Ad
Ad
Ad
Pages: « 1 ... 8 9 [10] 11 12 »   Bottom of Page
Print
Author Topic: Clarification on Print Resolution  (Read 59656 times)
John R Smith
Sr. Member
****
Offline Offline

Posts: 1357


Still crazy, after all these years


« Reply #180 on: June 23, 2011, 03:37:08 PM »
ReplyReply

I just printed an image that natively came down to about 121 ppi after some cropping and wanting to print at about 36" wide.  I set the Printer Resolution to 360 and it came out beautifully at a 'normal' viewing distance - at least to my eyes.  I'm happy.

Mike, doing these tests has made me realise that I could print my 39MP files to 40x30 ins at 180 ppi using LR and they would look absolutely fantastic - no grain, pefectly smooth, beautiful tonality. Well, I could if I had a printer which would print that big. Bound to be snags . . .

John
Logged

Hasselblad 500 C/M, SWC and CFV-39 DB
and a case full of (very old) lenses and other bits
Farmer
Sr. Member
****
Offline Offline

Posts: 1631


WWW
« Reply #181 on: June 23, 2011, 05:45:04 PM »
ReplyReply

Well done, John.  You can't really beat actual printing to test these things.  Very nicely written up summary, too.
Logged

VeloDramatic
Newbie
*
Offline Offline

Posts: 15



WWW
« Reply #182 on: June 23, 2011, 05:54:04 PM »
ReplyReply

It may be long but this has definitely been an illuminating thread. Mr. Smith, appreciate that last summary but need one clarification. Am I correct in assuming that the same upsampling rules would apply to printing from Photoshop? That may have been made clear earlier in the thread but I'm scared to go back looking for it  ;-)

I should add I'm just about to upgrade my 4800 to a 9890 or 9900 and the regular cast of contributors here have provided lots of useful information across the board. I recently did my own print comparisons between the 4800 and a 7900 and clearly I didn't understand the fine detail selection until I came here.

thanks all.
Logged
Schewe
Sr. Member
****
Offline Offline

Posts: 5512


WWW
« Reply #183 on: June 23, 2011, 05:54:26 PM »
ReplyReply

But The Epson guy agreed that sending the image data at the resolution the printer is expecting should take the print pipeline out of the equation.

Not to throw a monkey wrench into the equation but we may not actually be done yet regarding output resolution...

It seems the x900 series printers actually ship with the ability to report 1440 as their native resolution. But to get there is kinda tricky...

Here's the way to do it but note this ONLY works if you select one of the "Proofing Paper" media settings...(also note I've not yet tested this but I'm gonna)

Here's the info:

"On the PC side it is Level 3 Fine 1440x1440
Check Finest Detail in this mode and Qimage reports 1440 ppi MAX resolution (as a confirmation)

White Semimatte is usually the default LUT of choice if you are going to make a profile in this mode for a different media. It has the highest ink duty limit.

On the MAC side select be Fine - 1440 and Finest Detail".

So, I'll be testing this to see if one can eek out any more image detail this way...it'll be a couple of weeks before I can get into this though. But for the geeks this may be another rabbit hole to go down :~)

Note, it requires the x900 series so a 4900, 7900 or 9900 is required. There is no similar ability on any of Epson other printers...
Logged
gromit
Full Member
***
Offline Offline

Posts: 133


« Reply #184 on: June 23, 2011, 07:10:20 PM »
ReplyReply

So, I'll be testing this to see if one can eek out any more image detail this way...it'll be a couple of weeks before I can get into this though. But for the geeks this may be another rabbit hole to go down :~)

Note, it requires the x900 series so a 4900, 7900 or 9900 is required. There is no similar ability on any of Epson other printers...

In my testing, the proofing paper media presets do have better ink-loading for modern (read non-Epson) rag papers but conversely significantly reduced gamut. Not sure exactly why the latter would be. Since ABW isn't supported for these, the presets are of limited use ... unless I guess you're using them for proofing.
Logged
Farmer
Sr. Member
****
Offline Offline

Posts: 1631


WWW
« Reply #185 on: June 23, 2011, 07:34:10 PM »
ReplyReply

That's an interesting thought, Jeff.  This mode was added really to support various RIP vendors for the proofing market (as would be obvious from the driver media mode you choose to access it).  

How well this mode performs for general photographic work will be interesting to see because, as Jeff says, it's designed for highest ink density so in the driver it's using a larger dot size (which also makes it quite fast).  This may counter any benefits from a higher input resolution and probably also accounts for the gamut decrease that Gromit notes.
« Last Edit: June 23, 2011, 07:38:26 PM by Farmer » Logged

John R Smith
Sr. Member
****
Offline Offline

Posts: 1357


Still crazy, after all these years


« Reply #186 on: June 24, 2011, 01:59:36 AM »
ReplyReply

It may be long but this has definitely been an illuminating thread. Mr. Smith, appreciate that last summary but need one clarification. Am I correct in assuming that the same upsampling rules would apply to printing from Photoshop?

I did no testing using Photoshop, and I just don't have the energy to do so (I never use PS, so it would be a steep learning curve for me). You really would have to run your own tests, but I would have thought that if you needed to downsample, PS would be a better choice.

John
Logged

Hasselblad 500 C/M, SWC and CFV-39 DB
and a case full of (very old) lenses and other bits
Ernst Dinkla
Sr. Member
****
Offline Offline

Posts: 2868


« Reply #187 on: June 24, 2011, 02:17:21 AM »
ReplyReply

In my testing, the proofing paper media presets do have better ink-loading for modern (read non-Epson) rag papers but conversely significantly reduced gamut. Not sure exactly why the latter would be. Since ABW isn't supported for these, the presets are of limited use ... unless I guess you're using them for proofing.

Are the proofing papers not for 90% using PK black? Do you mean the Fiber and Baryta versions of rag papers? Matte fine art rag papers are not really compatible with the proofing media presets.

Epson Proofing White Semimatte should deliver a very wide gamut, Epson advertises the gamut of its recent models based on prints with that paper. For example the 4900 set at 2880x1440 dpi should cover 98% of Pantone colors. It has a high white reflectance and little or no FBA content (in my measurements only two RC papers show that low FBA content). Lab: 97.2 0.3 1.3.  It holds its white in time too if my several months old window test tells something. The only problem I have with it is that there is a lot of bronzing with the HP Z ink sets, it will be better with Epson and Canon ink sets.

met vriendelijke groeten, Ernst

New: Spectral plots of +250 inkjet papers:

http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
Logged
N Walker
Sr. Member
****
Offline Offline

Posts: 300


WWW
« Reply #188 on: June 24, 2011, 02:21:55 AM »
ReplyReply

I did no testing using Photoshop, and I just don't have the energy to do so (I never use PS, so it would be a steep learning curve for me). You really would have to run your own tests, but I would have thought that if you needed to downsample, PS would be a better choice.

John

John,

For pixel peepers Lightroom and ACR have a very slight edge over Photoshop with the majority of images for uprezing - Lightroom uses adaptive bicubic algorithms, in linear space, based on the original image size and output. Some may beg to disagree with a few images and prefer Photoshop for downsampling - depending on the bicubic algorithm chosen in photoshop. There is a big difference between Lightroom downsampling and the Phoptoshop Bicubic sharper option - no need for pixel peeping here as Photoshops sharper option is much sharper and may not be to everyones taste.
« Last Edit: June 24, 2011, 03:59:01 AM by Nick Walker » Logged

Ernst Dinkla
Sr. Member
****
Offline Offline

Posts: 2868


« Reply #189 on: June 24, 2011, 02:47:59 AM »
ReplyReply

I did no testing using Photoshop, and I just don't have the energy to do so (I never use PS, so it would be a steep learning curve for me). You really would have to run your own tests, but I would have thought that if you needed to downsample, PS would be a better choice.

John

John,

With your critical eye it would be nice if you spend some energy on comparing Qimage's on the fly extrapolation and sharpening with LR's qualities. I do not think that Photoshop will improve your images but Qimage might.


met vriendelijke groeten, Ernst

New: Spectral plots of +250 inkjet papers:

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



Logged
Ernst Dinkla
Sr. Member
****
Offline Offline

Posts: 2868


« Reply #190 on: June 24, 2011, 03:01:17 AM »
ReplyReply


• Strangely, the absolute worst thing you can do is to resample the image in LR to the same value as reported for the cell size – for example, take a 360 ppi image resolution and then set the LR output resolution to 360 as well. Theoretically, it should make no difference – but the quality of the print is degraded compared with simply sending it to the printer with no LR resampling. I can’t explain why this happens, but it is observable and repeatable. I can also see the same result with the Restest file – comparing output direct at 720 with the same file output with the LR Resolution box also set to 720 ppi (the sample text is degraded).

John


John, a nice summary and all about a normal image.

The quote above describes the same observation you had earlier with the test target. I then thought it was related to algorithms not suitable for text, vectors. That is not the case it seems . It makes me wonder whether intelligent sharpening, anti-aliasing etc is not activated in LR if it does not resample on the fly to the requested printer input, possibly related to a simultaneous resampling/sharpening/anti-aliasing process when it is done on the fly. If I understand the difference between the routes of your two examples correctly.

On anti-aliasing in downsampling, it is available in Qimage and comes with a slider to adjust the strength. And I have written before that downsampling quality will  become more important with increasing MP in cameras. It has been good too when scanned film images have (aliased) grain aboard.


met vriendelijke groeten, Ernst
New: Spectral plots of +250 inkjet papers:
http://www.pigment-print.com/spectralplots/spectrumviz_1.htm
Logged
John R Smith
Sr. Member
****
Offline Offline

Posts: 1357


Still crazy, after all these years


« Reply #191 on: June 24, 2011, 10:43:43 AM »
ReplyReply

Ernst

I have downloaded the trial version of Qimage, but I am not going to have any time to test it out for a while, as I am going away next week. I just had a brief look at it, and so far I have to say I found the user interface a bit off-putting.

Doing tests like this certainly forces you to re-think a lot of assumptions, which is a very good thing. My first reply to Mike on this thread was basically correct on procedure, but backed up by the wrong science. Essentially, the reason that upsampling a file to 360 or 720 in LR produces a better print is probably absolutely nothing to do with some hypothetical matching of image resolution to printer resolution (as I implied), and everything to do with the fact that LR upsamples the image using some pretty neat anti-aliasing and smoothing routines. The results I have come up with now are strictly empirical (they work, but I’m not entirely sure why) and the hell with the theory.

Which leads me to another thought, and an incorrect assumption. I notice when running these tests that at 720 ppi size and output, even with an 8x loupe on the print I cannot see anything like the detail which is in the original file at 100% on screen. I still don’t see all this detail at 360 ppi (equivalent to a 20x15 ins print), and in fact it is only at 180 ppi (equivalent to a 40x30 ins print) that I can see everything on the print that is in the original file. Upsampled in LR to 720 ppi this prints as smooth as you like and is in fact the closest representation of the original image. Which means that, up to a certain point (which is probably about 180 ppi or so) the bigger you go with a digital image and an inkjet print, the better it gets. This is of course entirely contrary to darkroom printing, where the best possible quality is from a contact print from the negative, and anything larger than that progressively degrades the IQ.

Now I, in my innocence, had assumed that the best print quality would come from printing the file at exactly the same ppi as the highest output from the printer – so in my case, it would be a 720 ppi output file and 720 ppi from the printer, giving a print size of 10x7.5 ins. After all, one pixel in the file would print as one pixel on the page, so all of the image detail and information should be there. This would be my digital “contact print”. But no, it doesn’t work – in fact I don’t see anything like all of the image data until I get up to 180 ppi or so. I’m really not sure why this is (dither pattern obscuring detail? Inability of printer to lay down a continuous tone in highlight areas? Droplet size too large?). It seems that to do what I would like to do (print very high-quality small prints) I would need a printer with a much greater nozzle density on the print-heads. We could speculate – the current Epsons have 180 nozzles per head, so perhaps I would need 720 packed into the same space with probably a sub 1 picoliter droplet size to do the job.

I don’t think that we will be seeing such a printer anytime soon – think of the clogging issues for a start  Wink

John
Logged

Hasselblad 500 C/M, SWC and CFV-39 DB
and a case full of (very old) lenses and other bits
BartvanderWolf
Sr. Member
****
Online Online

Posts: 3801


« Reply #192 on: June 24, 2011, 01:03:40 PM »
ReplyReply

I have downloaded the trial version of Qimage, but I am not going to have any time to test it out for a while, as I am going away next week. I just had a brief look at it, and so far I have to say I found the user interface a bit off-putting.

Hi John,

That's a common first reaction. Not that I like every aspect of it, but it's actually very efficient for the plethora of options it offers. The best way to get acquainted is by following some of the learn by example scenarios or the videos. By mastering common and frequently recurring tasks, it becomes easier to learn some of the more infrequently used ones.

[...]
Quote
Which leads me to another thought, and an incorrect assumption. I notice when running these tests that at 720 ppi size and output, even with an 8x loupe on the print I cannot see anything like the detail which is in the original file at 100% on screen. I still don’t see all this detail at 360 ppi (equivalent to a 20x15 ins print), and in fact it is only at 180 ppi (equivalent to a 40x30 ins print) that I can see everything on the print that is in the original file. Upsampled in LR to 720 ppi this prints as smooth as you like and is in fact the closest representation of the original image. Which means that, up to a certain point (which is probably about 180 ppi or so) the bigger you go with a digital image and an inkjet print, the better it gets. This is of course entirely contrary to darkroom printing, where the best possible quality is from a contact print from the negative, and anything larger than that progressively degrades the IQ.

There are (at least?) two possible explanations.

The first is the limitations of human visual acuity. Normal resolution of the human eye is limited to something in the 300 PPI ballpark. This is also a function of contrast, lower contrast loses resolution sooner. You may ask yourself, why then do we use higher resolution? Well, there is also a thing called Vernier resolution, and our brain/eyes are very good at discriminating much higher levels of detail when slight offsets are involved.

The second reason has indeed to do with dithering. Dithering is used to blend colors in between the readily available ink colors. So for certain colors the resolution is sacrificed for accurate colors. However, for the detail that's close to one of the available ink colors resolution can be boosted at 720 PPI. The benefit of being able to do that at 720 PPI is that small sharpening artifacts are virtually invisible (below visual acuity) but lower spatial frequencies (say at 360 PPI and lower) will also be boosted (potentially without artifacts). It is therefore also possible to increase the amount of sharpenng at 720 PPI, if the printing application allows to tweak that. Hence my earlier remark about limited control in LR, whereas e.g. Qimage allows to adjust the amount of smart sharpening that's applied after resampling. It also allows to tweak for the specific output material used.
 
Of course, when you upsample enough (e.g. your 180 PPI input resolution) then every little bit of resolution available in the original file will be much easier to see, but also more risky to sharpen without creating visible artifacts. Again, having control over the amount is helpful. Also the type of sharpening will make a difference. Deconvolution sharpening is more likely to avoid halos such as we know them from edge contrast enhancing methods.

Cheers,
Bart
Logged
VeloDramatic
Newbie
*
Offline Offline

Posts: 15



WWW
« Reply #193 on: June 24, 2011, 01:15:23 PM »
ReplyReply

Thanks John,

I did in fact mean, uprez when I used the term upsample. Sorry if that confused the issue/question. Though my workflow is Lightroom centric I've stuck to using Photoshop for printing out of habit. In conjunction with the new printer I'll invest some time in understanding the Lightroom print module.

::Michael
Logged
NikoJorj
Sr. Member
****
Offline Offline

Posts: 1063


WWW
« Reply #194 on: June 24, 2011, 02:50:58 PM »
ReplyReply

Which means that, up to a certain point (which is probably about 180 ppi or so) the bigger you go with a digital image and an inkjet print, the better it gets. This is of course entirely contrary to darkroom printing, where the best possible quality is from a contact print from the negative, and anything larger than that progressively degrades the IQ.
That's something I would agree with, and I've heard too 200dpi as the maximum of MTF for inkjets - sounds plausible to me but I didn't see any hard proof btw.
Dithering would made an ideal suspect for that indeed, thanks Bart!


And thanks to all for this informative thread.
Logged

Nicolas from Grenoble
A small gallery
Ernst Dinkla
Sr. Member
****
Offline Offline

Posts: 2868


« Reply #195 on: June 24, 2011, 03:12:38 PM »
ReplyReply

Ernst

I have downloaded the trial version of Qimage, but I am not going to have any time to test it out for a while, as I am going away next week. I just had a brief look at it, and so far I have to say I found the user interface a bit off-putting.

 I’m really not sure why this is (dither pattern obscuring detail? Inability of printer to lay down a continuous tone in highlight areas? Droplet size too large?). It seems that to do what I would like to do (print very high-quality small prints) I would need a printer with a much greater nozzle density on the print-heads. We could speculate – the current Epsons have 180 nozzles per head, so perhaps I would need 720 packed into the same space with probably a sub 1 picoliter droplet size to do the job.

I don’t think that we will be seeing such a printer anytime soon – think of the clogging issues for a start  Wink

John

John,

Qimage's user interface will never score a prize in a world that likes iGadgets and iApps. It will beat them on print functionality though.

I think you need more inkjet print area to get all the detail of an old contact print. And you must have very good eyes if you can see all the detail in a contact print.

Beyond the Epson R2400 B&W quality there are inkjet printers with 1.5 to 2 picoliter droplet sizes, 16 bit drivers, 4 to 7 monochrome B&W ink sets. Black Only inksets squirting 1.5 picoliter droplets only from 4 channel heads to improve Black Only printing.  Check the DigitalBlackandWhiteThePrint forum at Yahoo to see what has been developed in time, Jon Cone's products and methods of course, Paul Roark's many experiments, Roy Harrington's QuadTone RIP, the Bowhaus boys, all of them and the interaction with forum members created a wealth of information. That forum has almost 10K of members, must be one of the largest lists on inkjet printing.

Clogging does not have to be an issue, Paul mixed HP Vivera PK ink with ink medium to quad sets for several Epsons and they behave better on the printer than the OEM inkset does. There are turn key solutions available with a short learning curve and they are as easy and convenient to use as the OEM solutions.

met vriendelijke groeten, Ernst

Try: http://groups.yahoo.com/group/Wide_Inkjet_Printers/
Logged
gromit
Full Member
***
Offline Offline

Posts: 133


« Reply #196 on: June 24, 2011, 06:22:03 PM »
ReplyReply

Are the proofing papers not for 90% using PK black? Do you mean the Fiber and Baryta versions of rag papers? Matte fine art rag papers are not really compatible with the proofing media presets.

Yes, you're right. It was a while ago that I did the tests so the comparison in gamut would have been against baryta papers.
Logged
gromit
Full Member
***
Offline Offline

Posts: 133


« Reply #197 on: June 24, 2011, 06:30:47 PM »
ReplyReply

With your critical eye it would be nice if you spend some energy on comparing Qimage's on the fly extrapolation and sharpening with LR's qualities. I do not think that Photoshop will improve your images but Qimage might.

I did tests comparing Lightroom 3, Qimage and Blow Up 2 (all at 720ppi) and got the best results to my eye with Blow Up 2. I encourage others to do similar tests and form their own conclusions.
Logged
John R Smith
Sr. Member
****
Offline Offline

Posts: 1357


Still crazy, after all these years


« Reply #198 on: June 25, 2011, 02:31:38 PM »
ReplyReply

So for certain colors the resolution is sacrificed for accurate colors. However, for the detail that's close to one of the available ink colors resolution can be boosted at 720 PPI. The benefit of being able to do that at 720 PPI is that small sharpening artifacts are virtually invisible (below visual acuity) but lower spatial frequencies (say at 360 PPI and lower) will also be boosted (potentially without artifacts). It is therefore also possible to increase the amount of sharpening at 720 PPI, if the printing application allows to tweak that.

Bart, that started me thinking. At first it seemed counter-intuitive to me that you could use more sharpening on a smaller print, but when you test it out it makes sense. Sharpening artefacts do of course become more visible the further that you enlarge the pixels in the file, and less so when the detail is in fact very small. So I ran another routine on the cups on the table from my test print of the VW Campers, sized to exactly 720 ppi which results in a print size of 10x7.5 ins (a small print in everybody’s view around here). I did this with the LR output sharpening set to off, set to Standard, and set to High. There is visibly enhanced detail in the pattern on the cups with Standard, and High gives the best result. Most importantly, I can see no obvious sharpening artefacts as a result – and I am fanatical about sharpening halos in particular, if I see them I will just tear the print up.

I then ran another test to see if altering my capture sharpening could improve things further. As I think you suggested, deconvolution sharpening could result in fewer artefacts, so I went back to the Develop Module and altered my sharpening to Radius 0.6, Detail 100, and Amount 38 (my original settings were Radius 0.9, Detail 35, Amount 55). The next print gained a little more acutance as a result with output sharpening still set to High, with some fine lines on the cup patterns now becoming visible under the loupe. Just for fun, I am going to attach 1200 ppi scans of the prints so you can judge for yourselves, bearing in mind that this is a very tiny section of the finished print.

And I think that has now about hit the limit for my “small” prints at 720 ppi via Lightroom to my 2400. The real gain with inkjet printing seems to come from the freedom we get to print very large, and actually gaining quality as we do so with big MF files. I have learned an interesting lesson, though, which is that you can really ramp up the sharpening on a small print from a large file.

John
« Last Edit: June 25, 2011, 02:57:01 PM by John R Smith » Logged

Hasselblad 500 C/M, SWC and CFV-39 DB
and a case full of (very old) lenses and other bits
Schewe
Sr. Member
****
Offline Offline

Posts: 5512


WWW
« Reply #199 on: June 25, 2011, 02:48:04 PM »
ReplyReply

I then ran another test to see if altering my capture sharpening could improve things further. As I think you suggested, deconvolution sharpening could result in fewer artefacts, so I went back to the Develop Module and altered my sharpening to Radius 0.6, Detail 100, and Amount 38. The next print gained a little more acutance as a result with output sharpening still set to High, with some fine lines on the cup patterns now becoming visible under the loupe.

The output sharpening in LR 3 is designed to work optimally when the capture sharpening in Develop's Detail panels is set optimally. If the Detail settings are off (or not set optimally) then the output sharpener in Print will be off.

The key really is to nail the capture sharpening so the Amount, Radius, Detail and Masking as well as Luminance noise reduction (I consider luminance noise reduction to be the 5th sharpening slider) are all set so the image looks good at 1:1. I'm often in the mid 40's with Amount and occasionally higher and similar Radius and Detail (plus some Edge Masking) with medium format digital captures from by P65+. YMMV...
Logged
Pages: « 1 ... 8 9 [10] 11 12 »   Top of Page
Print
Jump to:  

Ad
Ad
Ad