Most digital cameras, from point-and-shoots to my D200, have video outputs.
This makes it easy to plug into any TV for big, bright slide shows at friends' homes or in motel rooms while out shooting.
So why do the pictures always look awful?
There are two very simple and significant reasons. These apply to all video standards worldwide, with minor variations in the numbers. My numbers are for NTSC; PAL and SECAM are similar as far as still photos are concerned.
1.) Low resolution. Television is only 640 x 480 pixels!!! (Actually it's 720 x 483 non-square pixels if you're in NTSC Hollywood.) The image coming from the video output is guaranteed to look awful!
2.) Composite color. To make a very long story short, the three Red, Green and Blue color channels are mixed together into one composite video channel. That's why you only have one, not three, video cables which plug into the TV. This system was invented in the 1950s to make color TV compatible with the B/W TVs of the day, and, yes, your digital camera's output works perfectly with any B/W monitor if you find one with a video input. Unfortunately it also blurs colors into each other. If you have a red flower against a green background you'll see horizontal smearing of the red into green. This makes the image even worse than a 640 x 480 JPG!
WHAT CAN YOU DO?
You can't. Forget the video output if you want quality. Bring a cheap flat screen monitor and plug it into your laptop if you want sharpness.
If you have a multi-format TV (common in Europe and unheard of in the USA), set your camera to the PAL video output format. It has about 100 pixels more resolution, but the image may flicker on CRT TVs because of the lower field rate (50 instead of 59.94 Hz). You can't play PAL images on TVs in the USA; they only play NTSC.
Ditto for making DVD movies of your images. DVDs can improve quality a little over regular video as explained below, but the resolution is still crappy for still images. Sorry. If you do make DVDs you can try to hide the soft images by having them pan and zoom instead of remaining still.
SO WHY DOESN'T TV LOOK THAT BAD?
Because TV images move. When our eyes follow motion we can't see details as well. As an object moves our brain can integrate together details gained in sequential frames, which also improves the perceived image.
Freeze your VCR and you'll see how bad TV looks with still images!
DVDs: Progressive vs. Interlace (Advanced Topic)
This can get a little complex. I worked as a video engineer for many decades and will use some terms beyond the scope of my photo website. I'll explain why DVDs can look better, but I'll excuse myself from explaining details of these terms.
DVDs can look better paused compared to VCRs because they can take advantage of progressive, as opposed to TV's interlace, scanning.
TV video scans half the horizontal pixels (the odd lines), and then goes back and scans the rest (the even lines). This is great for motion and eliminates flicker since it scans twice as often, but awful for still images since the vertical resolution is reduced almost in half. We can't change this. This is the way video has worked since black-and-white TV was invented and standardized in the 1940s.
Many DVDs and DVD players cheat and take advantage of 3:2 pulldown to convert 23.98 FPS movies into 59.94 field video. DVD players can read the information from movie DVDs as complete and separate frames. DVDs from video sources can't do this. Of course this requires you have an advanced monitor capable of progressive scan, which motel TVs can't do. Oh well!
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