I want to buy a point and shot digatal camera with lot of zoom 15 or 20 opical zoom any advice. I have an olympus 510 and it got 10 opical zoom but the indoor picture come out full of noise or grain but I like the zoom it's great Anna
You need the "fastest" lens you can get for telephoto and low light (indoor) photography. Why? To get a fast shutter speed. You can hand hold successfully up to 3X zoom and then you need a tripod or rock solid camera support to reduce shake. As you approach 8x zoom, a fast shutter speed is mandatory in most cases.
What may have happened to your high zoom shots is automation to gets at least some level of exposure. As you zoom out, the speed of the lens falls. By speed, I refer to effective lens opening stated as f/number such as f/8. This means that the effecive lens opening is its focal length divided by 8. Most of the time, the maximun f-stop is mentioned in the sales literature. What you should watch for is the maximum f-stop over the entire zoom range. You will find that many high zon lenses fall to small openings at large zoom. When met with a small f-stop, an automatic algorithims has three choices: It can increase the shutter open time (slow the shutter), increase the ASA rating, or a combination of both. On many point-snd-shoot cameras, noise appears at ASA greater than 200, and noticable shake effects at shutter speed slower than 1/100 sec at 35mm equivalent of 100mm focal length. Getting a more expensive cameras with a nominal lense will not cure these problems.
I have a Canon Power Shot S series IS camera with 12X zoom. Here's what makes this camera work: The lens is rated at f/2.7 to f/3.5 over the zoom range. An opening of f/3.5 at 12X zoom is almost unheard of in point and shoot cameras. It was this feature that lead me to buy this camera while accepting other dislikes. There were enough likes to make the purchase worthwile. For one, it has one of fastest boot-up times in the industry. It is ready to shoot 1 to 2 seconds after turning it on.
I perfer ths color renidition and sensors used by Nikon. it took me a while to sort out the burnouts in my pictures with my Canon. My gut feel is that the Nikon system as a better dynamic range. But, when you can get only one camera that has to doa lot of things, this Canon was one fo the best at that time (3 years ago). Over that period, improvementsa nd other offerings have appeared.
My advice: For your want, get the fastest lens you can get, but it should have minimal distortion, chromatic abberation, etc.
A note about zoom:
Not all zooms are alike. One maker's 10X zoom may not be equivalent to another 10X zoom. The starting point set the lense apart. (I'm going to use the more familar 35mm film equivalents for sake of discussion.) A normal lens lies in the range of 50 to 55 mm for 35 mm film photogaphy. Suppose the bottom of the range is 35mm (somewhat wide angle), then 10X zoom becomes 350 mm. If the starting number is 28mm, then 10X zoom would be 280 mm. As you can see the second lense has considerably less zoom than the first even though both are 10X zoom.
In my case, I would sacrifice a little at the high end to gain a little more wide angle. Several times during the past year, I have needed a bit more wide angle.
There are two schools of though about image stabalization. Its a boom for the non-techinal ocaasional shooter who has trouble holding a steady camera. There are those who claim superior results by turning off the image stabalizer and use a very steady camera mount with remote shutter release.
In bright light, the image stablization can be turned off with no ill effects provided the shutter speed is fast enough.