Straight photography has always been inferior to oil painting in its
ability to "hold a wall". Enlarge even the best 35mm negative or
digital SLR RAW file to the width of a living room sofa and you don't
have to stand very close to notice softness and lack of contrast.
Nobody ever approached a grand Rubens painting and said "It is getting
fuzzy and uninteresting as I look closer."
One of the best lenses in the Canon EOS
system is the 50/1.4, a very simple design that does not demand a
lot from the lens designer. The image below (of Elsa Dorfman, Boston's best-known
portrait photographer), however, illustrates what the actual pixels
from the 21MP sensor of an Canon EOS 1Ds Mark III, $8700 (review) look
like. The original image, viewed at normal sizes, has a fair amount
of punch, contrast, and seemingly infinite detail, just what you'd
expect from a camera that was state of the art in 2008. The detail of
the view camera lens, however, taken from near the central sweet spot
of the 50/1.4, shows that the contrast and sharpness of the letters
"Fuji Photo" is not great.
| Original |
100 percent crop |
|
|
How large would you have to blow the image up before someone would
begin to see these lens quality limitations? A typical viewing
distance is 12 inches. The 100-percent crop is about 320 pixels in
size and probably shows up on your computer monitor at just over 3
inches in width. Let's say that an image from the 1Ds Mark III would
have to be enlarged to 72 pixels per inch to look truly crummy when
viewed up close. The Canon SLR puts out an image 5616x3744 pixels in
size. At 72 pixels per inch, that would be 78" wide.
Could things start to look crummy in smaller enlargements? Sure.
This image was taken with one of Canon's best lenses using studio
strobes, which freeze camera shake and subject movement. Had we used
a cheap zoom lens or handheld the camera at 1/60th of a second we
would probably get disappointed sooner.
Could we get better results from a single image? Probably. In the
old film days, guys such as Andreas Gursky
used 5x7" view cameras and 6x17cm roll-film cameras (example: Fuji 617), plunked down on heavy tripods, and printed up to ten feet in
width. They quickly discovered that enlargers and enlarger lenses
weren't that great either.
The first gifts of the digital revolution: line-at-a-time scanning and printing
This first gifts of the digital revolution for photographers who wish
to compete with painters were the drum scanner and line-at-a-time
digital printing systems. After exposure, the image never went
through another lens. The film was scanned one line at a time by the
drum scanner. The print, made as a wide roll of paper fed through an
LED or laser-based printer, was exposed one line at a time as well.
The corners and edges of the print could be as sharp as the center,
assuming the original image was of high quality from corner-to-corner.
Some of the more interesting prints to come out of this first wave
were photo
mosaics, notably those by Robert Silvers.
The second wave of the digital revolution
Starting in the early 2000s, physically large and very high resolution
CCD and CMOS sensors became available. Canon produced 24x36mm sensors
to sit behind standard 35mm lenses. Specialized studio photography
companies produced sensors up to 36x48mm in size to sit behind medium
format and view camera lenses. As of 2008, easy-to-buy examples of
these image systems include the Canon 1Ds Mark III (21 MP, just under
$10,000), the Mamiya 645ZD (21 MP, just under $10,000), and the
Hasselblad H3D (39 MP, over $30,000). These are discussed in the "Digital Cameras"
chapter of Making Photographs).
With a tripod and/or studio strobe system, could you use one of these
systems to create a single image that would look great when enlarged
to six or eight feet in length? Probably. What if sensor fabrication
improved to the point that 60x60mm sensors become available, full
frame on an old square-format Hasselblad or Rollei, and requiring less
physical enlargement to get to a huge size? Almost definitely.
There are some problems with this approach. Many of the most
compelling images are created in environments where it is not
practical to use a tripod or a huge camera. Not everyone wants to
spend $10,000+ on a camera system or lug that much weight.
Would it be possible to create a compelling 6'-wide print using a $200
camera?
The answer is "Yes, if you collage multiple images from that camera."
What do you need? (Old School)
- stack of 8x12" print from any old lab
- Analog Cropping Tool (a.k.a. "scissors")
- acid-free Fome-Core poster board
- 3M Adhesive Transfer Gun and acid-free "Scotch ATG" tape
What do you need? (New School)
Thanks to improvements in technology, you no longer need to spend big
$$ on high quality scissors and as much as $100 on the Adhesive
Transfer Gun. Only the following items are required to make a
100-percent digital photo collage with high individual image quality:
- A desktop computer system with enough memory and disk to handle
very large files. (budget $5,000+ just for the RAM; see below)
- As large a monitor as possible for that desktop computer.
- A desktop photo editing tool capable of handling a canvas with at
least 200 pixels per inch, up to the size of the final print. If
printing 8' square, for example, that is approximately 20,000 pixels
on each side or 400 megapixels.
- A lifetime of skill with that photo editing tool.
- A database of images that you want to display together in the
collage, scanned from film into digital files or originated with a
digital camera.
- A good lab that can take a huge digital file and make an ink-jet
print or line-at-a-time print on traditional paper.
An advantage of the all-digital approach is that it is possible to
rethink and reposition collage elements. A significant disadvantage
is that you're working at a different scale. When working with
scissors and tape it doesn't take any special skill to visualize how
the thing will look full-size; it is inherently full-sized. When
working on a 30" LCD monitor, however, you have to imagine what the
finished much larger piece will look like. Sometimes scale changes
everything.
How big can each image appear within the collage?
With digital SLR images, limit enlargements to no more than 200 pixels
per inch, e.g., with an older 6 MP digital SLR, that's 10x15", with
the 12-13 MP SLRs, that's 15x22". The medium format backs and the
Canon 1Ds Mark III, if used on a tripod, should be able to cover
20x30" of the collage with excellent quality.
With point and shoot cameras, the megapixel numbers are not very
meaningful. The sensor is tiny. The lens is not very good. They
could deliver 100 megapixels out of the camera and it would still be
unwise to attempt to cover more than 8x12" of the canvas with an image
from one of these things.
What desktop tool?
The Gimp is free, open source, and
fully capable of creating collages, with each photo in its own layer,
very similar to the Photoshop tutorial below. Reading camera RAW
files will require a plug-in (free and kept up to date for the latest
cameras).
LumaPix's FotoFusion was
purposely built for creating collages. The $300 "Extreme" version can
supposedly handle a 20,000-pixel square file. photo.net members have
spoken highly of this product in the
wedding forum.
The best thing about FotoFusion is that it is structure-based rather
than pixel-based. You work with tokens representing the full-size
image, which makes placement and size adjustments instant. When you
are happy with your collage, you "export to file" and specify the
final image size. You can then walk away and eat dinner while the
application renders an enormous file. FotoFusion can save JPEG, PNG,
PDF, TIFF and Photoshop-format files. One serious limitation of
FotoFusion is that it cannot work with camera RAW files. You need to
convert all of your photos to JPEG (or TIFF?) before they will be
readable by FotoFusion.
Adobe Photoshop
is the tool that most people already have on their desks. This is the
tool that the printing lab will have. Photoshop can be painful for
photographers because it is really more of a graphic artist's tool.
Photoshop's pixel-based rather than structure-based nature means that
you are working interactive with full-size files, which will be
excrutiatingly slow unless your computer has an enormous amount of RAM.
Here are some arguments in favor of Photoshop:
- collaging is a graphic arts-style activity, something for which Photoshop was intended
- in the hands of a skilled user, Photoshop can do everything;
learning more about Photoshop and practicing with Photoshop will pay
dividends on other projects
- Photoshop offers relatively bulletproof engineering and it seems
likely that future versions will be able to keep up with higher
resolutions and larger files.
- Photoshop is savvy about using multiple CPUs to accomplish tasks
more quickly; this is valuable given that the average higher end
desktop these days ships with a quad-core processor.
Note that Adobe Lightroom does not offer any collaging functions.
What desktop computer?
A 400 megapixel file with three bytes per pixel (one for each color)
will occupy 1.2 GB of memory. Every time you edit the image Photoshop
may have to make a copy in order to provide the "undo" function. For
reasonable responsiveness, you probably need a computer with at least
10 times as much memory as the file size and plenty of free hard drive
space as well. When working with FotoFusion, you could probably
reduce memory requirements to 5X the final image size.
Note that 5X or 10X 1.2 GB puts you over the 4 GB limit that a 32-bit
processor can address. Microsoft Windows wasn't designed as a 64-bit
operating system, so it would probably be safest to go with the
dreaded, but more recently developed, Vista. It isn't easy to buy a
PC with a lot of RAM. In the happy world of Dell, it is only their
"Precision Workstation" that is sold with RAM configurations between 8
GB and 64 GB.
In the Macintosh world, the 2008 MacPro, accepts up to 32 GB of RAM.
The Mac OS X operating system is a variant of Unix that goes back to
the late 1960s. Unix has run on all different kinds of hardware and
never had a lot of 32-bit specific assumptions baked into it, so it
should work fine as you add more and more RAM.
Making multiple size prints
Suppose that you want to print your collage in a range of sizes, from
8' wide down to 2' wide. As noted above, Adobe Photoshop is a
pixel-based tool rather than a structure-based tool. You must
complete your collage at the maximum size and resolution that you will
ever need. For printing at smaller sizes, the lab can reduce as
necessary or you could save out the file with fewer pixels. With
FotoFusion, you need only go through multiple Output steps, each time
specifying a different final size.
This tutorial
Should you choose to use The Gimp, you're probably a true computer
nerd fully capable of figuring everything out for yourself.
Should you choose to use FotoFusion, you can simply follow the
instructions included with the application and use their technical
support services as required. FotoFusion was designed for collaging
and therefore you need not sift through unrelated commands to find the
relevant ones for making a collage.
Should you choose to use Photoshop, we hope that this tutorial will
prove helpful. Below is a step-by-step guide to using Adobe Photoshop
CS3 on Windows XP to build a collage. The commands and ideas should
be transferable to future versions of the programs as well as to the
Macintosh version of Photoshop.
Step 1: Fire Up Photoshop
Click left on the Start Menu, which should bring up a list of programs
installed on your Windows machine. Click left on the "Adobe Photoshop
CS3 icon" to start Photoshop.
Pull down File->New to bring up a dialog box. Give your new collage a
name, e.g., "Summer Trip 2007 Collage". Set the width and size in
inches to the final size of the print that you want, e.g., 36 inches x
24 inches (this is about as large as you'd want to go on a PC with
less than 3 GB of RAM). Set the resolution to 300 pixels per inch if
the lab is using standard LightJet printer or some other number that
the lab suggests. Set the color profile to "Adobe RGB (1998)" unless
the lab specifically instructs you otherwise. Leave the pixels
square. The range of printable luminance is less than 8 bits per
color and most labs would prefer an "RGB 8 bit" file to a 16-bit file.
Step 2: Place Images on the Canvas and in Layers
Pull down File->Place and select an image file to open. It is best to
work from the original camera RAW image and resize from there.
A "SmartObject" will show up on the canvas. Note that a new layer,
named with the image file name, has show up on the Layers window at
right.
Click left on the canvas outside the image and drag to rotate the
image. Click on any corner of the image to resize while holding down
the shift key to retain the image proportions.
Hit the Enter key to finalize the image resize and rotate.
Click left anywhere on the image and drag to reposition.
Repeat until all of the images are loaded and approximately placed.
Step 3: Crop an image that has already been resized and placed
Over in the Layers window, click right on the layer corresponding to
the photo that you wish to crop. Select "Edit Content" from the menu
of choices. The Camera RAW dialog box will come back up, allowing you
to change exposure or crop. Once done, the changes will be applied to
the already resized, rotated and placed photo on the collage canvas.
Note that cropping only produces rectangular-shaped final images.
Step 4: Take virtual scissors to an image.
Suppose that we want to cut a non-rectangular shape from our original
photograph. Click left on the photo that you wish to edit in the
Layers window. This should highlight the layer, meaning that any
changes will be applied only to this layer.
Click right on the layer and select "Rasterize Layer". This kisses
goodbye all of the flexibility of a Smart Object, but it enables
the full range of Photoshop adjustments.
Click right on the lasso tool and select "Polygonal Lasso Tool" (the
freehand lasso is too much freedom for a humble photographer). Using
the Navigator window at right, zoom in on the section of the collage
that you wish to work on.
Use a series of left mouse clicks to surround the part of the image
that you'd like to retain. The last mouse click should be right on
top of the first click so that Photoshop knows to close the polygon.
You now have flash selection lines.
Pull down Select->Inverse to select everything BUT what you just
surrounded with the polygon.
Pull down Edit->Clear to wipe out all the pixels in the selection
within the currently selected layer (i.e., the clear command
won't clear pixels in other photos).
Pull down Select->Deselect to remove the flashing selection outlines.
Step 5: Resize an image that has already been placed
Click left on an image within the collage. The Layers window should
show the corresponding layer.
Pull down Edit->Free Transform to get back to the size and shape
transform controls that were available during the initial Place
command. Remember that holding down the Shift key and dragging from a
corner will preserve the image's aspect ratio.
Step 6: Adjust overlaps
When images overlap, an image that is higher in the Layers window will
appear on top of and obscure a portion of an image that appears lower
in the list of layers. Click left on a layer and drag it up or down
to change whether it appears on top of or underneath another photo.
Step 7: Add some borders
When photos overlap it may not look right because the pixels of one
photo blend into those of another. Physically collaged photos will
have some sort of edge. Left click on a layer, or a photo, to select
it. Pull down the Layer->Style command and there are a lot of
"blending options". Stroke is the simplest, adding a constant color
border line around the photo. In the example below, gray borders, 7
pixels in width, have been added to some of the photos.
Click left to select a photo whose border looks good. Pull down
Layer->Style->Copy Layer Style.
Click left on another photo in the college. Pull down
Layer->Style->Paste Layer Style. Now this photo will have the same
border.
Step 8: Save your finished work
Save your completed work in a .psd file. This preserves all of the
layers and all of the flexibility of Smart Objects.
Step 9: Export for printing
For low-budget printing services where what they want is a JPEG photo,
pull down File->Save As. Select "JPEG" from the Format menu.
Semi-Automatic
With The Gimp, once there is a master file open, use "File->Open as
Layer" and use shift-click or control-click to select multiple photos
to place into layers.
FotoFusion has an AutoCollage option. The collages that it produces
look more like high school senior portrait packages than something
you'd want to print and frame, but it does get a big batch of files
onto the canvas quickly.
You would think that Adobe Photoshop would be able to do this with the
Action recorder and its powerful batch processing tools, but I
couldn't figure out how. The solution seems to be Dr. Brown's Adobe
Photoshop CS3 Scripts (free), notably the Place-A-Matic. There is
a link to a tutorial video on the site.
Fully Automatic
Jamie
Zawinski distributes a
Perl script that automatically produces collages. The results
have just enough randomness in placement to look as though a human
assembled them. He explains more in this Weblog posting.
Conclusion
For about $10,000 in hardware and software, it is possible, even for a
person with limited digital postprocessing experience, to make as good
a collage as an 8-year-old would make using scissors, tape, and a
stack of proof prints.
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, February 24, 2008; 03:28 P.M. 
