Smridevan wrote:
After further scrutinizing both files in great detail and looking at the sharpened image from the D800 vs D800E, I'm starting to think that the D800E's resolution advantage over the D800 can be negated by simply sharpening the D800's image. Since the AA filter is pretty weak on the D800 as you said, it wouldn't require that much sharpening to match the resolution. Any adverse effects from sharpening would not be an issue since sharpening is not heavily applied. Is this analogy valid? Or am I missing something?
That's pretty much what I am finding after playing around with a number of samples. Since the files are so large though, it does require a greater amount of sharpening than I'm used to with 24MP files.
This discussion has been very helpful. Thanks, Tariq, for bringing this up! I decided to cancel my D800E pre-order and go with the D800. Saves me a few hundred bucks and potential headaches in the future.
Smridevan wrote:
This discussion has been very helpful. Thanks, Tariq, for bringing this up! I decided to cancel my D800E pre-order and go with the D800. Saves me a few hundred bucks and potential headaches in the future.
Smridevan wrote:
... I decided to cancel my D800E pre-order and go with the D800.
Wise man. The old 1Ds has a rather weak AA filter which, when combined with my 280/4, creates an alarming amount of false data at wider apertures. The Apo-Telyt is indeed sharp! I don't see the additional megapixelage of the 800E to be any help with this lens. Note that color moire, luminance moire and false color are all special cases of false data, and cannot be corrected in post. Only low-pass filtering before sampling is the solution for those who prefer true data. My experiments at f/16 (not yet posted here) show residual oversampling.
philip_pj wrote:
Hi Tariq, is it those little areas of magenta near some very fine branch ends, I see one for example at the top left, and a few other spots also...it looks like fine detail got replaced with the same content shape, but in colour?
I occasionally see something similar to this but not so pronounced for similar content (nature photography) with the Distagon 21mm on A900, and always thought it was some minor CA. But it seems to surround the fine detail, whereas here it seems to have replaced it - pretty ugly IMO! Whatever, a good catch by them and you....Show more →
If you look at your images at 100% or 200%, with sharpening and chrominance NR off, you'll probably see that every single image that has some fine details (of sufficient contrast) going beyond the Nyquist frequency has these cyan and red-orange spots. Increase saturation if you don't immediately see them (and no, it's not chroma noise that I'm talking about).
About the term "moiré pattern": it seems to have been derived from the name of a kind of fabric that shows these interference patterns (the weaves of two layers of the fabric create interefence). http://en.wikipedia.org/wiki/Moir%C3%A9_pattern
So, logically, the word moiré should refer to the patterns in our context. False color is just a demosaicing artifact due to undersampling of the image details.
AhamB wrote:
If you look at your images at 100% or 200%, with sharpening and chrominance NR off, you'll probably see that every single image that has some fine details (of sufficient contrast) going beyond the Nyquist frequency has these cyan and red-orange spots. Increase saturation if you don't immediately see them (and no, it's not chroma noise that I'm talking about).
About the term "moiré pattern": it seems to have been derived from the name of a kind of fabric that shows these interference patterns (the weaves of two layers of the fabric create interefence). http://en.wikipedia.org/wiki/Moir%C3%A9_pattern
So, logically, the word moiré should refer to the patterns in our context. False color is just a demosaicing artifact due to undersampling of the image details....Show more →
Thanks for correcting the terminology. But if the false color is just a result of demosaicing of an under-sampled detail than why is there a difference between the D800 and D800E? Don't both camera's have the same sampling frequency?
Sorry if the answer is obvious - I'm having a hard time grasping this from this perspective.
netexpress wrote:
Thanks for correcting the terminology. But if the false color is just a result of demosaicing of an under-sampled detail than why is there a difference between the D800 and D800E? Don't both camera's have the same sampling frequency?
Sorry if the answer is obvious - I'm having a hard time grasping this from this perspective.
The answer is that the AA filter in the D800 does in fact help minimize the false color artifact.
Tariq Gibran wrote:
The answer is that the AA filter in the D800 does in fact help minimize the false color artifact.
To elaborate a bit: the AA filter is a low-pass filter, so it cuts off spatial frequencies above the maximum that the sensor can accurately sample (-> Nyquist frequency) by blurring them. I believe that the rays are split up in two directions and spread out so that you don't get sharply defined rays that only fall onto only some of the subpixels.
I think that false color can also be called color aliasing. If you understand the concept of aliasing -- color aliasing is the same thing, except in color (undersampling against a Bayer array).
@Smridevan: Definitely. I remember denoir has posted some samples of it. There are also some samples in the Ricoh GXR-M thread that show it.
AhamB wrote:
To elaborate a bit: the AA filter is a low-pass filter, so it cuts off spatial frequencies above the maximum that the sensor can accurately sample (-> Nyquist frequency) by blurring them. I believe that the rays are split up in two directions and spread out so that you don't get sharply defined rays that only fall onto only some of the subpixels.
I think that false color can also be called color aliasing. If you understand the concept of aliasing -- color aliasing is the same thing, except in color (undersampling against a Bayer array).
@Smridevan: Definitely. I remember denoir has posted some samples of it. There are also some samples in the Ricoh GXR-M thread that show it....Show more →
Good answer That makes sense now. You explain the concept in very simple terms. I love it when things can be broken down that way
The old 1Ds has a rather weak AA filter which, when combined with my 280/4, creates an alarming amount of false data at wider apertures. The Apo-Telyt is indeed sharp! I don't see the additional megapixelage of the 800E to be any help with this lens. Note that color moire, luminance moire and false color are all special cases of false data, and cannot be corrected in post. Only low-pass filtering before sampling is the solution for those who prefer true data. My experiments at f/16 (not yet posted here) show residual oversampling.