The Nikon D800E is generating a lot of interest among many landscape and macro photographers and one question that has been popping up a lot, is why the Nikon D800E is $300 more expensive than the Nikon D800? I received a number of comments like “why is Nikon charging extra for something the D800 does not have?” (meaning why Nikon charges extra money for a camera without an anti-aliasing / low-pass filter). In fact, both the Nikon D800 and the D800E have anti-aliasing filters (see the illustration below), it is just that the Nikon D800E has two of the filters reversed that cancel each other out. So some of the extra charge is coming from the required change in the manufacturing process. Additionally, the Nikon D800E version will ship with the Nikon Capture NX 2 software, which costs around $129.95 retail.
Now about that low-pass filter on the Nikon D800E – both the D800 and the D800E have low-pass filters, but they behave differently. Typical Nikon low-pass filters actually contain of 3 different layers, as shown on the top illustration below:
As light rays reach the first “horizontal low-pass filter”, they get split in two, horizontally. Next, they go through an infrared absorption filter (illustrated in green color). After that, the light rays go through the “second vertical low-pass filter”, which further splits the light rays vertically. This light ray conversion process essentially causes blurring of the details.
Now with the Nikon D800E model, Nikon took an interesting approach. We know that the full low-pass filter cannot be completely removed, because it would cause the focal plane to move as well; plus, the camera still needs to be able to reflect infrared light rays. Instead of making a single filter with one layer, Nikon decided to still use three layers, but with two layers canceling each other out. As light rays get split into two with a vertical low-pass filter, then through the IR absorption filter, those same light rays get converged back when passing through a reversed vertical low-pass filter. Hence, instead of getting blurred details as in the first illustration, we get the full resolution.
I am not sure if the above method is the best way to deal with the issue, but I suspect that Nikon decided to take this route for cost reasons. It would probably be more expensive to produce a single IR absorption filter layer coated on both sides, than continue to use the same layers, but in a different configuration.
The above information will be added to my Nikon D800 vs D800E article I posted last night.