Big E-Mail Scans

I do genealogy research and often exchange scanned documents (not requiring high quality) with others. Sometimes I get scans from others that open in OE as very large documents. I have to take them into an image program and resize them in order to print or otherwise use them. Some of the correspondents I deal with know even less than I do about scanning and it's pitfalls and ask me what they should do to correct the problem. I know that my scanner program, Vistascan, when the scan destination is e-mail, automatically scans at 75 dpi and in jpg. format and that seems to work well. I am reluctant to to try to tell others since I don't know any specifics of other scanners and programs. Is it a good rule of thumb to tell others to set their scanner at 75 dpi and jpg. format?

 

This is a subject that can take a while to explain and for some can be kind of confusing. In general, 75 dpi - 100dpi should be about right for email type stuff. The size of the image you receive depends on the dpi's it was scanned at and the resoultion that you have you're monitor set to. The higher the dpi the image is scanned at, the larger it will be. It will be both larger in size on the monitor and it will also be a larger file size (take up more space on your hard drive). As for you're monitor resolution setting, the higher the monitor resolution setting the smaller the pic will be. So, if you view a pic that was scanned at 100 dpi on a monitor set to 1024x768 it will cover less of the screen area than it would if you had you're monitor set to 800x600. Are we getting confused yet??? Try viewing a pic on your puter with the monitor set at one resolution and then change the resoultion of the monitor to a higher or lower resoultion and look at it again.

Scan a pic at two different dpi's and look at the two using the same resolution setting on you're monitor and see the difference. As you can see, there's really know way of know what's best for the other person unless you know how they have their monitor set.

One more thing. The biggest advantage of scanning things at lower dpi's when emailing them is the fact that they will be smaller in size (hard disk space) and not take as long for that person that's using dialup to download to his or her puter.

If you're scanning a pic to print it, you would want to scan it at a higher dpi (for quality) but even then you run into the limitations of you printer which is another subject itself.

Have a look at the following web page. It can explain it far better than I can. If you do a lot of scanning of pics it or if you just want to understand this better it will be worth your time.

http://www.scantips.com/

 

Zander - Thanks for your input. I think I now understand enough about scanning to know that there are apparently too many interconnecting variables to generalize. However, the link you sent me to, which is now in my Favorites, did confirm that in general one should normally scan at 75 to 100 dpi and in jpg. format for e-mail. Again, thanks.