[slartibartfast01]

sure, but why would an AU restrict anyone here? Would not astrotraced images at ISO 400 (pushed if necessary) be a perfect basis for stacking?

That is a workaround. Not sure what an AU is.

[MMVIII]

That is a workaround. Not sure what an AU is.

Wait, stacking multiple images is an allowed workflow, pulling them up 2EV is a workaround. Got it. AU would be the Accelerator Unit, IIRC Ricoh might have called it like that once. Nevermind.

[Rondec]

I think the point about the loss of fine detail when stacking many astro shots to reduce noise makes sense though. Probably not an issue in general photography but a big issue for those that care about these things.

This has not turned out to be an issue though. Ian Norman on Lonely Speck did an extensive review on the K-1 II where his initial review was totally positive. He was then contacted by DP Review to mention the accelerator "issue." He went back and did some careful evaluation and added these paragraphs:

"While I don’t personally have the original K-1 with which to compare this K-1 Mark II, in DPReview’s full review of the K-1 Mark II, they showed that the original K-1 could resolve slightly more detail at ISOs above 400. It’s it a big difference? Not really. In practice, the difference is very small and I never felt disappointed with the K-1 Mark II’s capability to resolve detail at high ISOs.

Most importantly, the problem is not detrimental to star details and does not present the same problem as the Sony star-eater issue. I do, however, agree with DPReview and I wish that manufacturers would stop trying to apply noise reducing techniques to RAW files. These operations are much better saved for JPEGs or for post processing when the photographer can make the choice of how much or how little noise reduction to apply."

(Full Review here: Pentax K-1 Mark II Astrophotography Review – Lonely Speck )

The reality is that unless your practice is to shoot a K-1 II and K-1 beside each other and then pixel peep the images, you are not going to notice anything at all with regard to loss of detail. Certainly noisy images appear to have more detail, but all noise reduction techniques are going to remove a little bit of detail along with noise. The question is if it is meaningful. Are there images that shot at iso 800 on a K-1 II that are completely spoiled due to the accelerator that would have been fine on a K-1? Is the reduction in detail noticeable at a normal printing size? Does the accelerator make work flow more efficient and reduce the need for noise reduction in post?

I have shot plenty of bad high iso images on my K-1 II, but they are bad because of me, not because of the accelerator. Honestly a tiny bit of fine detail is not going to make or break most images, it is other things like subject, lighting and composition which end up making the difference. On the other hand, my wife shoots weddings and it does save her time because she has less noise reduction to apply to certain images out of camera.

To me, the RAW purity thing has almost religious overtones. Some people wanting their RAWs totally pure and some people just wanting the best images they can get. It's a tiny group in all actuality. The majority of folks these days shoot straight of camera jpegs with plenty of in camera processing already applied. They simply don't care at all. And DP Review folks are the biggest hypocrites because they are totally OK with Sony massaging their RAW images and producing artifacts in certain situations, but they attack Pentax for something significantly less heavy handed.

[slartibartfast01]

Wait, stacking multiple images is an allowed workflow, pulling them up 2EV is a workaround. Got it.

I am not sure what you mean by this but I was agreeing with you.

[MMVIII]

I am not sure what you mean by this but I was agreeing with you.

sorry, misunderstood you.

[Rondec]

Just to put an image to it, this is my nephew shot with my new daughter at iso 6400 on the K-1 II. I think the image is a touch soft, but it is what would expect from a back lit, slight under exposed iso 6400 image shot with either the K-1 or K-1 II.



I don't really have much more to say. I do think (a) that people are pretty ingrained and those who feel strongly that any manipulation of RAW data is bad will continue to feel that way, (b) most people who own a K-1 II or an upgraded K-1 are happy with the images they get from their camera (I have seen a couple of folks who weren't but they seem to be the exception) and (c) DP Review is not going to give Pentax a good review regardless of the SLR they release. It is bound for a silver award before they ever lay hands on it.

I would say one thing more. I don't think Pentax thought there was any point in releasing a K-1 II with the accelerator disabled. I believe they thought that the accelerator was the whole point of the camera. Anyone who didn't like it would just get a K-1. The differences between a K-1 and K-1 II are slight improvements in auto focus, hand held pixel shift and the accelerator. That is to say the main difference is the accelerator. Don't like it? The best thing in that situation was not to pay more money for a K-1 II and complain but get a used K-1 and shoot with that. I don't know going forward what Pentax will do -- maybe just have it kick in at higher iso levels -- but I'm guessing they are going to stay with the tech.

[lukulele]

Just to put an image to it, this is my nephew shot with my new daughter at iso 6400 on the K-1 II. I think the image is a touch soft, but it is what would expect from a back lit, slight under exposed iso 6400 image shot with either the K-1 or K-1 II.



I don't really have much more to say. I do think (a) that people are pretty ingrained and those who feel strongly that any manipulation of RAW data is bad will continue to feel that way, (b) most people who own a K-1 II or an upgraded K-1 are happy with the images they get from their camera (I have seen a couple of folks who weren't but they seem to be the exception) and (c) DP Review is not going to give Pentax a good review regardless of the SLR they release. It is bound for a silver award before they ever lay hands on it.

I would say one thing more. I don't think Pentax thought there was any point in releasing a K-1 II with the accelerator disabled. I believe they thought that the accelerator was the whole point of the camera. Anyone who didn't like it would just get a K-1. The differences between a K-1 and K-1 II are slight improvements in auto focus, hand held pixel shift and the accelerator. That is to say the main difference is the accelerator. Don't like it? The best thing in that situation was not to pay more money for a K-1 II and complain but get a used K-1 and shoot with that. I don't know going forward what Pentax will do -- maybe just have it kick in at higher iso levels -- but I'm guessing they are going to stay with the tech.

For a moment a pause on the technology. Congratulations on your daughter and the wonderful image above. I’v got a spare Spotmatic II for her when she’s ready for manual and film.

[Class A]

Some people wanting their RAWs totally pure and some people just wanting the best images they can get.

This is a genuine question: What makes you assume that you are talking about a disjoint set of people?

Why is it not possible that people that don't want to see raw data messed with also just want the "best images they can get"?

The choices made by the "accelerator" unit are not always the best for everyone.

Thanks a lot for including the following part when quoting Ian Norman:

"I wish that manufacturers would stop trying to apply noise reducing techniques to RAW files. These operations are much better saved for JPEGs or for post processing when the photographer can make the choice of how much or how little noise reduction to apply."

Does Ian's wish make him a "raw purist" who is needlessly concerned about principles instead of just wanting to get the best images possible? I personally don't think so.

And DP Review folks are the biggest hypocrites because they are totally OK with Sony massaging their RAW images and producing artifacts in certain situations, but they attack Pentax for something significantly less heavy handed.

I entirely agree.

I hope nobody thinks that I'm defending these jokers.

[BigMackCam]

I do think (a) that people are pretty ingrained and those who feel strongly that any manipulation of RAW data is bad will continue to feel that way, (b) most people who own a K-1 II or an upgraded K-1 are happy with the images they get from their camera (I have seen a couple of folks who weren't but they seem to be the exception) and (c) DP Review is not going to give Pentax a good review regardless of the SLR they release. It is bound for a silver award before they ever lay hands on it.

As I've mentioned before in these forums, my Sony A99-based Hasselblad HV saves lossy compressed raw files. With later models, Sony offered firmware updates to provide lossless uncompressed raw capability, but the A99 and earlier didn't make the cut. The lossy compressed files can show compression artefacts at very high contrast borders, visible when pixel peeping. Some folks were up in arms about this when it was discovered. I'll admit, I wasn't too keen on it either... But the fact of the matter is, for most photography, it's simply not an issue unless you look for it at 100% or greater reproduction. Most Sony shooters simply didn't worry about it. Many, though, did - and updated their cameras with uncompressed raw capability. Then, when they saw the size of the resulting files and the performance overhead associated with writing them, they quickly forgot about artefacts and went back to saving lossy compressed raw

I mention this because, though not quite the same thing, it's not entirely dissimilar. Most photographers won't be adversely affected by the accelerator's noise processing, and the majority of those who believe they might probably won't either. For a select few, it could be an issue - but how much, and how often, is debatable...

[Class A]

He was then contacted by DP Review to mention the accelerator "issue."

Is that documented somewhere?

It seems very odd that DPReview would try and influence what a third-party had to say about the K-1 II, doesn't it?

If that is true it gives credence to the notion that someone at DPReview has an axe to grind with Pentax. Maybe because Ricoh didn't gift them a review copy, or something like that.

[microlight]

my Sony A99-based Hasselblad HV saves lossy compressed raw files

Can you clarify please, Mike? Raw files can be compressed or uncompressed, but I thought it was always lossless as otherwise you're throwing away data. Similar to audio files where lossless can be uncompressed (e.g. WAV) or compressed (e.g. FLAC) but not lossy like MP3, where data cannot be recovered. Surely to retain all of the original data, the compression has to be lossless - if it's lossy then by definition, it can't be 'raw'? (and vice versa.)

[BigMackCam]

Can you clarify please, Mike? Raw files can be compressed or uncompressed, but I thought it was always lossless as otherwise you're throwing away data. Similar to audio files where lossless can be uncompressed (e.g. WAV) or compressed (e.g. FLAC) but not lossy like MP3, where data cannot be recovered. Surely to retain all of the original data, the compression has to be lossless - if it's lossy then by definition, it can't be 'raw'? (and vice versa.)

It sounds unbelievable, right? But 'tis true...

I'll point you to a good article on "the other site" that both explains in detail and shows a good example of the artefacts around high contrast borders:

The Raw and the cooked: pulling apart Sony's Raw compression: Digital Photography Review

Interestingly, there was even an update to Sony's raw processing software to carry out edge noise reduction, which I'm sure was added specifically to address the border artefacts issue I mention. Sadly, it has an overall softening effect, so it's pretty much useless in my opinion. In any case, I prefer to use Darktable, RawTherapee or Lightroom.

I'm not sure if the lossy compressed raws are even an option on the later cameras. Certainly, it's possible to bypass the compression altogether and save as uncompressed raw.

Even with this raw heresy, the files from my Hasselblad HV look great. Oh, and the 24MP raw file sizes are incredibly compact

[photoptimist]

The evidence for raw smoothing is two-fold:

1. visual comparisons clearly show that the K-1 II applies smoothing to noisy detail.
2. 2D Fourier Transform analysis shows clear signs of smoothing.

You don't get better evidence than this.

Yes, there is evidence of processing in the RAW files, but......

What that analysis cannot show was whether that process affected just the noise or also affected the signal. Advanced algorithms for noise reduction and signal estimation are a lot more sophisticated than just averaging some pixels together. An Fourier Transform is an inadequate analysis for assessing these kinds of non-linear processes -- just because some high-frequencies have been affected does not imply that all high-frequencies were.

Thus, the statistical evidence does prove that the RAW is "cooked" but that does not mean it makes mush. Instead they may be cleaner and still al dente.


P.S. I'd bet that Pentax was surprised by the pushback on the K-1ii's accelerator given that they'd put the same technology in the K-70 and KP without complaint. You'd think that if the accelerator ate stars or made mush, it would have been noticed but it was not.

[microlight]

Nnnnnnobody expects ... 'the other site'!!


I don't want to hijack the thread (sorry) but darn right it's unbelievable! Thanks for referencing the article, but it just reads as closely analogous to the audio example I mentioned, even down to the application of a lossy compression curve that 'is used to map the 14 bits of captured data down to an 11-bit space', generating a lossy data set. Then the kicker: 'This means it doesn't make sense to retain all the information about bright regions of the images, since a lot of that information will just be recording the subtleties of the noise' and 'This will, theoretically, reduce the dynamic range available in the files'. This is exactly the same rationale that Sony (oh, look) used when they invented the lossy MiniDisc system back in the early 90s; they were hacking out the high frequencies and saying that they were only throwing away the souds that humans couldn't hear, so it didn't make any difference. This was promulgated in the MP3 rationale to make mobile music more space-efficient (and the rest is history), but if you critically compare a 320kbps MP3 with a high-resolution file of the same music, there is a clear difference, and I think that this is what DPR is seeing in the Sony files.


It seems that what Sony calls lossy raw files are effectively JPGs, since the DPR review just shows up what happens if you try to process them too far. If they don't offer them any more then it may be because they got rumbled.

[lhsms2]

1. Hybrid viewfinder patent and LCD (flocs) size used there.
(The paper on k-1 is the lcd screen size).

2. Af line on mirror. (5x13 ??)
(Af sensor entrance and guidelines are wider than before)

Links to some interesting patents.

??2018-151588 | ???????IP Force?

??6515452 | ???????IP Force?

??2017-138544 | ???????IP Force?

??2017-138508 | ???????IP Force?

??2017-194526 | ???????IP Force?

??2017-191295 | ???????IP Force?

j-platpat