Mike Chaney's Tech Corner

I've been experimenting with trying to get the optimum print settings wrt detail/speed, for my printer and came across this web site http://www.inkjetart.com/tips/ppi/index.html (and many others).
 
I would like to suggest that you print out the two pdf files linked from the inkjetart site, and examine the print with a high power magnifying glass. I am particularly interested in the results for Epson printers. Do not print from Qimage or anything other than the free pdf viewer print function. (If you really must use Qimage, then you will need to turn off sharpening, resizing and most everything else - but for your own personal amusement you could leave those settings as normal, but I'm not interested in those results at this time). For my 4000 printer, 180PPI and 360PPI were both excellent, and 240PPI not too bad, others had the expected artefacts and everything above 400PPI gave a pink tone (this was using 2880*1440dpi print settings.) I am particularly interested in the results for the 2200 series printers.

Best wishes,

Ray

Qimage does not read pdf files!
cough .... Mike Chaney is THE expert on this and his expertise is built into Qimage, see http://www.ddisoftware.com/qimage/quality/
A fundamental feature of Qimage is that is sends data to the printer at its native resolution, the values reported by the driver just above the
page preview. That prevents the driver from "messing" with the pixels in some unknown fashion and allows the Qimage superior interpolation algorithms to reign supreme  8)
Terry.

Hi Terry,

I guess you are not interested, then? Worried what you may see?

Best wishes,

Ray

Hi Ray,
Interested, yes but worried no. That stuff seems to be something that Mike has been aware of for years and Qimage takes care of it better than any other program.
The author of that article sad "The question comes up every so often: "what ppi should I have on my source files?""
For Qimage users, the answer is, don't worry about it, you can leave the image alone as far as any re-sizing and tagged ppi are concerned, Q takes care of it for any printer you are using. This stuff about re-sizing images and what ppi should be used is a hang-over from the way you have to use other programs to get the optimum print quality. The real work flow bonus of Qimage is that is not necessary. The print interpolation, smart print sharpening and anti-aliasing controls are all you need; once set to your preferences, they can be left alone in most cases.
That article came to the conclusion that 360ppi was best for their Epson printer, that is half the native resolution of most Epson's. The Qimage web pages explain the advantage of going to 720ppi. For Canon's and HP's the number is 600ppi. Qimage reads this data from the driver and interpolates accordingly.

Sorry if this sounds like a lecture  ::) and you may be well aware of it, but other readers may not, so it is worth re-iterating now and again to explain why Qimage produces excellent prints. No apologies for being an enthusiast for Qimage  ;D
Terry.

Terry.

That all sounds very interesting and informative, but, does it have any relevance to 'print to file' for lab printing?

I usually upload my prints to Fugi for printing.  I used to use ProAm who required 402dpi, fugi don't seem to mind.

Jeff

Hi Jeff,
I have never used a lab for printing but from what others have said, I understand the lab will often specify a preferred resolution. I would assume it's worth finding out what equipment they are using and go from there. I have a local Epson Service Centre who offer a service of printing on a 4880 - they use Qimage, so no worries there  ;)
Terry

Terry,
Sorry for butting in, but!
This has been one of my pet irritations for years.
We would have debates at our club meetings week after week and the folks that cut their teeth on Photo Shop just never understood that ppi means pixels per inch, and without inches specified, you don't have ppi.
As I have seen, Photo Shop opens images with an arbitrary selection of a ppi. Lately they tell me the default is 180. It used to be 72, and the initial print size showed in Photo Shop as 42 x 28 inches (something like that depending on the image resolution divided by 72.
This was not a real print size,,,, just something to reflect the arithmetic.
Then, based on the print ideas of the '80s where 300 DPI was the goal, they worked their images into a size they wanted and interpolated the ppi tp 300 and then later, 360.
Interpolation is the very essence of digital printing.
Interpolation is inescapable (except in an extremely rare perfect match). Interpolation is the reason why Qimage makes the absolute best prints.
The interpolators in Qimage were written by Mike Chaney to be better that the run of the mill interpolators like Bicubic.

In simplified terms, interpolation will add pixels in the correct proportion, correct colors, to bring the number of pixels to up to match the native input of the printer.
In a sense it is "faking" the image for the sake of being able to choose the size print we want.
So we don't want to fake too much as that is not going to improve our picture after a certain point is reached.
Since Qimage has the best set of interpolators and Qimage's algorithms utilize them to perfection, I submit to you that more than  *ONE* interpolation is  degrading your image. So why do it twice.

It seems that old batch of seaweed I must have 300 or 360 PPI washes up on the shore from time to time.
Qimage takes your image (and remember what I pointed out earlier, there is no ppi until we know the i,) and depending on the size of your intended print, now knows the ppi and will interpolate to the native input resolution of *your* printer.
I have yet to see the instance where (making your own prints) anything is gained by interpolating to 300 and then redoing the interpolation at print time.
Let's take an extreme example of a shot you took of a Heron at a distance, and after cropping you find that your 11 x 14 print is showing that it will be printed at 105 ppi.
You will be amazed at the print Qimage will make for you because of the quality of the Fusion interpolator, plus the one time interpolation done at printing time.
If you choose to get that image to 300 ppi first because there was a note in a bottle that washed ashore with that old seaweed, then it will be interpolated again at print time.
That's fake pixels on top of fake pixels.

Mike Chaney is the recognized printing expert and digital image expert on the planet.
He sells Qimage not to compete with CS4 etc, but to give all digital photo producers the best prints that can be made. That's why there are so many professionals, and amateurs alike who print with Qimage regardless whether they start their processing in CS4 or Paint Shop Pro etc.
The best kept secret, it seems, is that Qimage will allow a user to process his work (Raw shots as an example) better and easier than Brand X at 750.00 a pop.
That's why people like Terry and Fred and many other converts are trying to tell anyone who wakes up in 2010, to try Qimage for other things besides printing.

Sorry for the long dissertation. It's just a passion with me, and I love my Qimage.
I took 71 raw shots yesterday at the waterfront in Sarasota, Fl.
I have a problem with Qimage. (I am tongue in cheek serious)
I usually use the blue filename as an indicator that I already checked and adjusted that image if needed. If a filename was still black, it meant that I hadn't looked at it yet
Lately, Qimage is decoding my Raw shots so perfectly that they don't need any fill  or exposure adjustment at all, and I find that I am giving a -1 or a +1 fill just to turn the filename blue.
I have to talk to Mike about that!  ;D

When I was a youngster, my dad would take my brother and me to the Polo Grounds in New York City to see the Giants play baseball. Their star player was Mel Ott.
He was a terrific ball player, but better yet was the light he invented.  ::)
I got an OTT LITE finally. I usually depend on the Sarasota sunshine for my natural lighting to judge prints, but this thing is wonderful!
Why didn't you tell me it was this good.?

Fred

No problem. Wow! there should be a sticky on your post  ;)
When I discovered Qimage in 2004, it was that feature that just said to me: "of course, that's it, logical thinking". I first wanted  Q to print multiple images on a page ( I still do) and soon discovered that small down-sized prints look better too, not just the big ones.

I did, that's why you ....
Before Christmas, my son asked if there was anything I would like as a present, I said an Ott Lite please. What a useful tool! I do a lot of printing during the evenings, especially over the winter and I can now get really good correlation with daylight without having to wait until morning. I have for some time been able to make prints that match what I see on my monitor but now I can compare side by side at my desk.   8)

Terry.

It is quite funny, if it wasn't so sad. It was a simple request. I was looking for folk to actually try something for themselves, a simple printing exercise, to take a few minutes. I was interested in a number of aspects, depending on the results. I posted here, because I thought there may be folk interested in the mechanics of printing, interested in seeing how this stuff works for themselves. I mentioned Qimage, since, unless you set most things off, it will try and compensate? for some artefacts that occur.

Instead of actually trying the simple tests, in the manner I suggested, we get the usual load of unrelated twaddle about how wonderful Qimage, Mike, father Christmas and all are. What a load of ***! Just try printing the images, report what you find, or stfu. ::) Don't hijack the thread.

On the page referenced, there are tif files for the separate patterns, which you may have been tempted to print in Qimage, and there is plenty of software that can convert pdf's to a format that Qimage can handle, that is why I suggested not using Qimage, since you are unlikely to know how the file conversion works, never mind what artefacts Qimage interpolation introduces, unless you turn it all off.

Not everything is about 'how wonderful Qimage/Mike is'. Open your minds, think outside the box. A number of folk use other software too, for specific purposes. This section is headed printers. It is not about Qimage, it may not be even about printing onto normal media, maybe not even printing at all, as you know it, - but thanks to some, it is likely to  never be about anything on this topic, thanks to the way this has been sent off course, by folk who think they have the answer to everything.

I hope I have irritated you guys in the way you have irritated me, by your hijacking of the thread.

Best wishes,

Ray

No not really but I do apologise if you feel the thread has been hijacked. I hope you will apologise for the unfriendly and rude tone you a have used.  :o

Whatever, that stuff on that web page is "old hat" for Qimage and just web page filling fodder. Ok. anyone new to Qimage or thinking about using it may not be aware of the implications of using different print resolutions so it's useful for them to find out. However it's not the whole story and Qimage completes it as it is explained on the Qimage web pages and in Mike's articles. Why re-invent the wheel!
That's the point, Qimage does a better job than anything else, isn't that why you use it - or maybe you don't?
I'll ignore the rest of the rudeness and continue to try to help other with using Qimage as I said without apology for my enthusiasm it.
Terry.

What he said, plus...
Ray, I have no idea where you get the idea that you have been thwarted in some way.
No one is stopping anyone from doing the tests you suggest, nor has anything been said referring to your tests.
As Terry said, we are Qimage enthusiasts and after so many years of experimenting and comparing, we KNOW that Qimage does the best job.
Right on target! Why reinvent the wheel?
Artifacts? Qimage offers an artifact free Hybrid SE, and an anti aliasing slider when downsizing to eliminate artifacts, if you so desire.
Oh what's the use.
You feel threatened, and I don't know why.
Have a fine day!
Fred

Fred, Terry,

I'm not at all feeling threatened. Also, I do not think I've been 'rude'. I also help folk, I think. You still do not understand anything of what I was asking, a simple request to print some pages and say what you saw, but instead you persist in extolling the wonders of Qimage for doing everything. The question is not about Qimage, nor any printing software. But, it seems that many aspects of the possible application of printers is beyond you, and you wish to needlessly promote the wonders of Qimage. The question was not about Qimage, (how often does that need to be said?) but If anyone believes any software, or even a manual method, can invent information (upsize) without introducing artefacts, then indeed, I would ask, what is the use?

I use Qimage, I persuaded Mike, with some help of a few others, to introduce the canvas folds. He thanked me for my efforts, both publicly and privately. Mike is 'big enough' to fight his own corner wrt his software, I think it does a disservice to him/it in that you immediately leap to his/its defence, even when there is no attack.

Most folk use this forum, only when they get a problem - they are takers, not givers. Once they solve the problem, they often do not say it was solved, they just clear off until they get another problem. Most folk do not initially give enough details of the problem, but you tend to leap in with a Qimage fix. However, often when more information is forthcoming it is found to be something different, maybe memory issues, or whatever. I had thought my question was fairly concise, but I guess you assumed that it was qimage related, or in some way Mike's status was threatened, or at least that is how I see your odd reactions. You were not prepared to answer the question, never even possibly looked at the images, but thought you had to leap in and say something, thus prejudicing any other potential 'experimenters efforts'.

By now, instead of getting half a dozen or so sensible responses, allowing me to assess what I wanted to assess, I have to spend time justifying my actions, explaining the irritations that your actions cause, etc.  I think I may start another topic, emphasising that it is not a Qimage aspect, and hopefully, within the membership there will be some who can think outside of the box, so to speak.

Best wishes,

Ray

Wow, I'm going to address the original question and ignore the rest.  I'm not able to test an Epson as I have an HP and a Canon at the moment and no (working) Epsons.  I'm also not able to test HP/Canon properly because no driver-resolution (600 PPI) test is provided at that link: quite an oversight I should think given that all Canon and HP printers run at either 600 or 1200 PPI.  I can provide some insight into the methods, however, and I have run very similar tests in the past so let me give you my findings on this subject.  I did extensive testing on this years ago and have had a similar test online for many years.  Just click the "Quality Challenge" link from the Qimage web page and the test charts are at the top.

The bottom line is that all printers produce the best quality at their "native" setting.  For Epsons (since you asked), this is typically 720 PPI except for wide format printers that run at 360 PPI unless you specify "Finest Detail" in the driver, at which time you'll get the full 720 PPI.  Manufacturers specify this native resolution because their halftoning algorithms work based on the native resolution.  For example, if you pass 720 PPI data to an Epson printer that prints at 5760 x 2880 DPI, the halftoning algorithms take your 720 PPI input data and map that to an array of 8 x 4 (32 total) printer dots.  Manufacturers usually have baseline halftoning algorithms that work on the native PPI, meaning that for an Epson, whatever you send it is going to end up at 720 PPI before the dots get placed on the page anyway!  This is why sending non-integer-multiples give drivers a problem.  If you send 300 PPI to a 720 PPI driver, or even something more odd, like 518 PPI, the driver has trouble because it's interpolation algorithms are very basic.  In fact, sending 518 PPI can be worse than sending 360 PPI!  For Epsons, if you send 360 PPI, it is almost as good as 720 PPI but not quite, on most papers.  If the printer/paper couldn't handle any detail at all past 360 PPI, the driver wouldn't request 720!

That link in your original post is simply showing that drivers do best at the native resolution reported by the driver (the 720 you see above the preview page in Qimage) or simple fractions thereof (1/2, 1/3, 1/4, etc.).  So an Epson runs well at 720, 360, 240, and so on.  Canon's run well at 600, 300, 200 and so on.  Why pick the largest: the "native" resolution, for Epsons, usually 720?  Because while there will generally be no real artifacts at 360, there is some resolvable detail that the printer can produce between 360 and 720 PPI.  So we run it at max (720) to get the most detail possible?  There is no down side, and no discernible artifacts caused by printing at 720 versus 360.

Mike

Ray,
Back to the beginning:
I downloaded the tiff versions of those images and did some prints. I used Epson Archival Matte paper although gloss would probably have been better.
I used just the 300, 360 and 720 ppi images, test as follows with comment about resolution and artefacts/moire effects.
Test 1. Set Q to use the native resolution of the images and turned off interpolation and print sharpening.
The results are similar to what I got when I first did Mike's Quality Challenge tests some time ago.
300ppi, poor as shown on that web site.
360 ppi good.
720ppi very good and the extra detail can be seen as Mike says - this is where gloss paper would be even better.

Test 2. as above but I turned on Hybrid SE Interpolation but no print sharpening.
300ppi good
360ppi good
720ppi very good, again gloss paper would show better results.

 I used "very good" rather than "good" because the fine detail of the 720ppi image can be seen.

The key thing in this test is how Qimage improved the 300 ppi result - no surprises there  ;D

Hope that helps and encourages a few other to repeat the test  and do Mike's web site tests too with Canon or HP printers - if they are not convinced of Qimage's efficacy that is.  ;)

Terry.

Thanks Terry,

Did you try printing the pdf's from the acrobat reader print function? iirc you have a r1800, which will give higher resolution than my 4000. Among other things, At this time I  am interested in what happens when it attempts to print beyond its native resolution. On close inspection, I get the pink tone that I mentioned starting at 380, but at 720 upwards there is hardly any black ink at all. I would not expect that to happen with your printer with these charts - maybe beyond 1440lpi?

Thanks Mike for your explanation. I'd seen it before, or similar. It is why I bought your software a few years ago, having tested it out for myself with your demos.

Best wishes,

Ray

No, I did not try that, I'll see if I get a moment later today to do so. I'm using an R800, so basically the same as yours, just smaller.
Terry.

Just a little extra information.
About 18 moths ago I gave a presentation to my Photo Club on Qimage. I prepared some "real world" images to demonstrate the advantage of using the printer native resolution.
Another interesting related fact related that was noticed by someone else at the club, and demonstrated, is that it is best to prepare images for projection with the same size as the projector resolution, e.g 1024 x 768 pixels. When a a higher resolution version of an image was projected, it was not as sharp. So again, don't let the driver mess with the pixels  ;).
Terry.

I have now printed the pdf version of the InkjetArt test images. I made sure any scaling was turned off and set the printer driver (R800) to the correct paper (archival matte) with the colour control neutral/standard.
The results on resolution were as expected and as Mike explained with reference to simple fractions of the native resolution. There was no pink appearance anywhere. The main difference between printing the pdf and the individual images via colour managed Qimage was that the pdf images were quite dark, especially the higher resolution ones. Thus it was difficult to see the pattern lines on the darker section of the 720ppi blocks. 960 & 1440 were just complete dark grey blocks.
My conclusion would be that going above the 720ppi native resolution is a waste of time & resources. It makes me wonder whether the "fine detail" setting on some HP printers that give 1200 ppi, rather than the usual 600ppi, is worth it too.
Terry.

Thanks, Terry.

The native res of my printer is 360, whereas yours is 720. Also, of course, the printer drivers will be different, and most likely will handle 'errors' differently. I expect, given a fine enough lpi, all printers would give what at first site would appear to be odd results.

Best wishes,

Ray

Fred-
I agree with you there.  People many have not understood the difference between PPI and DPI for years.  The camera manufacturers tend to cloud the issue even more in their advertising.

OTOH, PS really will let you open a file at many different resolutions.  (I think the old 72 was a by-product of screen resolutions.) 

That said, and being an avid believer in "let Mike do the interpolation"  ::), I now leave the PS sizes at whatever the cameras spit out.  We know we can do the math of LXWxPPI=X and get different size/resolutions of the same equivalent--but why?  I can edit a (hypothetical) 24x36 at 120 using "fit to screen" just as easily as anything.  Then hand it to "Mike" to make it a 12x18 print.

Less is more with interpolation.

Can anyone comment on my situation?  I have been using an HP 8750 for a long time now and previously I always used 300ppi for prints.  After reading this thread, and some other similar info from various photography forums, I've been printing with 600ppi.  I use the printer's "Best" quality setting and usually print with Qimage.  I honestly am not really sure if I'm seeing a difference between 300 and 600ppi.

Should I continue with 600ppi?  Should I be printing at "Maximum Quality" (interpolated 4800x1200) setting instead of "Best" quality?  I print from 16 bit Tif files in Adobe RGB, and use the canned HP paper profiles with HP Premium Plus paper.

Start by reading Mike's latest article here.
http://ddisoftware.com/tech/articles/march-2010-smart-photo-printing/
It tells you why you should use Qimage for ALL printing, see also his comments in this article:
http://ddisoftware.com/tech/articles/september-2009-digital-photography-reality-check-308/
especially those related to 16 bit printing!
Your comments give the impression you are sizing images before printing in Qimage. If so that is a definite NO NO. You must let Qimage do all the interpolating and never re-size in another program. That could explain you not seeing any difference between 300 & 600 ppi.
I assume your "Best" and "Maximum Quality" setting are driver settings. They determine the ink spray pattern "density", the latter being much slower to print. "You pays your money and takes your choice" - try the different driver settings, with identical Qimage settings, and check the print, with a magnifier if you need to.
Whatever, look at the Web site and do the quality challenge to be convinced about using the full native resolution.
See http://www.ddisoftware.com/qimage/quality/
Qimage will determine the "Native" resolution from your driver; I'm not familiar with your Canon printer but Canon's native resolution is normally 600ppi. Just use your original image and print using that.
You can see what native resolution Qimage is using by looking just above the page preview on the main screen; both the printable area and resolution are given.
Hope that helps. Come back if all is not clear.
Terry.

Terry, you're making some assumptions which are incorrect.  When I print with Qimage, I don't resize at all, but I may crop slightly for composition purposes.  And I will continue to work with 16 bit Adobe RGB Tifs (from the original Canon CR2 Raw files converted with ACR 5.6).  My printer is the 9 ink, 13x19 predecessor to the HP B9180 and B8850.

I just want confirmation that even if I don't notice it, I'm probably better off using 600ppi.

Chas,
I'm pleased to hear it.  ;D
It is worth doing that little check given on the Qimage web site, it's quite revealing even though it's not a real-world image.
I appreciate there are advantages at the editing stage but from Mike's articles, the jury is still out with respect to printing especially when there are few 16 bit drivers around.  :o
Terry.

OK...  I've been printing for several years and have always:

Shot in Raw
Converted to 16 bit Tifs, Adobe RGB
Printed from 16 bit Tifs (300 ppi)
Gotten excellent prints at every size from 4x6 to 13 x 19.

The only change I recently made was setting the ppi to 600 to match the native resolution of my specific HP printer. Previously I used 300 ppi.

Mike's articles are written in a scatological style and I'm not sure of what he is recommending.  Should I convert from 16 bit to 8 bit files before printing?  Should I go back to using 300 ppi?  Does it make a difference? Yes or no answers will suffice.

The thing is... I don't have a "problem" per se.  I'm an advanced Photoshop user, I know my way around color management, I use a professional level photo printer and my prints are excellent.

Doing some research on 16 bit printing, I think I answered one of my own questions.  My HP 8750 printer specifications say it can handle "TIFF 24-bit RGB Uncompressed Interleaved".  These are 8-bit files (8x3=24).  My understanding though, is that the driver automatically downsamples the 16bit files to 8bit, AT THE POINT OF PRINTING.

I also found this article by Mr. Chaney:
http://www.steves-digicams.com/knowledge-center/hype-or-hero-take-2-16-bit-printers.html

I think my course of action is to continue to work in a 16 bit environment right up to printing, and then convert from 16 to 8 bit before printing, regardless of whether I print from Qimage or Photoshop CS4.

Comments?

Maybe I can help a little although from your scatological post, there's not much you don't already know.
The choice of 600 or 300 ppi is made by you in your driver. Qimage only reports that selection to you.
Qimage will interpolate your image to the native input ppi that you have chosen.
What Terry has been trying to tell you, but your mind is already made up and closed, is that you are making 300 ppi images in Photo Shop unnecessarily, which is doing an extra unnecessary interpolation.
If you are using Windows and Qimage, your image is changed to 8 bit anyway before it will print through Windows. Again, another unnecessary step to make 16 bit images.

The best method it to convert your raw images to TIF or JPG in your current Raw processing app,and open them in Qimage.
Set the print size, and Qimage does all the interpolating with the best interpolation algorithm, and matches the required native input resolution for your printer.
600 vs 300?  I would use 600 unless my image was so large (like a stitched pano) that the file would be too large for your computer's resources.
Fred


 

No, I'm not...  I'm making 600ppi images.  And, it's done automatically through the export presets in Adobe Camera Raw.


Again, 16 bit is in the ACR presets.  It's not another step for me.  I do a lot of editing and retouching in Photoshop CS4 and prefer to edit in a 16 bit environment for as long as possible before printing.


Please re-read my previous reply.  And you don't have to sell me on the benefits of Qimage.  I own it, I use it, I love it!


Now that's the answer I was after.  Thank you Fred!   ;D

Chas,
You said previously:
My assumptions do now seem to be correct because you now say:
This is what I was trying to get at previously and do as Fred suggests and leave Adobe's crude interpolation algorithms alone. Let Qimage do the work with its superior algorithms. Did you read Mike's latest article and look the samples and the "Reality" article, it's all very clear to me?
Terry

So, are you saying that I shouldn't set the presets from ACR to open the file in Photoshop as 16 bit, 600 ppi?

Hi Chas,
I'm not really familiar with CS4/ACR settings but from your screen snap, it does seem that the original image pixel size is being maintained (no re-sizing), ie. 2848x4272 pixels. The 600ppi is, I think, just a tagged value on the image. This, in reality is meaningless, because an IMAGE only has a pixel size, it has no inches so ppi is only relevant to prints.
There is often confusion about this matter so you need to think in Qimage terms for printing, linear dimension for prints.

Your earlier post (reply #21)
talked about so I just want to make sure, the image you use from ACR in Qimage is still 2848x4272 pixels?

Assuming the 600ppi is a tag, IF you used Qimage's "Original size" option, your image would print at 2848/600 x 4272/600 = 4.75" x 7.12". There are a few guys who like to work that way, but it's much easier to use linear (inch) dimensions in Qimage, after all that's what you need to specify for a print size.
In a word, the 600ppi in ACR does not matter, if it's only a tag. (perhaps someone can confirm that)
Accept what Q tells you is the driver's native resolution, (600 for HP & Canon, 720 for Epson), or lower if at a lower than maximum driver quality setting.
I hope we are nearly there now, sorry to go on about this but I had the feeling there was something that was causing confusion - for both of us  :o
Terry

No confusion and I do appreciate your time.  I understand that the 600ppi setting I enter is meaningless until/unless I print.  I set that because I still occasionally print from Photoshop and it's just one more step saved, and one more pre-print setting that's easy to forget.

Regarding the 4800x1200 interpolated...  That's an actual print quality setting in most HP photo printers. I didn't mean to imply that I used any software to interpolate to this resolution. Best = 600 dpi, Maximum = 4800x1200 dpi.  I always print with the "Best" setting.  I guess most of the residents of this forum are Epson or Canon users and not familiar with the prosumer level HP printers.

Regarding 16 bit files, of course I knew that Qimage handled any required interpolation automatically, but I thought you guys were telling me I HAD to send Qimage an 8 bit file.  Anyway, I learned something today.   :)

This is DPI, the printer nozzle spray pattern number, not to be confused with PPI, print pixel resolution.
On my Epson, all the "Photo" quality settings are 720ppi with dpi of 1440, 2880 and 5760.
Terry.

Yes, leave it in 16 bit after you leave ACR.  Do not convert to 8-bit; nor should you re-size to 300ppi, 600ppi or anything else.  Beyond cropping (you can leave the ppi box blank) do not resize.  Let QImage do all the interpolation as it prints.  MUCH better than CS interp.

Seth

Seth, thank you,
This was the bit of information I did not have in trying to help Chas in a recent post I made. My suspicions are confirmed, he has been re-sizing in CS  :'(
And thank you for emphasising this most important point; only one interpolation is needed for best quality and that's the Qimage one.  :)

Also for Chas,
That web site is defunct as far as Mike's articles are concerned, they are all here on this one. I did provide the links to similar articles on an earlier post and the one above is there too.
Terry.

Terry, please put your suspicions to rest. I certainly DON'T resize in Photoshop when I'm going to print with Qimage. Never have.  But I WILL resize in Photoshop when I'm printing from Photoshop.