Slide Scanning
Scanning slides is a great way to preserve them for future generations and offers many more unique and creative ways to display and use your images. Any slide can be converted and preserved in a digital format. If you have something unique, please call to see if we can convert it for you.
Each conversion includes...
- Individual review of each slide to balance color, contrast and sharpness including matching film profiles where possible
- Reducing dust and scratches where possible
- Batching in folders and named according to your convention
- Two levels of service depending on your budget and needs (full automatic or manual review and correction)
- Cropping out the casing if it is a mounted slide
- Turning the slides in the proper direction
- Choice of resolution
- Saved as DNG, TIFF or JPG files
- Stored on DVD, CD, external hard drive, or on a digital frame/memory card
- Optional keyword, XMP and custom image tagging for retrieval and archiving
For
our purposes resolution refers to the amount of digital information in
a digital file. We are expressing this information as "points per inch"
or PPI (DPI or dots per inch is usually used when referring to printer
resolution). The more "points" in a single inch the smoother the image
will appear ...up to a point. At some level more does not necessarily
mean better. More "points" generally means bigger files that are harder
to use and manipulate. More "points" can also bring increased digital
noise, which can generally be removed but still requires additional
work. Finally, more "points" does not necessarily make the image look
better. At some point the naked eye cannot easily discern a quality
difference by moving to a higher resolution.
The key is to figure out the optimum resolution needed based anticipated use of the files.
Example 1 - Printing on a home inkjet printer
To
print a nice print on an inkjet printer requires approximately 240 dots
per inch (DPI). For easier calculations we will increase that to 300
DPI. (Side note: You should experiment on your own printer with the
paper you use. Smaller resolution will use less ink. Go to the minimum
you feel yields an image that you like on the media you use.)
If
you want to print an 8 x 10 image you would need 2400 dots (8 x 300
DPI) of information by 3000 dots (10 x 300 DPI) of information.
If your starting image is a traditional 4 x 6 photo you would need to scan it at 600 PPI on your scanner.
2400 dots (needed to print) divided by 4 = 600 PPI
3000 dots (needed to print) divided by 6 = 500 PPI
Choose the higher resolution needed to be safe.
Example 2 - converting a slide for the same inkjet print
We
know that we still need approximately 2400 x 3000 dots to make an 8x10
print on an inkjet printer. So, to convert a 35 mm slide to a digital
file that will be reprinted as an 8x10 print we calculate the needed
resolution this way:
A slide measures approximately: 1 inch x 1 inch
2400 / 1 = 2400 PPI
3000 / 1 = 3000 PPI
In this example we would want to scan a slide at 3000 PPI to be able to print a quality 8x10 print.
Example 3 - large format printing
At
some point you may want to print a very large print. In this case you
would want to choose a high resolution on conversion and then would
have to rely on photo editing software to resample the image for large
prints. Different programs resample images in different ways. However,
the goal is the same in each instance. The software looks at the pixels
and extrapolates the information to add more resolution. Thus the goal
is for the software to create a smooth looking image at enlarged sizes.
Example 4 - for viewing on TV or Computer
In this case you do not need as much resolution compared to printing. Even the resolution on HDTV is only 1280 x 720.
A
1 x 1 35mm slide could be converted at 1500 PPI and still have plenty
of resolution to display beautifully on an HDTV. A standard television
is about half of that resolution. The question comes about the future.
How much resolution will TVs display in the future. As mentioned above
at some point the naked eye will not see a noticeable difference so it
is hard to tell how much more resolution will be needed.
Example 5 - cropping and zooming
One
thing to keep in mind is that after converting an image to a digital
format you may want to crop and then zoom in on a part of that image.
This would have the effect of having scanned in a smaller photo which
would require greater scan resolution to get to the same size as the
original. If you think you will be cropping and zooming your images,
add to the initial scan resolution to account for this.
File Formats
The most popular choices for file format are:
JPG (also written as JPEG): This
is a popular format because the file sizes are smaller (which makes
them easier to use and manipulate). It is also very compatible and able
to be opened by all kinds of software and operating systems. This is
the most popular choice. The downside is that to get these benefits,
the file data is compressed and some data is taken out. Some color
information will be lost and the ability to do post capture editing
will be more limited. Of course you can still do some editing on the
image. However, the amount and level of editing will be less compared
to some of the other format choices. For most uses this format is ideal
and is the most popular choice. Save the Image will provide 100%
quality / minimum compression files to give the highest level JPG
possible.
TIFF:
This is an uncompressed file format that retains full image
information. It is an excellent format for color reproduction and for
reprinting images. The downside is that the files tend to be quite a
bit larger and require more processing power and space to manipulate,
store and edit.
DNG (Digital Negative):
This is a relatively new format developed by Adobe. It is intended to
be a universal format that has the advantages of a RAW file (a
digitally captured image that has minimal processing done to it and
allows for a wide range of editing and manipulation). This format tends
to take up more space and can be more difficult to manipulate (usually
only higher end photo editing software can handle these files).
So
why bother with a DNG file? It is the most image information available
and will allow for the greatest level of post capture processing and
editing. Versions of the data can be saved in various formats and with
various adjustments while preserving all of the original data captured
at the time of conversion.
The best of both worlds...
One
recommendation is that you can get both DNG + JPG at the same time.
This way you have the full information files but also a set of
workable, smaller sized files to use immediately.
|
