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Author Topic: A new Printer/Media Resolution test target  (Read 27987 times)

Bart_van_der_Wolf

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A new Printer/Media Resolution test target
« on: April 27, 2015, 06:30:57 am »

Hi folks,

Due to the recurring questions about print resolution (limited by printer and or medium), I sat down and created a super (too ?) critical resolution test target which should reveal any shortcomings in the output process. It's merciless, and currently in the testing phase of design, but I wanted to share it already, in case someone can use it in it's current stage for optimizing their output workflow.

There are two versions available for download and personal use, mainly intended for testing inkjet printers:
Test target for 600 PPI printers (e.g. Canon / HP)
Test target for 720 PPI printers (e.g. Epson)

If printed at the indicated PPI resolution, the final target output should have a square size of 130 millimetres (5.11811... inches).

There is a number of patterns on the target that will allow to quite accurately measure the actual resolution that the printer/ink/media combination can produce. That's also useful if one is searching for a medium that has relatively low ink diffusion characteristics. Some media are sharper than others, on the same printer.

There is a central 'star' shaped pattern that should be resolved all the way down to the green concentric circle near its center. There is also a red circle at half the maximum resolution, which should help to estimate intermediate resolution in any orientation (not only horizontal or vertical). Inside the green circle is a pattern of sinusoidal 'rings' which also get higher in resolution as they approach the green circle, and they are very sensitive to ink diffusion which tends to make the rings seemingly darker as the detail gets smaller. Differences in print-head alignment and paper feed accuracy should show by the appearance of aliasing patterns and differing resolution between horizontal and vertical resolution limits.

At the bottom edge of the target is a greyscale. Actually it's a combination of 5 greyscales that each use more steps to produce the full gradient. The top one is 32 steps, followed by 64 steps, 128 steps, 256 steps, and finally virtually continuous tone (16-bit/channel precision). There is no dithering in the gradients, so they should show discontinuities and non-gray profiling issues quite well.

On the left and top edge there are blocks of uniform resolution, each with 4 patches with horizontal, vertical and diagonal sinusoidal patterns of the indicated resolution, marked in cycles/mm (assumes correct print resolution, 600 PPI or 720 PPI, was used). In principle, these should print at equal (medium-grey) density regardless of the pattern orientation. But differences in print-head alignment and paper feed accuracy may cause density differences and/or aliasing patterns, especially on the higher resolution patches. Non-linearities in the match between output profile and media can also cause what appears to be aliasing patterns, but they are actually something else.

The top left-hand side patches are at the printer's maximum resolution, 1 pixel wide lines. That level of resolution is much higher than normally required for good print resolution. Good resolution is achieved at 5 cycles/mm, and excellent print resolution is achieved at 8 cycles/mm, when viewed at reading distance in good (not too dim, not too bright) light levels. The 'excess' resolution can be put to good use when using high quality output sharpening, and for subjects with very fine lines or sharp edges and high contrast.

At the right-hand edge of the target there is continuous sweep of diagonal sinusoidal patterns that should ideally look like a smooth increase of resolution without aliasing patterns or disruptions. They are also resolution marked in cycles/mm, and the range is chosen to be able and encode the sinusoids relatively accurately, and encompass all practically relevant levels of output resolution.

There are also two smaller pattern blocks of 1, 2, and 3 line wide gradients that allow to estimate if and how the highest resolutions will start to lose the ability to mix intermediate tones. They attempt to show the trade-off between resolution and color mixing of intermediate tones by the printer driver's dithering algorithms.

Finally there is a small patch of high and very low contrast lines, 1, 2 , and 3 pixels wide, at the top left corner of the grey square of the star background.

Make sure to first do a head alignment on the actual paper (thickness) that the target will be printed on. It will save you from disappointing results, which may still occur due to the overly critical nature of the target. The patterns on the target itself are virtually artifact free, so any irregularities that show up, must be caused by the output workflow (e.g. profiling), or printer driver settings or mechanical printer tolerances. The target itself is tagged as having an Adobe RGB colorspace, but one can always assign another colorspace to see if the profile conversions to the output medium have any adverse effects on resolution.

That's about it for the moment.

Cheers,
Bart
« Last Edit: January 28, 2017, 06:26:16 am by BartvanderWolf »
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Mark D Segal

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Re: A new Printer/Media Resolution test target
« Reply #1 on: April 27, 2015, 08:56:10 am »

Hi Bart,

This comes in handy just at this moment for me, and I have downloaded it - many thanks for making it available.

I have one question for you - I have always been given to understand that the native output resolution the Epson printing process works with is 360ppi for all but the "Finest Detail" setting, which when selected changes the driver's "native resolution" to 720ppi, which setting is only recommended for vector graphics, not photographic prints. Hence the Epson professional printers are actually "360 printers" for most purposes. Is your target equally usable for 360 and 720? (This of course is not to be confused with the Print Quality settings - 720, 1440, 2880 in dpi).
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Bart_van_der_Wolf

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Re: A new Printer/Media Resolution test target
« Reply #2 on: April 27, 2015, 09:12:39 am »

Hi Bart,

This comes in handy just at this moment for me, and I have downloaded it - many thanks for making it available.

Hi Mark,

You're welcome, and good timing then...

Quote
I have one question for you - I have always been given to understand that the native output resolution the Epson printing process works with is 360ppi for all but the "Finest Detail" setting, which when selected changes the driver's "native resolution" to 720ppi, which setting is only recommended for vector graphics, not photographic prints.

There has been some confusion about that, but by selecting 'finest detail' option you do not hurt your images at all, even for normal (non-vector art) images. In fact, as also Jeff Schewe confirms, when your image detail is enough for the output size (i.e. > 360 PPI), it is better to upsample to 720 PPI than to throw away detail that you already have. This of course assumes that the image has not only enough pixels, but also enough intrinsic resolution in it.

Quote
Hence the Epson professional printers are actually "360 printers" for most purposes. Is your target equally usable for 360 and 720? (This of course is not to be confused with the Print Quality settings - 720, 1440, 2880 in dpi).

So for the above mentioned reason, I suggest to print it at 720 PPI with 'finest detail' selected. Of course you can also print it at the same output size (130mm) without the 'finest detail' option, and see what (detail) is lost (and automatic driver induced resampling artifacts gained). Alternatively you can print the target at 360 PPI at twice the size (260mm), and you should also be fine, without resampling artifacts, but at a lower resolution (and it obviously takes more ink and paper).

Cheers,
Bart
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Mark D Segal

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Re: A new Printer/Media Resolution test target
« Reply #3 on: April 27, 2015, 09:17:53 am »

Thanks for your quick response Bart. While I appreciate your technical insight into this matter, it has been a subject of considerable uncertainty with changing views over time, hence I shall do some further research on it - both hands-on and consultation. May not be the last word either, but perhaps useful. Your target will be helpful for this and pleased to know I can use it at 360 too. Thanks.
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Ernst Dinkla

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Re: A new Printer/Media Resolution test target
« Reply #4 on: April 27, 2015, 10:29:00 am »

Hi Mark,

You're welcome, and good timing then...


Cheers,
Bart

Well a week later than the last target collage that I made :-) Including a 600 PPI sinusoidal pattern that might have been your work too but I am not sure. Can be improved so I certainly will try your new target.

Met vriendelijke groet, Ernst

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Re: A new Printer/Media Resolution test target
« Reply #5 on: April 27, 2015, 10:35:15 am »

Add my thanks for this, too, Bart.

I have just downloaded it and expect to learn a good deal about just how my 3800 behaves with the various settings.

Eric M.
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MHMG

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Re: A new Printer/Media Resolution test target
« Reply #6 on: April 27, 2015, 10:48:08 am »

Bart, Thanks! As with the other Mark, this is timely for me as well. I've been printing with a new Epson Surecolor P600, and it's the first printer I've ever owned with a whopping 5760 dpi setting. In fact it only offers a choice of "superfine 1440 dpi", "photo1440 dpi", or "5760 dpi" with various combinations of High speed on and off, and finest details, etc., but no "2880 dpi" setting. This jump to 5760 of course went begging for some quick and dirty test prints to see if I could tell the difference in print quality at normal viewing distances, and my tentative results so far now also beg for further detailed investigation. Your target is going to come in handy. For my first test I sent the printer an image with lots of fine frequency details, and the source file was over 450 dpi, so first I upsampled it to 720, then put the different driver screening options through their paces. Well, it's subtle, really subtle, but it's also pretty obvious that the battleground isn't the resolution. It's how the driver screening pattern is handling the mid frequency modulation. So, the 1440 dpi setting are arguably just as "sharp" maybe even a tad sharper to my eye than the 5760 dpi, but the 5760 dpi does have some inherent "analog" smoothness that can't just be ignored. Anyway, it's a challenging effort to say anything definitive at the moment, but your target is going to help me get there.

FWIW, the well known fact that acutance or perceived sharpness in and image does not always correlate with resolving power plays out magnificently with many digital output devices, inkjet maybe even to an extreme. Here's an article I wrote some time ago about the new (at the time) Fuji Drylab printer which was a four color inkjet technology intended for the 4x6 photo finishing market. http://www.aardenburg-imaging.com/news.47.html

I compared its output to the Fuji Frontier 390 (RA-4 wet process) printer and to a six color home inkjet photo printer. If you scroll down and look through the various pictures in the article of the young lady (my daughter) and her new puppy, there is a very good example of this acutance versus resolution issue. The Fuji Drylab could not reproduce the fine ribbed lining detail in her sweater, yet to anyone looking at the prints, it was decidedly sharper than the Fuji Frontier 390 output that it was replacing. On a more subtle scale, I'm pretty convinced that this is also happening in the P600 driver such that the 1440 dpi output is probably going to be the "preferred" setting for most uses as it is faster yet seems to sacrifice little or no apparent perceptual print sharpness even though I suspect your target is likely to show that the 5760 dpi setting outperforms on resolution.

best,
Mark
http://www.aardenburg-imaging.com
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Bart_van_der_Wolf

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Re: A new Printer/Media Resolution test target
« Reply #7 on: April 27, 2015, 10:52:36 am »

Well a week later than the last target collage that I made :-)

Ha, these things seem to inspire each other without knowing about the other work in progress. Must be telepathy.

Quote
Including a 600 PPI sinusoidal pattern that might have been your work too but I am not sure. Can be improved so I certainly will try your new target.

Well, it might be something I made for testing of camera resolution. But this target is specific for printers and probably goes a lot further, and maybe too far, in challenging the printer. It takes extremely little misalignment or paper feed issue to produce artifacts as a signal that there is an issue (however minor it may be).

It may be too sensitive, since also changes in gamma (strong profile adjustments?) can generate aliasing artifacts. I'd like to hear it if that is the case, so I can perhaps redesign parts of it when I get some time. And I'm not sure if on the Mac it is possible to assign the output profile to the target and then print it as if there is no profile involved, to circumvent profiling effects.

Feedback is appreciated.

Cheers,
Bart
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Bart_van_der_Wolf

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Re: A new Printer/Media Resolution test target
« Reply #8 on: April 27, 2015, 11:01:31 am »

Bart, Thanks! As with the other Mark, this is timely for me as well. I've been printing with a new Epson Surecolor P600, and it's the first printer I've ever owned with a whopping 5760 dpi setting. In fact it only offers a choice of "superfine 1440 dpi", "photo1440 dpi", or "5760 dpi" with various combinations of High speed on and off, and finest details, etc., but no "2880 dpi" setting.

Hi Mark,

Yes, these high DPI settings are mainly changing the dithering behavior, but not the real resolution. Resolution is still limited to 720 pixels per inch on Epsons, and only if the 'finest detail' option is used (otherwise it drops back to 360 PPI).

Quote
FWIW, the well known fact that acutance or perceived sharpness in and image does not always correlate with resolving power plays out magnificently with many digital output devices, inkjet maybe even to an extreme.

Yes, there s more to it than just resolution. And there is also a lot that post-processing can do for an image even before it gets sent to the printer driver.

Quote
Here's an article I wrote some time ago about the new (at the time) Fuji Drylab printer which was a four color inkjet technology intended for the 4x6 photo finishing market. http://www.aardenburg-imaging.com/news.47.html

Thanks, I'll have a read later.

Cheers,
Bart
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Re: A new Printer/Media Resolution test target
« Reply #9 on: April 27, 2015, 11:08:40 am »

Hi Bart,

This comes in handy just at this moment for me, and I have downloaded it - many thanks for making it available.

I have one question for you - I have always been given to understand that the native output resolution the Epson printing process works with is 360ppi for all but the "Finest Detail" setting, which when selected changes the driver's "native resolution" to 720ppi, which setting is only recommended for vector graphics, not photographic prints. Hence the Epson professional printers are actually "360 printers" for most purposes. Is your target equally usable for 360 and 720? (This of course is not to be confused with the Print Quality settings - 720, 1440, 2880 in dpi).

Hi Mark:

Here's a column you might enjoy:

http://theonlinephotographer.typepad.com/the_online_photographer/2010/01/how-sharp-is-your-printer-how-sharp-are-your-eyes.html

I have printed large prints from stitched 645D files at 360 and 720 ppi on a 4900; I was unable to see any significant difference even with a 10x loupe.

Tom
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Mark D Segal

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Re: A new Printer/Media Resolution test target
« Reply #10 on: April 27, 2015, 12:01:17 pm »

Hi Mark:

Here's a column you might enjoy:

http://theonlinephotographer.typepad.com/the_online_photographer/2010/01/how-sharp-is-your-printer-how-sharp-are-your-eyes.html

I have printed large prints from stitched 645D files at 360 and 720 ppi on a 4900; I was unable to see any significant difference even with a 10x loupe.

Tom

In light of Epson's clearly stated advice on this matter and my own previous trials, this is a consistent observation.
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Ernst Dinkla

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Re: A new Printer/Media Resolution test target
« Reply #11 on: April 27, 2015, 12:04:02 pm »


It may be too sensitive, since also changes in gamma (strong profile adjustments?) can generate aliasing artifacts. I'd like to hear it if that is the case, so I can perhaps redesign parts of it when I get some time. And I'm not sure if on the Mac it is possible to assign the output profile to the target and then print it as if there is no profile involved, to circumvent profiling effects.

Feedback is appreciated.

Cheers,
Bart

I noticed that your new target has AdobeRGB assigned and recently I went for sRGB with B&W work for some practical reasons. Will see how I can reduce any influence but the tone range curves are close. The 16 bit dithering in Qimage Ultimate is another hurdle to take, the one Mike added after your comments on 16 bit profiling etc.

Dotgain indicators that show at which density dotgain happens may help to optimize the output. With multiple ink channels and (custom) partitioned monochrome inks in use, dotgain is no longer just showing up near Dmax. Feedback on that can help in tweaking media presets or simpler in a choice of a better media preset

Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
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Bart_van_der_Wolf

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Re: A new Printer/Media Resolution test target
« Reply #12 on: April 27, 2015, 12:46:32 pm »

I noticed that your new target has AdobeRGB assigned and recently I went for sRGB with B&W work for some practical reasons. Will see how I can reduce any influence but the tone range curves are close.

That's correct, in an attempt to have a predictable uniform gamma, but you can just assign sRGB instead if that suits your B/W workflow better. Gamut should not be an issue when printing B/W with color ink for toning or neutralization.

Quote
The 16 bit dithering in Qimage Ultimate is another hurdle to take, the one Mike added after your comments on 16 bit profiling etc.

That's the reason why I designed the target as a 16-bit/channel image (to allow a test of the dither options). Qimage will dither the 16-bit input to 8-b/ch when reading and converting the file, and then offers an optional dithering after profile conversion and output sharpening. The initial dither, going from 16 to 8-b/ch, is not optional. One can eliminate it though, by first creating an 8-b/ch version of the target and then use that version as input for testing.

Quote
Dotgain indicators that show at which density dotgain happens may help to optimize the output. With multiple ink channels and (custom) partitioned monochrome inks in use, dotgain is no longer just showing up near Dmax. Feedback on that can help in tweaking media presets or simpler in a choice of a better media preset

Yes, that's what I had in mind with some of the gradual versus discrete resolution design. In principle, assuming a neutral profile, the density of the different fixed resolution patches should be the same (on average), but due to dot gain or ink diffusion the higher resolution patches will become darker than average (because the paper white will get contaminated). Some papers behave better than others.

I have thought about adding 'white dots on black' patterns, or cross-hatched patches, for dot gain analysis. But for the moment I decided that it might be better to create some neighboring patches with significantly different resolution. That's why I divided the full and half cycle/mm patches in two full cycle difference neighbor sequences, bordering to the medium grey of the star background.

The benefit of discrete resolution patches is also that they tend to make a clearer 'now you see it, now you don't' difference. The gradual sweep allows to pinpoint intermediate values for the most meaningful resolutions, if half cycle/mm differences are too large a jump for some particular application. The central 'rings' in the 'star' are very sensitive to dot gain effects, unless the dot gain compensation in the output profile is perfect.

Cheers,
Bart
« Last Edit: April 27, 2015, 12:53:48 pm by BartvanderWolf »
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Re: A new Printer/Media Resolution test target
« Reply #13 on: April 27, 2015, 12:58:07 pm »

Thanks for the target! I do want to test this on my Epson 3880, I've done a head alignment and will print with Glossy paper.

I want to make sure I understand the parameters of testing. I understand I need to output the document as is, at 720PPI with and without using Finest Detail settings in the driver.
Would it be fair and correct to resample the target itself to 180PPI, 300PPI and make the print so it's the same size as above?
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Re: A new Printer/Media Resolution test target
« Reply #14 on: April 27, 2015, 01:15:32 pm »

I have one question for you - I have always been given to understand that the native output resolution the Epson printing process works with is 360ppi for all but the "Finest Detail" setting, which when selected changes the driver's "native resolution" to 720ppi, which setting is only recommended for vector graphics, not photographic prints. 
In the two prints I just made, the Finest Detail makes a visual difference and shows no moiré like the print without this setting being on. The 1.42 area shows detail with this setting on, without it's nearly all a solid gray! As Spock would say, fascinating!
IF I had a true 720PPI's of data, it appears it would be a mistake not to have Finest Detail at least with Bart's image. For real images, I'm not sure but I don't know why not.
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Bart_van_der_Wolf

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Re: A new Printer/Media Resolution test target
« Reply #15 on: April 27, 2015, 01:47:54 pm »

Thanks for the target! I do want to test this on my Epson 3880, I've done a head alignment and will print with Glossy paper.

I want to make sure I understand the parameters of testing. I understand I need to output the document as is, at 720PPI with and without using Finest Detail settings in the driver.

Hi Andrew,

Yes, you'd want to enable the 'finest detail' option, if you want to test for the highest attainable resolution on your paper of choice. By not checking the box for  'finest detail' the printer will default to downsampling to 360 PPI when the target is printed as 130mm size.

Quote
Would it be fair and correct to resample the target itself to 180PPI, 300PPI and make the print so it's the same size as above?

You can resample the target and see what the effect is, although resampling may/will create its own artifacts (which is why we want to avoid the printer driver doing it). That's what the discussion about printing at 360 or 720 PPI is often about, the lackluster resampling quality of the automatic resampling to either 360 or 720 depending on the driver parameters. It's best to sent high quality 'pre-sampled' data at exactly whatever resolution  the printer driver expects. Predictable behavior is the result we are usually after, even if it's not 100% perfect.

If you are thinking of other types of printers, e.g. c-print types or dry process, then it depends on the technology it uses which target to use, the 600 or 720 PPI version. It might be wise to then let the print engine use the built in PPI tag and output at whatever (larger) size that leads to. A Durst Lambda or Epsilon for example might be best tested with the smaller 600 PPI target version, to keep the output size low, but it might want to print at  254 PPI, or 300 or 400, who knows (the printer operator should, but ...).

Cheers,
Bart
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Bart_van_der_Wolf

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Re: A new Printer/Media Resolution test target
« Reply #16 on: April 27, 2015, 02:00:36 pm »

In the two prints I just made, the Finest Detail makes a visual difference and shows no moiré like the print without this setting being on. The 1.42 area shows detail with this setting on, without it's nearly all a solid gray! As Spock would say, fascinating!
IF I had a true 720PPI's of data, it appears it would be a mistake not to have Finest Detail at least with Bart's image. For real images, I'm not sure but I don't know why not.

Thanks for the feedback, it seems to do what it is supposed to (show real resolution limits, however small they may be). This allows to compare media choices, when detail must not be compromised by ink diffusion. It also demonstrates the effect of the 'finest detail' option.

Whether it's significant/useful enough to use 720 PPI, assuming enough detail is in the source image to exceed 360 PPI at the intended output size, is still an open choice. But do remember that with specific output sharpening (after resampling to 720 PPI), one can do more sharpening because there are more pixels to sharpen. At 360 PPI we need to be much more careful and avoid sharpening artifacts, because visual acuity on average is good enough to spot the trouble at reading distance.

Cheers,
Bart
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Re: A new Printer/Media Resolution test target
« Reply #17 on: April 28, 2015, 11:35:38 am »

Bart: thanks so much! This is a thing of beauty and I can't begin to imagine how you created it. Presumably not line by line in Photoshop. <g> Fun just to zoom it in and out using scroll wheel, watching the moire patterns morph on the monitor.

Bit of feedback from a less-technical user.  I have a 3880 and have printed it so far on a PLPP clone, a PGPP clone, and Hahn. Photo Rag Baryta.

Both on my monitor and my 720 prints the left and top patches look just fine with a loupe, but each vertical box is lighter and each horizontal is darker than the diagonals in the same set, which are equal. This seems to be more along the lines of moire, given the way this disappears under a loupe or in the case of the monitor, when zoomed in to 100%.

My 3880 is maybe 2 years old and had never had a head alignment run, so I printed it before and after an auto alignment at 720 PPI. Both look identical, right down to the naked-eye-visible and loupe-visible moire patterns. Since I'm seeing clear line separation without moire right into the 9s, I'm taking that to indicate my alignment was and remains good. As well as a paper fineness test, this may serve people just as much as a head alignment check.

Another interesting thing for me was to print the target at 720 and 360 (no other change than Finest Detail checked or unchecked). The individual lines look equally fine. They just bleed together a bit sooner without Finest Detail being enabled.
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Re: A new Printer/Media Resolution test target
« Reply #18 on: April 28, 2015, 12:29:32 pm »

Bart: thanks so much! This is a thing of beauty and I can't begin to imagine how you created it. Presumably not line by line in Photoshop. <g> Fun just to zoom it in and out using scroll wheel, watching the moire patterns morph on the monitor.

Hi Dale,

Indeed, I used some software assistance to do most of the calculations into pixel values for me. The coarse display sampling will indeed show all sorts of aliasing when zooming in/out.

Quote
Bit of feedback from a less-technical user.  I have a 3880 and have printed it so far on a PLPP clone, a PGPP clone, and Hahn. Photo Rag Baryta.

Both on my monitor and my 720 prints the left and top patches look just fine with a loupe, but each vertical box is lighter and each horizontal is darker than the diagonals in the same set, which are equal. This seems to be more along the lines of moire, given the way this disappears under a loupe or in the case of the monitor, when zoomed in to 100%.

My 3880 is maybe 2 years old and had never had a head alignment run, so I printed it before and after an auto alignment at 720 PPI. Both look identical, right down to the naked-eye-visible and loupe-visible moire patterns. Since I'm seeing clear line separation without moire right into the 9s, I'm taking that to indicate my alignment was and remains good. As well as a paper fineness test, this may serve people just as much as a head alignment check.

Yes, alignment seems to be consistent, and it's a good way to check if things deteriorate over time or not. When mixing different paper thicknesses it may help to do a more frequent realignment.

It is most likely that the (horizontal) head and (vertical) paper-feed pitch is slightly different (paper transport slipping slightly between rollers?). This could be verifiable by measuring the squareness (130 x 130 mm) of the printed target. The target is very sensitive to tiny differences, so it might also be a bit of moiré but that would more likely produce more noticeable waves of brighter and darker cycles, out of sync with the sinusoidal pattern. So my guess is non-squareness, although it might be too small to cause real issues in practice.

Quote
Another interesting thing for me was to print the target at 720 and 360 (no other change than Finest Detail checked or unchecked). The individual lines look equally fine. They just bleed together a bit sooner without Finest Detail being enabled.

Yes, for some subjects it can make a difference, for others it is not important. Especially very fine line and edge detail, together with output sharpening after resampling, will benefit most.

Thanks for the feedback.

Cheers,
Bart
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samueljohnchia

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Re: A new Printer/Media Resolution test target
« Reply #19 on: April 30, 2015, 03:12:42 am »

Hi Bart, thank you for the targets. These are brilliant. Previously I used your camera resolution target to check alignment and positioning accuracy for my printer.

The single pixel lines are super taxing on the printer. My Canon iPF8400 can resolve both the horizontal and vertical lines perfectly when it first arrived, but it underwent a carriage assembly replacement and now the vertical lines (perpendicular to the direction of head travel) are not as crisp or well defined as the horizontal lines. The patch looks a little more dense, if memory serves.

I am working on other things at the moment but I would love to try out the new target soon. Getting the printheads to be perfectly aligned is surprisingly difficult. I have tried to run several manual and auto (including the intitial setup adjustment, which is the most thorough) and realised that the initial head adjustment is the best and most likely to be successful for my iPF8400. The manual adjustment was too unpredictable and dodgy, and does not print adjustment patterns for yellow and one other color I think, because I suspect it would be too faint to see. There usually still is some minor positioning errors over the page, especially in the initial few inches of the paper because of the curl from the roll.

I have seen a definite resolution difference between 300ppi and 600ppi data sent to this printer. Ming Thein has also shown a big improvement going from 360 ppi to 720 ppi on the Epson 9900 on his blog.

This is great, can't wait to try it! Thank you.  :)
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