computer while you narrate and cue for the next slide. It is common
for the astronomer to be at the screen, away from the computer, to
better point out features in his pictures.
Presentation software
-------------------
Just about every digital slideshow is made in one format, a PPT
file that plays with Microsoft's PowerPoint. You can build slideshows
with other applications but they will play ONLY with them. For sure
they will NOT play on your host's computer.
While PowerPoint is THE means of compiling slideshows there is at
least one workalike. The free software OpenOffice is a set of business
programs parallel to Microsoft Office. The module corresponding to
PowerPoint is Impress. It is cosmeticly different from PowerPoint but
it has all of its features for making and playing slideshows. It
outputs the finished show as a PPT file for playing on a regular
PowerPoint host.
Office, with PowerPoint, is almost never included with the
computer as purchased. It is a commercial product that you buy at a
nasty high price. Newer computers may include a PowerPoint player that
ONLY plays existing PPT files, those you download or borrow. They can
NOT create new ones.
If you do career-related work at home or field your company may
issue MS Office to facilitate that work. Install it on your home
computer, under agreement with your boss, for the occasions you do
company work there.
Colleges may offer MS Office in a slim version on CD with a
student discount. The school's edition may include templates and forms
for your work. Some of them may be handy for making slideshows.
A real kludge
-----------
In the absolute absence of PowerPoint, Impress, other slideshow
application, you can give a show with WordPad. This is part of Windows
as a basic word processor that allows pictures to be included in your
documents. The effect during projection is untidy, but it does work.
Your slideshow is a document consisting of your pictures laid into
it in the presentation sequence. You manipulate them with the word
processing features, like cut & paste, scaling, rotating, and so on.
The trick is to scale the pictures to be EXACTLY one field high.
When you do 'PgDn' WOrdPad indexes to the next picture with no overlap
beyond the screen borders.
You have all of the program's Windows dressing on the projection
screen, which absorbs some of the screen's real estate. In a pinch,
this method of slideshow honestly does the job.
The one crucial factor is that you must build the slideshow on a
computer that you bring to the host. It is VERY risky to bring the
slideshow file to play on the host's computer. Oh, it WILL play, but
the screen resolution, fonts, margins, Windows gadgets, other display
parameters will surely differ from yours and corrupt your show.
All in all, you BETTER get hold of PowerPoint, Impress, other
program that makes and plays PPT files.
Digital pictures
--------------
By the 1990s computers could collect pictures from the first digital
cameras as computer files. In the early years, cameras tended to use
proprietary formats for their pictures, requiring the use of their
special software. Pictures could not be exchanged among computers
without this software..
This situation quickly vanished when the JPEG standard was
adopted. Today all digital cameras output their images in JPEG (or
JPG) form. Picture handling software accept JPG files for easy moving
around thru electronic means.
The opening of the Internet in 1993 for public use broke all
barriers to exchanging digital images. They were attached to email and
posted in websites. My colleagues simply make a file copy of the
picture I request and send it to me by email. Or they give me the link
to the picture in their website.
Cameras improved, too, from the clumsy bulky expensive units of
the 1990s to truly tiny and cheap models today. It is now usual for
people to carry a digital camera with them all the time, a practice
only occasionally done for a film camera for its weight and size. Now
in the 20-thous there is the convergence of mobile computer and
telephone that includes picture-taking features.
Camera pictures
---------------
Considering now the real digital or 'silicon film' pictures, there
are many sources. First is the camera image. This is a picture you
shoot thru your camera. 'Camera' is very broad, and becoming broader
every year. It's any device that 'takes a picture' like a camera. The
device is small and light enough to carry to the target and capture
its image. A camera can be en embedded photography feature of an other
electronic device.
It may be a picture of real scenes. It can be a picture of
television screens, books and magazines, signs, other pictures,
tabletop mockups, It can be posed like a group photo or award
ceremony. The image is captured in the usual picture-taking mode thru
your camera.
Be SURE your camera is saving the picture in JPEG or JPG form.
While this is not the very best way to save a digital image, because
it throws out detail during its saving process, it is the universal
format for just about all computer handling. Look thru the camera's
menus and verify that you ARE capturing JPEG/JPG images. You could be
in for a real irritating surprise later if the pictures are in some
cockamamie format that no computer program can decipher.
Scanned pictures
---------------
These are pictures scanned of a target. 'Scanner' is here a
general term for a picture capturing device to which the target is
brought. It then is placed on or in the device to capture the image.
It can be a regular scanner, acting much like a photocopier with a
glass window, lid, crawling light. You can scan just about anything
more or less thin and flat. It may be pages from books and magazines,
postcards, print photographs, small flat artifacts like medals and
coins.
Other scanners can be a holograph, X-ray machine, sonograph,
laser, to name only a few. The target has to come to the machine and
be placed in or on it to get its image.
Be sure to capture the picture as a JPEG/JPG file, not something
else. If this is not among the choices in the scanning process, surely
BMP is. That's the one to go with.
Borrowed pictures
----------------
These are pictures already in computer form that you extract from
their source. Taking a picture from a digital source is quick and
simple. If the picture comes on a CD, DVD, or other digital medium,
copy it to your computer. You may do a copy/paste or drag/drop action.
If the picture comes from a webpage or email, right-click INSIDE
this picture and pick 'save picture as ...' or 'save image as ...'. A
file handling panel opens in which you shayshay to your target disc
and enter a filename.
Captured pictures
---------------
In some cases the picture displayed on screen is embedded in the
webpage in a way that prevents separating it out for saving. In other
cases, you may produce a display from a computer program and want to
keep the display as is from the screen.
Grab the scene by pecking 'PrtScr'. This captures the entire
computer screen into the Windows clipboard. To realize the image, open
your picture editor, and do 'Edit/paste'. The screen comes up within
the document panel of the editor.
Many astronomy programs have a 'save' option in its menus. The
program instructions explain what this really means. In some cases it
means to save the configuration settings as a default for future runs.
Nothing is saved from the screen into a picture file.
In some cases only the steps that produced the picture are saved.
Play them back later to recreate that scene. You have to study the
instructions and play with the program to understand what's going on.
Other programs do have a real capture function for the screen
display with all its colors and detail.
In the absence of a proper screen capture within the program, peck
'PrtScr' and realize the image in your picture editor.
I make extensive use of 'PrtScr'. It is a powerful means of
building slides that are, uh, fabulous, so say my audiences.
One point to mind is that when you run a DOS program under
Windows, the 'PrtScr' does not work properly. It may be turned off or
it may try to, well, print the screen on an attached printer. With no
printer or one shut off, you can hang up the computer and force a
three-fingered salute.
Remember that 'PrtScr' can hold only ONE image at a time. You MUST
move it to the picture editor and save it, before cutting the next
image. There are applications that allow capture of many pictures into
a buffer. You retrieve the pictures later in any order you want.
Saving and naming
---------------
To save a picture with the programs own saving function, do 'save
as ...' and NOT 'save'. 'Save' keeps what ever name the picture had
before, which you may not know or you forgot. You may have a hassle
finding the file later without knowing its name. Worse, 'Save' will
without any warning overwrite a existing file of the same name. You
could without knowing it destroy a good file, now forever gone.
'Save as' presents a file handling panel in which you see the
proposed file name and lets you key in your own filename. Name the
picture in some manner to later easily find it. In general, do NOT
save it under the proposed name and directory.
The original pictures will have pretty flaky names. When saved
that way they are scattered all over your computer and are tough to
collect later. Purposely enter your own name.
I name my pictures after the show and a sequence number, like
'alcon01', 'alcon02', 'alcon03', and so on. The sequence is that of
acquiring the pictures. You'll shuffle the images into a presentation
sequence later.
Use TWO digits for the number because you WILL collect in your
preparations of a show more than ten pictures. Two digits allows up to
100 pictures as your fount for the show. If you happen to run over
that, as I did for AlCon's Coney Island show, continue with hex
notation: 'A0, A1, ..., A9, B0, B1, ...'. That's a LOT of pictures to
choose from for a thirty-slide presentation!
Pictures you come onto will prevalently be in JPH form, but BMP
and GIf are common. All three can be used as is in the slideshow
program. Be careful to leave the filetype alone when saving. It's in a
separate input box near the one for the filenmae. As long as it's one
of the three JPG, GIF, BMP, you're set.
Renaming the pictures makes them all gather together in one zone
in the file listing of your target disc. You may make a new directory
with a germane name to save the pictures into. My pictures for the
2009 Astronomical League convention were held in directory 'alcon09'.
Pixels
----
Chemofilm has a thin layer of chemical made of microscopic grains.
The blending of these grains to the bare sight makes up the complete
picture. The grains are randomly dispersed in the film and are
impossible to reference or modify individually.
A digital picture also has microscopic grains, called picture
elements or pixels. They are arrayed in a grid like tiles. They,
unlike film grains, can be addressed individually for manipulation by
the picture editor. Each pixel has an X-Y coordinate, like on a graph,
by which the editor knows which is which.
When light impinges on a pixel in creating the picture, the pixel
acquires a value or count. This corresponds to the transparency or
density of a grain in chemofilm. Most digital pictures work with a
range of value from 0 to 255. O is darkest; 255, lightest
Actually each pixel has FOUR values, one for white, red, green,
and blue. The mix of these values makes the pixel show the correct
color and luminance in the scene. Besides showing the image on screen,
the picture editor can display the values for any pixel by setting the
cursor on it or keying in its coordinate. This information is very
useful when manipulating the image and is a faculty entirely wanting
in film pictures.
Because of the grid arrangement of the pixels, a picture is often
dimension by the number of X and Y pixels, like '640 x 480'. This
menas there are 640 pixels on the X-axis and 480 on the Y-axis.
Image manipulation
----------------
Unlike chemophotography, it is easy to manipulate a digital
picture. You need an image or picture editor. Paint comes with Windows
but you may want something more full-featured. Photoshop or Photoshop
Elements are the top dogs in picture editing. There are many other
good editors.
I personally use Paint Shop Pro, a commercial program with lots of
features, all simple to get at and use. GIMP is a new other favorite
one and it's free for download. Being more complex, it is harder to
learn.
You are free to modify your pictures to suit your presentation.
When modifying a borrowed picture, note that it is adapted from its
original source'.
Examples of manipulation are:
-----------------------------
* altering overall brightness
* altering overall contrast
* altering color balance
* negating colors
* altering highlights
* erasing sections
* removing blemishes
* erasing sections
* adding text
* combining pictures
* converting picture formats
----------------------------
Before working on your slideshow pictures familiarize yourself
with the picture editor's features and operations. Experiment with
scrap picture. Give yourself plenty of exercise with the program. One
evening isn't enough for a program newly unpacked..
Look for and learn to use the 'Undo' feature! This undoes the last
operation and restores the picture to its previous state. Many editors
can undo only the very last operation, so you MUST pay attention to
your work to avoid horrible irrecoverable mistakes.
It is well at the start to work on a COPY of the original picture.
If things go too wrong, junk the picture and cut a fresh copy.
Make intermediate saves. That way you don't have to reconstruct
all the previous steps if you have to junk the picture. Pull back the
last saved one and continue from it.
Altering overall brightness
-------------------------
The original picture, such as one taken at night with your camera,
may be too dark. The picture editor has tools to lighten (or darken)
the image. All parts are changed by adding a certain count of
brightness steps to each pixel in the scene.
There's a limit to how bright or dark to make the picture. When
the pixels start to saturate, reach their upper or lower limit of
count they stop brightening or darkening. Further effort to apply
light/dark distorts the brightness regime of the picture.
A few editors may add this count in a proportional manner to
prevent saturating pixels already at a high count. Reverse thinking
for darkening a picture to prevent saturating near value 0..
Too much brightening can also veil details in the brighter areas.
Too much darkening conceals details in the shaded areas.
In general apply bright/dark to highlight the important parts of
the picture.
Altering overall contrast
-----------------------
An editor has many ways to change contrast, some with strange
names and concepts. Here I explain the usual sense of contrast, what
happens when you turn the contrast knob on your [old] picture-tube
television or computer monitor. The scene details are muted or
exaggerated and shadings are accentuated.
Extreme high contrast makes the scene black or white all over. Too
low contrast gives an overall gray cast.
Some where in between you may capture all the texture in the scene
with a pleasing range of dark and light shades.
Altering color balance
--------------------
For graphical images, illustrations, cartoons, graphs and plots,
charts, you better leave the colors alone. For photographs the color
rendition can be badly skewed by the ambient lighting to yield an ugly
picture. You can to some extent correct this imbalance of color by
applying more or less of the three primary colors to the image.
Programs differ on the means of doing this. They in general tell
you what portion of red, green, and blue is in the picture and you
change this mix. The program may use the subtractive colors of cyan,
yellow, and magenta, but the concept is the same.
As a first cut, note the color that's in excess, like red for a
picture taken under incandescent lighting. Reduce the portion of red
(or increase that of cyan) and assess the result. Here's a guide to
the relation of the primary colors to help select the ones to play
with.
red
/ \
(minus green) magenta yellow (minus blue)
| |
blue green
\ /
cyan
(minus red)
Each color is the blend of its two adjacents and is the negative
of its opposite. To increase one, you may decrease its opposite or
increase its adjacents.
A more complete chart includes a radial component for brightness,
from black in the center to white around the edges.
Just how much fiddling with colors you do is pura mente a matter
of personal taste. It also depends on your acuity of color perception,
which tends to weaken with age. If you're squeamish about messing
around with the colors in your picture, it's better to leave them
alone. Have the 'Undo' button handy.
Negating colors
-------------
This a very welcome feature of my slideshows. Time and again I and
others are annoyed by the blast of white space on the projection
screen in a darkened room. The picture a white page with black or
colored lettering, like charts, diagrams, graphs, text. Many of us
find it hard to read the lettering against such a harsh background.
A scene with dark background and light lettering is vastly easier
to read and is orders more comfortable to view in the dark. For
graphics, charts, plots, other line work, I routinely negate the
colors before saving the picture.
The dark lines and letters are now white (or light color) and the
field is black (or dark color). For such pictures the exact colors
often don't matter. They were arbitrarily chosen for the original with
no peculiar meaning.
There may be a caption that refers to the original colors. 'the
red curve is ...'. You have to remove this caption with the erase
feature, explained later.
I use negative colors for starcharts, too, if the original has
black stars on white field. Apart from the ease and comfort factor,
the scene looks more real compared to the sky.
The picture editor has a feature for 'negative' ,'inverse',
'reverse', 'complementary' colors. It takes the count of each pixel in
the four colors and subtracts it from the maximum value of 255. A
pixel with count 25, a darkish one, becomes one of 230, a bright one.
A pixel of count 240, a bright one, becomes one of value 16, dark.
Altering highlights
-----------------
This is a tricky subject but it's like applying contrast to just
the bright, dark, or intermediate areas. This is usually done by
specifying the ratio of each segment in turn.
There seems to be no common method across programs for what the
numbers mean. You got a lot of playing around to do. The idea is to
judge that certain parts of the picture are good while others need
enhancing. You then apply highlight to those parts as part of a high,
middle or low lighted zone.
The trick is that if you enhance one feature in the scene, you
also enhance other features within the same lighting category, how
ever the program defines that. It may not matter or it can upset
previous alterations you did.
A curious feature of highlight is that some program do not act in
a linear manner with the numbers. If you alter one zone, its new base
value may also be changed, so you can not obviously backtrack to the
previous state by adjusting the numbers manually. You better know how
to pull the 'Undo' cord.
Extracting sections
-----------------
This takes a delineated section of one picture and keeps just it
as a new picture. Do this when there is a particular part of the
picture you need in your show without distractions from unwanted
parts.
One major application is to trim a screen-capture image. The
picture has the Windows dressing around the edges and all you really
want is the scene inside one of the panels.
This is a two-step process. First delineate the desired section
with the 'Box' feature. This turns the cursor into a rubber band that
when dragged over the picture ropes in a rectangular section. The
usual instruction is to start at the upper left or lower right corner
of the desired section and sweep to the opposite corner.
When the mouse is released a marquee, a line with chaser lights
running around like on a theater sign, is left behind. If you continue
the extraction procedure, the area inside this marquee will be
captured into a new image.
You have the chance to back out, like with a right click or the
'Escape/cancel' button, and try again. When satisfied you got the
correct selection, invoke the capture. Do study the program's
instructions.
The selection will appear in a new picture panel, ready for you to
continue working on it. It's wise to first save this picture in case
you goof up and need to start again. You fetch a copy of this new
picture and not go thru the extraction steps all over again. Save
within the naming system of your other pictures.
Your program may have other selection shapes, like a circle or a
lasso. These I find poor methods for making slides, which must be
rectangular in shape. On the other hand, a circle could be useful to
extract a section that is then pasted into a 2nd picture. See the
section on combining picture later.
Erasing sections
--------------
Erasing in digital image manipulation really means overwriting a
section, like painting over a wall. The trick is to choose a color
that blends with the surrounding area so the work does NOT look like
you painted over a wall.
This method is for small extraneous bits of an image that can
distract your audience, like a lamp in a shaded area that doesn't mean
anything for the slideshow. You want to erase the lamp and leave a
uniform dark area. You may for a graphic want to erase the labels or
caption to later add in your own. You may have to erase parts of the
whole picture that protrude into a new selection you extracted.
The editor has some way to pick up the color of a point in the
scene and show that it's picked in a color patch some where in the
margin of the screen. Look carefully at the area you want to erase. If
the color around it looks smooth and uniform, your work is simplified.
use the pickoff feature to grab the color of a point next to but
outside of the erasing area.
Then with the eraser, airbrush, mop, spraycan tool, go and 'paint'
over the erasing area with this color! Be very gentle at the edges of
the erasing area so the tool strokes don't show. Use short bursts from
the spraycan, for instance.
If the color graduates around the erasing area, you must do the
erase process in several stages. First erase around the point where
you picked off the color. When you move to a part where there is a
shift in color, stop. Pick off a new color from near this next spot
and continue. The spraycan can help blend the erased portions to make
a smooth transition around the erasing area.
Removing blemishes
----------------
This is a finer version of erasing sections. There may be a couple
pixels out of order in the picture that should be removed. They could,
for example, be dirt on the paper you scanned or on the window you had
to shoot thru with your camera.
First pick up the color next to, but not within, the rogue pixels.
Then use a pencil or pen tool to 'dab' or 'peck' at the pixel. It will
turn into the new color and blend into its surrounds.
Adding text
---------
Among the best manipulations of a picture is adding titles and
labels and captions. You may want to name parts of the scene and
attach a date or location note. You may want to point to certain parts
and mark certain points. All of this is done thru the editor's 'text'
and 'draw' features.
Choose a simple open typestyle. Fancy, thin, condensed styles are
tough to read from a distance. My own runaway favorite is 'Comic sans
serif' that resembles handwritten block lettering and is extra clear
and legible.
I myself stay with horizontal text, not trying aligned or rotated
text. This leaves the audience upright in its seat. The thing to mind
is the color of the text on the background it sits on. Some programs
will automaticly make the text a contrasting color, like the negative
of the base color, while others use a fixed color that you choose.
I and others are routinely frustrated by text, on webpages and
slideshows, that plain disappears over some parts of the background. A
compromise method is to use 'shadowed' or '3D' text. This is text
written with a shadow behind each letter or a raised shape with
shadowed sides.
This text is legible over just about all backgrounds, from light
to dark. I uss it for labeling photos of the Moon, where the text can
fall on maria and terra alike. For text on a uniform background, like
the sky in a starchart, I use flat text of a light color.
You have the chance to see your text in the scene before dropping
it into place. Each program has a 'hot spot' where the text will sit
when let go in the picture. Study the instructions.
Pay attention to the size of the text! It has to be legible from
th audience seat several meters from the projection screen. It can not
be tiny lettering you can read with your nose against the computer
screen. it also can not so large it overwhelms the scene like a
billboard.
Size the text by importance and possible obstruction of other
features of the scene. I use a large size for a title and a smaller
one for labels within the scene.
You probably noticed how on my starcharts the labels don't
interfere with each other and hardly ever cover important stars?
That's because I do NOT let the planetarium program insert its own
labels. Most are ineptly placed and sized. I manually label each and
every star, cluster, planet in my charts.
I label only the items I need, leaving every thing else blank. i
place the labels so they don't interfere or obscure other parts of the
chart. If the label is too long for a single row of text, enter it
piece by piece on separate rows. You do have to gauge the row spacing
and centering.
Use leaders to attach a label to its target. This may be a couple
dashes, hyphens, like I do for my starcharts. The front and back
slashes are also good leaders. In some cases it's best to draw a short
line with the 'line' tool from the target to an empty area and then
attach the label to it.
Combining pictures
----------------
This can be useful when you want to have a small inset within a
larger picture, like a detail of a starfield to one side of a
constellation picture. The exact process is unique for each picture
editor, so studying the instructions and experimenting is a need.
Open both the main and inset pictures. Note the shape and
proportion of the inset picture. Do 'copy' on the inset.
Select in the main picture an area, usually in one corner, of the
desired size and of the same proportion as the inset. This is done
with the 'Box' feature to enclose the desired area.
Now do 'paste'. The program may ask if you want to paste into the
selected area. The inset is bunged into the main picture within the
selected area.
An inset may also be round, if it was extracted with the 'circle'
function. The target area to paste this inset into has also to be
round.
You may with the 'line' and 'text' features point to the region in
the main picture covered by the inset with a suitable label.
It may be good to outline the inset with a border using a thick
line with the 'line' tool. Or do a proper 'border' on the inset before
copying it.
Save the picture under a new name, because you may want the
unaltered main picture for some other purpose later.
Usually only one picture fits well onto an other. Trying to make a
collage can be messy. The standard application is the inset detail for
a region in the main picture.
Converting picture formats
------------------------
It may be necessary to convert a rogue picture format into one
that PowerPoint can accept, notably JPG, GIF, and BMP. The easiest way
to do this is to open the picture in the picture editor and then save
it into a file of the other format.
This assumes you have an editor that accepts many different
formats. Some take in only a few kinds of picture, leaving you with no
way to work with the rogue one.
With the picture open on screen, do 'File/save as'. In the file
handling panel that opens, you must change not only the filename to
your numbering scheme, but also the filetype. This is in a picklist
near the filename. Select JPEG or JPG.
Assembling the show
-----------------
Having acquired, manipulated, saved all the pictures you may need
for your show, you must now arrange them in the presentation order.
One way is to print the pictures one by one and then write on each its
filename. This last step is vital because many programs print pictures
without their filename. With no name right on the picture you will
never be sure which picture you're holding in your hand during the
sorting process.
To save paper you may print two or four pictures per sheet. More
than four pictures are too small to see well what they are. Label and
cut out the pictures.
With the pictures properly labeled, shuffle them into order. The
order WILL NOT be the same as the acquisition sequence. When you
actually build the show you must pull up the pictures in the
PRESENTATION order by calling for them by their ACQUISITION number.
Got that straight?
Recite the show while looking at each picture. Is this picture
really needed? Is its features already part of an other picture? Is
there something missing that needs a new picture? Is the text clearly
legible at arm's length (to simulate a back-row seat)?
Try not to duplicate scenes. One or two of a given scene is
plenty. Each picture should have its own internal value to support the
show, not just to give more examples of the same point.
Just do NOT throw up pictures for the hell of it. Maintain a flow
of thought or theme so the pictures link together. Think of the awful
slideshws you saw before. Why were they so terrible? Then avoid those
features in your show.
In this winnowing process you'll set aside many of the pictures
you gathered. You may even set aside some you manipulated in the
picture editor. Keep these for possible future shows or to customize a
show for other audiences. Leave them in the show's directory.
Fire up PowerPoint
----------------
I use PowerPoint, as does virtually every one else. First thing I
do is choose a background for my slides. I find that a plain one-color
field is best. I do not use a wallpaper background or one with a
design on it. After picking a soothing color, I tell PP (short for MS
PowerPoint) to keep this background for all the slides in this show.
I make my first slide by doing 'Insert/new slide/insert (again)/
picture/from file'. I shayshay to the show directory where I stored my
pictures and scroll to the first one in the presentation order.
This is the first one in my stack of printouts. from the hand
written label on that picture I know which of the files to call up.
Let's say this is alcon07.jpg. It's the 7th picture I acquired but the
first in the show.
Alcon07.jpg is bunged into the background on the slide panel. To
the left of this panel is a list showing slide #1 in progress. As each
new slide is built it's added to this list. You can view any slide by
clicking it on this list.
In general the picture will be way off sized to fill the whole
panel. It has handles around it by which to pull and drag it into the
largest size that fits within the panel. I like to fill the panel and
leave a thin border of background around the slide. Gauge the margins
top/bottom, left/right. The top and bottom may be unequal but the left
and right should be the same.
When satisfied with the arrangement, I move the cursor off of the
panel and do 'Insert/new slide/insert/picture/from file' for slide #2.
I repeat the fetching, sizing, aligning process all over again for
slide #2. This slide is also placed into the list on the left.
I work thru all of the slides to complete the show. Along the way
I save the show, in case of computer or power glitch, under the name
of the presentation, like 'alcon.ppt'. If I have to give the show to
the host to play thru his computer I name it 'pazmino.ppt'. That makes
it easy for the host to fetch when it's my turn to speak.
Having done all of the slides and packaged the show, I switch to
'View/slide show' and try it out. I usually find that a slide is out
of place or I forget to put one in.
I switch to 'View/slide sorter'. This lays out the slides like the
chemo ones on a backlighted table. By drag and drop I rearrange the
slides into proper order. Where a slide is missing I note between
which two it belongs. In the 'View/Normal' mode, where the slide show
is compiled, I scroll to the place to insert the missing slide and do
'Insert/...'. The new slide is inserted between the others.
Extra functions
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PowerPoint has a wide selection of slide transition. This is the
way one slide changes to the next. I so far haven't used anything
fancy. I stay with the click! of the old slide projector. The
transitions can add interest but please don't make a show just for
that.
PowerPoint allows adding video and audio to the slideshow. These
are treated like any other slide, except that its content is sound or
movie. I haven't needed this facility yet.
You can also make evolving slides where its text comes up bit by
bit with each advance to the next slide. This is done by making the
slide with the first bit of text. Pick THIS SLIDE as the next new
slide and add the next bit of text. Repeat until all the text is
displayed. You really have several slides but they are in register
except for the new lettering on each successive one. It looks like the
one slide magicly adds text as you speak.
Modifying existing shows
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Occasionally you'll find a PPT file ready to show as is. If the
show is a good one, you may show it to your audience, just like you
show paper albums, posters, films which obviously you didn't make
yourself. The title or closing slide usually gives the attribution.
However, as in my case for both epsilon Aurigae and LCROSS shows
at the NYSkies Seminars in summer 2009, the original slideshow was too
shallow for our astronomers. I modified them by adding slides from
other sources and omitting some of the original ones. I noted in the
title slide that this show is adapted for NYSkies.
Open the existing PPT file and then work with it just like for a
new one. If you do this, be SURE to add text to the attribution slide
that this peculiar show is adapted for your talk. This is essential if
your show is preserved in the meeting procedings.
Testing the show
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It may take a couple iterations to get the show into final form.
One crucial thing to mind well is that the show has to fit within the
time slot for your talk. If this is 20 minutes, you have to show and
narrate your slides within 20 minutes and no longer. Have a clock in
front of you to mind the time. A sports watch is good because you can
zero it at the start of your talk.
Recite the chow, aloud if you must, at a slow and steady pace.
Don't rush. Don't mumble. Say each word clearly and audibly. As you
flip to each slide state what is shows and point out its features.
You save lots of time by leaving out noise words like 'Here is a
slide of ...', 'The next picture is of ...', 'I took this picture to
show ...' . Just state the substance of the picture and you'll be
amazed how easy it is to keep within your time allotment.
If you interrupt the show and have to resume, start the slideshow
again. Right-click in the first slide. On the popup menu pick 'go' or
'go to slide' and then scroll to the slide where you left off. This
resumes the show from that point. You do not have to go thru the show
all over again from the beginning.
Save the final show on your computer and on the medium needed for
the presentation. This is typicly a storage card, stick, CD. Label the
medium with your name and meeting so the host returns the right one.
That's all there is to it!
Working the computer
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I offer assorted tips and hints for giving your slideshow at the
presentation session. Here are several relating to the computer. In
the next section are some for the delivery process.
If you have your own laptop with the show loaded on it, you must
know how to work it in the dark. Laptop keys can be hard to read in
the dark. Place bits of masking tape on the critical keys. Mark the
alt/F4 keys to close PowerPoint and then your computer after your
talk. The light colored tape stands out in the dark and its texture
gives tactile clues to press the right keys.
Have with you the video cable to attach your laptop to the host's
projector. The host should have this, but it can go missing or, yes,
the previous speaker took it away by mistake. You also need the power
brick, specific for your laptop, to prevent low-battery problems
during your show. You will also need it for using the machine else
when nd where during the meeting.
Know how to turn on the video socket for an external display. Some
computers always echo the screen to the video output socket. Others
require some queer key combo to turn on the socket. The host's
projector NEEDS the signal from your computer to project your show.
Because you may not have used this feature before, you have to study
the computer manual.
If possible sit down next to your computer to minimize blocking
the projection screen from the audience. If you have to stand or
there's an obvious zone of blockage, advise the audience about it.
Offer that it can shift seat for a clear view.
You may attach a remote control for the computer, using an
infrared connection. Be sure this works by actual test and keep a
clear sightline from the wand to the sensor on the computer. This is
one way to let you walk around by the projection screen and still
operate the laptop by yourself.
Do NOT count on a wireless Internet connection during your talk.
In all places I went to, the signal strength wavered all day with
frequent dropouts, languid speed, and dead spots. To show what a
webpage looks like, make a slide of it from a PrtScr capture. The
image is a static one, but that's better than getting tripped by a
lazy signal or slow service during your talk.
Giving the show
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Inspect the floor for wires, then avoid that area to the max
during your talk. Stepping on wires can unplug equipment, sometimes
not noticed until they are next needed. Tripping on wires can injure
you in a fall. The host should try to gather the wires into a side
space, cover them with hunks of rug, or station an agent to deflect
people away.
Put any glass of water, a common courtesy for speakers, away from
the computer and projector. You do not want to spill water on them.
One trick is to take a drink before the meeting and leave the rest for
after the talk.
If you prefer standing by the projection screen, away from your
computer, ask the host for an agent to run the computer. The taped
keys will make his life a whole lot easier when faced with an
unfamiliar keyboard.
When speaking, look at the audience, not the computer. Speak
slowly and carefully because the audience in the dark no longer has
visual clues to your words.
Where spelling is important, say the letters with the phonetic
alphabet. The universal standard is the NATO system, but the ham radio
system is still common in the US. You may use any unique distinct
words that clue the audience to the initial letter. Make sure the
words are indeed unmistakable.
do NOT fiddle with paper notes! You will mix up the sheets, drop
them. They rattle and crinkle in the microphone.You look down at them,
not at the audience, they may be hard to read in the dark. By testing
your show before your talk, you know the sequence and content of your
slides. The image itself is the clue to your narration.
Insurance
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Electronics are wonderfully, when they in fact work. It can happen
that your computer, the host's machine, the projector, cables, power
cords, fail. You slideshow is killed, along with perhaps many others.
There is an insurance policy you can take out. After you arrange
your pictures in the order for the show, get a printout of them on
viewgraph sheets. These are clear plastic sheets that go thru the
printer like paper and take up the picture as a see-thru image.
The sheets MUST be compatible with your printer to prevent
kaboshing it with melted or shredded plastic. Read the package label
carefully before buying the sheets.
Stack the sheets in the show order, with blank paper sheets in
between. You may use the preliminary printouts of the slides so you
picture on paper clues you to the next image in your show. Put the
stack in an envelope or folder with strong bands to prevent a
disastrous spill.
Ask the host to have at ready a viewgraph project, also called an
overhead projector. If the electronic gear konks out, have the
overhead machine rolled out for you.
You give the slideshow by placing the see-thru pictures on the
window, like a photocopier, right side up and top toward the back of
the window. An arrangement of lamps, mirrors, lenses projects the
picture onto the screen.
The set of pictures, in presentation order, sits on one side and
the spent pictures go in a pile on the other. Your narration has to
louder and clearer to hear above the fan noise in the projector. You
must also stand to one side to avoid blocking the beam from the
projector.
The viewgraphs will be of lower quality than the digital slides
and may be only in gray-scale, depending on the printer. In a
contingency they'll save your show from being called off.
Laser pointers
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Please use a GREEN pointer. A red one often is too weak. Its dot
gets lost in a busy scene. It is further more surprising how many
people's eyesight is only weakly responsive to red! To them red is
perceived as a dim dark tint.
Laser pointers come in several colors, but so far red and green
are far and away the most easily available, Go for the green, even if
it costs a little more.
Be EXTREMELY CAREFUL with your pointer!
NEVER aim the beam at or near other people or into a space
occupied by people.
NEVER sweep the beam into the audience by accidently holding the
trigger between slides. LET GO OF THE TRIGGER instantly the laser is
taken off of the projection screen. This is a real problem in meeting
halls with mirrors or other shiny surfaces and fixtures.
NEVER horseplay with a laser to play tag or sci-fi warrior.
NEVER attract a person's attention by 'dotting' him.
NEVER leave your pointer loose where innocent people can play with
it, specially children. When not in use, keep the pointer out of
reach.
NEVER experiment with the pointer from your hotel room or open
field to determine its range. From safely-conducted tests, the
ordinary green laser pointer sends back a visible reflection off of
stone or brick out to about TEN KILOMETERS away. The beam is still
easily noticed after a twenty kilometer round trip and absorption by a
dull wall. Now that you know, there's no need to experiment.
Let only competent persons borrow your pointer and then only under
your immediate supervision. You really don't want liability by
reckless application of your pointer behind your back.
A good strategy is to treat the laser pointer like a firearm and
apply its safety principles. In fact, an ordinary commercial green
laser pointer IS a weapon that is used in crimes. Apart from the
headlines of firing at aircraft, the pointers are used to dazzle or
distract sports players, vehicle drivers, farm and zoo animals, kids
and gang members, neighbors, and police in chase. Being caught
misusing a laser pointer can earn you deep time, fines, civil
penalties, and professional and public disgrace.
Conclusion
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Presenting slideshows was always a part of an astronomer's skills.
From chemophotography the method is by the 20-thous just about
completely shifted to digital imaging. Apart from the form of the
prime images now being on silicon rather than film, there are now many
more ways to obtain the prime images.
Once having these pictures, you may manipulate them in useful ways
with ordinary picture editors. They allow for extensive customization
of the pictures to accommodate your audience.
Assembling the slideshow is done on computer with PowerPoint or a
workalike, taking about as much time as it did to assemble a film-
based slideshow. Once compiled, the show is saved to digital medium to
bring to the presentation host.