Homebrew PCBs

Phil,

Thanks for the data and update.

I started to make  a set of similar measurements with different materials,
inks, ink colors, and printers but with all the measurements I ran out of
time to present it.  Someday hopefully.  (Work is interfering with my
hobbies again)

Bertho

 

From: Philip Pemberton   Sent: Monday, March 19, 2012 20:56



Well, I'm sick of playing with LaserStar, so I figured I'd do a little
experiment.

I took a piece of LaserStar film I'd printed on my Kyocera FS-C5200dn,
and measured the HD and LD (maximum and minimum density, respectively)
using an X-Rite 890 photographic densitometer.

I then repeated the test with a sheet of JetStar Premium I printed on a
Canon iP4600 (this was a "scrap" sheet; I accidentally printed the
artwork with mirroring enabled).

Here are the results:

JetStar-P -- Dmin=0.07, Dmax=1.82, HD-LD(avg_all)=1.58, HD-LD(B)=1.75
LaserStar -- Dmin=0.20, Dmax=1.19, HD-LD(avg_all)=1.23, HD-LD(B)=0.99
-- Dmin=0.20, Dmax=1.11, HD-LD(avg_all)=1.14, HD-LD(B)=0.91

Dmin = minimum log-density (LD / film base / "base fog" / "stain")
Dmax = maximum log-density (HD)
HD-LD(avg_all) = density ratio averaged across R/G/B channels
HD-LD(B) = density ratio, blue channel only

The first LaserStar reading is the "best case" figure (highest Dmax,
lowest Dmin). The second is the "worst case" figure (lowest Dmax,
highest Dmin). Dmin remained static (as you would expect), but Dmax was
all over the place for LaserStar.

JetStar returned a consistent Dmax, so there isn't a best/worst case
Dmax for it.

To summarise, we have:

* A 2:1 improvement in base fog -- JetStar lets more light through at
the blue end of the spectrum. This helps to improve the contrast ratio
slightly (and probably shortens exposure times).

* A 1.64:1 improvement in maximum density at the blue end of the
spectrum -- the ink from the inkjet is far more opaque than the toner at
these wavelengths.

* A 1.7:1 improvement in contrast ratio (HD-LD) on the blue end of the
spectrum, not taking the patchiness of laser toner into account.

* Better consistency on the inkjet -- the densitometer detected only
two density regions on the JetStar film; on the LaserStar film it
detected six!

Given these results, I'm not surprised that JetStar works a lot better
(certainly given this combination of equipment).

Does anyone have any comments?

Thanks,
-- 
Phil.





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