A70 questions

Well, I am very new to digital photography, and this is my first camera. My questions is what is ISO? why are the different numbers?
Second, when I upload to my pc, I do not see the date on the photo, how to enable the date? I can see it clearly on my LCD but not after uploading it. help.

ISO is film speed. It indicates how sensitive the film is to light. 100 is slow, 800 is fast.

Example:

Think of ISO 100 as poster board, and ISO 800 as tissue paper. Now take a fat marker and attempt to draw something on the two pieces of paper.

Now, which paper bleeds more? Which paper yields a sharper drawing?

Because ISO 100 is slower, it allows you to capture sharper detail.

Ok, but sometimes I try slow ISO, the pictures become gloomy, and sometimes the shutter speed is just too slow. How many seconds to ISO?
And the upload picture detail part?
Is this camera very durable-the LCD, is it like scratch proof, or do I need to buy a plastic laminate to prevent from scratchs?

Low ISO numbers are used for bright conditions. Because the speed is so slow (film is not as sensitive), it requires a lot of light to get the correct exposure. Conversely high ISO numbers are used for dark conditions for the opposite reason. The reason you try to use the lowest ISO possible is because you sacrifice picture quality (graininess) when you go to a higher ISO.

If you use a slow ISO speed in dark conditions, the camera will slow down the shutter speed or open the aperture to allow enough light in to get the 'correct' exposure. It's probably gloomy because the shutter speed and aperture are not set to allow enough light to enter. You may need a tripod.

There's no ISO to second formula. It's just light sensitivity relative to each other. The term 'speed' is a misnomer. If memory serves me correct, using ISO 50 as a reference, ISO 100 is 2x more sensitive, ISO 200 is 2x more sensitive than that, ISO 400 is 2x more than that, etc...

Re ISO - already answered above!

Re date - It's in the exif data - see other postings re exif data (do a search) in this forum for explanation.

Re LCD - don't peel off the plastic film until you have to due to age/scratches/peeled etc. Once you have (or if you already have) many places sell suitable plastic film to replace it with. The screen scratches VERY easily - and is a real pain once scratched - I finally got my film from Jessops!

For LCD Protectors check link:

http://www.daproducts.​com/index.htm