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Tuesday, September 24, 2013

Removing AA Filters is a Mistake for the Industry, Said IR

http://www.imaging-resource.com/PRODS/olympus-e-m1/olympus-e-m1A.HTM

Via Image Sensors World

Quoted:-

"Low-pass filters, the lack thereof, and moiré

There's been a strong move in the camera industry lately to remove low-pass filters (aka anti-aliasing filters or LPFs) from cameras, in pursuit of greater image sharpness. The Olympus OM-D E-M1 is one of the latest camera models to join this trend.

At IR, we feel strongly that eliminating low-pass filters is a bad idea, and a mistake for the industry. While the vast majority of natural subjects aren't subject to aliasing and moiré issues, many man-made objects have the sort of regular patterns that trigger the problem.

The real problem is that once you've got moiré or color aliasing in your images, it can be very difficult, if not impossible, to remove."

"As noted above, these examples don't point a finger at Olympus alone: The same or worse can be found in the output from virtually any high-end camera built without an LPF."

They have their daily life example images to prove that they are right. Of course, as the most basic thing for digital sampling, the Nyquist theorem should NOT be violated!

Comments (26)

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SpendsalotonPentax's avatar

SpendsalotonPentax · 598 weeks ago

Out of the thousands of exposures I've had from my K-5IIs only two showed any moiré. Image detail is however much better than my original K-5.
Rataskanken's avatar

Rataskanken · 598 weeks ago

Same experience as SpendsalotonPentax, although I stopped spending on this brand last year after 35 years in favor of a Nikon D800E, and this year a D7100. In the tens of thousands of images I've captured with these two LP-filter free bodies, I've seen moiré at a single occasion. But then I mostly take photos of nature, where highly repetitive man-made patterns are pleasingly absent. With high quality optics, the added crispness I get by far outweighs the drawback of a single image in ten thousand showing moiré, which can be dealt with in software anyway.
Who cares about more details in pixel peeping, once the colors are wrong.

I am member of a photo club where we use different cameras. I have played with Canon 7D/5D mkII (great colors), Sony NEX 5 (Very good colors), Sony NEX 5N and Pentax K5 (average colors) and the worst colors Pentax K5IIs and Nikon D800/E (shitty colors). Those who do not believe, instead of listening to fan boys and vendors, can check themselves on a calibrated screen the new test picture on dpreview (look at the red becoming orange, the dirty yellow ...).
My K-5IIs has very rare moire pattern.
1 reply · active 598 weeks ago
...if they would remove the Infrared filter also and replace it by a optional solution... I would take any moiree!
Image detail just cannot be "much" better with no filter. True, it is somewhat better, but it cannot be "much" better. Whatever you compare - K5 with K5IIs, D800 with D800E - the difference is small and can only be seen in very big enlargements and ONLY if you have both versions to compare! Hey, whatever images I ever made with my K5 - everybody I show these react "WOW!" NOBODY has EVER commented: "see, your images lack detail". They never compare "center sharpness" to "corner sharpness" - things that only unhappy pixel peepers look for. The reason is that clients NEVER compare the actual image to anything. They are just impressed with the darkened backgrounds and contrast, and etc., as with my recently made basketball game photos. What is much more important is lighting, not silly "pixel peeping". For this reason I am completely confident about using my K5 for an upcoming wedding shoot in the end of November. Sure, the quality of the images will not on depend the camera!
9 replies · active 598 weeks ago
The most amazing remark I heard was "because we have such a resolution in our sensors, the lenses are already doing the job of the filter. "
So if you dont see any moire your lenses are so bad that they are doing the job of the filter. rofl
I guess that the filter is usefull but instead of making them better doing the research and making a complex expensive filter they now expect software to do the job, and you get more detail and they get extra money in the pocket.
The most lenses ARE a natural LP filter. It's sharpness/resolution is not unlimited!
Dan Johnson's avatar

Dan Johnson · 598 weeks ago

Real Medium Format DSLRs (16bit color depth) and the D-645 have no moire filter (sans AA) because it hinders the performance of the lens, much like an overly dense image-sensor. The K-5III (as described will need much better lenses) why cheap-side the camera while paying large coin for great glass, tell Ricoh the MegaPixel Race is over and it's time to use the obviously better approach to low light performance (only as many large pixels as needed) it increases speed at no extra cost by the way, to the tune of 8MP is twice as fast as 16MP and will give you 11" by 17" prints. FanBoys can go else-ware, use onOne's Genuine Fractals , or both if they enjoy paying for prints that make 13" by 19" look small!
I haven't seen moire patterns from my K-5IIs up to now.
6 replies · active 598 weeks ago

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