Thanks, you threesome : Jerry, Ray and Russ, well there's work ahead for me in the New Year about photos and prints. All I ever did was scan, perhaps crop, maybe fiddle with brightness and contrast and print ! With my camera I just shoot, import and let the photos sit or make slideshow to run by my husband. Well now, with all your input, I am mov ed to delve deeper into this subject. So, while not understanding much of dpi and ppi, I at least know there is a difference. So keep on discussing and I keep your explanations in a separate folder for further reference Marta,
On Jan 5, 2006, at 8:15, RWhite at neffpackaging.com wrote: > > > > > LuAnn, > > Russ is exacty right. It's the old GIGO theory/ (garbage in, garbage > out). > Things always look better on your monitor, don't they? > Where I work, we always have to check to make sure that hi res images > are > 300 ppi. A lot of folks confuse dpi with ppi. > If i ever need to enlarge a scan, I take that into consideration when > scanning. If I want to enlarge a 3" x 5" to 6 x 10, I always double > the > scan resolution to 600 dpi. My scanner won't let me dictate ppi. > If I want to enlarge a scan 4 times original size, I scan at 1200 dpi. > We > output everything at 2400 dpi/ 175 lpi. That's when input vs. output > reolution comes into play. > Good luck, and watch those input resolutions. > > Ray White > Neff Packaging Solutions > 1700 Watterson Trail > Louisville, KY 40299 > Tel: 502-491-1820 ext.330 > Fax: 502-491-7701 > www.neffpackaging.com > > > > > "R. D. Preston" > <preston.r.d at earthlink.net> To: > macgroup at erdos.math.louisville.edu > Sent by: cc: > owner-macgroup at erdos.math.lou Subject: > Re: MacGroup: iPhoto sharpness > isville.edu > > > 01/05/2006 01:51 AM > Please respond to macgroup > > > > On Jan 4, 2006, at 10:10 PM, LuAnn Johnson wrote: > >> >> I edited some pictures with iPhoto, and sharpenening them just a >> little made them look clearer on the monitor. I then put 8-10 on >> one 8.5x11 page in Appleworks drawing and printed them at Wal-mart >> for a friend to use in scrapbooking. The results are horrible - >> everything is splotchy and grainy - the way it looks when I over- >> sharpen. >> >> I printed them again on my home HP printer, and they are just as bad. >> >> The pictures look perfect on my monitor, so I don't know why this >> is happening. Could it be because I shouldn't have adjusted the >> sharpening? >> >> When I've done slideshows on iMovie, I have always sharpened the >> photos just a bit, and they look much better. The pictures that >> look great in iMovie look horrible when printed. >> >> Any advice or suggestions? >> >> Thanks. >> >> Luann >> > > Hello Luann, > > Well, it's been a very long time since I've discussed this, but I'll > attempt it > (albeit setting myself back a at least a decade) because my photo- > application > of choice is Photoshop 3 ? now years old. However, the basics > should still > be the same. As I see your described problem, it's just the > understanding of > a key piece of the photographic/print process that you need. > > <: Resolution :> > > If you can, check the resolution of your photograph. If you are > starting with > a traditional photo, it is probably a continuous tone, and I'll > assume you've > scanned it in. Check the scanning software settings for resolution > reference. > > Traditional photographs are continuous tone from lighter to darker > shades, > have used some sort of screen in the bulk printing process to break > up the > image so the printing presses and printers can print a facsimile of > the > photograph. Modern digital cameras refer to pixels, megapixels, > etc., which > is roughly similar to resolution, but much finer. > Many photographs found on/for computers have a 72 dpi resolution, by > default. High quality photos may (should) have a much higher res. > > References: > -- "D.P.I." (dots per inch) > -- "L.P.I." (lines per inch) > -- "P.P.I." (pixels per inch) > > Monitors have two kinds of resolution. There are differences, but > commonly, > monitors have a (device) pixel density of 72 ppi. This is > different from the > choices offered under the 'Displays' prefs (software), which only > changes > what you see on screen, not the device pixels themselves. > > Printers print at certain resolutions, and may offer several > different choices > of available screens in different *patterns*, and possibly dpi/lpi > density to > choose from when applying to a photo to print. When you see a > printer > resolution reference of 300 dpi, 600 dpi, 1200 dpi, etc., that's > the general > resolution for print output. > > For decent quality output for any unaltered photo, you should have a > minimum > of 300 dpi; 150 dpi is course, but can work. If you are altering a > photo and plan > to publish by printing, your picture should probably have a minimum > 600 dpi > resolution. > > Internally, your photo may be a 72 dpi (course resolution), and when > sharpened, > it will have essentially made the pixels *more* course from pixel > to pixel. When > you view these pics on similar monitors/devices, they look fine. > Printing, however, > will amplify these differences, not improve them. If you are going > to publish to > CD or Web, monitors will display your images fine, but if you are > going to publish > by printing, *start* with a relatively high resolution picture (300 > to 600 dpi). > > If I haven't been too terribly wordy, I hope this helps. > > > Regards, > Russ Preston > > > > | The next meeting of the Louisville Computer Society will > | be January 24 at Pitt Academy, 6010 Preston Highway. > | The LCS Web page is <http://www.kymac.org>. > | List posting address: <mailto:macgroup at erdos.math.louisville.edu> > | List Web page: <http://erdos.math.louisville.edu/macgroup> > > > > > | The next meeting of the Louisville Computer Society will > | be January 24 at Pitt Academy, 6010 Preston Highway. > | The LCS Web page is <http://www.kymac.org>. > | List posting address: <mailto:macgroup at erdos.math.louisville.edu> > | List Web page: <http://erdos.math.louisville.edu/macgroup> | The next meeting of the Louisville Computer Society will | be January 24 at Pitt Academy, 6010 Preston Highway. | The LCS Web page is <http://www.kymac.org>. | List posting address: <mailto:macgroup at erdos.math.louisville.edu> | List Web page: <http://erdos.math.louisville.edu/macgroup>
