I have
specialized in the processing and printing of digital
photographs since 1997, and since 1999, have fine tuned
that specialty to wide format digital photo printing. I
must say, the technical advancements in digital cameras,
digital image processing software and digital photo
printing systems is absolutely amazing. In the past couple
years, these technical advancements have taken leaps and
bounds in print output capabilities.
Most individuals who have ventured into the world of
digital photography in recent years, have a somewhat
working knowledge of computers. They usually know how to
get their latest photos from the storage card to their
computer's hard drive, and printed out on their desktop
printer. Beyond that, well who cares as long as the photo
prints look OK.
Many of these individuals have even gone so far as to
delve into the subject a little deeper, and have read or
heard about the resolution needed for good quality prints,
a bit about file types, and even touched base with a
version of Adobe Photoshop to process and enhance their
works of art. This is all fine and dandy, but the problem
that arises is that most of the knowledge they seem to
collect in their search, is either outdated or dished out
by those who sound like they know more than they actually
do.
While it is true that you need a certain level of image
file resolution to produce a fine quality photo print, how
that level of resolution is achieved is another matter.
Digital photo printing should be done with an image file
that is at 200 to 300 dpi minimum, (actual term would be
ppi for an input file, or pixels per inch). As important
as the digital photo's resolution is to achieve this
resolution and print output size without resampling the
original digital photo file to produce this resolution and
print size. The absolute finest quality photo prints will
be produced with the unresampled, original photo file.
To produce the larger print sizes now available on the
affordable medium format digital photo printers, requires
photo enlargement techniques. Most people simply open the
original photo file in their version of Photoshop, and
resize the file by entering the width and height
dimensions, resolution dpi they want, leave the resample
option checked and click the OK thinking all is just
great. This will resample the photo file and degrade the
original image quality. Photoshop uses a simple bicubic
resampling method to resize the file. This method actually
recreates and artificially produces new pixels for a
higher image resolution and larger print size. This is the
action that degrades the original image.
The Photoshop resampling will have to work if that's all
you've got. If your photo enlargement is not too big, the
degrading of the image may not be too noticeable. If you
require photo enlargements much larger, or prints in the
range of 16x20 and larger, simple file resampling will not
produce quality results. That is why you hear all over the
Web that very large print sizes are just not possible,
even from the newer high resolution digital cameras. NOT
SO! I print and ship photo enlargements as large as 40x60
from 6 megapixel cameras and guarantee customer's
satisfaction. Have never had one returned!
To achieve high quality photo enlargement of digital
photos requires a slight shift in processing thinking and
a certain file handling methodology. You will also need to
purchase additional digital processing software, besides
your image editing application such as Photoshop. One
application is a Photoshop plug-in utilizing fractal
technology for image resolution boosting called Genuine
Fractals. The second application, and most important, is a
very high quality RIP software, or "Raster Image
Processing" program that will reprocess input files
before printing. RIP software is available, and highly
recommended, for use with all medium format and large
format digital printers where photo enlargement is the
rule of thumb. Most quality RIP software applications
today also include complete color management features,
along with many other amazing editing and enhancement
features.
Instead of preparing your digital photo for printing using
Photoshop, you will only use this program to set up the
file for photo enlargement and perform some sizing and
cropping functions, and any image enhancements. Any
required photo enlargement and image resolution building
will be performed with Genuine Fractals. Digital
processing to a proper output resolution will be done with
the RIP software, which does a much, much better job of
resampling the photo file than Photoshop. There are some
enhancing functions that should not be performed on the
image file until after the photo enlargement is at target
print size. Read more photo
enlargement tips here.
The best way to describe this advanced photo enlargement
methodology is to walk through an example photo
enlargement using a standard high resolution digital
camera with a set large format target print size. For this
example I will use a Canon 6.3 megapixel digital camera
format with a 3072x2048 pixel dimension and a target print
size of 30x40. This target print size will require photo
enlargement and photo cropping.
Please note that the RIP software I will be using in this
example will reprocess the final set up file to a
resolution of 360 dpi before sending to the printer. It is
best to use a set up dpi that is an even variable of the
final reprocessed dpi. The lowest set up resolution I use
for large format photo enlargement is 90 dpi. The key to
the finest quality photo enlargements is to never resample
the file in Photoshop.
Using Photoshop CS and photo in landscape orientation:
Start by opening the original photo file in Photoshop CS
then:
Click image > image size
uncheck resample and enter "90" in the
resolution field.
Produces an image: width 34.133 in. x height 22.756 in. at
90 ppi.- OK
Save in Genuine Fractals file format - encoding lossless.
Open the same file in the Genuine Fractals format.
You will note the same image specifics from the Photoshop
sizing.
For the width and height fields select "inches"
and enter: height- 30 and width- will automatically be 45.
For width and height fields re-select
"percentage" and you will see a photo
enlargement of 131.836 % is required for this print size
at 90 ppi. - Click OK
Please note that Genuine Fractals states photo
enlargements up to 400% are possible, but experience has
taught me that to maintain original image quality, it is
usually best to keep this photo enlargement percentage
within a maximum of about 225%. The quality of the photo
enlargement depends on the pixel density of the original
file.
Resave this processed file in a Photoshop format (.psd) or
.tif format.
Re-open .psd file in Photoshop CS. To crop for the 30x40
print size without resampling this file: Select crop tool
> enter in the crop tool parameters:
Width - 40 in height - 30 in, and resolution 90.
Drag the crop tool over the entire image and click view
> snap to > document bounds, to keep the crop lines
within the edges of the image. Click crop check mark to
set crop.
You now have an image that is 40"w x 30"h at 90
ppi. Now is time you would want to apply any image
enhancements to the photo enlargement, and the very last
function would be to sharpen the image using the unsharp
mask filter.
Send the photo enlargement to the printer through the RIP
software and the image will be re-processed to 360 ppi,
and print with amazing original image quality. We provide
a chart of photo
enlargement capabilities by digital photo megapixel
resolution for an easy reference. All the photo
enlargement sizes are figured utilizing the processing
methodology described in this article.
Wide format photo enlargements yielding original image
quality are absolutely possible if the original file is
processed correctly and you avoid resampling the image
pixels in your image editing software. Of course, high
quality results require the use of these advanced software
applications and this will also require reaching a bit
deeper in your pockets. |
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