View Full Version : Scanning question


imann08
07-24-2006, 07:15 PM
I'll try to explain this as well as I can. Hopefully, it's not original to me. I'll use one I have as an example but this happens on all my scans.

I have scanned an image at 600dpi and then reduced it to 300dpi. The issue occurs even if I leave it at 600. When I show the image at 100%, it almost looks painted. Absolutely awful, even after I've retouched it. When I take it down to 25% on screen, it looks great. It looks like I want it to. When I print it out, the one a cut to 300dpi appears as though it were at about 35% onscreen which is still real nice. the onscreen percentage is equals is an estimate. With the 600dpi onscreen images I have to cut it down to 12.5% obviously but it still prints out just fine.

My question is why doesn't it look good at 100% and why doesn't it print as it looks at 100%. Especially at 300dpi which is fairly standard stuff. Does everyone see what I'm seeing or am I a freak show? The bottom line is that I am getting a good print out so everything turns out fine but I want to know why what I'm describing happens and why it doesn't appear as it prints at 100%. I have always heard that anything other than 100% is less than adequate on screen.

Anyone know this stuff?

recrisp
07-25-2006, 07:21 AM
While you're right about the image 'should' look good at 100%, that all depends on the quality of the image to begin with. While it may appear to look good at a smaller magnification, and print O.K., if it looks odd, or even bad at 100%, that would probably mean that there's either pixelation going on, or it's out of focus, or something similar I would think. The main thing is, if it prints O.K., and you're happy, then all's good.

I have seen many images that were pixelated (from the web) that were pretty good looking prints, but people that are used to looking at faults in images might see 'stuff' in there that shouldn't be, but by the naked eye, it'll pass.

I will say that when you've got an image that is at 300 resolution, it is larger than normal visually, so of course you will see more imperfections at that size. What I usually do is click on "Print Size" and then magnify it one more time, 'cause Print Size is usually at a magnification that isn't visually appealing. (Good magnifications are, 12.5, 25, 50, and 75, anything over that, or in-between isn't good) That will give you the approximate view that it'll print at, if it looks good, then you should be happy enough with the outcome. The printed piece will look even better than your screen will show anyway...

So really, looking at it at 100% is like looking at anyhting with a magnifying glass, you will see imperfections at closer inspection, and to me, that's normal.

I hope that's what you were asking... :)

Randy

imann08
07-25-2006, 10:47 AM
That is sort of what I was asking and it does help me. The advantage of 300ppi only show up in print at 100% and not onscreen because you are getting what is essentially a blow up at that point. I do see little imperfections that I cannot see in print or at 25%. It doesn't come across as pixelated to me as much as seeing those imperfections.

I just always thought that viewing at 100% was the best size to view things at and you would get a lesser quality view at a lesser or greater size. I didn't realize that putting the resolution at 300ppi would effect that. As a matter of fact I see some recommendations in books that insist to make changes at 100% because of that.

The other thing is that I never see this in stock photos that I get at 300ppi. At least no where near the extent that I see it on the scans of old printed photos I take.

The bottom line is that it prints as I want it and viewing it a print size is a good idea. I just didn't understand what was going on and am still a bit confused on the matter even after your explanation. Thanks a bunch though.

recrisp
07-25-2006, 11:34 AM
Isaac,

I know it can be confusing, and I may be confusing you more too, and I don't mean to, but an example would show what you mean, that way we could see what you mean, and not as much guessing... heheh I do ALL of my cloning and smudging type stuff at 100%, well, that is, if it's not too large of an area. I still go down to size, meaning approximately 25% (or 50%) to see what it looks like though, 'cause that's about what it'll end up looking like. I scan, or even resize images from 72 to 300, that's even what the large companies do, or did. It all really depends on the lighting, the camera's settings, and the camera as to how good the image will be beforehand anyway. So with certain images, the image might be pixelated, or have grain in 'em, and grain might be present in the 100% view, but it's harder to see in the printed version, while pixelation might show up. (All depending on what the print size will be too) There's too many if's, in other words...
I'd just keep on doing what you're doing, fix bad spots at 100% and if you want it as perfect as you can, view it at 100% to fix whatever it is that bothers you. I know it bothers me that some things aren't perfect in my images at 100%, so I fix it, I don't like to send out stuff to customers that might come back and bite me on the behind later! heheh

Randy

Flora
07-26-2006, 05:06 AM
Hi,

.... a lot dipends on the scanner .... but not all of it .. :wink:

Trying to learn about scanning 'the right way' I had found big help here:

http://www.normankoren.com/scanners.html
http://www.normankoren.com/makingfineprints2.html

and here:
http://www.jdhartsell.com/scanning.html

Here is a relative recent PCWorld article on the topic...
http://www.pcworld.com/howto/article/0,aid,124718,pg,1,00.asp

Hope this helps...

imann08
07-27-2006, 09:53 AM
Thanks recrisp. You basically handle things the way I have been handling them. I just thought that at 100% it should be perfect and any other % it would not be with those >100% being worse than those <100%.

Flora, thanks a bunch for the links. I'll take a good look them. I hate this scanner, calibration, dpi, etc etc stuff.

Kraellin
07-27-2006, 12:12 PM
imann,

forgive me if this has already been answered. i normally read all the posts before answering but am not this time. so, just ignore if already handled.

you posted in your first post: I have scanned an image at 600dpi and then reduced it to 300dpi. The issue occurs even if I leave it at 600. When I show the image at 100%, it almost looks painted. Absolutely awful, even after I've retouched it. When I take it down to 25% on screen, it looks great. some scanners do the same thing that digital cameras do. they digitally enlarge rather than optically and then claim 'high resolution. basically that is nothing more than artificially adding pixels to get a 'higher resolution'. it's not really a higher resolution. it's an enlargement. or, if you wish, it's an artificial higher resolution. it's basically the same thing you do in photoshop when you want to enlarge. digital cameras do and so do digital scanners. so, read the fine print.

check your scanner specs and see if there isnt something about this. and if so, find what the real scanning resolution is and try scanning at that. and even if you cant find anything in the manual or spec sheets about this, try scanning at 300 and 200 and 100 and see if it isnt better.

craig

imann08
07-28-2006, 01:39 AM
Thanks Craig, that is very helpful. That helps explain why the image doesn't look good at 100% as it should. Thank you.

Flora
07-28-2006, 03:11 AM
Hi,

Isaac,

you are welcome... :pleased:

I hate this scanner, calibration, dpi, etc etc stuff. .... that makes at least two of us!!!! :wink: :wink: :wink:

Craig,

thank you so much for your great explanation :bigthmb: :bigthmb: .... Gosh, I wish I knew more about this things .... but I usually end up with the urge of throwing my scanner/printer out of the window when faced with 'neverending' complex explanations ... :vampire:

Kraellin
07-28-2006, 12:18 PM
imann, flora,

you're welcome.

on digital cameras it's easy to spot since they almost always say 'optical resolution' and then 'digital resolution'. the only one worth looking at is the 'optical'. so, if the camera says '3x optical' and '24x digital', the only value worth anything there is the '3x optical'. also be aware that some cameras will say 'digital zoom', which is exactly the same thing as 'digital resolution' and not worth a darn thing if you have photoshop or Paint Shop Pro or any other enlargement software. when i go window shopping for cameras i always check for at least 10x optical. the rest i simply ignore. a 5 megapixel camera with a 3x optical isnt as good as a 3 megapixel (in most cases and somewhat depending on what you shoot) with a 10x optical.

and of course, the best way to go is with a digital slr with high megapixels. there your lenses are going to determine the optical settings and the more pixels the better.

scanners are no different, really. scanners had a slightly different way of saying the same thing, however and i forget what that is now, but you do want to pay attention when you buy a scanner.

craig

skydog
07-28-2006, 12:55 PM
Any scanner recommendations for slides or negatives? I'm seeking the best value for the $$. thanks

Kraellin
07-29-2006, 10:03 AM
skydog,

there are already some threads on this. you might try the hardware forum.

if i remember correctly, there are 3 ways to go, a dedicated negative scanner, a typical flatbed scanner with the negative scanning hardware added in, and i 'think' someone had a way of doing it with photographing, but not real sure on that last one.

craig