Old 27-01-2007, 06:08 PM
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EzyStyles (Eric)

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Happy snaps digital camera. Which one??

Hi Guys,

Just sold my Sony T9 digital camera and currently looking for another. Came across the Canon IXUS 900ti which is a 10 mpixel camera. Thoughts on this camera or maybe other alternatives? Think the 900ti can do some video astrophoto work on planets as it can produce 1024x768 videos and can also do ISO3200?

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Old 27-01-2007, 06:43 PM
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jjjnettie (Jeanette)
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My brother in law has that camera. He is very fussy about such things, and he is suitably impressed with it.
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Old 27-01-2007, 08:40 PM
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Whenever considering a P&S for low light, work out what the physical pixel size is. Signal to noise is directly proportional to pixel area assuming everything else is equal.. The pixelsize of the sensor in this camera is 1.9 micron square. The 350D is 6.4 micron and the ratio of area is about ten to one. The 350D will have ten times the signal to noise of the Canon Ixus 900 Ti.
Large pixel numbers are just marketing hype in P&S. Their noise at ISO 100 is about the noise of a 350D at an ISO of 1000+.
Look here for sensor sizes etc.

They are designed for one thing taking pictures at high light levels and even then the noise is quite noticeable if anything higher than an ISO of 100 is used.

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Old 27-01-2007, 09:42 PM
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ballaratdragons (Ken)

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Bert explained it very well to me not long ago.

Pixel quantity verses chip size comes into it.

Imagine 8 million pixels on a tiny chip, then 8 million on a huge chip. The pixels on the small chip are tiny.

Now compare it to buckets and thimbles. Spread out 8 million buckets and 8 million thimbles. When it rains, what happens. The rain overflows the thimbles quickly while the bucket happily keep collecting rain.

The same with light. Millions of tiny pixels on a small chip will spill the light into neighbouring pixels and flood everywhere.

Whereas larger pixels contain the light within the pixel and allow even longer and clearer exposures.

The 'Millions of Pixels' on a small chip is advertising for the masses. And it works!

Joe Average would rather have a camera with 8 million pixels than 2.5 million. But they are usually on the same size chip!

If you want a Gazillion pixels, then you also need a BIG chip with BIG pixels

* I hope I explained that right Bert.
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Old 29-01-2007, 02:03 PM
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Just wondering what happens then if you lower the resolution of the camera. Does it just sum a block of adjacent pixels to simulate a lower resolution?
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Old 30-01-2007, 12:42 AM
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EzyStyles (Eric)

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thanks guys for your informative reply. It really helps with your analogy Ken
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Old 30-01-2007, 09:24 AM
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acropolite (Phil)
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Eric, given your prime prerequsite is for happy snaps I'd suggest going through a review site e.g. Steve's Digicams. I recently bought a Canon A710 for HRH. Liz. It's a lovely little camera, light, compact, has Image stabilisation (even on video), 6x optical zoom, adequate video capabilities (640x480) and excellent battery life from 2 removable AA size batteries. The only downside is poor red eye reduction (uninmportant if you post process) and lack of RAW image capture. I bought this model based on review recommendations over the 900ti as the difference in resolution would be hardly noticeable and the cost difference was substantial.
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Old 30-01-2007, 03:05 PM
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astro_south (Andrew)
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I also brought the A710IS for the wife to replace our aging A40 2Mp point and shoot. It has heaps of features, and has performed admirably since Christmas. It is easy and fun to use (I know because I have probably used it more than Leisa) and produces some very nice images - very happy with it.
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Old 30-01-2007, 03:25 PM
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janoskiss (Steve H)
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If you want a compact digital with best noise performance in low light the Fuji finepix F30 is it thanks to the "super-ccd" chip (well it was a couple of months ago; maybe they have newer models now not sure). Nothing else comes close in the compacts. Goes to ISO 3200, but realistically ISO 1600 is the highest you'd want to use (see my comet shot in the mcnaught images thread). Great value at around $400. Only gripe is chromatic aberration. Canons have better lenses, but not the low-light performance, in the more expensive compacts.
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