In article <i%tjd.133$>,
says…
That is more than "only like a hunch". (Do you have more than a hunch?)
No, my view is only a hunch too. Our considered opinions about these hunches simply differ, which is a common situation when there are no facts. My own view is that printing at around 300 dpi works very well in general, and I cant see any of the supposed improvement at 720 dpi, real or interpolated. A few say they do, but I dont.
OK, thanks Barry, I was just inquiring if there was any evidence to confirm that story. I understand the answer to be no.
I suggest that you examine the principles of what I say, before getting to
the
specific numbers. That is why I made up numbers such as 1/250th inch in the post you are replying to.
I understood your 250 dpi case, and about aligning ink dots in it. I just couldnt imagine how this exactness much matters when the situation needs to fit in several more ink dots than can possibly fit the printed pixel area. It seems like picking nits when the actual pixel area is not well defined (intentionally randomized all around the limits of where it should be), and the ink dot is larger than we imagine it to be, and that vague situation is not about any one ink dot anyway, and I gave it a 297 dpi image file. It is about the averaged color of the pixel space on paper, the best our tools allow creating it, which is not that great for discrete ink dots.
Are you talking about dpi or ppi? Are there any inkjet printers that work in the 300 dpi region? I can’t find any in my Jessops catalogue. But, where inkjet printers are concerned, I think dpi numbers are marketing BS anyway.I don’t care about dpi numbers, because I am a photographer, and what matters
to
me is how a driver+printer displays the pixels I give it on inches of paper, not some esoteric marketing measure of "dots".
Yes, now that the motor stepping specs are much smaller than the ink dot diameters, then the motor specs dont say much now. I agree, only the final results on paper matters today.
OK, I’ll bite. My use of dpi always means image resolution (pixels per inch) if the usage context is about image resolution. Or it always means printer motor stepping ratings (or so-called ink drops per inch) if the context is about printer motor stepping ratings. Depending on the usage context, my term dpi always means the only thing it can possibly mean… if about images, then it is about images. I suspect we may not find many English words that only have one meaning. 🙂 Context always decides the meaning, we are used to this.
The term PPI is also fine, no problem with it at all, and I will understand ppi too if you prefer to use it. And if you’ve been around the block once, as you have, then I expect you to understand dpi too. Dpi was technical jargon in the older days (a few years ago), and pixels are infact conceptual colored dot of sorts. Nevertheless, dpi is simply the universal name for image resolution, and always has been, for years and years. PPI is relatively new usage, and it is fine too. Regardless of preference, we must understand it with either name, dpi or ppi, because we are certainly going to always see it both ways.
I know some people either dont or wont understand, but sometimes its best to just accept how things are. We really do need to understand either way.
If you might want to argue it, you must also deal with the fact that all scanner specifcations say dpi, and almost all (but a few exceptions) scanner software does too, and I assure you that scanners use of dpi definitely never means ink dots… scanners dpi will always mean pixels per inch of image resolution, in the classic sense. Even continuous tone printers, dye-subs and Frontier-type printers, are also rated dpi, and these certainly always mean printing pixels too, not single-color-ink dots. I doubt you are saying they are all wrong too? I cant solve that problem. They do know what they’re doing, so I just go with them, because that is what dpi means, in the context of image resolution.
Does the Windows GDI return dpi or ppi? Qimage works in ppi, not dpi. As it should, of course.
I have not seen the newest Microsoft photo editors, but I’d guess they are using ppi too. But otherwise I really doubt Windows itself or GDI has ever said ppi once. Actually, GDI printer rating in dpi would be correct for your limited reserved definition for dpi, and my point was that the GDI printer rating is about your motor dpi instead having any meaning in terms of ppi and pixels. Today’s Windows XP advanced video setting still says dpi too (for logical inches), and this is the same video value GDI shows.
(And what is an agreed, standardised, definition of "dpi"? Is there one? TIFF talks about ppi, not dpi. Photoshop dialogues are ppi, not dpi. Ditto PSP, I think. The ink-droplet technology is at least as important as the dots per inch, even if that means the same as droplets per inch, which is variable if you have variable droplet sizes).
The prepress industry has used dpi forever, with both meanings in context, but one never heard ppi until recent years. But there are so many newbies today using scanners and cameras, and they often dont understand much of the details at first, so the photo editor software has largely changed to say ppi (Irfanview is one exception). So usage is changing slowly, but this is a relatively new thing, last few years, to help newbies understand the difference. Certainly I do agree this recent distinction (ppi for images/dpi for printers) is less confusing for the newbies. I have no problem with ppi, and my own book was changed to say ppi a long time ago because it is more clear for newbies. Nevertheless, I always still say dpi myself in person, thats just how I learned it, and how I think, and what it is, because dpi is simply the name of it and always has been, IMO.
Other preferences are fine too, PPI is good and very descriptive, but the main thing is that we all really need to understand both ways. Those that imagine a law is written in stone saying the term dpi is reserved for printers ink dots are simply wrong, they just dont know how things are, and always were. That is merely their preference.
—
Wayne
http://www.scantips.com "A few scanning tips"