Having recently bought a Nikon D3s and still using the D300, I’m now actually working with two different sensor formats. The D3s has the FX sensor whilst the D300 has the DX.
So What’s The Difference?
It’s all about the size of the recording sensor or chip. That’s the bit on DSLR’s that replaces where the film sits in an SLR camera. They’re still pretty fragile things and you don’t want to go messing around with them too much. To protect them make sure you are fastidious with camera and lens caps. Any dust that gets onto the sensors can become a problem. (more about cleaning the sensors on another post)
The FX sensor on the D3s is 23.9 x 36mm (.94 x 1.5 inch.) whilst on the D300 it’s 15.6 x 23.7mm (.66 x 1 inch) 35mm film comes in at 24 x 36mm – to all intents and purposes the same as the FX sensor.
The DX sensor being smaller than the size of film means there is a magnification or crop factor when using non DX lenses, and as all Nikon equipment has been designed from the base upwards, all existing pre digital lenses are compatible with the newer digital bodies. On DX cameras the chip is smaller than 35mm film so the same lens used with both systems will give a different image size, or angle of view. The DX chip is simply discarding some of the image created by the lens. With the FX sensor there is correlation with the 35mm film cameras and once again, for us of the ‘old school’ a 500mm lens is what it always was. When using the DX chip the 500mm lens produces an image size equivalent to 750mm. In other words you would need a focal length of 750mm with a film camera or a FX chip to produce the same magnification, or angle of view. The Nikon DX chip has a magnification factor of 1.5. Simply multiply the focal length of a non DX lens by the DSLR’s camera magnification factor to see what focal length would be required to create the same angle of view with a film or FX camera. For example a 500mm lens used with a camera that has a 1.5 factor would show the same angle of view that a 750mm lens would show on the FX camera.
For the last few years, with the D200 then the D300, I’m used to ‘seeing’ this magnification when shooting in the field. When I use the D3s the image now appears further away than I’m used to and that’s quite apparent when photographing birds at some distance. It takes a little getting used to and It’s not always the case that the D3s would be the camera of choice for all situations.
Same Number Of Pixels – So What’s Going On?
The interesting point when comparing the two cameras is that they both have the same number of pixels on the chip, 12Mp (12 million pixels) The density of the pixel arrangement on the chip therefore differs considerably between the two. They are more densely packed on the DX chip than they are on the larger FX chip. The D3s, however, has larger pixels which are able to gather light more efficiently. They also have a micro lens layer grabbing every possible photon of light. It is this arrangement, size and the micro lenses that make such a difference in the camera’s ability to function superbly at low light levels.
What’s The Difference Then?
To begin with it must be said that both cameras are capable of producing fine prints at A3+ and if working at the lower end of the ISO range (up to 1600 ISO) then it’s not really possible to see much difference between the two. I’ve enlarged images from both cameras and would not be able to differentiate between them at these ISO settings.
The D3s is unsurpassed in low light situations and at the higher ISO range, maintaining an extraordinary print quality at settings way beyond the capability of the D300.
Other differences are related to the speed of operation – frames per second, a greater range of features within the menus and a better build quality. The other main difference is the price, the D3s coming in at a couple of thousand pounds more than the D300 – It very much depends on what you are shooting as to whether the extra price tag is worth it.
When To Use Each Camera:
I always have both cameras in the bag on any shoot and the D300 is not simply acting as a back up, there are times when I would use it in preference to the D3s.
As the pixels are more tightly packed on the D300 it actually produces greater detail than the D3s if the conditions are ideal and low ISO settings (up to 1600) can be used. This pixel density also has an advantage if the image is going to be significantly cropped. The D300 in this instance would give a better result when the image is enlarged, having more pixels within the crop than the D3s.
I have noticed there is more vignetting with the D3s than the D300 and this is apparent with all lenses. It’s not a huge issue and with a little care in the post production stage can be illuminated entirely. The DX chip uses the central area of the image circle produced by the lens whereas the D3s uses all the full edge to edge portion of the circle.
Both cameras have 51 AF points and they are configured in the same way on both cameras. This means that on the DX chip they cover a greater area of the image area and as a result it can actually be a little easier to focus on rapidly moving subjects on the smaller chip than on the larger chip size of the FX cameras, where they are effectively concentrated towards the centre of the chip.
Of course both the above can be countered on the FX camera by switching to the DX format crop, which along with other format crops is available on the more expensive D3s.
Greater Sensitivity Of The D3s Sensor
This is where the D3s scores considerably over the D300. The workable ISO range of the D300 extends to 3,200 and I find that that’s even pushing it a little. The D3s, however, has a workable range of up to 12,800, a full 2EV over the D300 and with no image deterioration; it’s even possible to shoot beyond this. This has obvious advantages. It allows for faster shutter speeds or greater DOF and of course the ability to extend the working day to cover dawn and dusk, crucial in wildlife photography. When shooting on the higher ISO settings there are associated problems with contrast, colour saturation and dynamic range. With the D3s these effects are reduced considerably. I’ve recently been woking with both Barn and Tawny Owls in seriously low light conditions and with the D3s it’s been possible. With the D300 I would have had to call it a day much earlier.
The smaller size and lighter weight of the D300 makes it the preference for any travel photography when weight and size is a real consideration. If you are limited to the amount of equipment you are able to take or are trekking then I would always opt for the D300 DX format.
I’ve really enjoyed and benefited from using the D3s in certain conditions where the light levels are low or I’ve needed that extra couple of stops. I’ll still continue to to use the D300, however, as a ‘first option’ when the conditions are favorable and I’m after that extra detail. Both are really fine cameras which I find are suited really well for wildlife and documentary photography and both will remain in my camera bag at all times.