Digital Imaging/Photos/Photography Tips
This page contains a few simple imaging tips for preparing photos
to include in the Culver Class of '57 website or the Golden Roll
Call for our class.
The simple rule of thumb is scan shoot and store the image
at a higher quality or resolution than you might expect to use
it, then you will have enough image pixels (or compressed quality)
for enlargements, cropping or photo enhancement.
General Concepts
The quality resolution of digital images, whether scanned prints
or digital photographs is generally expressed in 'pixels' or dots/inch
(dpi). Digital cameras range in total pixels from 2-3 megapixel
upwards to 12 megapixels for professional camera. The low quality
images that are captured on cellphone devices barely weigh in
at about .300 megapixels. In general, the higher the number of
pixels, the better the quality of the image to be able to enlarge
for display or printing.
In the case of digital images that are compressed an stored
in a .JPG (JPEG) format there is another very important paramter
of resultion quality and that is the amount that the image has
been compressed (% compression). This is also referred to
as the image quality: e.g high, normal, basic or draft.
Most images created from digital cameras are stored in JPEG
format. The algorithm used in the compression of the image discards
data which it determines is not necessary depending upon the amount
of compression desired. This is why the process is called "lossy",
as some of the quality is, in fact, lost.
Resolutions of Output Devices
You can see from the resolutions below, if a photo is prepared
from the web or a pc at 72 dpi and is enlarged for printing, the
quality will suffer in the print media. If you are scanning
for web and print, consider using 300-600 dpi to scan the image.
- Printers - 300-600 dpi
- Web Page Graphics - 72 dpi
- TV monitors, PC monitors - 72 dpi
Scanning Photos
If you are scanning color photos or documents, use the following
setting for best results for web graphics and printing, along
with the capability of cropping and enhancement in graphics software
like Adobe Photophop:
- Scanning resolution - "300 dpi"
- Image Mode - "Color", "Photo"
- Output quality - "Best" or "Highest"
Digital Cameras
Most digital cameras allow the photographer to select the quality
mode of the stored image. "High" or "Fine" will produce the
best JPEG image. "Email", "PC", "Basic" or whatever settings
you are allowed will provide small image files that are low quality.
Creating photo images in TIFF or RAW format is not necessary except
when you wish to provide very high print quality or large images
for framing.
Portrait Photography
And while we are on the subject of cameras, I would like to share
a tip regarding portrait photography. I always use a flash, even
outdoors (or especially outdoors) when I am shooting people with
a background of outdoor objects. The reason is simple. A flash
used in this setting provides a soft fill lighting for the faces
of your subjects, regardless of the outdoor lighting. This will
tend to highlight the facial area of your subjects. Too often
I see outdoor portraits with over darken facials due to the automatic
setting of the cameras averaging the light of the full composition.
Transmitting Digital Images
Some photo software allow you to simply select a photo on your
harddrive and embedd the photo in your email. The problem with
this process is that the software assumes that you wish to just
send a small file image (electronic snapshot) of your photo and
proceeds to highly compress the image (small file size) for easy
transmission in the email.
The receipent of your email will thank you for such a small
email file, but will receive an image that will not be useful
for printing in this highly compressed, 'lossy' mode.
If you intend to have the image enhanced, enlarged or printed
then use your email client functionality to "attach" the image
file as a file to your email without allowing your photo software
to highly compress the image file.
- Bill Mueller, Class of '57
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