First of all, using a 300DPI image is probably overkill. You should clean the image and photoshop and make the frame size 2 or 3 times the size of DV if you want to do moves. If you have a frame size that big, 72 DPI is usually all you need unless you want to start zooming out of someone's nostrils. You'll get a lot more RT with a lower DPI rating too. 72 DPI is the target for all raster graphics: TV, web, etc. Most people totally overkill image size and DPI. The only way to really optimize the scan is to use Scan Guide Pro from Neotron, so you can scan correctly from the get go. The DPI and frame size are then altered in Photoshop.
You
really need to look at your stills in a video monitor, not the Canvas. I really think that all people should use a video monitor, not just the rich and famous. A TV set will do in a pinch but is not quite as good. Most people wrongly do not monitor their output. If they did, we'd see a lot fewer of these posts - which are
very common.
This gets by a lot of people: you have to render out your stills at Full Quality. Make sure in the Sequence>Render menus, the dark green FULL bar is checked.
Also monitor your video in Safe RT and at Full Frame Rate and High Quality.
Last but not least, if you scanned your images, JPEG is the LAST choice you should make, since it is a lossy format. Much better to use PICT. One should only use JPEG if the images are coming raw from a digital still camera. Otherwise: PICT, PSD OR TIFF are the best choices.
Please check out my book, "Effects and Motion Graphics in Final Cut Pro". Many of these issues are discussed in detail.
Kevin Monahan