which has more info: 4mp jpeg or 640x480 300 dpi scan?

[robfilms]

i have photos to scan. the photos will be part of a slide show that will appear on a website and/or a video presentation on a 4x3 standard definition monitor.

on the scanner, i was going to use a 640x480 300 dpi setting.

i also have some photos which are quite old and in glass fronted frames that i dare not remove for fear of damaging the photo.

i was thinking of trying to scan these framed photos but the scanner's light will bounce off the framed photo's glass and cause a hot spot.

i could also try to take a photo of a photo with my digital camera. which leads me to this question:

which has more info: 4mp jpeg or 640x480 300 dpi scan?

any and all thoughts or tips as to how i can achieve my goal of a quality digital image would be very helpful.

be well

rob

[space-time]

what is "640x480 300 dpi scan?" 640x480 what? mm? pixels? somehow "640x480 300 dpi scan?" does not make senses.

if the photo was 6 x 4 INCHES, and you scan at 300 dpi (DOTS PER INCH), then you get a file with 1800 x 1200 pixels, or 2.1 MegaPixels.

It's not only about the number of pixels, but also about compression, etc. You need to try each and choose the one that look the best to you.

[bik]

Assuming 640 x 480 means 640 pixels by 480 pixels, the 300dpi then only refers to how large it's presented.

2.13 inches by 1.6 inches at 300dpi = 640x480.

640 px by 480 px = 307,200 pixels, or about 1/3 of a megapixel.

So, 4 megapixels is much larger.

As space-time alluded, you're only talking about size in pixels, but compression also plays a role. That said, 4MP is much better.

[Mr645]

Since your using the images for web and a slide show. There is little reason to scan larger then the resolution of your display. 640x480 pixels is plenty for the web, but today's TV's get higher. I make a lot of slide shows that are displayed on modern LCD TV's, typically at 1920x1080 pixels.

Generally, a scanner will produce better copies of photos then a Digital camera, unless your using a DSLR with proper lenses

[wickedsteve]

640 X 480 = 307,200

one megapixel = 1,000,000

1,000,000 > 307,200

[ScottG]

I don't think that scanning photos in glass-fronted frames will work terribly well, so I would certainly try taking photos of the photos- using a tripod or some other way to hold the camera steady and no flash. Having said that, I would also scan the photos, and compare the resulting images side-by-side, and see which is best.

cheers

scott

[robfilms]

[quote Mr645]Since your using the images for web and a slide show. There is little reason to scan larger then the resolution of your display. 640x480 pixels is plenty for the web, but today's TV's get higher. I make a lot of slide shows that are displayed on modern LCD TV's, typically at 1920x1080 pixels.

Generally, a scanner will produce better copies of photos then a Digital camera, unless your using a DSLR with proper lenses
thank u all for your thoughts, they are quite helpful.

i'm sorry if my description was a bit confusing. i was only on my 2nd cup of coffee when i originally posted and i need 3 to start making any sense.

mr645-

i can appreciate 1920x1080 but only if the tv can handle high def. even 720 sets won't handle 1920x1080. not knowing how the client will be presenting the scans in the future, my thinking is always to make sure it looks great in standard def 4x3 and then see if they are going 16x9 widescreen or high def.

as to you last comment, why do u think scanning produces a higher quality? i do have access to a dslr with a 50mm/f1.7 lens which often produces great images. i'm thinking with the pixs i cannot scan, i'll shoot w/my pentax.

again, thanks everyone for sharing your obvious experience.

i'll get to work after my 3rd cup and keep u informed.

be well

rob

[Jimmypoo]

You would have to have a copy stand and proper lighting and lens that wont have edge distortion, vs using a scanner. And the scanner can magnify the scan greater than capturing it to a small, but dense piece of film.

[M A V I C]

Scanning them will create a better image than that with a digicam. For starters, on a scan the lighting is perfectly even.

640x480 pixels at 1 dpi is the same image at 640x480 pixels at 100,000,000 dpi.

If you're never going to use the photos again and they'll never be used larger than 640x480, then 640x480 scan is fine. If you're going to use a Ken Burns effect... scan them at a higher res (eg, 1024x768.)

Personally, I scan everything at full size, 300DPI (unless there's an immediate need for higher res.) Then I can use them again later, bigger, or pieces of the images without having to rescan.

For example, I've scanned in stuff like dirty 2x4 boards at 1200dpi.