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Author Topic: ACPU FOR THE PC - Enlargement factor?  (Read 963 times)

Mick Sang

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ACPU FOR THE PC - Enlargement factor?
« on: January 31, 2021, 01:30:12 pm »

Hello,

Does anyone know the exact percentage of enlargement by which profiling charts must be printed from a Windows PC using ACPU so that they can be accurately read by an i1Isis-2? I've searched the topic and it has been discussed. But, the discussions were old and inconclusive. I wonder if a solution has been found.

If there is no exact answer for ACPU, how do PC users go about printing charts accurately for an i1Isis in order to make custom profiles?

Thanks in advance,
Mick
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digitaldog

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Re: ACPU FOR THE PC - Enlargement factor?
« Reply #1 on: January 31, 2021, 02:02:32 pm »

Windows, no idea. On Mac, I can get away with 4-5% with no issue, but I NEVER build custom targets at the minimum size i1P allows, not enough fudge factor so to speak. Ideally no scaling of course but you can get away with a tad, at least on Mac.
I placed a line on my targets of a specific measurement. Then my customers can ensure it's not scaling by measuring the line after output.
ACPU is apparently more picky on Windows than Mac but again, I can't specifically comment on that.
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Rhossydd

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Re: ACPU FOR THE PC - Enlargement factor?
« Reply #2 on: February 01, 2021, 06:16:46 am »

The original Isis has no problems reading the slightly oversized charts from ACPU printed on Windows machines.

Have you actually tried measuring a chart ?
If it doesn't work, just get out a ruler and measure the chart and put the numbers into the software.
« Last Edit: February 01, 2021, 07:07:09 am by Rhossydd »
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JRSmit

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Re: ACPU FOR THE PC - Enlargement factor?
« Reply #3 on: February 01, 2021, 06:59:40 am »

I use the drycreek utility on my Windows platform. It does not scale like acpu. Check drycreek Photo site for this utility.
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Mick Sang

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Re: ACPU FOR THE PC - Enlargement factor?
« Reply #4 on: February 01, 2021, 10:38:48 am »

Thank you to all.

Yes, I tried reading charts from a PC about 7 years ago on an i1Isis-1 and they failed. But, I seem to recall  that they printed at roughly 95 - 96% of the actual size. This is the first time I've read that they were OVER-sized. One way to the other, the charts will be printed by a person who is far enough away that I'd rather they be correct. If I were printing them, I certainly would simply measure and adjust. But, in this case, I can't do that.

I will try the Dry Creek Photo utility.

Thanks again to all,

Mick
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Rhossydd

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Re: ACPU FOR THE PC - Enlargement factor?
« Reply #5 on: February 01, 2021, 10:50:52 am »

I seem to recall  that they printed at roughly 95 - 96% of the actual size. This is the first time I've read that they were OVER-sized.
Yes, my mistake. It's all so long ago and such a non-issue the details were forgotten.
I've been reading ACPU charts in the Isis without problems for years.

Not an issue with the handheld spectros either. The only problem I've encountered was reading them with a DTP-70 which needed modified reference files, but nothing too difficult.
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JRSmit

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Re: ACPU FOR THE PC - Enlargement factor?
« Reply #6 on: February 01, 2021, 11:26:13 am »

Also the patch size should not be too small , advice the aperture +4mm .
For me the result is no measurement errors of any kind anymore.
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digitaldog

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Re: ACPU FOR THE PC - Enlargement factor?
« Reply #7 on: February 01, 2021, 12:39:57 pm »

Also the patch size should not be too small , advice the aperture +4mm .
For me the result is no measurement errors of any kind anymore.
+1, just don't expect X-rite's minimum values for creation to work with ACPU, make the patches bigger. I have both Mac and PC users printing my targets and unless they setup the print driver to scale by mistake, I don't have any issues with ACPU. 
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Mick Sang

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Re: ACPU FOR THE PC - Enlargement factor?
« Reply #8 on: February 03, 2021, 11:19:27 pm »

Quote
I've been reading ACPU charts in the Isis without problems for years.
Quote
I have both Mac and PC users printing my targets and unless they setup the print driver to scale by mistake, I don't have any issues with ACPU.

Ok, so I wonder if the issue is related to old operating systems on the PC? The charts which I printed from a PC were done many years ago on a Windows XP machine. The patches were reduced as I mentioned. But, since you and Mr. Rodney have not encountered issues, I presume your PC is running the latest Windows OS whatever that is?

Thanks for your help,
Mick
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Rhossydd

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Re: ACPU FOR THE PC - Enlargement factor?
« Reply #9 on: February 04, 2021, 04:31:07 am »

Ok, so I wonder if the issue is related to old operating systems on the PC?
No, they work regardless of which platform, Mac/PC and OS versions won't make much difference.
Possibly look at whether the charts are cut to size correctly, possibly which driver and software version is being used.

I'm currently on Win 10, it's all worked well on Win 7 before that and client's charts can come from almost any system.
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Mick Sang

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Re: ACPU FOR THE PC - Enlargement factor?
« Reply #10 on: February 05, 2021, 01:05:04 pm »

Quote
I'm currently on Win 10, it's all worked well on Win 7 before that and client's charts can come from almost any system.

Well, all I can say is that at the time when we printed charts which we had printed regularly from the MAC with total success, this time when printed from the PC version of ACPU on 2 different Windows XP machines the prints were reduced to roughly 96% despite the request for 100%. I haven't printed charts from a PC since then and wondered if the issue persisted over the years. Obviously, we were not alone as I have heard and read about the issue many times over the years. Who know? In any case, I'm very glad to see that it appears not to be an issue any longer.

Thanks to all again,

Mick
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Mick Sang

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Re: ACPU FOR THE PC - Enlargement factor?
« Reply #11 on: February 05, 2021, 01:06:51 pm »

Quote
I placed a line on my targets of a specific measurement.

Good idea.

Mick
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digitaldog

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Re: ACPU FOR THE PC - Enlargement factor?
« Reply #12 on: February 05, 2021, 01:07:28 pm »

But, since you and Mr. Rodney have not encountered issues, I presume your PC is running the latest Windows OS whatever that is?
I have no idea (or need to know) anything about my clients systems. What I can tell you, when my clients print using ACPU as instructed, I don't get any errors from my iSis.
I too placed a line with correct measurements on my targets.
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Doug Gray

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Re: ACPU FOR THE PC - Enlargement factor?
« Reply #13 on: February 07, 2021, 12:39:59 am »

Hello,

Does anyone know the exact percentage of enlargement by which profiling charts must be printed from a Windows PC using ACPU so that they can be accurately read by an i1Isis-2? I've searched the topic and it has been discussed. But, the discussions were old and inconclusive. I wonder if a solution has been found.

If there is no exact answer for ACPU, how do PC users go about printing charts accurately for an i1Isis in order to make custom profiles?

Thanks in advance,
Mick

On all Windows versions I've used 2000, 8, and 10, ACPU reduces images by 3.5% so I decrease the DPI in Photoshop by 3.5% (with resample off). Then ACPU prints accurate sized images. I use standard 6mm patches on the i1isis xl and print either direct from i1Profiler or Photoshop with "null transform" to disable color management. Both are accurate.
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Alan Goldhammer

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Re: ACPU FOR THE PC - Enlargement factor?
« Reply #14 on: February 13, 2021, 09:18:58 am »

I use the drycreek utility on my Windows platform. It does not scale like acpu. Check drycreek Photo site for this utility.
This is what I use as well.  The ACPU printing bug with Windows is well known and still persists with Win10.  A number of us complained to Adobe some years ago but as this was just produced by Adobe as a convenience they saw no need to address it.  The shrinkage percent is as described (my measurements were the same as what Doug notes) but they did not make a difference when I manually read charts with an i1 Pro.
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digitaldog

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Re: ACPU FOR THE PC - Enlargement factor?
« Reply #15 on: February 13, 2021, 09:27:56 am »

This is what I use as well.  The ACPU printing bug with Windows is well known and still persists with Win10.  A number of us complained to Adobe some years ago but as this was just produced by Adobe as a convenience they saw no need to address it.  The shrinkage percent is as described (my measurements were the same as what Doug notes) but they did not make a difference when I manually read charts with an i1 Pro.
I will repeat again: with well constructed targets, my clients have no issues with ACPU on any OS and the bug, which does exit, should only show on an auto an Spectro like an iSis. Do NOT use minimum patch sizes out of X-rite software and the battle is mostly over.
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