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Old Aug 22, 2010, 2:04 PM   #6
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Join Date: Oct 2004
Posts: 265

Originally Posted by shoot21 View Post
i thought canon sd4000 was the best camera to buy, nice pics and HD videos but when i zoom the photos i can see this problem

i don't know if the correct term for this problem is blur or noise, but the photos look like they were taken with a cellphone or with a sony cybershot

I stop buying sony cybershots for this reason, but now canon? what a shame! so what canon camera should i get if i dont like this kind of photos?
Hi Shoot21,

For image-1 you said "but when i zoom the photos i can see this problem". One major reason why blur can happen when you zoom is because the SD4000 lens is rated at F2.0 at wide and F5.3 at tele. That is almost a 3 stop difference. Each stop loses 1/2 the light of the previous stop. So 3 stops is not 1/3 the light but 1/8 the light.

When you zoomed in you lost a lot of light. I’ll bet that the shake warning appeared on the screen when you took that photo. If so, the camera was warning you that the image would probably be blurred (unless you happened to hold the camera rock steady at the instant the shutter was tripped). The great loss of light combined with the zoom (which amplifies shake) results in blurred images. The reason loss of light results in blurred images is that in lower light situations, the shutter has to remain open longer to compensate. Shutter speeds slower than about 1/60 second make it hard to hold the camera steady for that duration. Sometimes 1/30 second is ok but things go down hill below 1/60 second.

One way to overcome the shake warning if it comes on is to zoom back out in steps until the warning goes off. Zooming back out lets in more light which allows faster shutter speeds resulting in less blurred images. Then crop the photo in post processing to get the zoom you wanted. Just be aware that the more you crop, the more apparent the imperfections will become. But the image of the menu will still be a lot better than the one you posted. Using sharpening and a noise reduction software like the free "Neat Image" can make this type of pseudo zoom look very acceptable.

IMAGE-2 Girl’s face:
You listed “ISO 5000, F2.0”. In most small sensor cameras, the maximum ISO with acceptable noise is about ISO 400. It might be higher with the SD4000 but for sure ISO 5000 is light-years too high to expect noise free images from a small sensor camera. If there’s a way to limit the maximum ISO that the camera will use, try experimenting to see what ISO value is acceptable to you and set the max to that number. You can override that setting for “gotta take the picture no matter what” situations.


Last edited by skylark; Aug 23, 2010 at 3:17 AM.
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