We were curious to see what improvements there are in the Nikon D300 compared to the Nikon D200. To find out we performed a few simple tests.
Almost all of the tests you are about to see were done on the actual RAW file using Matlab. This means that there is no image processing involved and that the results are as pure as they get. You can use these results to understand which camera will perform better in the real world when using the RAW software of your chose.

Dynamic range

A desired improvements is more dynamic range. To test this we photographed a special 41 transparent step chart with 13.6 EV stops of dynamic range. We define dynamic range as the number of steps between maximum saturation where the sensor can no longer capture light and the floor noise at the 1db limit. This means that dynamic range is limited by noise. We estimate a margin error of 0.15EV in our measurements.

The chart bellow shows the dynamic range in EV of each channel in each of the ISO settings.

ISO	Nikon D300 12 bit			Nikon D300 14 bit			Nikon D200
	G	R	B	G	R	B	G	R	B
100ISO	11.6	11.3	12.6	11.6	12.3	12.6	12	12.6	13
200ISO	12.6	11	11.6	12.6	11.3	12.6	12.3	11.3	13
400ISO	12	10.3	11	12	10.3	11	10.6	10	10.3
800ISO	10.3	9	10.3	10.3	9.6	10.3	9	8.6	9
1600ISO	8.6	8.3	8.6	9	8.6	8.6	7.6	7.3	7.6
3200ISO	7.6	7.6	8	7.6	7.6	8	6	6.6	6.6
6400ISO	6.6	6.3	7	6.3	6.3	7
All values are EV (1EV = 1 stop)

As you can see, the green channel, which is the main channel, has about 0.3EV more dynamic range at 200ISO, the base ISO setting for the Nikon D300. It is interesting to note that the Nikon D200 gains some dynamic range at 200ISO in the green channel but loses some in the red channel. Comparing the base ISO setting of both cameras, the Nikon D300 gains 0.6EV more dynamic range in the green channel, which is not bad at all.

Because noise limits dynamic range it is no surprise that the Nikon D200 has only 7.6EV of dynamic range at 1600ISO while the Nikon D300 shows an excellent result of 8.6EV.

As for the long debate of 14bit vs. 12bit, we can clearly see a small advantage to having more bits in dynamic range. Sometimes having more accuracy means better signal to noise ratio at the low signal parts of the image.

Signal to noise ratio

To test signal to noise ratio we used the same data from the previous test. This time however, we calculated the signal to noise ratio from the 2 brightest stops of the chart. The results represent the ability of the sensor to gather light and are less relevant to the electronic side effect noise of the image. This is because the sensor is overwhelmed with photons and the extra electronic charge has very little effect on the overall charge.

The higher the result the better the sensor is capable of capturing light. The pixel size of the Nikon D300 is approximately 5.54 µm while the pixel size of the Nikon D200 is 6.09 µm. That alone should give the Nikon D200 slightly better performance. But there are many more factors to consider, such as the density of the microlenses and the spectral distribution of the color filters on top of each pixel.

The results are very interesting indeed. At seems that in most cases at low ISO settings the Nikon D300 has a better signal to noise ratio, even though the pixel size is slightly smaller. This means that Nikon (or shall I say Sony?) has done a very good job.

Noise floor

Noise floor is calculated by using the same data used in the previous tests. But this time we calculate the standard deviation values at the lower two EV steps. These results indicate the overall performance of the system. In most cases the last two stops contain some signals from light, but also contain some electronic noise that should not have been added to the image. Lower results are better.

From these results there is no doubt that the Nikon D300 is a big improvement on the Nikon D200. This is probably due to Nikon’s better handling of the electronics in the D300 but it is more likely due to the fact that CMOS sensors can separate non photon noise from light signal and subtract that noise from the each pixel. This is something CCD sensors can’t do. The result is a much less noisy RAW file. Once again, we see a small advantage to 14 bit accuracy which reduces the rounding (upwards or downwards) of signal and noise.

Noise reduction improvements

The following is for the JPEG shooters among you. While the improvements above were all about RAW files and sensor SNR, here we will discuss improvements Nikon has made to their noise reduction algorithm. The low SNR and low noise of the Nikon D300gives us a better starting point for noise reduction algorithms, so we will try to highlight some improvements in the Nikon D300 that bothered us in the Nikon D200.

All the crop images below are taken from our studio setup with the same 50mm Nikon lens (at f8) at 1600ISO. All crops are 100% of our studio setup.

Chroma noise and pleaseing grain

One thing the Nikon D200 was free of is chroma noise in flat areas. This is not different in the New Nikon D300. Only when setting the noise reduction setting to the OFF setting there is some chroma noise.

Grain is one of the most important aspects of noise reduction – get grain right and people will accept your image as pleasing (something that adobe seems to miss). By clicking the Luma view you can see that the Nikon D300 has a little less visible grain. I do not particular like that, and I much prefer the Low result of the Nikon D300 for grain.

Shadow grain

Grain in the shadows was one of the most problematic issues with the Nikon D200. While most of the tone range filtered well, the dark tones contained too much grain. This made images with mostly dark tones look very grainy and noisy.

Here the shadows are filtered much better. This helps the image look more pleasing and appealing overall. I do feel that the Normal NR setting filters a bit too strongly, I much prefer the Low setting as it leaves some nice looking grain which makes the image look a bit more natural.

Details

One of the common misconceptions photographers have about noise reduction is the loss of detail. Performing noise reduction does not necessailry mean losing details. In many cases, details that are otherwise hidden by noise can be “extracted” by detecting fine edges. On the other hand, if the algorithm is incapable of detecting those fine edges some unneeded filtering may occur. In reality, there is always a tradeoff that needs to be made between details and filtering. If the algorithm is very good, this tradeoff is small as it is possible to filter noise and detect fine edges as well. But even then, there will be a small tradeoff which in many cases the camera maker lets the user choose.

The Nikon D300 has a small advantage over the Nikon D200 when it is set to Normal NR. But once again, using the Low setting shows those nice little details. I am quite pleased with the Low setting.

Shadow detail

Details in the shadows is yet another issue that bothers us with the Nikon D200. We are happy to see that Nikon has improved this issue.

As you can see, there is good progress here. The Nikon D300 shows better results in every setting. I prefer the Low setting as it gives good balance between edges and grain.

False colors

False colors are a side affect of noise reduction. Those are little color noise leftovers nikon left behind on edges. I am happy to say there is a good progress on this issue too.

As you can see only when the Nikon D300 is set to OFF some false color artifacts appear. There is also very faint false color with the Low setting. This problem seems to be handled very well now.

Final words

Both in our lab tests and in real world the Nikon D300 shows over all less noise than the Nikon D200. This is very true for RAW files that are now more usable then ever. When using JPEG files from of the Nikon D300, we see some very good progress on Nikon’s ability to reduce noise (performance which many different RAW converters can only dream of). The big breakthrough was accomplished with the Nikon D200, but now all of those image processing problems in the Nikon D200 have been solved or improved. The main noise reduction improvement stems from the fact that Nikon can now filter dark tone more strongly than highlights or mid tones.

I much prefer the Nikon D300 1600ISO JPEG results when it is set to Low NR setting. There are more details with not too much extra color noise, but more important the monochromatic grain with the Low setting looks more pleasing. As a results, the whole image looks more pleasing and detailed.