another scanning question

back alley · 04-23-2005

i think this is basic but i don't know the answer. up untill now my scanning was for the web but, if i want to scan with printing in mind, what size do i need to save the scan at?

for the rff gallery i usually save at about (long side) 800 pixels x ? so that it fits the screen but for a print do i need to save at a particular size so that it translates to a certain print size.

for example, for an 8x10 print is there a certain size to save at?

make sense, do i?

joe

FrankS · 04-23-2005

Hi Joe,

I'm not all that digital photo savy either, but with digital printing in mind, wouldn't you save at the max resolution your scanner is capable of?

bmattock · 04-23-2005

Joe,

Scanning size is somewhat disconnected from printing size. Printing size is a function of dots-per-inch on the printer, not on the screen. Very confusing stuff. Take a look at this:

http://www.wholesaledigital.co.za/m42home.htm

In general, though - I scan at 3200 dpi and that eqates to 4300 x 4600 or something like that - my 35mm scans come out at about 22 to 28 megabytes each. That would let me print very nicely at well past 8x10, and I never want to print larger than that, so I'm good. Hope this helps - I'm a bit fuzzy on the whole thing myself.

Best Regards,

Bill Mattocks

back alley · 04-23-2005

i'm not talking about resolution but the actual size of the image.
like for the book, we needed to save the image at something like 2100 x ?, i think.

as to resolution, i have read conflicting reports about what to save the image at.
for now i am saving at the second highest resolution that my scanner is capable of and at 1000 pix on the longest side.

i have a buddy with a good printer and he will print off some pics for me.

i'm getting curious about hard copies and printers now.

joe

bmattock · 04-23-2005

Joe,

Sorry, that's where my knowledge just pooped out. I'm in the dark past that. I just save at max res on my scans and upload jpg versions of them to Walmart - get back slick 8x10 prints in about an hour, very cheap, look great. But I dinna know what would be the minimum rez I could get away with.

Best,

Bill

back alley · 04-23-2005

hey bill,

my scans seem to be around 200+ kb.

which is bigger mb or kb? doh!

i believe i have already mentioned elsewhere that math is not my strong suit...
joe

back alley · 04-23-2005

hhmmm, i think we're outta sync here bill.

this stuff is confusing and i really don't know if my question is at all relevant.

joe

FrankS · 04-23-2005

megabites are 1000 times bigger than kilobites (I think). If you've got a buddy doing the printing for you, then take 2 files with you of a picture, one at max scanner resolution and the other at the second highest, and see what works best. Scan at 100%.

richard_l · 04-23-2005

The optimum resolution for most photo quality printers is around 300 ppi (pixels per inch), so just multiply the dimensions of the print (in inches) by 300 to get the pixel dimensions. For an 8" x 10" that would be 2400 x 3000. However, as the others have indicated, it's best just to save at the maximum resolution of which your scanner is capable.

back alley · 04-23-2005

that's a good idea frank. unfortunately i wasn't smart enough to start thinking about all this till i made a bunch of scans and saved them all at the same size.

i will follow your suggestion though, with the next batch.

joe

bmattock · 04-23-2005

Quote:

Originally Posted by backalley photo

hey bill,

my scans seem to be around 200+ kb.

which is bigger mb or kb? doh!

i believe i have already mentioned elsewhere that math is not my strong suit...
joe

1mb is 1024kb. I only have to know that because my day job is software programming.

When I reduce my images to post online, I typically end up with a file less than 100kb in size as well. But I would not try printing that.

Best,

Bill

back alley · 04-23-2005

so, my 200 or so kb size scans are not gonna print well at 8x10?

damn...

joe

shaaktiman · 04-23-2005

I think I understand your question, maybe this will help.

As a general rule, for inkjet printing, you want to scan to a size that allows you to print at 300 dpi. 200 is really the minimum though to get decent results. So, if you are printing something that's exactly 8 x 10, you want an image that's at least 1600 x 2000 pixels (to print at 200 dpi) and optimally 2400 by 3000 pixels (for better results at 300 dpi.)

You should also avoid "res'ing up" your image to get to the desired final resolution. It will get rid of the jaggies if your resolution is really way too low, but your image will just get mushy and soft instead. Scan at the resolution that you plan on printing at. So, if you're planning on scanning a piece of 35mm film and you want to print an 8 x 10 at 300 dpi, you should scan it in at around 2200 dpi, (not accounting for cropping.)

adam

FrankS · 04-23-2005

Film rules!

Scarpia · 04-23-2005

Today I received the May 10 edition of PC Magazine. There is an excellent article on this topic on page 72 and while it concerns itself with printing pictures from digital cameras the principles are certainly adaptable to scans. Try www.pcmag.com and if its not on there it is well worth buying a copy.
Kurt M.

back alley · 04-23-2005

my head hurts...

joe

schaubild · 04-23-2005

I always try to scan with the optical resolution of the scanner, in the case of the Nikon 8000 this would be 4000dpi. This gives me a lot of image information to work with (6x9 slide with 48 bit colour depth gives a ca. 340 mb TIFF). I do resizing and some sharpening if required just before print.
If I know I'm using the image only for the web I scan at 1200 dpi and work on it. Then again resizing, sharpening as last steps before publishing.

The reason for these procedures: I learned a long time ago from a pro that it's easier to make the quality of an image worse than vice versa. Just try to imagine you did THE shot, only to find out you degraded the quality to save memory and can't now get a decent output? So I shoot or scan with max resolution all the time. Just my 5 cent...

jan normandale · 04-23-2005

Joe

most of these answers are pretty helpful regarding what you can do with a printer taking into account max dpi for that printer. The calculations are also pretty helpful and you should save those. Finally the advice to scan at max and then 'adjust the resolution' in the software .

What image management software are you using?

Jan

GeneW · 04-24-2005

What Jan said!

For images you want printed, scan at max resolution of the scanner. Then when you edit them, you'll need to crop the image to the proportions of the print size -- same as enlarging.

In PS or PSE this is easy. For your print image, select the crop tool and in the dialog window set the attributes to (for landscape)

Width: 10 in
Height: 8 in
Resolution: 300

Adjust image as wanted with levels and brightness controls, remove dust specks and scratchs, perform any desired dodging and burning, sharpen with a little USM, viewing image at 100% while sharpening, then Save As to a slightly different filename so you don't overwrite your original scan.

Think of your max-res scan as your digital negative. You can re-use it for different print sizes or sizing for the web.

Gene

RObert Budding · 04-24-2005

Take a look at the following site. You can also buy the info in printed format for reading in the John.

http://www.scantips.com/

Robert

Kin Lau · 04-24-2005

If you're using the Canon 27xx, then scan and save at 2720dpi. That's the best quality, and saves you from having to rescan later.

back alley · 04-24-2005

more info...good...

i use photoshop 7 and am still in a major learning curve.
gene, you told me that before, about saving in a different name, wish i had remembered it.

robert, thanks for the site, will read soon.

joe