what am I doing wrong??

[debbie]

Okay, I have the Canon S3 IS and when I take a photo in macro of anything outside it is so nice and clear, even when I use the full 12x zoom. Same goes for using the macro inside for my orchids etc. But when I go to take photo in macro without the zoom just right up close to my fish tank they are blurry. The fish is not moving at the time of picture taking but what the heck am I doing wrong. I was hoping to get some nice clear crisp shots with this camer of my fish.....

 

[maxalmon]

One thing i've learned is that just a micro amount of algae on the inside of the glass will cause focus problems, even if you can't see it, the infrared focus system will.
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Have you tried manual or does your camera offer this.
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Another problem is the actual ingredients used in the making of the aqurium glass, some glass has more lead in it, some not so much. You'll notice some glass is really green or blue, some is ultra clear.
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Another problem is glass thats not smooth, it's called "aberation" and it's another one of those instances where you can't really see it, but it's enough to throw off the focus.