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My quick D800 versus E test

Yes, it's a new design -- and clever.
I'm not sure what aspects are new. It looks to me like the standard design that's been used for a long time. See the description of opticl low pass filters here.

I agree that it seems to be particularly well implemented. Although part of what makes this easy is simply the high resolution of the camera. More linear resolution means you need less blur. It also means that the unwanted (visible) effects of the filter will effect frequencies where there's rarely much useful optical information from the lens.

The basic strugle with anti aliassing filters, whether in optics or in audio, is that perfect analog filters are impossible to design. A perfect one would be a brick-wall filter ... one that blocks everything above the chosen frequency, and lets everything below that frequency through, completely unimpared.

Since no one knows how to make such a thing, engineers compromise. The effect of a real filter corresponds to a curve, not a wall. The nyquist limit is placed somewhere in the middle of that curve. This means that detail a little above that limit, if the contrast is high enough, can still cause visible aliasing. And detail a little below that limit will be blurred. The game the enginners play is to design as steep a curve as possible, and then carefully balance the strength and center frequency of the filter to give the best performance over the reange of likely uses.

Still we see a subtle difference between the filtered and filterless cameras. If we could have a perfect filter there would be none.
 

Steen

Senior Subscriber Member

It's difficult to judge much out of the Wikipedia link you posted, Paul, since it has no illustration to support the very short description.

Maybe useful to repeat here the link that Jack already provided back in post # 48.

http://www.nikonusa.com/en_US/IMG/I...ies/Moire-D800-D800E/Media/OLPF_schematic.pdf



Could it be the Waveplate that is the new 'solution part' of the arrangement, at least it got its own specific note in the illustration ... ?



"OLPF schematic" by nikonusa.com (here downsized and linked to the original):




 
I don't think the waveplate is new. it's basically a circular polarizer, which is necessary after the light passes through the first low pass filter.
 

Jack

Sr. Administrator
Staff member
AIUI, none of the individual components are new or unique, but the arrangement with the waveplate is.
 

gazwas

Active member
To my eyes, I'm left feeling underwhelmed at the differences the much hyped AA filter free D800E produces. Not sure if to be unimpressed at how little sharper the 800E is or impressed at how sharp the regular D800 is.

What I find most distracting about both these shots and I'm not sure if its a jpeg compression, processing, lighting, lens or exposure thing but some of the bright white and highlight areas of the images have an unusual and unpleasant "glow" to them. Reminds me of Nikon D100/D200's of old.
 

mathomas

Active member
I felt I could see a difference even just at the default "full screen" size of my little MacBook Air, in Safari. I brought both images up and used Command-` between the images. I identified the one ending in "60" as the E version.

I then clicked on the images to magnify them to 100% and was certain that "60" is the E version. Definitely more detail.

I have no dog in this hunt. I will never own either of these cameras. I have no use for 36MP images (shocking on this site, I know :)). But the difference was obvious and clear to me.
 
J

julianv

Guest
From what I understand, the OLPF used in the D800 is a design that Nikon patented about 10 years ago.

Patent US6392803 - Optical filter and optical device provided with this optical filter - Google Patents

This is probably similar to the OLPF in other recent Nikon DSLRs. I think Canon uses a similar construction, so maybe they are paying royalties, or cross-licensing patents with Nikon.

The configuration in the D800E, where the birefringent layers are oriented to cancel each other out, might be new and unique. I don't know if this has been patented.
 
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