Clarification on Print Resolution

[John R Smith]

So far it is telling me more about LR than any other thing. That text in images decreases in quality with programs aiming at good photo quality is not new to me either. There is a setting in printer drivers for fine detail that may enhance your text and lines even more (and could request 1440 PPI or 1200 input) but does not improve a photo image in most cases.  Different horses for different courses.

That's right. And what works well for a bunch of geometric lines is not necessarily best suited to the average photograph. But text - especially the serifed text used in the test file - does have a lot in common with the problems of digital landscape photography - smooth curves and fine lines have to be rendered using (not enough) square pixels. My photographs usually include a great deal of very fine, high-frequency detail - grass, trees against sky, complex vegetation. All in B/W with no colour information to trick the eye and flesh things out a bit. So this whole debate is very important to me.

John

[Mark D Segal]

It would be nice if you do that with another program than Lightroom. I see that John's testing is hitting on limitations in that program, limitations that might be excellent for normal printing but obscure what we want to measure.

I think there is a chance to use a 3800 or 3880 of a friend next week so I can do a test too on an Epson.


met vriendelijke groeten, Ernst

New: Spectral plots of +250 inkjet papers:

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

I would use Photoshop for that.

[Mark D Segal]

John,


As I understand it from discussions with Mike Chaney of Qimage the application may send a Windows image file format to the driver so not a Tiff etc and my best guess is that that happens in both cases without any extra flag. What you probably observe is a sharpening step (or another adaptation step to the media you selected) in LR that is not switched off, one of those black box things that makes this program not ideal to reveal what the driver itself does. It is like testing an Imacon scanner without knowing that even a zero on the sharpening setting still means sharpening is done, you have to set  say a -60 or -120 number to get rid of the sharpening in its software.

The other way around, how the application could know what the driver likes to receive on input resolution, is by looking for an API call by the driver in Windows. that is where applications like Qimage and LR collect those numbers and use them for the best adaptations of the images to that request. Qimage does that more transparent and you can switch off all adaptations if needed, like for testing.


met vriendelijke groeten, Ernst

Try: http://groups.yahoo.com/group/Wide_Inkjet_Printers/

My experience working with Lightroom is that when you turn sharpening off by setting the Amount to Zero in both the Develop module and the Print module, it really is OFF. There is no sharpening taking place under the hood. But for safety it may still be better for testing purposes to do this in Photoshop where you know that unless you explicitly sharpen, there is none. But this is only an observation based on differences between settings the user can control. Aprt from the programmers, who knows, for any application, what really goes on under the hood before the image hits the display or printer that could be akin to *some* measure of default sharpening just to make the image minimally acceptable.

[John R Smith]

Apart from the programmers, who knows, for any application, what really goes on under the hood before the image hits the display or printer that could be akin to *some* measure of default sharpening just to make the image minimally acceptable.

Indeed. A good example of this was again LR itself, where in LR 2x some NR was applied even if you had all the NR settings at zero. Not that we realised this, of course, until LR 2.7 came out, and suddenly zero really meant zero. Which remains the case in LR 3x with PV 2010, of course. However, you have to work with the photo-editing and printing application of your choice, so the important thing is to optimise the results from that. I personally would prefer to work with a situation where all aspects were user controlled.

John

[Mark D Segal]

Indeed. A good example of this was again LR itself, where in LR 2x some NR was applied even if you had all the NR settings at zero. Not that we realised this, of course, until LR 2.7 came out, and suddenly zero really meant zero. Which remains the case in LR 3x with PV 2010, of course. However, you have to work with the photo-editing and printing application of your choice, so the important thing is to optimise the results from that. I personally would prefer to work with a situation where all aspects were user controlled.

John

John - beg to differ - I understand the logic of what you are saying - you want test results that show the merits of a workflow with what you are using - that makes sense. But from the point of view of "pure science" you want to use an application that is best suited for the purposes of the test. I think you are coming from the practical perspective of "I want to know how what I use works", whereas Ernst is more interested in the objective issue of what the Epson driver versus the application really does, and what settings are technically optimal. Both perspectives of course are valid but may call forth different approaches.

On the question of being in a situation "where all aspects were user controlled" - be careful what you wish for. I think we are in a situation where we don't even know quite what there is that needs to be controlled under the hood, and we may be overwhelmed if we had to manually set everything the software does to fashion the initial appearance of an image.

[John R Smith]

On the question of being in a situation "where all aspects were user controlled" - be careful what you wish for. I think we are in a situation where we don't even know quite what there is that needs to be controlled under the hood, and we may be overwhelmed if we had to manually set everything the software does to fashion the initial appearance of an image.

Mark, nice one. I was was thinking of that as I wrote it actually - "be careful what you wish for, you might just get it"  

I was rather hoping that by now a zillion other LL Forumites would have weighed in with their own tests using Ernst's file on their own, more recent Epson printers. Lazy lot, aren't they? I will probably be getting an R3000 later in the year, so I shall run the same tests again on that. Personally, contrary to other possibly more expert opinion, I anticipate the results to be the same - the printer expects 720 ppi input for all photos on gloss media, and anything else will be resampled. I know that there have been improvements on the new printers to the inksets and the dithering algorithms, but my guess is that all of this applies to the output side alone, not the input.

PS By-the-by, we still have not really had an answer to this question, I think - "how does the printer know what resolution the incoming print spool file actually is? Is this information in a file header somewhere, or does the printer analyse the data in some way?"

John

[Garnick]

You should upsample (if you are going to) BEFORE you run the final output sharpening...PKS 2 can actually do both at once in the Output Sharpener for Inkjet.

Hi Jeff,

I'm somewhat confused by your response to the upsampling question. You mention that PKS 2 can do both at once in the Output Sharpener for Inkjet. I read that to mean that PKS 2 can both sharpen and upsample simultaneously. I've just checked in again to see if there was something I had missed, but can't seem to find an area within the PKS 2 dialog that will allow me to change the resolution while retaining the image output size. It's probably right there staring me in the face, but so far I haven't located that particular capability, nor is it mentioned in the manual. Perhaps I am misreading your response. If so, please advise.

Thank you,
Gary


 

[Alan Smallbone]

Thank you for the trials. I have some questions. You hit on a limitation in LR for the higher than 720 PPI resolution, you can not half the size of the image based on your 720 PPI test an by that get 1440 PPI without bothering whether LR says what resolution it has? The other one, you hit on a driver limitation for the glossy paper media preset to get 360 PPI input resolution, there are no matte paper choices or even uncoated paper choices that brings it down to 360 PPI? I am still not happy with LR for tests like this. It could even be that if the driver asks for 360 PPI Lightroom still sends 720 PPI, even if you resampled the file to 360 PPi in Lightroom.

So far your testing says to a degree that the 2400 driver has one fixed input resolution at least: 720 PPI.

Ernst,

I was going to run some of the testing and use Qimage Pro, however, it keeps saying that the max for my Epson 4880 is 360 dpi so I am guessing that is a limitation of the older Qimage Pro, since the Epson driver runs at 720dpi.

Alan

[Schewe]

You mention that PKS 2 can do both at once in the Output Sharpener for Inkjet. I read that to mean that PKS 2 can both sharpen and upsample simultaneously.

Yep, my bad...I was thinking of the ability to resize without resampling. So if you want to upsample you'll need to do it in Photoshop before the final output sharpening.

[Garnick]

Yep, my bad...I was thinking of the ability to resize without resampling. So if you want to upsample you'll need to do it in Photoshop before the final output sharpening.

Thanks Jeff, much appreciated!

Gary

[Ernst Dinkla]

Ernst,

I was going to run some of the testing and use Qimage Pro, however, it keeps saying that the max for my Epson 4880 is 360 dpi so I am guessing that is a limitation of the older Qimage Pro, since the Epson driver runs at 720dpi.

Alan

Alan,

That is very unlikely. If you set the highest image qualities + 1440 or 2880 dpi etc for a gloss paper in the Epson 4880 driver it should jump to 720 PPI.  You ought to see that 720x720 above Qimage's preview. The extrapolation options are below that preview window and you can select the resampling algorithms there + the Max = 720 PPI in this case, a lower setting = 360 PPI (so in this case the driver will do the rest = 2x ) and OFF (the driver does all) + the degree of smart print sharpening, default 5 and a range of 0 to 20. For testing check that it is all OFF or zero and also that no print filter is set and control that the job log shows the target image resolution as you would like to see in relation to the requested printer input resolution. I was almost at a point to install that driver but I rather avoid that, there are already 4 drivers installed and I can not afford a problem on that system right now. There must be 4000-4900 owners with Qimage that can verify what I expect. I recall it was possible more than 5 years ago with an older Epson wide format and an older Qimage.

met vriendelijke groeten, Ernst

Try: http://groups.yahoo.com/group/Wide_Inkjet_Printers/

[Bart_van_der_Wolf]

Ernst,

I was going to run some of the testing and use Qimage Pro, however, it keeps saying that the max for my Epson 4880 is 360 dpi so I am guessing that is a limitation of the older Qimage Pro, since the Epson driver runs at 720dpi.

Hi Alan,

There is no limitation in QI, but you must set the Epson printer driver to "Finest Detail" (assuming the driver settings are similar for your model) to enable it. QI uses whatever the printer driver reports as being available, when you select max quality.

Cheers,
Bart

[Farmer]

For "Pro" model Epson printers if you wish to use 720ppi input resolution then as Bart says you need to select "Finest Detail", otherwise it will run at 360.  This option/control is not available in non-Pro printers and is defined on the other media and resolution settings.

[Alan Smallbone]

Thanks Phil and Bart, I was going to swear I had set to "finest details" but now that I have gone back and looked in the setup it appears to have not been set, I am guessing I forgot that I changed it doing some experiments. Doh! Doh! Thanks for dealing with the "dumb question" and senior moment. :-)

Alan

[Bart_van_der_Wolf]

Thanks Phil and Bart, I was going to swear I had set to "finest details" but now that I have gone back and looked in the setup it appears to have not been set, I am guessing I forgot that I changed it doing some experiments. Doh! Doh! Thanks for dealing with the "dumb question" and senior moment. :-)

No problem, what matters is that it's solved. It's the result that counts, and that's what this thread happens to be about.

Cheers,
Bart

[Mike Guilbault]

I thought the "Finest Details" setting was for printing vector graphics or text.  Does it really improve quality in a photo?

[Farmer]

That's the primary design purpose, and it does it partly by accepting 720 input res.  Generally, I've not seen an improvement in output unless there are a lot of clean edges or straight lines.  There's no downside, apart from the increased spool file size and perhaps slightly longer processing time.

Whether it makes a visible difference to your images at a normal viewing distance (or even a close viewing distance, excluding using a loupe) is really up to you to determine through testing.

[Schewe]

I thought the "Finest Details" setting was for printing vector graphics or text.

Correct...it aliases edges in vector graphics such as type or EPS graphics...not intended for natural photographic images.

Upsample to 720 PPI is you want 720 PPI output.

[Bart_van_der_Wolf]

I thought the "Finest Details" setting was for printing vector graphics or text.  Does it really improve quality in a photo?

Hi Mike,

That as well. Do note that the setting is called finest detail, not "only for vector graphics or text". That option allows the printer to use (or upsample to) 720 PPI, which has the effect of rendering more detail (above 360 PPI) if it's present in the image data. Fine lines or text benefit from printing at 720PPI to avoid visible artifacts (e.g. jaggies).

Text and vector graphics are fed to the printer driver as rasterized image data, just like a continuous tone image. It makes no difference for the driver, it does not discriminate. A pixel is a pixel.

Obviously, processing 4x as much data (720 PPI versus 360 PPI in 2 directions) slows down the printing process, that's why it is an option, and not set by default. It helps to reduce complaints about slow printing.

Cheers,
Bart.

[Ernst Dinkla]

The 720 PPI requested input at Finest Detail etc setting is for the Wide Formats, I guess the desktops go for 1440 then. For the HP Z3100, the requested normal input resolutions are resp 300-600 PPI. While it becomes 1200 PPI with Maximum Detail selected (HP Prof Satin RC paper for example). In the Z3200 PCL3 or PS3 driver I can not get it that high, it stays on 600 PPI input but the droplet distribution jumps to 2400x1200 dpi like it does on the Z3100 (HP Prof Satin RC paper for example). The menu structure is different in the drivers but Qimage does not pick a 1200 PPI input either for the Z3200 so I guess HP brought it down for some reason, possibly an unrealistic long processing time needed for that setting.


met vriendelijke groeten, Ernst

New: Spectral plots of +250 inkjet papers:

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