Using an i1 as a press densitometer

[Lammy]

Is it possible to use the Xrite i1 as a press densitometer? I mean I know in theory it CAN read a color bar. But is anyone actually doing it as a practical application.

 

[meddington]

It's a bit more cumbersome than a typical handheld as it has to be tethered to a computer, but with the right software it can work great. For spot measurement for density, TVI and LAB, check out the spectral tools in BabelColor CT&A. SpotOn for strips.

 

[rich apollo]

Bodoni Systems can use an i1 at press side. They sell a "ruler" to allow for measurement of long colorbars (40") and their pressSIGN software gives ink key adjustments just like any other press side controls.

 

[alvarorb]

Yes, with Bodoni's pressSign you can get density readings, TVI curves, plus know if your press sheet falls inside a determined color space (GRACoL, SWOP, ETC). I'd use an i1 for smaller presses. Due to inconsistencies on hand speed, on a big press it's much more accurate to read with an automated spectral device (Intellitrax, SpectroJet, ETC).

For more information you can visit our webpage:

 

[meddington]

I guess I limited my answer to patch or control strip measurement, which wasn't really the question. In addition to PressSign as mentioned, there's MeasureColor for actual press colorbar measurements with an i1. Or if your press is supported, you could possibly close the loop with InkZone

 

[Johu]

I guess I limited my answer to patch or control strip measurement, which wasn't really the question. In addition to PressSign as mentioned, there's MeasureColor for actual press colorbar measurements with an i1. Or if your press is supported, you could possibly close the loop with InkZone

I have experience with both InkZone and Presssign and they both can use i1 as a measurement device as you syated. There is just one "problem" with i1 regarding density measurement. I1 does not have polarization filter so it basically measures "wrong" values (mostly too low). Lab values are okay, but density values not. You can see this by comparing i1 measurements to any densitometer, even spectral based as the i1 is. This is only a problem if you have density targets set by some other device than i1.

In Presssign this is not compensated, so what we do is not take the density readings as such, but only the suggestions on how much to go up or down or if it already is okay. Even if the values are not comparable the proportions are.

In InkZone these values are compensated by a factor as a result of extensive testing and comparison between i1 and a densitometer. Digital Information (InkZone sw vendor) has also custom built an automatic track for i1 which allows automatic readings directly from software.

So the answer to the original question is, yes you can use the i1 for pressreadings. But you need to know the limitations.

 

[gordo]

John wrote:

There is just one "problem" with i1 regarding density measurement. I1 does not have polarization filter so it basically measures "wrong" values (mostly too low)

It is not a question of wrong.

In Europe the standard is for the instrument to be set to Status E - polarized.
In N America the standard is for the instrument to be set to Status T - unpolarized.

Also, a spectrophotometer interpolates density values from spectral information which is different from how a densitometer measures density. That will certainly make the resulting values different.

Best gordo

 

[meddington]

Also, a spectrophotometer interpolates density values from spectral information which is different from how a densitometer measures density. That will certainly make the resulting values different.

Are there any manufacturers left that utilize traditional densitometric filters? Most densitometers are now "spectros" limited by licensing to report only densitimetric values, but often upgradable to full fledged spectros. That said, i found that the i1s I've used correlated quite well with older filter based densitometers.

 

[gordo]

Are there any manufacturers left that utilize traditional densitometric filters? Most densitometers are now "spectros" limited by licensing to report only densitimetric values, but often upgradable to full fledged spectros. That said, i found that the i1s I've used correlated quite well with older filter based densitometers.

Well, do most print shops have the latest in instruments? I doubt it. Also, spectros readings differ between brands and even within a brand. There's enough variation there to cause the resulting values to be different. So you may get a "good" correlation - or you may not.

In any case I didn't think anyone still used densitometry ;-)

best, gordo