Photoclubalpha

There seems to be a trend now where some manufacturers are not fitting AA filters any more, such as Pentax, Fuji Etc. What do members think.
Its claimed to give much sharper and detailed images but at the exspense of more artifacts ect. Looking at the test pictures from the Nikon D5200 they are exceptionally sharp and detailed but the camera still has an AA filter.

According to this articlehttp://www.techradar.com/au/news/photog ... g--1160397 you don’t have to get involved with RGB spatial frequencies and Nyquist limits bla bla, (which as I understand, mainly concern stuff that happens within the lens-filter-sensels system), apparently the biggie that has the most influence is external HF patterns, there is not much need for a strong AA filter these days according to them and there are some cameras that get along ok with a neutral AA filter like the D800E.
I assume you would still be able to find some frequencies that cause moiré no matter what filter is on the sensor in your camera, but having a neutral AA filter is supposed to increase the odds of finding some.
For example (from what I’ve read) you could have a corrugated roof (or anything with a regular striped pattern) that at a particular distance has the correct high frequency pattern that causes moiré in an image produced from a particular camera-lens-magnification-sensor, and the same subject doesn’t produce moiré at a different distance-magnification with the same camera and lens.
Greg

I remember the DPR and other reviews on the Olympus E-520/420/620/30 where they all said the AA filter had been strengthened over the older E-510/410 which had much weaker filters exhibiting far sharper detail.
Needless to say they preferred the older cameras IQ and the E-510 got the gold award at the time for IQ and low noise, which was not bad for a 4/3 sensor camera over the APS-C cameras of the same period. Sadly Olympus got left behind by the APS-C sensors and the rest is history.

Agree, bit of a shame about the Olympus DSLR's (they were getting better as time went on) but we know they never stood a chance with the APS-C tidal wave.
I often wonder what would have happened if Olympus went APS-C, who knows what we'd see on the market now.

I know the A57 has a very light AA filter, but moire can be a problem at times as I've seen in real world shots.
Curiously there don't seem to be many complaints from D7100 about moire so maybe something changed sensor wise

The new Pentaxes without AA filters are starting to get some flack although in a small way for the increase in moire at higher ISO, they say its not that noticable but there on occasions if you look hard enough.

If Olympus had gone APS-C, all the lenses would need to be changed to new focul lengths for the bigger sensor or the bodies made huge.

An interesting direction from Pentax on the K-3

Anti-aliasing ‘simulator' to combat moiré

In a bid to boost image quality, by showing more detail, the K-3 does not have a low-pass filter on the camera's imaging sensor.

However, this leaves the image vulnerable to moiré effects - such as those seen when photographing striped clothes, for example.

So, to help combat this, the K-3 features an anti-aliasing ‘simulator' built into the camera's shake-reduction (SR) system.

Billed as a ‘world first', users can adjust the anti-aliasing filter effect level to suit the subject.

Ricoh Imaging says this ‘reduces the moiré effect by moving the SR unit at the sub-pixel level in a circular motion during image exposure'.

Microscopic vibrations are applied to the sensor to generate the ‘same level of moiré reduction effect as an optical anti-aliasing filter'.

Barry, I'v been told that Nikon switched to Toshiba sensors on the D5200 and D7100, this could be one reason.
Atgets, thanks for that interesting explanation on the Pentax sensors
Complicated for my simple mind but I can understand the jist of it.

Evidently the K-3 is using a Sony sensor not a Toshiba one. Maybe a new generation model from their older 24mp ones.

Is it worthwhile to have the AA filter removed in either A700 or A900?
I understand the Moire pattern issue but looks like it is worth the occasional
mishaps with Moire pattern. www.maxmax.com can remove them for about $450
and shipping. Just curious.

Sury

Not sure its worth while on a Sony, but I have heard of them being removed from Olympus EXXX 4/3 cameras and people have been pleased with the results. Some moire can be dealt with in PP.

I am curious to know why it would not be worthwhile on Sony? Is it because it is already
a weak filter (from what I gather)?

Sury

I think Barry said the A57 has a weak AA filter. I can't vouch for other Sony models. Its probably not worth it if that is the case.
I get all the detail and sharpness I need from my A37/57 cameras.
I guess having a good quality lens giving sharp pictures is more important than removing the AA filter.