QTR-Quadtone RIP

Yes, a simple black/white/medium gray ceramic standard would be
nice...  Unfortunately, this little beastie is built for use by folks
with little knowledge in a production environment...  It only accepts
paper strips, and it's almost impossible to do spot readings with it.
 It auto-scans, measures density, and uses a few color filters to
approximate the Cyan, Magenta, and Yellow densities.  It's really only
good for linearization.

The calibration strip is just a sticker with a black and white pattern
on it, stuck onto a strip with a different pattern...  The
densitometer recognizes the pattern on the strip and knows a
calibration sticker will follow.  Then it reads the sticker.  I'm not
even sure that it measures the density/reflectance of anything other
than the unprinted parts of the autocalibration sticker.  

Bottom line, this densitometer is nearly useless for color profiling,
but works dandily for simple linearization.  

When the day comes that it says it needs calibration, I'll probably
need to buy the $50 sticker from X-Rite...  Unless I can find another
densitometer cheaper than that, or decide to go for an old
spectrophotometer, which can be used for color profiles.


DRK

DRK

--- In QuadtoneRIP@yahoogroups.com, Ernst Dinkla <E.Dinkla@...> wrote:
>
> davidkeasey wrote:
> 
> 
> > The information I am looking for is this:
> > 
> > 1.  How can one obtain an auto-calibration strip without having to pop
> > for the $50 that X-Rite wants for this little puppy?  Since I only
> > want results that are internally consistent (that is, I don't need to
> > match outputs between different devices, or to something done by
> > somebody else), the "certified media" provided by x-rite seems to be
> > overkill.  Is it possible to simply define your own calibration strip
> > (in a program like Corel Draw, for example) then print off a batch of
> > them?
> 
> With the printer you want to calibrate ?
> Shouldn't the horse not be at the other side of the carriage ?
>   If you know the data the patches should have (and keep for 
> several years) you could make trial and error prints and 
> measure them with a calibrated instrument that is twice as 
> good as the one you have. Or make a collage of the best 
> patches. But somewhere in universe you need an anchor point to 
> measure from.
> ====

==== Snip ===
> 
> Would it not be enough to have some black and white ceramic
> tiles ? You could ask a local printshop to measure them with
> their calibrated densitometer/spectrometer. If stepping wedges
> are needed then Kodak has several but I do not think that
> would be a cheaper way to get what you need. 50 dollar gets
> another color if you start to think of all the roundabouts you
> have to take.
> 
> If you need separation stepwedges after you have the 
> densitometer calibrated then you can make them with for 
> example ColorPort by X-rite. It's free on their site.
> 
> Ernst
> 
> 
> -- 
> 
>                     --
>            Ernst Dinkla
> 
> 
> www.pigment-print.com
> (         unvollendet         )
>