digital camera and laser pointer

I was playing with my laser pointers this evening and my camera. I noticed that when I put the dot on the wall and viewed it through my camera it showed the the dot and the beam appeared to be a faint purple color, but when took the pic all it showed was the dot on the wall. What am I seeing, any ideas?

Your Camera is showing you what your eyes cant see. The purple color is what IR light looks like on your camera.

If the preview shows strange effects, this is likely to be caused by high exposure of the sensor or the auto white balance going nuts from all the green light. If it were caused by IR picked up by the camera, it would be visible in preview mode as well as in the captured image.

Some cameras in awb mode will render the rest of the scene a bit purple/magenta trying to compensate for the unusual load of green in the captured shot too. Please post the picture when in doubt.

Benm said:

it would be visible in preview mode as well as in the captured image.

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That's not always true. I've had many cameras that don't take the picture you are viewing through the preview mode. I never understood this. It should take the same picture you are viewing but many times it doesn't. Maybe the higher end ones do.

Nah, there is a technological difference between live preview and the actual picture you take. Live preview leaves the sensor active all of the time with the shutter open, while the actual image taking involves exposing the sensor for a period of time determined by the shutter.

This causes the preview to be noisy in dark environments and sometimes overloaded in bright ones. It also gives rise to odd artifacts like strange bands of light emanating from bright spots in the composition - often very apparant when taking pics of sunsets and such high contrast scenes.

These prolbems are most pronounced with budget compacts, but even good SLR's suffer from them when previewing on the display instead of through the ocular.

Digicams can have severe problems handling laser spots in preview mode, because the contrast beween a laser spot and the area around it is very large - much larger than highlight/shadow ratios seen in natural scenes.

HHmmm interesting. I thought I was doing something wrong. IMO it should take the image you are viewing. The shutter is already open, why no let it capture a single frame from the rolling preview?

If you check my profile I have some nice sunrise photos I took. Didn't have much of a problem with light bending. My secret? Take a ton of photos with different settings LOL. I took over 600 pictures that morning, and only about 10 came out the way it was suppose to.

Tech_Junkie said:

HHmmm interesting. I thought I was doing something wrong. IMO it should take the image you are viewing. The shutter is already open, why no let it capture a single frame from the rolling preview?

If you check my profile I have some nice sunrise photos I took. Didn't have much of a problem with light bending. My secret? Take a ton of photos with different settings LOL. I took over 600 pictures that morning, and only about 10 came out the way it was suppose to.

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Because the preview is not in 10 Megapixels xD