Another Slideshow Question

[Timoleon]

My winter project (if I don't go mad first) is to put my family's 7,440 slides, covering about 50 years, onto DVD I'll probably end up using Ulead DVD Pictureshow. I've got to scan the damn slides first, of course. I've got a decent Microtek scanner that does slides, and I could scan at a fairly high resolution if I have to.

My question is (and I've done some surfing and reading about "lpi"): What resolution, that is, dots per inch (dpi) should I scan the slides in at to get the maximum quality on my television screen? Is it a waste to scan at more than 1200dpi, because DVD displays at 720 (704) x 480? Or do slides need a high resolution because they are so small? Will a high resolution reduce nasty effects like "moire"?

Also, I've read that a straight slideshow --- no SVCD movies, transitions, etc.; displays the pictures more sharply. Is this true? If it is, I don't need no stinking movie...

Any help would be much appreciated --- I'm very much in the dark here!!

[calicogirl]

The dimensions of a slide are approximately 1.375 x .93" inches
The finished scan should be 720 x 480 pixels
With these numbers in mind, we can determine what DPI will result in 720 x 480
Let's start with the 1.375" dimension. That 1.375" must contain 720 pixels.
Here is the formula: 1/1.375 x 720 = 523 DPI

We can check the 523 DPI result by doing the same with the other dimension
1/.93 x 480 = 516
This number is slightly different from the 523, because the ratio of 1.375 : .93 is not quite the same as 720 x 480, but it's close enough

Since some scanners only allow you to choose from predetermined resolutions, scanning at 600 DPI will give you close enough result. Many authoring programs, such as DVD Workshop do an excellent job of taking an image that isn't quite the proper size and producing an excellent result.

So I'd go with 600 DPI

Melissa

[Timoleon]

Thanks, Melissa! I'll begin the grind tonight

[Dodzzz]

'cos the output images from my scanner is always blurred (a little), I'd go for (based on calicogirl's formula X 2) = 1000+ dpi.
so I'd scan it at 1200 dpi.

this also happens to my 2.0 Mpixel kodak digital camera, when I shot at full resolution (about 1600 x 1200) the effectiveness (sharpness) is about at half of it.