A few scanning tips
This image was scanned at 600 dpi optical on a Microtek Scanmaker III with TMA. This image size is 506 x 779, and is the maximum possible size I could get from the 35 mm slide at 600 dpi. The edges were not quite straight, and were cropped just enough to be straight. It is shown full size so that you can judge the size. It is large enough for many purposes, but probably not for printing. Printing it at 150 dpi would give 3.4 x 5.2 inches. It would be half these dimensions if scanned at 300 dpi, or if printed at 300 dpi. There is great potential for larger film sizes.
The image below is the same slide, scanned at 2820 dpi on a Minolta Scan Dual II film scanner. This small image is from an area of 0.20 x 0.15 inches at the center of the slide (smaller than a pencil eraser), and shows the greater detail available at higher resolution. The full frame image was 28 MB and 2552x3775 pixels (compared to 506x779 pixels above at 600 dpi), so the full frame image could be printed at 17x25 inches at 150 dpi (or at 10.6 x 15.7 inches at 240 dpi).
To get sufficient printable image size, 35 mm slides need much more scanning resolution than a 600 dpi TMA can provide. However, a TMA on a quality flatbed has great potential for larger film sizes, like 4x5 or 8x10 inch sheet film. Large film is the real purpose of a TMA, but 35 mm film needs a dedicated 35 mm film scanner, which typically offer 2400 to 2800 dpi capability