HowTo? Print half of A3+ sheet with ACPU for profiling with std iSis?

[l_d_allan]

I'd like to make a series of profiles for my Canon Pro-9000-2 that can handle up to A3+ (13x19"). I've got 3 types of Canon A3+ and also Costco Kirkland.

• The maximum width for the X-Rite Standard i1iSis (non-XL) is just over 8.5" letter size.
• My thinking is to cut the 13x19" into two narrow halves of 6.5" x 19"
• However, I haven't been able to figure out a way to get a "Custom Paper Size" to work with ACPU. It's maximum size is Letter, and no provision for anything custom.
• I've experimented with the Canon print driver to define a custom paper size of 6.5"x19". It seems to almost work, except that ACPU seems to ignore that custom size. The bottom is truncated, so the target is useless. Drat.
• I suppose I could carefully cut the 13x19" to make a single 8.5x11" sheet target, but that seems wasteful and non-optimal.
• Or ... I could hope that a profile made for the exact same paper except letter size instead of 13x19" would be satisfactory. Lame?
• For example, I have both Costco Kirkland letter size glossy and Costco Kirkland A3+ glossy.
• Or use CS4 with No-Color-Management, but my experience is that CS4 on a PC doesn't really have as much CM turned off as ACPU.
• I base that on seeing > 1.0 De2k difference between a ACPU-printed target and a CS4-printed target, when using MeatureTool's Compare utility.

[Rhossydd]

I could hope that a profile made for the exact same paper except letter size instead of 13x19" would be satisfactory. Lame?

If the paper is the same type it doesn't matter what size the sheet/roll is.

• Or use CS4 with No-Color-Management, but my experience is that CS4 on a PC doesn't really have as much CM turned off as ACPU.
• I base that on seeing > 1.0 De2k difference between a ACPU-printed target and a CS4-printed target, when using MeatureTool's Compare utility.

How have you drawn that conclusion ?
What sort of figure are you seeing with print variability, measurement repeatability and what tests did you do to establish print stability prior to measurement ?

[l_d_allan]

If the paper is the same type it doesn't matter what size the sheet/roll is.

That hasn't been my experience. For example, the iSis measured profile for HP Everyday letter size 8.5x11" glossy gives mediocre results, for me, to use with 5x7" sheets. To me, that suggests that 5x7 HP Everyday Glossy is different from 8.5x11" HP Everyday Glossy.  Yes, certainly that could be lack of experience, care in "experimental design", and/or ability on my part. YMMV.

How have you drawn that conclusion ? (that CS4-based profiles vary and were inferior to profiles made from an ACPU print?)
What sort of figure are you seeing with print variability, measurement repeatability and what tests did you do to establish print stability prior to measurement ?

Good questions ... actually great questions. I have what I consider to be the equivalent of a minor in Statistics (MSIE), but that was almost 40 years ago. I am aware that there are quite a few "degrees of freedom" where variability can accumulate/multiple in the multiple steps to making a print from a profile.

I appreciate that an underlying premise of my OP may be flawed:
Me: A profile made from a letter size sheet of the same type may not be useful for A3+ paper.
Reality: ?

I also agree that my conclusions were not based on a statistically valid sample size, using careful enough SOP, and/or using an informed enough experimental design. My speculation is that we may both be from Missouri, the "Show Me" state (except I recall that you now live in GB?)

>>>> A little learning (knowledge?) is a dangerous thing ... A. Pope
>>>> So is a lot ... A. Einstein   :-)

This semi-dangerous, semi-learned, semi-newbie also recalls reading and asking some related questions on LuLa pertaining to ACPU vs CS4. The impression I got was that ACPU (on PC's?) was reasonably close to ACPU, but "close as in grenades" rather than "close as in De2k < 0.5".

But ... you can read all kinds of foolishness on the net, including my ramblings. YMMV.

However, I'd rather leave this thread intact for the original question (custom, over-size prints from ACPU), and address the underlying issue in a separate thread. OK?

[Rhossydd]

My speculation is that we may both be from Missouri, the "Show Me" state (except I recall that you now live in GB?)

Absolutely NOT, I'm English born, breed and resident.

the iSis measured profile for HP Everyday letter size 8.5x11" glossy gives mediocre results, for me, to use with 5x7" sheets. To me, that suggests that 5x7 HP Everyday Glossy is different from 8.5x11" HP Everyday Glossy.  Yes, certainly that could be lack of experience, care in "experimental design", and/or ability on my part.

Do you seriously think that HP (or any other manufacturer) would use different construction processes for different paper sizes of the same paper type ?
Have you ever come across any manufacturer offering different profiles for different page sizes of the same paper type ?

There will be differences in how images appear dependant on their size, but that's a different issue to the pure colour management of the printing system.

Why not do tests to check ? print out a chart at the same size on different paper sizes (cut down to size if you want to check larger sheets) then measure them and see if there are differences that can't be explained by the repeatability of your printer and measurement system.

but "close as in grenades" rather than "close as in De2k < 0.5"

First of all what De2K are you discussing about ? Average of all reading? best 10%? worst 10%?
So the issues you need to consider are:
How repeatable are the reading of the same chart ? read the same chart(s) often and at different times. Do you always get exactly the same reading ? I'll bet you don't.
Does a smaller patch size (as ACPU delivers on Windows) effect measurement accuracy ?
How consistent is your printer ? Print the same chart out several times, then read it, how much does that vary ?

Once you know the above, then measure the difference between CS4 output and ACPU output. Is it significant ?

I've done all this. First when ACPU was released with an i1Pro and again with a newly calibrated DTP-70.
The DTP-70 is more consistent than the i1Pro.
With the DTP-70 Average read accuracy on a standard 6mm patch is 0.44 De2k, that falls slightly with the smaller  5.76mm patch from ACPU to 0.61 De2k.
Page to page consistency is around 0.58 De2k on my Epson Pro 3800
Average measured differences page to page between ACPU output and CS4 output is 1De2k, take away the read error and printer error and that's not a lot.

There are other sources of error that may influence results, maybe temperature of the spectro makes a difference and it's certainly very important to let the chart fully dry before reading (different papers and inks will behave in different ways).

Overall I'm happy that the output from ACPU is so close to CS4 it's not significant enough to worry about in real world use.

[l_d_allan]

Great questions. Hope I can address them to your satisfaction ... in another thread.

In the meantime, I'll work on formatting iSis measurements from my log-book and Excel work-sheets.  I've got series of overall average test-print and 50% gray patch De2ks for drying times from 1 hour to 10+ days, and various barometric pressures as the weather went from sunny (high bp) to snowing (low bp).

Attached are the two test prints I used with the iSis. Note they may look odd in a browser because they use the ProPhoto working space to be that much more challenging, especially for non-Canon Staples matte paper using OCP ink. Also some more test-prints, including the very challenging ...
http://berean.zenfolio.com/isis_test_prints/h5ddc53a2#h5ddc53a2
http://berean.zenfolio.com/isis_test_prints

Very quick set of drying-series overall De2k numbers for low cost Staples double-sided matte (often free with rebate) with a 2000+ patch profile using ArgyllCms:
05-1717 = 3.67
05-1917 = 3.66
3.66
3.65
3.65
3.64
3.64
3.63
3.61
3.61


And please accept my apology for the ignorance about your locale. I think of Missouri as part of the USA, whereas it may be less applicable to say England is part of GB. Or not?

[Rhossydd]

Great questions. Hope I can address them to your satisfaction ...

I don't need to know "the answers". I'm just trying to point out a few things you seem to be misunderstanding and trying to stop you wasting a lot of your time and resources.

You think different paper sizes need different profiles because you've got different results ?
It's more likely that you're inconsistent in your workflow. If that's the case everything else is going to be falling apart as a result.

[eronald]

I think doing an occasional sanity check on an iSis is not necessarily a bad thing, since I once had a transport-damaged sample which passed diagnostics and made horrible profiles because of a head misalignment issue.

Apart from that I don't think that you will manage to get much relevant difference from various print paths with no color management, although your target tiffs can be slightly different according to where they are generated, and whether they are printed through an 8 or 16 bit print path,  in particular I seem to remember that Colorport has some sort of truncation bug which might actually be measurable if you have a super-precise and repeatable instrument like the iSIS.

Edmund