High ISO noise performance of Sony A900

[BernardLanguillier]

Isn't the A900 sensor similar to the Nikon D3 sensor? Both are from Sony.

Actually the D3 and D3s sensor seems to be a full Nikon design that is also not manufactured by Sony.

The D3x sensor is a Sony base with Nikon toppings and electronics.

Cheers,
Bernard

[ErikKaffehr]

Yes, indeed.

D3 and D3s and also D700 uses sensors developed by Nikon. The D3X uses a sensor which has much in common with the Sony chip but seem to pull out more performance.

This figure from DxO demonstrates the difference clearly, the curves for Nikon D3X and Sony Alpha 900 are quite similar but Nikon is higher. The main difference is that Nikon obviously found a way to utilize 14 bit readout with the Sony Chip. The D3S is very slightly better at high ISO and goes to higher ISOs. The D3s loses DR at low ISOs, probably because of readout noise in the external electronics.

So, the D3X uses that same basic chip as the Alpha 900, but uses it better (but not faster and cheaper).

Best regards
Erik

Actually the D3 and D3s sensor seems to be a full Nikon design that is also not manufactured by Sony.

The D3x sensor is a Sony base with Nikon toppings and electronics.

Cheers,
Bernard

[ErikKaffehr]

Hi,

I added figures from DxO showing the differences in Noise and DR for D700, Alpha 900 and 5DII, the figures are normalized for a constant print size. The reason that I did not include the D3X is that I wanted to have cameras roughly comparable in price.

Regarding the validity of DxO figures, there have been a lot of discussion about their value. Many posters with good insight in how sensors work say that the DxO figures make sense. On the other hand, specially MFDB users found that the DxO figures don't reflex their experience. After seeing some samples from Phase One P65, I may be closer to the second opinion.

My impression is that Nikon has managed, with the D3X, to build a camera that utilizes the Sony chip better than Sony's own. It seems also to pull a bit more MTF from the sensor and lenses than Sony. For really high ISO work the D3s, but also the D700 seem to be the champ.

Best regards
Erik

Following theft of 5D2 and roughly half my lenses by value, I think I need to consider alternatives as well as straight replacement when I get the insurance (would expect to get good price for 300/4IS, 1.4IIX 24-105 and 50/2.5 if I changed system). As landscapes are important and aim to do some studio portraits, I'm attracted to A900, although the only time I've tried it out, the body shape felt less comfortable than 5D2.

Apart from not having live view, the main issue is high ISO performance, which is important as I'm very much an available light person. I read somewhere that earlier versions of ACR did not handle Sony files very well and that latest ACR 6.2 (which I now have) is much better. Is this true and even if not, how well do Sony raw files at 1600/3200 respond to noise processing in ACR without softening?

[ErikKaffehr]

Hi,

I also show DxO-mark curves for D3X, Alpha 900, and 5DII

Best regards
Erik