DickK sent me this information via a Private Message and thought it would be a good thing to share with everyone:
What’s the best resolution for a photo to be used in ProShow?
This is a topic that comes up pretty frequently at ProShow Enthusiasts and this thread is an attempt to summarize the various discussions and pull the information in one place.
With digital cameras commonly capturing images of 5, 9 or more megapixels each, it seems like it might be a good idea to reduce those multi-megabyte files before using them in a slide show, so what’s a good size to use?
The bottom line:
In short, “use what you’ve got” would be pretty close to the consensus. With a couple caveats, there are few disadvantages to just using them as-is and there can be big disadvantages to reducing them a lot.
What’s the minimum pixel count for my pictures to look good in a slide show?
That depends. First it depends on the output format you’re going to use and second what you’re going to do with the images in the show. Basically, you need enough pixels from your image to at least match the resolution of the output. Probably the two most common outputs are standard definition DVD video and computer EXE. If DVD video is the output, then each frame of video is roughly 720x480 (varies: NTSC vs. PAL, widescreen or not, interlaced vs. progressive). If an EXE is the output, then each frame needs whatever the display is set to (e.g., 800x600, 1024x768, 1280x1024, etc.) if we’re going full screen.
So, if I use that minimum, everything will be fine, right?
Maybe. That’s where the second “depends” above figures in. It isn’t just the pixel count in the image that counts, it’s the pixel count ProShow displays after any zoom or crop. Those operations are only showing a fraction of your image and now that fraction needs the minimum pixel count. Let’s say you show only the upper, left quarter of the shot (or you cropped down by the same amount). Now only 25% of the image is on screen, but we need the same pixel count portion of the image, so the full image needed 4 times the required minimum resolution (twice the pixel count in each dimension). So that huge image isn’t nearly as much overkill as you thought!
If I use big images, what happens to all the “extra” pixels?
Not to worry, no pixels will be harmed in the making of your slideshow. Wink Seriously, they’ll get processed down to whatever the output format calls for during the video rendering step or the making of the EXE. That’s also what’s happening when your computer displays and image that has more pixels than your monitor’s resolution is set at.
Does it matter if the image came from my scanner instead of the camera?
Not for use in ProShow. Now, optimizing the scan process is another (big) topic of itself, but keeping it simple, ProShow doesn’t care where the pixels came from; what matters is simply having enough of them.
So, bigger is always better?
Mostly, but maybe not always. Large image files use more memory on your computer, so it’s possible that you’ll see some slowdown in ProShow (previews or editing) with big images—though most users don’t seem to see that. Likewise, big images in an EXE output make the computer work harder to display them, so a person with a PC that’s older or short on memory might see some jerkiness in motion effects. Lastly, it’s also true that an EXE output will be bigger if big images are used but, it’s rare that this becomes a significant issue.
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