A55's sensor is the best rated at DxOmark

[torak]

A55's sensor scored an overall of 73 points, making it the one of the highest sensor rated at DxOmark.

Comparing to Canon 550D (since both are similar in price)

http://dxomark.com/index.php/en/Cam.../645|0/(onglet)/0/(brand)/Sony/(brand2)/Canon

 

[vicpeh]

Not anymore. The Pentax K5 which apparently uses the same sensor trashed it......

 

[stonefish35]

Its always a joke to me when I see pple compare a $1200 A55 apsc to a $3000 5DII Full frame... :bsmilie: . In fact, if a $1200 apsc can be on par with a $3000 full frame, then what the ***** is the $3000 full frame doing ? Its simply a rip off to me..

Its flattery to the humble A55 to be compared with the top level bodies... :bsmilie:

 

[torak]

probably due to DSLT losing light, thats y the sensor works better on K5.

But do note that K5 is a semi pro model, while the A55 is just an entry level camera.

 

[Rashkae]

probably due to DSLT losing light, thats y the sensor works better on K5.

But do note that K5 is a semi pro model, while the A55 is just an entry level camera.

Also, the K5 uses much weaker antialiasing filters.

 

[alphabeta93]

the sick thing about the K-5 is that it has a 14 exposure value dynamic range.... i saw that with that DR capability you can rescue a 10 stop underexposed raw file in pp..

 

[alantkh]

Its always a joke to me when I see pple compare a $1200 A55 apsc to a $3000 5DII Full frame... :bsmilie: . In fact, if a $1200 apsc can be on par with a $3000 full frame, then what the ***** is the $3000 full frame doing ? Its simply a rip off to me..

Its flattery to the humble A55 to be compared with the top level bodies... :bsmilie:

the FF cameras are using 2 year old sensor lah. I think the new FF released next year will be REALLY impressive considering how good the k-5 is.

Still the 2 year old FF sensor still beats newest APS-C sensors on high ISO.

 

[alantkh]

the sick thing about the K-5 is that it has a 14 exposure value dynamic range.... i saw that with that DR capability you can rescue a 10 stop underexposed raw file in pp..

actually considering k-5 have compulsory noise reduction (on your RAW files) on ISO3200 and above, I wonder if they are doing some noise reduction at the under exposed areas in ISO 80 to get the 14 stops DR in measurements.....

The results for the k-5 for DR is REALLY good...

 

[night86mare]

actually considering k-5 have compulsory noise reduction (on your RAW files) on ISO3200 and above, I wonder if they are doing some noise reduction at the under exposed areas in ISO 80 to get the 14 stops DR in measurements.....

The results for the k-5 for DR is REALLY good...

can you explain to me how noise reduction at underexposed areas helps to improve DR? you don't seem to make sense to me.

 

[Ghostfit]

The K-5 results looks really good ! :thumbsup: ...thanks pentax for raising the bar, I can't wait to see what the A77 can do ! :devil:

 

[alphabeta93]

can you explain to me how noise reduction at underexposed areas helps to improve DR? you don't seem to make sense to me.

does he mean that the noise reduction in RAW files of the K-5 makes the test results give the 14EV DR? anyway i still dont understand what he means.

why is it that everytime sony produces sensors for other brands, with the same sensor, the other brands always does the circuitry and electronics better.

 

[night86mare]

does he mean that the noise reduction in RAW files of the K-5 makes the test results give the 14EV DR? anyway i still dont understand what he means.

why is it that everytime sony produces sensors for other brands, with the same sensor, the other brands always does the circuitry and electronics better.

noise reduction improving DR?

i think perhaps he could say that the pentax engine manages to squeeze out more DR from the sony sensor, but i'm quite sure that noise reduction processes do not improve DR.

 

[alphabeta93]

though he said "to get the 14 stops DR in measurements.....' not sure how DxO measured dynamic range though. actually DR can be affected by iso. as the black areas(black levels) is limited by how accurately a pixel can be measured, it is limited by the amount of image noise in darkness. dont ask me to go indepth about the physics of this. so if your sensor has lower ISO, or less measurement noise, it can actually increase the DR.

either its the NR features, or its the electronics. maybe pentax used a higer bit A/D converter in their sensor.

 

[alantkh]

can you explain to me how noise reduction at underexposed areas helps to improve DR? you don't seem to make sense to me.

What is dynamic range???

Basically it is derived from SNR measurements of different light intensity, ie when it gets so bright that the SNR gets clobbered by saturation or so dark that the noise overwhelm the signal. How can you say NR will not affect DR? It will DEFINATELY affect DR at the shadow range. most noisy camera's usually have poor DR.

S3pro and s5pro are the only cameras that improved DR on the highlight side...


http://www.dxomark.com/index.php/en...DxOMark-testing-protocols/Noise-dynamic-range

 

[alphabeta93]

aha like what i have mentioned earlier. so it is possible that the NR feature of RAW files in the K-5 is the factor to the 14EV DR. but anyway, i read somewhere that your camera can not acheive DR stops above 10. even though the bit precision of the A/D converter is 14. because its just a thereotical maximum of 14 stops on a 14 bit precision converter. so a digital camera can only in real life acheive between 5-9 stops. whatever it is, the fact that pentax managed 14 EV is possible from the NR feature.

more on S/N, DR and noise here http://theory.uchicago.edu/~ejm/pix/20d/tests/noise/noise-p2.html#SNR-DR trust me, its a headache to read.

but it may be other factors too, A/D converter, AA filter, etc.

 

[daredevil123]

I recommend this thread be closed.

Becoming a mud slinging brand war type of thread.

I think both k-5 and A55 are good. And same for the upcoming D7000 which uses the same sensor as A55.

In the end, the slight edge of one camera over another will not even be noticed by 99% of the users out there. And most of the 1% can only see the difference if they push really hard and pixel peep. And no, the slight edge will not make any user a better photographer. If skills suck eggs, picture will still suck eggs.

Hope this thread ends here.

 

[alantkh]

I recommend this thread be closed.

Becoming a mud slinging brand war type of thread.

I think both k-5 and A55 are good. And same for the upcoming D7000 which uses the same sensor as A55.

In the end, the slight edge of one camera over another will not even be noticed by 99% of the users out there. And most of the 1% can only see the difference if they push really hard and pixel peep. And no, the slight edge will not make any user a better photographer. If skills suck eggs, picture will still suck eggs.

Hope this thread ends here.

err... how come I don't see the mud slinging? where? don't be so sensitive lah. This is an online forum where people come and discuss things they like. If it is civil and rational, why not? I don't see anything wrong in discussing technical merits of different brands as it is a question a LOT of people ask themselves if they buy a DSLR

BTW, I don't own either pentax nor sony...

 

[night86mare]

What is dynamic range???

Basically it is derived from SNR measurements of different light intensity, ie when it gets so bright that the SNR gets clobbered by saturation or so dark that the noise overwhelm the signal. How can you say NR will not affect DR? It will DEFINATELY affect DR at the shadow range. most noisy camera's usually have poor DR.

S3pro and s5pro are the only cameras that improved DR on the highlight side...


http://www.dxomark.com/index.php/en...DxOMark-testing-protocols/Noise-dynamic-range

i am getting a bit confused.

i think i shall stick to taking pictures..... take the techies' word for it. :bsmilie:

 

[alphabeta93]

i agree. we are not brand bashing or anything. just discussing on why the K-5 can have such great performance when it is essentially using the same sensor. anyway the K5 is the best DSLR announced in the last four years, according to snapsort.

also, technical aspects is an essential part of photography. and most of the time explains pretty much the differences in IQ and noise performance in cameras, for an example, i will use the A900 vs the D3x. people like me are just interested in it. actually i would very much appreciate if people can share links with me regarding the in depth physics behind photography, so i can read up more.

for example, im curious how they test the iso performance on the A55, since it only lets in 70% of the light.

 

[ed9119]

thread under surveillence

discuss with objectivity in mind .... thanks