David

http://www.photoclubalpha.com/forum/viewtopic.php?f=32&t=1580

-Sonolta

http://www.photoclubalpha.com/forum/viewtopic.php?f=32&t=1561&st=0&sk=t&sd=a

-Sonolta

http://www.photoclubalpha.com/forum/viewtopic.php?f=32&t=1561&st=0&sk=t&sd=a

http://www.photoclubalpha.com/forum/viewtopic.php?f=32&t=1580

-Sonolta

Also, as far as I have been able to tell from many shots (not tests, just shooting) the Alpha 900 captures more recoverable shadow detail and highlight detail, with its 12-bit conversion, than the Nikon does with 14-bit – at least with any currently available raw converter. I guess this is due to gain inside the camera, which also produces the higher native ISO, which also produces the higher noise. So you are right in one sense, an underexposed Alpha 900 ISO 100 raw corrected in raw conversion will probably produce about the same range as a correctly exposed Nikon ISO 100 raw. You would be applying the gain curve outside the camera not inside it.

David

The test target seen is as I have read others say , very well thought out , for shure the best I have ever seen .
I Believe these tests have uncovered the reasons for the mistaken Nikon advantage in High ISO noise . ( Evidently the difference in the way these two Cameras meter the seen in each ISO setting ). But I am not sure this is exactly how it works .

My question for you , is why not underexpose the ISO 100 shot with the Sony , to get the Highlight detail back in range . Probably a stupid question because it would’nt be a ISO 100 shot if you did that . Of course you could shoot in Manual and set the shutter to 1/2 the time . or use the EXP compensation in Auto Exposure . Either way the picture would probably be the same as the ISO 200 result .

I am close to taking the A-900 , I just wonder how the 12 bit effects the seperation of fine density differences compared to the 14 bit of the Nikon . I have seen from my own a-100 some photos have density bands or layers across the sky in some shots .

I have not checked to see if they were developed with 8 bit output or what went wrong .

The scene is intelligently and amazingly well thought out and shows very minor differences clearly. This is far better than any graphed testing.

What I see here are several things.
Firstly the overall noise differences show about 1 stop advantage to the Nikon at high iso only. I compared the photos with a one stop offset so that I looked at the Sony at, for example, 1600 and the Nikon at 3200. The noise at that 1 stop difference is not identical but overall it is the same. For instance, at that one stop differential in iso, the noise in the blue and green channel is better in the Alpha while, the noise in the Red is better for the Nikon. So overall those individual differences equalize out but at a one stop advantage going to the Nikon at high iso. If that is as a result of getting better dynamic range for the Sony than I feel there is no advantage to the Nikon processing as there are other offsetting gains that make up picture quality. But that is not like the overpowering three stop advantage for the lower resolution Nikon D700 in Comparison to the Sony a900. I can live with a one stop difference at high iso – especially since that difference is equalized by in camera antishake.

Secondly, there is trouble with the Nikon 100 macro. Look at both photos in iso 200 set (at full size) and move the photo about 1 jelly bean to the left of the middle pink bean, where there is a clear area with a light gray background. Then look for color fringing at the light to dark borders. The Nikon lens seems to have some trouble with a lot of color fringing in comparison to the Minolta. That characteristic is maintained thru all iso comparisons.

Thirdly when looking at the iso 200 photos for each system the Sony has a lot more fine detail and sharpness – in the pink jelly bean for example. But there are other areas where the Minolta image looks a lot sharper as well at isos from 200 to 800. I thought this might be from focusing differences and so looked at the plane of focus and saw that they are identical and transect the pink jelly bean at the same point. Perhaps that loss of detail and sharpness for the Nikon image might be related to the color fringing in the Nikon Macro. Ordinarily, I would expect some CA in the border areas but not so far into the central are of the frame. In looking on the internet the Nikon 100mm macro is not rated well and far below the Minolta. At http://old.photodo.com/nav/prodindex.html the Nikon gets a 3.9 out of a possible 5 and the Minolta gets 4.5 out of five. But many other lens rating sites show this as well. So the sharpness differences seen in the two sensors with the Sony way ahead might be because of the lower quality of the 105mm F2.8 Nikon Macro.

Which brings me back to the unbiased reality of this test. I believe the conclusion is that the Nikon has one stop less noise and the Sony better dynamic range. Those differences cancel out for me so I will save 5,000 US and go with the Sony. The difference in price will allow me to lease a Lexus for more than a year or feed my family for a year.

One other point is that no one makes a compact F1.4 50mm lens with antishake. If there is a two light stop advantage to the Sony in-body antishake function that puts the Sony ahead of the one stop advantage to the Nikon. Overall for night street photography, available darkness photos, or in home photos with available light the Sony with the 50mm 1.4 is far better and a lot cheaper. In addition, imagine walking around with the Nikon Behemoth and newly designed bulky large and heavy Nikon F1.4. That combination literally has dimensions of a soccer ball and weighs in the area of 4 lb (or about twice the weight of the svelte Sony with Minolta/Sony 50mm 1.4).

In any event, thanks so much for your time and effort. I was hesitant about the noise issue but now that all is in the open and clearly seen in your photos, I feel the a900 will soon find a home here at my place.

Mal

Re the Nikon, generally: it has a sensor/processing set up which, for a typical midtone 128 value, works out about 2/3rds of a stop higher in true ISO than the Alpha. On top of this, the Nikon metering in most situations is more generous, and often produces overexposure (the Alpha hardly ever overexposes any scene). In working situations, the Nikon can be as much as 1.5 stops brighter than the Sony for a given view in front of the camera.

As to which is preferable, I’m not sure. You just have know the cameras. But in noise tests it works against Sony.