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01-17-2014, 03:17 PM   #1
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Does the switchable AA filter pose difficult problems for RAW converters?

Prompted by the absence of K3 support in Apple's Digital Camera Raw (latest update 5.03), which is used by Aperture, I posted on the Apple Aperture discussion group asking why it had been bypassed in updates 5.01, 5.02, and 5.03, and received an interesting reply.
"We don't really know what Apple is working on, but on past experience there is usually a reason why they take their time. Support for Fuji X100 and X-Trans showed the benefits of this. Ligthrooms support for X100 was incomplete and the initial support for X-Trans was quite woeful. The Fuji forum at DPR had a lot of disapointed users, so while they got support faster, they continued to shoot Raw+JPEG and use the JPEGs. I don't know much about Pentax's JPEG engine though. In contrast, when X-Trans support finally came to Aperture, it made a much better job of retaining detail and reducing the colour bleeds, still not perfect but much better."

"So while I understand your frustration, you can perhaps take a little comfort in anticipating it will probably be worth the wait."

"If I were adding support for the K3, the thing that would trip me up is the switchable AA filter. This essentially means it's going to need different demosaicing parameters based on the AA filter setting. It will be interesting to see if any reports start to appear about how well Lightroom is handling that aspect."
So, the questions are:
  1. Does the switchable AA filter really make design of a RAW converter more difficult?
  2. Could this be the reason for Apple's delay?
  3. Did those utilities (e.g. Lightroom) that already have K3 support rush the job? Are there issues with the way they handle it?
  4. Does Lightroom even know if the AA filter is on?
By the way, I installed Pentax's Digital Camera Utility 5 last night (it came on disk with the K3), and tried it out. It's nice that it recognizes most of the K3 settings, such as WB etc, and gives the option of using the camera setting or over-riding it. However, as far as I can see from the EXIF it displays, there is no indication whether AA has been turned on or not. If so, how would any RAW converter be able to take account of it?

01-17-2014, 03:26 PM   #2
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Sounds like Apple baloney to me. There's no difference to an AA filtered shot and and a lot of the slightly OOF parts of an AA-less image, i.e. you don't need a different converter algorithm for different parts of an image, so why would you need one for an AA-less camera?
01-17-2014, 03:38 PM   #3
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You certainly wouldn't need to use different algorithms to get a proper image for different AA filter settings. Adobe may add certain optimizations but I don't think this the presence of the AA filter setting will hold up development or anything like that.

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01-17-2014, 03:44 PM   #4
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The x-trans sensor and the AA-filter simulation of the k-3 are completely different items.

The x-trans sensor uses a different filter pattern than the standard bayer filter pattern. The RAW converters that read the RAW files have to generate an image based on the activated signals from the filter pattern. Because most sensors use bayer filters, RAW converters are designed to average the signals from the bayer pattern to say "this pixel is actually this color based on the surrounding pixels".

The x-trans pattern is too different from the bayer pattern for RAW converters to use the same algorithms. The k-3 sensor, however, is still a bayer filter sensor. It only lacks the AA filter - which diffuses the incoming signal to the bayer sensor to reduce aliasing artifacts. Thus - RAW converters have no issues reading the output of the k-3 sensor. And since the AA-filter simulation is merely motion blur, the explanation that was given you is BS.

01-17-2014, 03:46 PM   #5
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QuoteOriginally posted by Paul the Sunman Quote
Prompted by the absence of K3 support in Apple's Digital Camera Raw (latest update 5.03), which is used by Aperture, I posted on the Apple Aperture discussion group asking why it had been bypassed in updates 5.01, 5.02, and 5.03, and received an interesting reply.
"We don't really know what Apple is working on, but on past experience there is usually a reason why they take their time. Support for Fuji X100 and X-Trans showed the benefits of this. Ligthrooms support for X100 was incomplete and the initial support for X-Trans was quite woeful. The Fuji forum at DPR had a lot of disapointed users, so while they got support faster, they continued to shoot Raw+JPEG and use the JPEGs. I don't know much about Pentax's JPEG engine though. In contrast, when X-Trans support finally came to Aperture, it made a much better job of retaining detail and reducing the colour bleeds, still not perfect but much better."

"So while I understand your frustration, you can perhaps take a little comfort in anticipating it will probably be worth the wait."

"If I were adding support for the K3, the thing that would trip me up is the switchable AA filter. This essentially means it's going to need different demosaicing parameters based on the AA filter setting. It will be interesting to see if any reports start to appear about how well Lightroom is handling that aspect."
So, the questions are:
  1. Does the switchable AA filter really make design of a RAW converter more difficult?
  2. Could this be the reason for Apple's delay?
  3. Did those utilities (e.g. Lightroom) that already have K3 support rush the job? Are there issues with the way they handle it?
  4. Does Lightroom even know if the AA filter is on?
By the way, I installed Pentax's Digital Camera Utility 5 last night (it came on disk with the K3), and tried it out. It's nice that it recognizes most of the K3 settings, such as WB etc, and gives the option of using the camera setting or over-riding it. However, as far as I can see from the EXIF it displays, there is no indication whether AA has been turned on or not. If so, how would any RAW converter be able to take account of it?
Well the response came from a discussion group participant. Hardly an Apple source.
01-17-2014, 04:00 PM   #6
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QuoteOriginally posted by Adam Quote
You certainly wouldn't need to use different algorithms to get a proper image for different AA filter settings. Adobe may add certain optimizations but I don't think this the presence of the AA filter setting will hold up development or anything like that.
Yeh, my initial thoughts too. However, the discussion group participant did seem to have some experience with this, so I raised the question. Looks like everyone agrees it's not an issue.

Now I just sit back and wait for Apple to add K3 support.
01-17-2014, 04:08 PM   #7
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Apple reportedly runs fairly lean in Cupertino, relying on small teams. They'll switch the teams around for priority projects (i.e., Mavericks, iOS 7, iWork makeover, etc.). My suspicion is that a relatively small team is responsible for Digital Camera RAW updates, and, our opinions notwithstanding, Apple won't pull all available personnel into Digital Camera RAW updating to ensure that K3 RAW files are properly handled. They'll get around to it on their own time and using their own logic as to priorities.

In regards to the anti-aliasing filter holding things up, I note that the Nikon D800E, Fujifilm EX-1, and Leica M8 (among others) are all supported RAW formats, with none of them having AA filters (as far as I know, at any rate). Come to think of it, they supported the K5 IIs, so they've supported Pentax RAW files without AA filters. Apple has dealt with RAW output without anti-aliasing filters before. If I recall correctly, I had to wait a while after I got my K5 before the RAW files were supported properly by Apple, so I'm not that surprised. Disappointed, yes, but not surprised.

Personally, since my K3 is aboard a UPS truck, I wish Apple would devote the whole company to this (I mean, how important can iPhone development really be to the future of the company????), but I'm resigned to the fact that they won't. I guess I'll be using the Adobe RAW converter to get the RAW files into iPhoto/Aperture for a while. I'll probably shoot RAW+jpeg for a while, too; just to be sure. Not too pleased by that, but I've spent a lot of my life waiting on Apple updates, so I'm kind of inured to the situation by this time.

I'd give Lightroom a shot, but I'm used to my workflows (playflows would be more accurate in my case), so I probably won't if my workarounds, well, work.
01-17-2014, 04:12 PM - 1 Like   #8
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QuoteOriginally posted by SteveB Quote
Sounds like Apple baloney to me
Absolutely. The quoted poster is probably just building self-esteem by worshipping Apple Corp., and the most likely explanation is that Apple is too cheap/lazy to put enough programmers on the project to implement the profiling data supplied by camera manufacturers on a timely basis. Look how many new profiles are added for every release of Lightroom. Photography software vendors don't manufacture cameras, so there is no incentive for camera manufacturers to withhold information about the characteristics of the RAW files from specific models of cameras from Apple, Adobe or any other software vendor in this market.

How to Reduce Moiré in Lightroom 4 Maybe Aperture doesn't have any tools for reducing moire. Switching the AA filter off should be a conscious decision by the photographer, not something to be defeated by a post-processing robot. The poster on the Aperture board is far less knowledgeable than s/he would like to believe.

You can flame away, but Apple kissed off the true power user market a long time ago. There are better profit margins in dumbing down your OS and applications so consumers with above average incomes and below average computer literacy will prefer your hardware. In Apple's mindset, supporting pro-grade image editing software is a cost centre with a relatively poor ROI.

01-17-2014, 04:23 PM   #9
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QuoteOriginally posted by stens Quote
Apple reportedly runs fairly lean in Cupertino, relying on small teams. They'll switch the teams around for priority projects (i.e., Mavericks, iOS 7, iWork makeover, etc.). My suspicion is that a relatively small team is responsible for Digital Camera RAW updates, and, our opinions notwithstanding, Apple won't pull all available personnel into Digital Camera RAW updating to ensure that K3 RAW files are properly handled. They'll get around to it on their own time and using their own logic as to priorities.

In regards to the anti-aliasing filter holding things up, I note that the Nikon D800E, Fujifilm EX-1, and Leica M8 (among others) are all supported RAW formats, with none of them having AA filters (as far as I know, at any rate). Come to think of it, they supported the K5 IIs, so they've supported Pentax RAW files without AA filters. Apple has dealt with RAW output without anti-aliasing filters before. If I recall correctly, I had to wait a while after I got my K5 before the RAW files were supported properly by Apple, so I'm not that surprised. Disappointed, yes, but not surprised.

Personally, since my K3 is aboard a UPS truck, I wish Apple would devote the whole company to this (I mean, how important can iPhone development really be to the future of the company????), but I'm resigned to the fact that they won't. I guess I'll be using the Adobe RAW converter to get the RAW files into iPhoto/Aperture for a while. I'll probably shoot RAW+jpeg for a while, too; just to be sure. Not too pleased by that, but I've spent a lot of my life waiting on Apple updates, so I'm kind of inured to the situation by this time.

I'd give Lightroom a shot, but I'm used to my workflows (playflows would be more accurate in my case), so I probably won't if my workarounds, well, work.
It's not having no AA filter that's the issue. Rather, that you can have it set to Off, 1, or 2 on the K3.

Yes, I'm using the Adobe RAW converter as a preprocess to importing into Aperture. It seems to work alright, except that the resulting DNG file's EXIF thinks all my images used manual focus when they were all autofocus. Strange.
01-17-2014, 05:45 PM   #10
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QuoteOriginally posted by Paul the Sunman Quote
It's not having no AA filter that's the issue. Rather, that you can have it set to Off, 1, or 2 on the K3.

Yes, I'm using the Adobe RAW converter as a preprocess to importing into Aperture. It seems to work alright, except that the resulting DNG file's EXIF thinks all my images used manual focus when they were all autofocus. Strange.
Again, the k-3 sensor is still a bayer sensor. The demosiacing algorithm for the sensor is no different than any other bayer sensor. The AA is simulated by motion blur - it does not change the structure of the sensor. Imagine you took a k-5 and shot a picture while it is sitting in a very slightly vibrating plate. You can still process the image, you would just notice that the image has a very tiny motion blur.

The xtrans sensor uses a different pixel configuration than a bayer sensor, and that is where the demosiacing issues come in.
01-18-2014, 04:30 AM   #11
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QuoteOriginally posted by Paul the Sunman Quote
It's not having no AA filter that's the issue. Rather, that you can have it set to Off, 1, or 2 on the K3.

Yes, I'm using the Adobe RAW converter as a preprocess to importing into Aperture. It seems to work alright, except that the resulting DNG file's EXIF thinks all my images used manual focus when they were all autofocus. Strange.
That you can change it is no issue either. As already pointed out the effect of the AA filter is no different from having slight motions blur or slightly out of focus images.

The only thing you might want to do differently for a photo with AA filter vs one which doesn't is to use slightly more sharpening strength and also a larger radius for the AA filtered ones. But in any case you wouldn't do that based on what the settings were but rather on what you see. If the image needs some sharpening to look better it doesn;t really matter whether that sharpening is needed because of the AA filter, slight motion blur or slight out of focus or lens softness.

I would also like to add that with all but the sharpest lenses in perfect focus the AA filter makes very little difference. With the 18-135WR for instance I found it next to impossible to distinguishe between the different AA modes, whereas a Tamron 90 SP macro would show a distinct improvement with the filter turned off. With the AA filter on and some careful sharpness boosting I got sort of the same sharpness but not quite.
01-18-2014, 10:47 AM   #12
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QuoteOriginally posted by RGlasel Quote
You can flame away, but Apple kissed off the true power user market a long time ago. There are better profit margins in dumbing down your OS and applications so consumers with above average incomes and below average computer literacy will prefer your hardware.
I regret that I must agree with you on this.
01-20-2014, 02:10 PM   #13
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QuoteOriginally posted by RGlasel Quote
You can flame away, but Apple kissed off the true power user market a long time ago. There are better profit margins in dumbing down your OS and applications so consumers with above average incomes and below average computer literacy will prefer your hardware. In Apple's mindset, supporting pro-grade image editing software is a cost centre with a relatively poor ROI.
Well, it's a mixture with Apple. I've used a huge variety of computers and operating systems continuously since 1972, including many flavours of UNIX over the last 25 years or so, especially linux. Underneath all the glitz, OS X is a fully configured UNIX, which is why scientists such as myself use macs so much. When I go to conferences in my field (solar physics) I see 60%+ of my peers with macs because they can do serious science with them at the UNIX level but also have the convenience of higher level utilities.

So, at its core OS X is a powerful OS. Unfortunately, Apple has an annoying tendency to think they know best. The level of configurability of the window manager for example is very limited compared to any linux WM. So yes, I agree with you, they tend to dumb down their interfaces, despite the underlying flexibility and power of the OS. And yes, we are unfortunately seeing the same thing with such utilities as Aperture 3.

I am withholding final judgement till I see the long anticipated Aperture 4: will they try to catch up with and surpass Lightroom, or will they abrogate the field and let Lightroom etc sail off into the distance whilst they and their users are left sitting on a rock?
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