Towards an improved B&W test image?

[keith_cooper]

I'm currently testing a couple of papers now being distributed by Canon (in the UK) under the Oce brand (Museo max 250 and Museo Silver rag).  As part of this I'm specifically looking at B&W printing, and using the experience to update my longstanding (2005) B&W test image.

http://www.northlight-images.co.uk/article_pages/black_and_white_test.html

I know that it has been downloaded many thousands of times over the last few years and I was hoping that a few copies might have been tried by members of the forum?

So, what I wanted to know, was what parts of it were of particular use (or not)? There are a few parts I'm looking to replace/update, but I don't want to remove something that has proved useful.

The only definite change I want to make is to include a proper 51 step ramp in it, that can be used to help create QTR 'linearisation' profiles, such as one of the ones at:
http://www.northlight-images.co.uk/article_pages/bw_printing/bw-print-correction.html

I know what bits I find of most use, but that's perhaps because I created it ;-)  Just wondered what others might find useful?  For example, would having both A4 and Letter sized versions be of more help to US users?

[Some Guy]

Keith, I enjoy your work.  Good stuff!

I've made a few charts over time.  One thing I've found with the downloads is whether they are sRGB, Adobe 1998, or ProPhoto and some are not specified.  Seem to become important at times and how some downloads appear, and readouts can be iffy with them.

One I made locally in PS for linearization is a 0 to 255 RGB chart in steps of 5 for linearzation.  Just a bunch of squares with the RGB value in them the ColorMunki Photo or i1 ProPhoto 2 should read and try and match against since they were made in PS and hopefully printed the same.  I also use a 21-step TIF image (Size: 2835 x 269 @ 360 dpi) in Adobe RGB 1998 along side some image borders to read from.  Just a grey scale overlay I pop in some.  I can sort of work the 21 steps in Qimage with the slope tool to make it a linear filter or whatever is is called there.  A 50+step would be too much to handle there.

I gave up on QTR as it operates somewhat poorly in Windows 8.1 with assorted error screens and running in the background once it crashes or closes.  Seems better suited to Apple OS than Windows.  Seems Roy lost the guru who did the Windows version.  So I just use the Epson driver via Qimage now, and I do not use the Epson ABW control as I find I can tint better B&W with the Adobe 1998 RGB left in the image.  I prefer my own tint over those of Epson so I need to leave the color RGB in the image as an option.

I also found some scans for the i1 PhotoPro 2 head not to read correctly if the end (marker?) bar is not there in the newest software version.  I did one yesterday in Optimize mode of the ColorMunki Photo and it included thin black end bars at the end of each row of chevrons, but the first two initial full-color ones did not have them, just the Optimized (3rd) one.  Puzzling.

SG

[Alan Goldhammer]

Keith,

I use the B/W test image when I'm looking at possible new papers to use and have found it quite valuable.  IMO it's the best one out there in terms of putting a printer and paper through paces.  I do use QTR but print out the step wedges from ArgyllCMS as it allows me to automate the readings with an i1 Pro so I would not see any value in a 51 step wedge addition.

thanks for asking!

Alan

[Mac Mahon]

Keith

I use your test image quite frequently.  Have never wished for anything more from it!

However, don't let that stop you making improvements:  like most other people I don't know what I don't know - an improvement we can't conceive of, may make life even easier!

Cheers

Tim

[chichornio]

Hi Keith,

Your b&w print test image from 2005 made me sell a lot a Canson Baryta and Crane Museo Max 365grs. prints. Great job!
I would like to have a b&w print test that only includes a gray gamma values from a 35mm and MF scanned negatives.

Best Regards!

[keith_cooper]

I would like to have a b&w print test that only includes a gray gamma values from a 35mm and MF scanned negatives.

Glad it was of use! - however I'm not sure of the characteristics you are looking for when you mention such scans?

I'm planning to make the 16 bit version available, as well as the jpeg, which would make it better able to take changes Gamma if that's what you wanted?

The original reason it was produced in GG2.2 was to make it easier to use with printer B&W print modes.

[Ernst Dinkla]

Keith,

To avoid the influence of resampling (in the application to print from or the driver) there should be versions in 360 and 300 PPI and possibly 600 and 720 PPI. The detail/checker target can get corrupted by resampling where the user actually wants to check the ink load the printer/printer setting/ink/paper-coating can handle. The linearisation target patches should still keep the dimensions that the spectrometers can handle so a simple resizing to get the different PPI resolutions is not the right way to do it.

Right now I prefer a 34 step wedge for linearising with 1 pixel wide lines, black and white etc, to check the detail loss / ink limits.

--
Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
January 2014, 600+ inkjet media white spectral plots.

[Eric Myrvaagnes]

Keith,

I too have found your test image of great value in its present form. I would be pleased to see the 51-step ramp and Ernst's suggested ppi variants (for me, the 360 and 720 would be most useful).

Thanks so much for providing this service.

Eric M.

[keith_cooper]

The 360 should be fairly easy to do, with the exception of the fine detail target, where I will have to try and remember how I created it some 9 years ago... ;-)

For 600/720 I'd want to go back to the original images and produce versions that did have real detail at that resolution? That might be a whole new image though...

[Bart_van_der_Wolf]

Right now I prefer a 34 step wedge for linearising with 1 pixel wide lines, black and white etc, to check the detail loss / ink limits.

Hi Ernst,

You'd probably agree that the 1 pixel wide lines should run both horizontal and vertical.

Perhaps a simple small 1 line wide hook or triangle/rectangle (one white one black) per gray step is even better, with the corners adding another challenge.

Cheers,
Bart

[keith_cooper]

A bit of delving into the archives (and still having a working copy of PS CS2) has come up with the original fine detail patterns - I've now updated it to give sharper definition and it works just fine at 360 and 300 ppi.

I'll tweak it a bit more and see if I can get the new version available for when I've finished testing papers.

Thanks for the feedback folks

[Ernst Dinkla]

Hi Ernst,

You'd probably agree that the 1 pixel wide lines should run both horizontal and vertical.

Perhaps a simple small 1 line wide hook or triangle/rectangle (one white one black) per gray step is even better, with the corners adding another challenge.

Cheers,
Bart

Dag Bart,

There is an older 360PPI set of 21 and 51 steps for download at my pages:
http://www.pigment-print.com/Quad%20QTR/Index.html

The 16bit, 34 steps, 300PPI is not there. I found the 21 step too rough while the 51 step can give issues with QTR's linearisation + profiling app. An iterative workflow with 21 and 51 steps should cure that too and better. As I was making quad ink partitions with Photoshop curves instead of QTR's partioning tool this in between number worked faster.

Yes, both vertical and horizontal lines. 1, 2 and 3 pixels wide and another check for bleeding into the shadows. The ink load with quad inksets can be high over the entire tonal range while with black only ink B&W the bleeding only happens near 100%. I tried to get a check over the range. Keith's checker pattern does the same in a sense but mine is more down to earth I think.

What I recall is that I made vector designs and aligned them to pixels later on with some adjustments to save me work on different PPI versions. I have to check the drawings, they are on another system.


--
Met vriendelijke groet, Ernst

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
January 2014, 600+ inkjet media white spectral plots.