This column will attempt
to provide solutions to problems readers may have in getting into and
using digital cameras, scanning, and using digital photographic images
with a computer and different kinds of software. All questions sent
to me will be answered with the most appropriate information I can access
and provide. However, not all questions and answers will appear in the
column. Readers can send questions to me addressed to Shutterbug magazine,
through the Shutterbug web site, directly via e-mail to: Fotografx@csi.com
or by US Mail to: PO Box 2830, Lompoc, CA 93438.
Q. I subscribe to
Shutterbug and have found your Digital Q&A section to be very helpful.
I am a bit confused on one point and was hoping you could help clear
things up for me.
I shoot primarily nature photos on transparency film. I have a 35mm
system as well as a Mamiya 6 6x6 system. I have been having my slides
scanned onto a Master PhotoCD at my pro lab and bringing them into Photoshop
5 on my Mac PowerPC. I have been adjusting the images in Photoshop (with
the help of Extensis Intellihance). If I want to print them I can output
the file to my desktop Epson Photo EX or take the file to the pro lab
where they can print it using a Lightjet 5000.
I have been considering getting a slide scanner to use at home and it
would seem that the Nikon 2000 has the best software. What puzzles me
is the print size that you say you can get from your 35mm scans. I have
read that to get "photo quality" digital output you really
need to provide the printer with around 300ppi of data. I have also
read that you can get away with sending around 240ppi of data to the
Epson Photo EX without any significant degradation of image quality.
My lab tells me that I should provide them with 305ppi for files destined
for their Lightjet 5000 printer. Given these parameters how is it possible
to get "excellent 11x14 prints" with the image file size
generated by the Nikon 2000 scanner or PhotoCD? What resolution do you
set your files at when you send them to the Epson printer? It would
seem to me that you must use files at a lower ppi or somehow "pump
up" the file size using an interpolation program. Which do you
use? I know that there are interpolation plug-ins available for Photoshop,
do you use one of these? What happens to image quality when you do this?
I have the same question about the Nikon CoolPix 950 camera. Nikon claims
that you can get a photo quality 11x14 print from their largest TIFF
file size, but I don't see how this is possible.
Ann Arbor, MI
Printer resolution refers to the number of dots the printer lays down
per inch and is unconnected entirely to how many pixels per inch are
in the image being printed. Standards are not fixed as to what a printer
needs in image resolution, and the high 1440dpi resolution of your Epson
EX is no indication of the image ppi resolution required to make a good
quality print. However to see the most detail a particular printer is
able to reproduce there is an optimum image resolution, which with your
Epson, is 240ppi or higher (you are right). That specification is for
an image of about 8x10" printed on letter size paper. In practical
terms with most images you can go as low as 180ppi in image resolution
and still obtain quite good quality prints with little if any loss of
image detail or sharpness.
Now consider if you increase the print size you also increase the normal
viewing distance of a print. By doing so you reduce the necessity for
defining detail as sharply because human vision cannot normally perceive
that fine a resolution of image information at the greater distance.
Thus the image ppi count can be lowered somewhat as print size is increased.
For an 11x14 I would say 150-180ppi should yield acceptable image sharpness
and detail definition for viewing at a normal distance.
So, now lets take a 35mm slide and scan it with the Nikon Super CoolScan
2000 at its maximum optical resolution of 2720. If you are scanning
the full frame you should get an image that's roughly 2700x4000
pixels. Now if we are going to print it with an Epson Stylus Photo EX
on 11" wide paper, then we size the image to 10.5" wide
which will produce a .25" border on the sides of the print. When
this image is so sized I think you will find the resolution is 257ppi.
Well over the optimum level for the smaller, letter size print for which
the 240ppi figure you referred to was given. In fact, I have taken image
files scanned with the Nikon LS-2000 up to 13x19", and they look
just as good if not better than I would expect of an "R"
print made by a lab directly from the slide. Now, being that you referred
to the Nikon LS-2000 and LaserSoft SilverFast 4 software driving it,
please consider this software supports interpolation beyond the optical
limit of 2720 to almost twice that, and over 5000ppi. It would be quite
easy to output just about any practical print size up to and including
16x24 for printing by a service bureau that demands 305dpi.
Q. I have enjoyed
reading and appreciate your thoughtful column in Shutterbug. The following
question stumps me, but I hope it will not stump you.
I want to buy a digicam for under about $750 that has a wide angle lens
which is the 35mm equivalent of 18-22mm so I can take pictures of sometimes
small rooms inside cabins, etc., for The Colorado Directory of Cabins,
Lodges, Country B&Bs, Campgrounds, and Fun Things To Do we've
been publishing for 20 years and also for use on our web site at: www.col
So far the only thing I've found is the Kodak DC200 which will
accept a 0.5 Tiffen add-on lens. Do you recommend it? I am not interested
in stitching photos together to create a wider angle.
As our directory is printed on newsprint with a resolution no finer
than 100dpi and as photos on the web are even courser, we don't
need high resolution, although we may wish to crop occasionally. Ideally,
we would like a 35mm equivalent of 20-80mm.
As we are a micro publisher and as we are on the road as of June 1 to
begin our annual summer sales trips, we need to buy ASAP.
Can you help, please? Thank you.
I can appreciate the reasons for your need in a digital camera. And,
you are probably not alone considering the real estate industry uses
digital cameras so extensively. I'm sure the manufacturers would
like to meet this demand. However, if you consider the very small physical
dimensions of the CCD chips used, 1/3 to 1/2", and that the modest
wide angle lenses for these cameras currently available are slightly
under 10mm in focal length, anything shorter would involve some severe
physical production challenges. The one most limiting factor would likely
be making a shutter/aperture for a lens of any shorter focal length.
It's not impossible but that kind of very precise micro manufacturing
is also very expensive, and without extreme micro precision, the aperture
accuracy and the optical imaging quality due to halation would suffer.
The only digital solutions that would be satisfactory unfortunately
are several times your budget in cost. The use of a Tiffen filter adapter
and an auxiliary lens I have not tried, but would have grave doubts
it would be a satisfactory solution in terms of image quality and usability
with anything other than an SLR like the Olympus D-620L. Personally,
I still maintain a couple of Canon EOS systems with some short lenses
and shoot color negative film. I proof it once processed, one whole
roll at a time, with a flat-bed scanner with a TPU, and then use a slide
scanner to scan the frames I want to reproduce. It's a very effective
hybrid workflow, and minimizes processing costs as well as labor.
Q. Recently on a
holiday I stumbled across a back issue of Shutterbug and was interested
to read about the development of digital adapters which effectively
turn basic 35mm SLRs into digitally enabled cameras. The article was
in the December '98 issue and was contained within a feature on
the photokina '98 exhibition.
Could you possibly tell me whether the adapters are available yet to
"Joe Public," and if so where I could expect to purchase
one here in the UK as well as what I should expect to pay? If they are
as yet not available on the retail market, maybe you could point me
in the appropriate direction for investigating things further such as
recommended literature, etc., on such devices. Kind regards.
Yours is a wish held by many, even myself, but unfortunately I know
better. First you have to consider essentially what you are looking
for is an inexpensive Kodak DCS 560, or at least the back and digital
parts. That camera model costs as much as a new sports car, and personally
I'd rather have the car. You can be assured, that if it were possible
to produce a back for any of the major 35mm SLRs which would, 1) provide
normal or close to normal lens functioning (angle of view), 2) have
a chip resolution comparable to a scanned 35mm image, and 3) cost as
little as you are hinting Joe Public could afford--Canon, Nikon, Olympus,
Minolta, et al., would be the ones offering this kind of digital back
for 35 SLRs at the next Photo Marketing Convention. The why of this
is quite simple. CCD area array sensor chips cost far more to develop
and involve a far larger manufacturing investment than any camera. In
other words, it is less expensive to design and build a camera to fit
the chips available than try to resolve the problem the other way around.
Q. I found your recent
columns in relation to large volume digital slide storage and scanners
very useful. My father recently died and had a huge number of slides
dating back to the 1940s. I have purchased the Nikon LS2000 scanner
and a CD writer drive. The SilverFast software will be ordered today.
My problem is that some of my siblings are not computer literate and
just giving them a CD will be of little use. I will need, for these
individuals, to get prints. I have an HP PhotoSmart printer and have
seen the results of the Epson 700 and have wished for a good bit more
in print quality from both of the printers. I wasn't thrilled
with an HP 895 or upper end Epson. I have been told that until you reach
the several thousand dollar range there is no better alternative to
these two scanners. I have seen some digital prints that I like the
quality of, just not these models. I hate paying over $10 per print
for digital images locally and would like to have some control over
the printing. I would appreciate any thoughts you might have on this
From your remarks I am somewhat of the impression the prints you find
inferior are not as good as the printers can produce, not because of
the printer but due to characteristics of the image file reproduced.
I have been able to make prints with the Epson Stylus Photo 700 and
EX which are definitely on par with typical photo lab "wet"
color negative prints. And, in terms of just the reproduction of tonality
and color, there is not a significant difference between the best ink
jet prints and much more expensive dye sublimation prints. Of course
there are other reasons to favor dye sublimation, like the speed of
printing and the durability of the print.
But, regardless of what specific printer or what type, to obtain an
optimum print result you must be reproducing from at least a close to
perfect color corrected image file and be using a system that has Colorsync
(Mac) or ICM 2.0 (Windows 98) color management fully implemented and
functioning correctly. This is essentially the digital equivalent of
the fact that even the best enlarger and print processor does not ensure
good "wet" color prints, it also takes skill on the part
of the operator as well as a good negative from which to print. For
what it's worth, the current Epson Stylus Photo printers are being
replaced with new models which produce even better results. The Epson
Stylus Photo 750 is now just being shipped to some stores.
Q. What is the maximum
usable resolution and color bit depth of films, like Ektachrome and
theory there is no maximum, but in practice of course there is. And,
there is really no direct correlation between how most of us think about
analog information in terms of resolution and the digital counterparts.
In real terms the answers to these questions are involved in what your
goals are in digitizing film images, and of that what you can afford.
High-end scanners today are capable of reading and recording just about
all of the useful information in a film image, and then some. Extremely
high (up to 8000dpi optical) scan resolution is used not so much to
extract more image information from a film photograph, but to record
it with sufficient pixels to make a reproduction of a particular large
size. So to one extent in determining scan resolution the output size
is the determinate factor. From my experience a resolution much over
3200dpi does not yield increasing amounts of image information, and
the 2700-2800 maximum resolution of consumer desktop 35mm scanners extract
most of the image information from a 35mm Ektachrome image.
Bit depth of better film scanners is usually 12 per RGB channel, and
in higher-end professional scanners 14 bit per RGB channel is common.
Considering the computer only supports 8 bits per RGB channel, current
scan depth is quite sufficient to be able to read even relatively narrow
density range images and map them to fully utilize the gamut of the
computer colorspace. In other words, better scanners are quite capable,
if they have effective software support, to map all of the information
in a film image which is possible to reproduce with the computer's
24-bit RGB colorspace.