Curve3 VS. Spot On! - Discrepancy

[Asures]

Does anyone use Curve2 or Curve3 and use Spot On to verify a calibration once completing a G7 run?

Does anyone else get radically different between the two results as far as the Delta E readings?

Just curious.

 

[Deleted member 16349]

Does anyone use Curve2 or Curve3 and use Spot On to verify a calibration once completing a G7 run?

Does anyone else get radically different between the two results as far as the Delta E readings?

Just curious.

What is the discrepancy? G7 only calibrates the gray line of the device and not the colour space. Are you saying that Spot On has a discrepancy with grays when compared to G7 grays? Curious.

 

[Asures]

Precisely!

On Spot On, the Delta E is 4.0 for CMY (Gray).

On Curve3, I get a Delta E of 8.0 for CMY (Gray).

Looking back at it, I should have taken the sheet and measured the L*a*b* values within the P2P area with a handheld to verify the 3/C area.

The L*a*b* values for CMY on Curve3 are reading L*21.21 a*-7.52 b*1.76 and Spot On is reading L*24.2 a*-3.6 b*-1.2...This is the same CGATS file imported into both programs. I can send you the CGATS file but this threw me for a loupe. No one can really give me defined answer as to why the radical difference between how the two programs can differ that much, other than get into a pissing contest about who has the better program (from both manufacturers).

Visually, the pictures appear to be close to the targeted proof.

 

[chromix]

On Spot On, the Delta E is 4.0 for CMY (Gray).

On Curve3, I get a Delta E of 8.0 for CMY (Gray).

Looking back at it, I should have taken the sheet and measured the L*a*b* values within the P2P area with a handheld to verify the 3/C area.

The L*a*b* values for CMY on Curve3 are reading L*21.21 a*-7.52 b*1.76 and Spot On is reading L*24.2 a*-3.6 b*-1.2...This is the same CGATS file imported into both programs. I can send you the CGATS file but this threw me for a loupe. No one can really give me defined answer as to why the radical difference between how the two programs can differ that much, other than get into a pissing contest about who has the better program (from both manufacturers).

I wasn't aware that we were invited to pee ;-)

If you send us the CGATS file then we're happy to take a look at it to see what Curve might be doing and if the dE values are calculated correctly.

regards,

Steve

 

[Asures]

I wasn't aware that we were invited to pee ;-)

If you send us the CGATS file then we're happy to take a look at it to see what Curve might be doing and if the dE values are calculated correctly.

regards,

Steve

Steve- can you send me your e-mail address? Or mine is [email protected].

Thanks.

 

[chromix]

(responded offline)

 

[chromix]

It turns out both packages are correct... or at least that's one way of looking at it:

There are two CMY patches on the P2P25x target (patches #1 and 125)

Both packages appear to be calculating the Lab values correctly for the two patches.

The difference is that Curve3 is showing the value for the 1st CMY patch and Spot On is showing the arithmetic mean for the two patches.

To get a third, also correct answer, turn on smoothing in Curve3 and you'll get a different interpretation of the CMY value.

In truth we had planned on Curve3 averaging duplicate patches and it apparently didn't get into this release. I'll make sure that gets changed in the next release.

I hope that helps.

regards,

Steve