Cold Cathode Fluorescent Lamp vs. LED

[Richard E. Thiess]

I'm thinking of upgrading my scanner. All previous scanners were Cold
Cathode Fluorescent Lamp scanners (HP ScanJet IIp, IVp and 6300c [not sure
about the Nikon CoolScan III]). I've been looking at a couple of scanners.
The LiDE 80 and the CanoScan 8400F; their street price is only about $20
apart. One is an LED, the other is a Cold Cathode Fluorescent Lamp. For
photo, slide and negative scanning; what are the pros and cons of each.
Small words of few syllables please, I'm the village idiot.

TIA,
Richard

 

[SteveB]

I'm no expert either, but I've read a lot of reviews, mostly in UK magazines
rather than the internet. The LED ones never seem to win any comparison
tests outright in these reviews, but I know they have devotees when it comes
to using scanner based colour profiling as they are less susceptible to
certain printed surfaces reflecting fluorescent light unpredictably, which
can give inaccuracies in apparent colour. I believe the effect is called
meteramism. LED white light is a more like a natural light basically.

 

[degrub]

Do a search on the archives of this newsgroup for Kennedy and Nikon and
LED and you should find a detailed technical discussion. My take is that
the LED source never ages for practical purposes, no warmup time, and
may present some difficulties with Kodachrome (that's why there is a
special setting on NikonScan), but otherwise IMHO a better light source
for scanning at the non-comercial level.

Frank

I'm no expert either, but I've read a lot of reviews, mostly in UK magazines
rather than the internet. The LED ones never seem to win any comparison
tests outright in these reviews, but I know they have devotees when it comes
to using scanner based colour profiling as they are less susceptible to
certain printed surfaces reflecting fluorescent light unpredictably, which
can give inaccuracies in apparent colour. I believe the effect is called
meteramism. LED white light is a more like a natural light basically.

I'm thinking of upgrading my scanner. All previous scanners were Cold
Cathode Fluorescent Lamp scanners (HP ScanJet IIp, IVp and 6300c [not sure
about the Nikon CoolScan III]). I've been looking at a couple of
scanners. The LiDE 80 and the CanoScan 8400F; their street price is only
about $20 apart. One is an LED, the other is a Cold Cathode Fluorescent
Lamp. For photo, slide and negative scanning; what are the pros and cons
of each. Small words of few syllables please, I'm the village idiot.

TIA,
Richard

 

[Wayne Fulton]

I'm thinking of upgrading my scanner. All previous scanners were Cold
Cathode Fluorescent Lamp scanners (HP ScanJet IIp, IVp and 6300c [not sure
about the Nikon CoolScan III]). I've been looking at a couple of scanners.
The LiDE 80 and the CanoScan 8400F; their street price is only about $20
apart. One is an LED, the other is a Cold Cathode Fluorescent Lamp. For
photo, slide and negative scanning; what are the pros and cons of each.
Small words of few syllables please, I'm the village idiot.

There is much more difference than the light source. The light source is
more just the result of the differences.

The 8400F is a "conventional" scanner, using CCD sensor, and a system of
florescent lamp and mirrors and a lens to focus the bed image onto the CCD
sensor. This system is relatively large and bulky (5 inches thick instead
of 1.5 inches) and is powered by AC from the wall power socket. This is
normal, and how it has always been done.

The LiDE scanner is a "compact" model using CIS sensor. No lamp, no mirrors,
no lens, thin because there is relatively little inside. Instead the full
width CIS sensor (Contact Image Sensor, as "in contact") is simply located up
extremely near the item being scanned. LED illumination is used because it
can be built into the same sensor chip, so that the zero spacing gap can
work. Because there is no lens, and no focused image, there is essentially
zero depth of field in CIS, so if source object is not touching the glass,
then the image will be very unsharp. This system is small and compact. Fax
machines use similar CIS chips.

If for portable use, this CIS model is good because it is powered from the
USB port (no power cord, uses the laptop battery). But if absolute image
quality is the goal, I'd bet on the CCD model (I have not used either of
these models).

 

[Dennis Herrick]

I need to scan LOTS of music to put it into a MusicPad
(http://www.freehandsystems.com). I have a Canon LIDE 30 which has been
doing good work in the past. For this project (started last week) I haven't
been able to get good enough quality. The suggested scan resolution is 75
dpi. The problem is the staff lines in the music -- they're very fine. My
scans have been giving me staff lines of varying thickness making it hard to
read.

I've tried scanning from 72 to 1200 ( and reducing in Photoshop) but still
haven't been getting much of an inprovement.

In a different thread, someone said:

If for portable use, this CIS model is good because it is powered from the
USB port (no power cord, uses the laptop battery). But if absolute image
quality is the goal, I'd bet on the CCD model (I have not used either of
these models).

I have some older HP scanners I could locate and try.... because this is all
B&W work, color quality is not significant at all. For this reason, I don't
think I need a new fancy scanner that can do great photographs.

I hadn't realized there were CIS and CCD scanners....

what should I be looking for to get the best grayscale of fine lines like
music?

 

[Dennis Herrick]

(e-mail address removed)
says...
If for portable use, this CIS model is good because it is powered from the
USB port (no power cord, uses the laptop battery). But if absolute image
quality is the goal, I'd bet on the CCD model (I have not used either of
these models).

I started a new thread on Scanning Music, but I need to scan lots of music
and was wondering of one of my older CCD scanners might do a better job of
the fine lines like the music staff lines (I've been using a Canon LIDE
30....)

 

[Dennis Herrick]

Sorry this got posted here!! I meant to start a new thread and I guess I
pressed the reply instead of new!!! Sorry...