Is 300 dpi adequete - is higher dpi worth the time

[sofasurfer]

I have some old 8x10 inch b&w negatives showing outdoor scenes. I took them to be scanned at a professional photo shop and indicated that instead of just scanning at 300 dpi I would like to get a higher dpi. The girl at the counter said she would have them scanned at max dpi. When I got them back they were scanned at 300 dpi. This seems very adaquet for my current needs but I wonder if I am losing anything with such a low dpi scan. How can I tell if I am able to get an enlargement as big as the negatives are capable of producing?

 

[Josh66]

What are the pixel dimensions of the scans? If they just scanned them at 300 ppi, it would be 2400x3000 - that does seem kinda small for 8x10 negatives...

 

[sofasurfer]

Ah, never mind. I just showed my lack of expertise. Actually, some of them are about 6x8 and when I looked at the pixel count I was looking at a 6x8er. The property window shows that they were scanned at 600 dpi (actually ppi, is that the same thing?). An 8x10 is about 5700x4400 dpi.
Thanks for your reply but I guess I need to come up with a more meaningful question.

 

[Big Mike]

they were scanned at 600 dpi (actually ppi, is that the same thing?)

The terms are often used interchangeably, but that's incorrect.

Dots Per Inch is a printer function and has to do with how ink is laid down onto paper.

Pixels Per Inch is a property of digital images, telling a computer the size it should be displayed at. In most cases, PPI is sort of meaningless. It can be 100, or it can be 1000...all it changes is the size on your monitor...and if you are using a program that zooms the image, then all it changes is the zoom level (and/or size).

The important number is the actual size of the image, in pixels.

Now, when you want to print an image, you can use the 300 PPI as a guideline...and know that 300 pixels, per inch of print, will be sufficient resolution for a high quality print. Actually, many will tell you that you don't need that much, and 240 is plenty, and even less is OK for larger prints.