Photoclubalpha

Thanks Don. You come up with some good ones!

Great site. On a first glance I couldn't find A700. Only 900, 350 & 100.
On a quick compare of A900, Canon 1DsMKIII & Nikon D3, well... not bad.
Thanks for the link. Don.

Hi All

But what does the info on that site mean to a newbie like me

looking at site, the a350 is better than the eos 450D and D60

http://www.dxomark.com/index.php/eng/Im ... and3)/Sony

Is the differance between the 3 cameras at iso800+ due to the sensors or firmware or both? since they are so close does it mean if Sony wanted to they could improve the high iso preformance of the a350?, I'll guess we will never know

Cheers, Stephen

The problem with these tests, is that there is no indication of image quality.
I can pull my compact camera about, lift the shadows..and make a nice little "thumbnail" for the web..maybe it could get near to 10 stops on a test, but it's completely unusable in the real world.

The texts about resolution, noise, and how the two affect each other are interesting reading for the technically inclined. See the sub-pages "Insights" and "Technologies." But the test data are as stupid and meaningless as in any gear review page. Read the articles but kindly ignore the numbers!

-- Olaf

Interesting link.

So why is Alain Briot there then? lol

No disrespect intended, something odd about his shots, not composition..I mean he never seems to have shadows in his shots, I find that very off putting and strange. Plus, go visit his site, his print prices are shocking! Granted, I expect to pay for the art a bit, but honestly...ouch!

Sonolta wrote:Pretty fair amount of positive press DxOMark has been getting...

I haven't seen any mention of DxOMark on the dpreview news page. Strange.

I don't know about the DXo numbers, maybe they are accurate.

From their site..
"Sensitivity is the ability of a sensor to provide a defined response for a given level of lighting. This information is used by photographers to determine the nominal exposure conditions. If the actual ISO sensitivity of a digital camera’s sensor is lower than the sensitivity set by the user, the image is underexposed; if the sensitivity is greater, the image is overexposed. To be easily understood by photographers, the ISO sensitivity of digital cameras has been defined such that it is similar to the ISO sensitivity of photographic film cameras, thus lower sensitivities require longer exposure for the same luminance to produce the same result. However, just as very sensitive films are known to be very grainy, parallels can be drawn for digital cameras, since high sensitivities are related to high gain and noise amplification."

"The intrinsic sensitivity of a digital camera is determined by the silicon structure of the sensor itself and cannot be changed, but the ISO of the camera can be artificially increased to arbitrary values by applying a gain to the signal. The price to pay is a proportionate increase of noise and eventually, a decrease of SNR for a given output value (see Explaining Noise Characteristics). The only trick is that the gain is applied before analog/digital conversion so as to avoid quantization effects. So the fact that a camera attains ISO 10000 is not a warranty of image quality; the noise level at this ISO has to be reported as well"



I can only comment on real world use. I don't think they have the A200 up there, last time I looked.

But, I know I get faster shutter speeds with the A200 at high ISO than the KM5d. BUT...the 5d is showing a good bit more shadow details..so my conclusion would be, that it's actual ISO rating at higher levels is more accurate/higher than the A200. No doubt some makers do play about with the processing in camera, and rate ISO levels that are not correct. As above it might be to have some headroom, makes sense for lower ISO levels, works against you at high ISO.

The A200 overall is pretty cautious exposure wise, so I am sure most of the differences are the sensor/processing..whilst the metering readings are not always the same, I put that down to different real ratings for ISO. The KM has no fear with showing great shadow details, the A200 is very different in this regards. Whilst I am a bit cautious about their DR figures (erm no mention of image quality with the DR), maybe the ISO ones are near the truth.

Have to disagree with their remarks on down sampling though. It's really not that simple..


A few odd things on DXo stick out pretty strongly..

Panasonic LX-3 has the same DR as the KM7d? Huh???

7d rated higher for high ISO than the 5d..

Fz 28 has a DR of 10.1....

Erm yeah right!!!

Not saying all their numbers are junk, but I have a hard time thinking a compact can match the DR of a 6mp DSLR..really, note a hope in hell..