[firecat666]

我有一個問題請各位C-Hing 解答，A33 同 A55 都用同一size 既 Sensor，A33 係一千四百萬素，A55 係一千六百萬素，咁除起上來每個cell (photo site)的size 來講，A33 大過 A55，咁理論上講A33 D image quality 應好過 A55，如果唔係，理論上應該怎講？我問過Sony Style o既 Sale屎，佢話應該係咁。想請教 C-Hing 睇法。
問題二：在A33 and A55 有過熱的情況下，sensor 温度升高，Noise 就會多，將咁多零件擠進咁細既 body度，散熱冇咁好，在這種情況下，A560 機是否是較佳選擇？

[firecat666]

One more question: How can we know the native iso sensitivity of a sensor?
If we can't, then we can't value its real quality. And we will never know how good or how bad while examining the IQ of a camera is caused by the sensor itself or from a software programming.

[小小生]

理論我唔識講
實際試過兩部機畫質上我睇唔到分別
A560都未出唔知

[firecat666]

Is anyone out there who getting my point?

[firecat666]

Still no one can answer my question.... Okay here's my calculation: Both A33 and A55 use the same size cmos (3.66cm^2). So A33's sensor density is 3.9m/cm^2 while A55's pixel density is 4.4m/cm^2. That means each cell size ( photo site) of A33 is larger than A55s'. As we all know a larger photo site has better performance, especially under low light environments. Now, if both the signal processing chains are identical, the theoretically A33 should has a better IQ than A55. Please show me where do I get wrong. MicroMax c-hing: Can you answer my question? .

[impala]

1400萬像素與1600萬像素，其差異度約12%；即1600萬會比1400萬密集12%。如果影響是以直線線影響，即各方面問題如熱效應及畫質都是以線性影響，即a55會比a33畫質差12%。
但個人會覺得不是囉，我們可以做個實驗，因為當你每升高一級iso(在相同暗之環境拍攝)，相片畫質會在某一階段iso時，會突然下降很多，証明畫質效果不是線性。因此a55與a33在某些情況下，相片效果應該是一樣的，只是去到臨界iso值，才會比a33差12%。

[firecat666]

Thank you Impala c-hing, I think you're right. Even though their performance are not linear, yet when we take the whole of each performance score into account, A33's IQ is better A55 at a cheaper price. Am I right?

[firecat666]

Still get no answer..... oh dear....

[logistica]

http://www.mobile01.com/topicdetail.php?f=254&t=1542849#
像素高一倍既A850對住D700, A850用副廠24-70 都樂勝D700用原廠24-70

[good]

又係d無知人器材先泱人..........什麼像素高就係好
答佢都on99

[firecat666]

logistica ching 你講得o岩呀，A850 full frame cmos 8.6cm^2; 24.6m，佢既pixel density=2.9mp/cm^2; A700 cmos 3.66cm^2; 12.2m，佢既pixel density=3.3mp/cm^2，即係話@ photo site 來講A850大過A700，A850既新一代CMOS唔好講，就算係同一代，佢都應該有比A700 好既IQ,我唔係o係度講resolution o既o野，哎....
阿Good ching，我邊有講高像素就係好？我而家就係要指出一味追求高像素未必是好事呀，明未？如果我係好似人地咁玩器材既話，我都唔洗重用緊A350啦，睇下我profile就知。話邊個on 99 都係冇禮！

[logistica]

hey! 我貼果條係Sony A850 2400萬 35.9*24, vs Nikon D700 1200萬36*23.9

[firecat666]

Sorry for my mistake. Even you use A850's sensor to compare with D700's, the result is still the same!
Go to this link and select the models to compare. D700 still wins A850.
http://www.dxomark.com
I've said that I was NOT talking about resolution...
24m vs 12m sure will get a better resolution. Yet when A55 vs A33, 2m more is meaningless. Sony's doing this by sacrificing the more important factors of IQ is only for marketing reason.
IMO Your compare of the 2 models make no sense and pointless. It's no more than an experience sharing. Too many factors involved, many of them are even uncontrollable. Now I need someone who really has the knowledge to affirm my assumption no matter how small the difference is.

[firecat666]

II must apologize to all the fellow members for my lousy English since I don't get the tablet with my netbook. I'm too old to learn typing Chinese. One thing I really want everyone who reads this to think about it: What is it behind my question.

[logistica]

唔講解像力 REF
http://www.dxomark.com/index.php/en/Camera-Sensor/Compare-sensors/%28appareil1%29/604|0/%28appareil2%29/441|0/%28appareil3%29/483|0/%28onglet%29/0/%28brand%29/Sony/%28brand2%29/Nikon/%28brand3%29/Canon
A850既色深, 動態範圍仍然優秀, 但Lo light ISO輸左