Paul,
Changing ppi does not equal upsampling.
Changing the number of pixels to a greater number is upsampling.
In your 256 to 1500 example, all you have done is tell your PRINTER that, instead of printing 3000-pixel wide image in just under 12 inches, to do it in 2 inches.
Your monitor does not change display based on ppi, so it will continue to display the image the same.
If you had an image which was 400×600 px, and resized it to be 800×1200 px, THEN PSE would have had to create new pixels — upsampling.
Byron
Paul,
Sorry to beat this to death… ppi never matters when you are looking at your image on-screen.
When scanning, ppi/dpi determines how many pixels you will use to capture the image, taking into account the image’s dimensions. A 2×2 image scanned at 100 ppi yields a 200×200 file. Scanned at 600 ppi yields a 1200×1200 file.
When printing, ppi/dpi determines how many pixels will be printed per inch… more ppi = smaller image given the same image dimensions. A 1200×1200 px image printed at 200 dpi yields a 6×6 inch image. Printed at 400 dpi yields a 3×3 inch image.
Byron
Hi Paul.
I too have read things like that, so, i experimented by enlarging a 2mp image, 1600 x 1200, up to nearly A4 and printed at 200res and another at 300 using photo paper in an Epsom 680 printer and givin the limitations of the camera – Oly C700UZ i thought what a great pic, i’m danmed if i can see any significant difference between these and the native size pic of the camera, there is very slight improvement in the detail at 300 but you have to look very hard to see it. I’ve also seen an A3 pic from a 3mp camera and the result could be described as stunning
I deduce there is a lot of misinformation out there about enlarging. Regards
Malcolm
PS Being a Web idiot i can’t show the pics
Guys, if you really want to see what upsampling is doing to your photos, try this. Make a copy of a photo that you have printed out at a normal size, like say a 4 x6 at 300 ppi, and reduce just the resolution to 72, leaving "resample" checked and keeping the physical dimensions (inches, centimeters) unchanged. Print that. You should see a noticeable difference. Save the file.
Now go back to the 72 ppi version and re-enter 300 ppi, keeping "resample" checked and leaving the physical dimensions the same. Print that one and compare it to the original print at 300ppi. You should be able to see how much softer it looks, because the interpolated pixels are never as definite as the original ones were. If you zoom way, way, in (like 1600%) on the photos onscreen, you should also be able to see the difference in the kind of pixels you have from the original to the resample.
If you just resample a little, or in small increments (the method Leen recommends here) it’s not too hateful, but it’s never as good as having real data.
Barbara, great exercise to show what extreme resampling will do!
Barbara (message #4),
What do you mean by "Make a copy of a photo…"? Are you talking about scanning the print?
–Paul
Barbara re 4.
What you say is true, it goes without saying that any enlargement degrades the pic to some degree, however in the real world of home printing, enlarging from 2mp to A4 and from 3mp to A3 – on my set up anyway there is no decernable difference although if i used a magnifying glass some change would be seen, of course there are limits, to enlarge from 2mp to A3 would be asking too much, however i have read of a program from Genuine Fractals which is supposed to do amazing things like make posters from 2mp.
This by the way is the view of those at Better Digital mag also – at least i think so. Regards
Malcolm
Paul,
Barbara means choose an image for which you have a hardcopy. Locate this file on your computer and create a duplicate/copy. She means a digital file copy. After making the changes she mentions, you will print out this version to compare.
What you say is true, it goes without saying that any enlargement degrades
the pic to some degree, however in the real world of home printing, enlarging from 2mp to A4 and from 3mp to A3 – on my set up anyway there is no decernable difference although if i used a magnifying glass some change would be seen, of course there are limits, to enlarge from 2mp to A3 would be asking too much, however i have read of a program from Genuine Fractals which is supposed to do amazing things like make posters from 2mp.
This by the way is the view of those at Better Digital mag also – at least
i think so.
Regards
Malcolm
Callum,
What you found is that the printed results are fine for your use. Barbara’s example is very clear, and you can see the effects of upsampling. But in the printed work, the results may not be as noticeable.
I read the discussions about upsampling and tried the 1.1x resizing method multiple times, compared the results to one 6x resize by Elements, and found that the 6x resize was "better" when viewed by my eyes.
Most of my output stays on the screen (web.) So that is my perspective. There is something I do not understand about the 1.1x resize, but I’ll keep chasing that til I get it "right."
Ed
Hello Ed.
I find this resampling very confusing and the 1 x 1 is a new one, although i’ve seen on the monitor what it does, what i don’t see is why would onyone even consider resampling if one is not going to print the result- eh – , if one can not readly see any difference in a printed enlargement why fight it.
Kind regards.
Malcolm.
Ps i’m chuffed with my A4
No one would bother with resampling if only viewing on a monitor. Resampling – either up or down – is relevant only to prints, and then the type of resampling, the amount of resampling, and the way in which the resampling is done becomes very important in some circumstances, but not always. What about it is still confusing you? In the past, we’ve found that an explanation crystal clear to one person is incomprehensible to somebody else. When that happens, we can usually find another forum member who is able to word things a bit differently and get the information across better.
Is this sort of information written down anywhere, systematically, as in a book–I mean where it is completely dependable? There must be some people who really know what is going on, have written it all down, and have had their claims survive public scrutiny. –Paul (Bullen)
I finally carried out the experiment recommended by Baraba in #4. I found it quite helpful, especially since the differences are _not_ striking. I mean that if someone hadn’t told me to look for these things, I might not have realized the differences. I don’t mean that the diffferences are not discernable. I mean that they subtle enough that with things being done at different times and not part of an experiment in which you can make direct comparisons, I would not have realized what was going on.
With respect to my question about whether this stuff is all written down somewhere, it does seem that optimal learning would include these sorts of experiments. It might help if there was a well-done DVD with animated graphics, etc. For some of us, it is pretty hard to visual what all the numbers mean without aids. I suppose they have (expensive) seminars and training sessions for this sort of thing.
Thanks.
Paul B.
Paul – part of the probkem that you are having finding good definitive information is I think due to the fact that digital imaging is a new and rapidly evolving technology. Parts of it (colour management for example) are so complicated and convoluted that very few people do seem to know what the correct answer is. And with each new version of photoshop the correct answers seem to change a bit!
In other cases – like for upsampling- my feeling is that there is no one-size fits all answer that is appropriate – some particular images taken by some cameras upsize quite nicely, and often only experiment can seem to tell what will work. From what I’ve read, the digital SLRs whose bigger sensors produce images with the least possible noise and distortion (the sort of thing that Leen uses) can be upsized quite dramatically. My G3 images can be upsized quite well – but trying it with my little Kodak with a tiny sensor and very high levels of jpg compression, the results were terrible. I’ve read (but not confirmed this as a general principle- it’s certainly true for my scanner which is quite noisy) – that scanned images do not upsize well.
Of course the problem with finding out this stuff, other than doing the experiments yourself, is that many users of Elements will probably not want to go much further than fairly basic photo editing – most material produced to teach Elements reflects that. And as you have noticed such rapidly produced entry level books tend to oversimplify – in some cases to the point of being misleading.The sort of questions that you are asking are good ones, but are probably asked by a relatively small section of the market (look how comparatively few regulars there are in this forum to discuss these things, given the number of people out there who must have both Elements and the internet…) – there isn’t the market out there to sustain many good technically advanced books/DVDs etc on Elements.
And of course optimal learning techniques vary widely with individuals – personally I don’t have the patience to sit through a DVD, I much prefer working through written material at my pace. And I’m a technocrat who finds the numbers often easier to understand than a verbal explanation. But having taught at tertiary level (not in this area) I understand that I’m probably in a bit of a minority there!
Susan S.
Susan,
Thanks.
And thanks to anyone else I didn’t thank.
For some reason I constantly find myself doing stuff in areas where it hasn’t been ‘reduced to a science’ yet. And if I pursue it long enough, I find myself wanting to make a manual. But I get forced on to other things before that is possible.
Paul B.
