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Forum: Pentax K-1 & K-1 II
08-21-2016, 07:58 PM
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DxO are not behind you, @Nicolas, I had to explain to you that sensor size is not part of their 'normalization.'
Any time you want me to be a guest speaker at your 'Total Light Believers Fan Club' meetings, I'm happy to be there. :)
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Forum: Pentax K-1 & K-1 II
08-15-2016, 02:03 AM
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@Gimbal and @Nicolas, you've some extraordinarily incorrect beliefs and I've marked them for future use for everyone to see. :-)
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Forum: Pentax K-1 & K-1 II
08-08-2016, 04:57 PM
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It has been explained to you, @Nicolas06, that you are clinging to the superstition of the Print Screen and its made up numbers.
No other testing site does this, just DxOMark in its ecccentric way.
That you are dazzled by DxO and their high profile is clear. :lol: As well as your fantasy of 'Total Light', an old wives tale plenty of other camera owners also believe in.
The Screen tab is real measurements, they never measured anything else.
If you keep talking about 'practical', go back to Post 169 and again, see for yourself the SNR is the same. :)
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Forum: Pentax K-1 & K-1 II
08-03-2016, 04:11 AM
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Don't do it, Kenspo, you are a rocker and have a soul!
I'm joking. I remember you saying that the Norwegian distributor, not Ricoh itself, is paying at the moment.
You are a professional and must go with wherever the work is, of course, for your career and family.
But do us a favour if you leave. When you do a Gary Fong style YouTube advertisement, touch an ear whenever you want to tell us the script is not true. :D
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Forum: Pentax K-1 & K-1 II
08-03-2016, 03:32 AM
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Forum: Pentax K-1 & K-1 II
08-03-2016, 03:19 AM
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Perhaps you should have explained that to Nicolas - have a look at his Post 106, for instance, where he is certain: "Because of how isos are defined, at the same iso setting, because the FF sensor is 2.3 time bigger its capacity has to be at least 2.3 time bigger than the minimal capacity required for the APSC sensor to expose correctly that sensitivity."
And where was your reply when in Post 103 he declared "There a relation between the sensor size and the signal ratio. If you use the same technology in both sensors, the larger sensor will get less noise because the absolute amoung of light received is greater, that is the signal is greater."
The topic is not the amount of the user's postprocessing (which we have seen in the examples above can be badly done) but the camera's noise performance, @Gimbal. :)
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Forum: Pentax K-1 & K-1 II
08-03-2016, 03:14 AM
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(Laughs). You would just try to change the subject from noise to something else over which there is no disagreement, @Nicolas, like post processing or resolution.
By the way, I hope it would not be you giving any of us the lessons on PP - you really butchered those RAW files. :)
And DxO's 'normalization'? Your post 110 showed you did not understand it. I had to explain it to you in Post 115!
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Forum: Pentax K-1 & K-1 II
07-26-2016, 10:07 PM
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Well, that's hypocritical of you.
Why did you imply otherwise in your Post 172?
Remember the topic is noise, not resolution. A K-3 has more resolution than the FF Canon 5D MkIII.
@Gimbal, you still have this lack of understanding. The SNR of the whole pictures using the full sensor areas of the K-5 IIS and D810 is the same - that's what DxO found. That's the screen tab. They measured the RAW files, and got 21.4dB and 21.5dB.
You can try and average out the noise though by downsampling in post processing - the more pixels the better, but this is software and your algorithm may have dreadful consequences as Nicolas found.
I speak as someone who shoots and post-processes both 16Mp APS-C and 36Mp FF.
Again, noise is all about the number of pixels, their technology and their well capacity, not the wafer underneath them. 'Total light' and 'sensor area' is bollocks.
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Forum: Pentax K-1 & K-1 II
07-26-2016, 09:52 PM
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Well, yes, that's the problem with postprocessing, Nicolas. We all do it in different ways. :)
We can see in your Post 157 it hasn't worked. That wall is a plain grey one that's not supposed to have any texture.
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Forum: Pentax K-1 & K-1 II
07-21-2016, 11:17 PM
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???
Look at the attachment above, Jbinpg ... the coloured specs on the K-1 shots with the lens cap on are chroma noise!
As for stacking and dark frame subtraction, neither are methods for obtaining clean, original data, they are postprocessing you do on the noise that's there in the first place.
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Forum: Pentax K-1 & K-1 II
07-21-2016, 10:39 PM
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Noise is the *ratio* of random data to information, Gimbal - this you seem to have redefined to suit your 'logic'.
An honest post from you would admit to us that the K-1 also in fact offers worse read noise than the K-5. See attachment.
You like astrophotography, right? Then you would remember writing these words about the topic:
It's not easy to understand the figures, I mean some of the samples with a low mean value looks much worse then samples with a higher value.
Anyhow, does this mean that if I where to shoot some deep space object like the Andromeda galaxy with a 200mm lens, (which means cropping to 100%) that I would be better off using the K5 than the K1?
The number suggests this, and if so it's kind of disappointing, I where expecting at least the same performance on a pixel level.
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Forum: Pentax K-1 & K-1 II
07-21-2016, 10:34 PM
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We aren't talking about resolution - that's Nicolas' distraction, we're talking about the noise.
Yes, I do think they're the same within the variation of two photos taken four years apart with only roughly the same setup.
And that's what DxOMark found in their much more precise, controlled measurements of a uniform subject, Gimbal - 21.4dB and 21.5dB 18% SNR when they did both cameras around ISO 6400.
Pentax K-5 II vs Nikon D800 |
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Forum: Pentax K-1 & K-1 II
07-21-2016, 10:30 PM
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Then resize them!
I have provided everyone links to the two untouched RAW files I guessed you used ... do as you like with them, zoom in, zoom out, pan to different areas.
Except don't try the postprocessing you did to prove things with.
In your Post 157, the top picture does not match what we can see of the K-1 file you began with (screenshot attached).
Kh123456789 thought they might be demosaicing artifacts - you were silent on the subject. But your weird smears to me look like you've attempted noise reduction and sharpening. What has happened to all the pink chroma dots in the K-1 image?
PS My apologies for calling you 'Nicholas' back there. No disrespect intended!
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Forum: Pentax K-1 & K-1 II
07-19-2016, 11:17 PM
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Look, I think Nicolas should simply have linked the two RAW files and people can see for themselves, without all his elaborate attempts at post-processing.
Hey, I'll do it:
http://216.18.212.226/PRODS/pentax-k5-iis/FULLRES/K52ShSLI06400NRAD.DNG
http://216.18.212.226/PRODS/pentax-k1/FULLRES/K1hSLI006400NRAD.DNG
Imaging Resource took the photos four years apart so they can never be the same ... shadows in different spots, the crayon box cover up rather than down, and so on - you can have fun spotting the differences. This is very rough.
But, say, bring 'em into the Lightroom Library module as I did (screenshot attached), make sure no additional presets are being applied (you can see I zeroed them) and choose comparison/pixel peep if you like.
Here's just one area. Back in Post 87, Nicholas claimed: "for quite challenging shoots in low light you'll benefit from better noise handling beyond the theoretical 1.3EV because the K3 is older and don't benefit of the same technology. Would you happen to be limited by your lens apperture rather than dof, the differnce will increase by 1.3 stop uppon the technology improvement. That why people say there 2EV difference, some even say 3-4EV."
The K5-IIs shot is on the left - it's four years older and APS-C. See if you think the brand new full frame K-1 shot on the right is twice (one stop), 4 times (2 stops), 8 times, or even 16 times better as Nicholas says.
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Forum: Pentax K-1 & K-1 II
07-14-2016, 11:17 PM
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Wow. I have nothing more to add ... good night! :)
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Forum: Pentax K-1 & K-1 II
07-14-2016, 03:56 AM
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Correct, Rondec.
Well, a K-1 cleans up better than a K5 II in Lightroom. If you did a resize (remove roughly three out of four pixels to get to 8Mp instead of a downsample), the performance would be the same, though, as you imply.
A Canon 5DS relies massively on downsampling from its 50Mp, because its Full Frame files are noisier than those from the Crop K5.
As I said earlier, I think anything in a signal chain - whether audio, data or photography - should be as good as possible at the start rather than hope that filters and boosters will do it all further down the line - they have costs of their own.
The bigger pixels in the K-1 give a native advantage in both noise and dynamic range over the K-3.
It's why I bought one, not the other. :)
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Forum: Pentax K-1 & K-1 II
07-14-2016, 03:36 AM
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Gimbal! :lol:
The man who once said: "So compared pixel by pixel the A7S is way ahead, it has huge pixels compared to the K50. When printed at the same size the gap closes slightly, although the A7S still wins by a great margin due to its larger total sensor area."
Here's the news: the print tab doesn't consider sensor size ... never has, never will. DxOMark explain that quite clearly.
They even present the equation, if you care to look - the link is earlier in the thread. What is the saying ... "You can lead a horse to water ..."?
The equation applies equally to phones and 1" sensors, so don't try to deny it. :)
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Forum: Pentax K-1 & K-1 II
07-13-2016, 10:27 PM
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Norm was so right about you.
The subject is noise, so don't talk instead about the tradeoff between noise and resolution. You could have 100 million tiny pixels crammed into a 1" sensor whose images post processing (the "Print Screen") couldn't rescue.
No, Nicolas, DxO measured the K5-IIs camera as having exactly the same noise as the D810. That's real life. That's what's in the RAW files. Then you go to a computer and try to do something about it.
DxO then guess in the Print tab at how much you might be able to improve the JPGs when you postprocess. It's a hypothetical amount that has nothing to do with sensor size or the type of image or the ISO, just the numbers of pixels involved. If you simply resized the picture, there would be no benefit at all. You have to resample as well, to do averaging.
I can say that your alarming thoughts - not supported by DxO - in this thread so far have included:
Post 97: "They will not have the same noise. The noise will be significantly lower on the FF because while the light density will be the same, the total amount of light received will be different."
Post 103: "There a relation between the sensor size and the signal ratio. If you use the same technology in both sensors, the larger sensor will get less noise because the absolute amoung of light received is greater, that is the signal is greater."
Post 106: "Because of how isos are defined, at the same iso setting, because the FF sensor is 2.3 time bigger its capacity has to be at least 2.3 time bigger than the minimal capacity required for the APSC sensor to expose correctly that sensitivity."
This is the sort of stuff that comes up in DPR threads - that's how bad it is! :-D
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Forum: Pentax K-1 & K-1 II
07-13-2016, 12:49 AM
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That's exactly right, Biz-Engineer.
Have a look at the Screen tab, not Nicolas' misleading Print tab estimate, and it's clear to see the 5dB difference thanks to the pixel size and better technology.
Lesson? Have a low amount of noise in your original image, and you don't have to do much post processing, which of course destroys detail too.
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Forum: Pentax K-1 & K-1 II
07-13-2016, 12:33 AM
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Again, we're not talking about the level of detail, or viewing distances, or resolution, we're talking about noise.
Norm Head was right, that when you are incorrect on some fact, you start talking about something else - for many posts - that was never in dispute.
If one in twenty pixels in a D810 RAW file is noise, it's also one in twenty pixels in a K5-II file.
That's what DxOMark measured, and reported in the so-called Screen tab. It is actually what you get when you open the files up in Lightroom or Photoshop or whatever. The noise performance is virtually identical.
The Print tab is *not* the real world. They never measured the noise again after downsampling, they just made some projection from the Screen tab. They would estimate my Samsung Galaxy S6 phone camera would downsample the same as a flagship FF Nikon D4 according to them, because they both have 16Mp.
You have (as usual) changed the topic again, but ... of course I agree totally with what you just said. :)
Your K-3 and FA31 together will be a fantastic combination.
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Forum: Pentax K-1 & K-1 II
07-11-2016, 04:37 PM
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You are now off the topic.
The topic is that the FF D810 RAW files are just as noisy as the K-5 IIs RAW files, because their pixel size and technology is the same.
You are now talking about postprocessing. That is not due to sensor size, but the numbers of pixels. There are some phones that have more pixels than some FF cameras.
Cropping or magnifying an image will not change which pixels are noise and which are not.
For the Print tab, DxOMark arbitrarily decide to project (again, they do NOT measure) noise remaining after re-sampling, not resizing.
The resampling loses detail but reduces noise by averaging ... looks at three black pixels and one white, for instance, and replaces them with two black. When noise reduction goes too far, we know about it ... the people in the pictures suddenly look like wax dummies.
The APS-C K-3 downsamples equally well in the DXO 'normalizing' process as the full frame Nikon D750 - it gets about the same 5dB increase. This is of course troubling to the Full Frame Fetishists who worship the 'Print' tab.
Nicolas, you have said many times on this forum that APS-C may well be good enough for you for a long time to come - please don't change your mind and spend money based on incorrect assumptions.
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Forum: Pentax K-1 & K-1 II
07-10-2016, 10:51 PM
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Well, I've learnt so much good stuff these last few years from yourself and all the other members that it's a shame to see misinformation like that Total Light/DxO print graph BS pop up again in a quality forum like this.
And Nicolas, it's only about what you've written, nothing personal ... in fact I'm excited you're getting the FA31 (I don't have one) and am looking forward to your pics! :-)
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Forum: Pentax K-1 & K-1 II
07-10-2016, 10:06 PM
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You've a lot of learning to do before talking so frequently and copiously about these matters, Nicolas.
Their only measurements are the screen tab. They are the contents of your RAW file on your SD card, it is the Real World.
You do not understand the methodology of the print tab - it's a postprocessing 'what if', a hypothetical, and they only take into account numbers of pixels - never sensor format size.
My source is DxoMark themselves - what is yours? :)
Detailed computation of DxOMark Sensor normalization - DxOMark |
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Forum: Pentax K-1 & K-1 II
07-10-2016, 04:06 AM
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Yep, it's just the number of pixels in the case of the K5II, I'm happy to report, that helps when you do your noise reduction and downsampling. It's also the size of the pixels in the case of the K-3.
So it's not sensor size - APS-C cameras can have more pixels than FF. :)
The actual noise at ISO 1600 will be about 26 dB for both the K-5II and K-1. That's on a scale where 0dB is a pixel of noise for every pixel of the subject. Every 3dB gives you a 100% improvement.
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Forum: Pentax K-1 & K-1 II
07-10-2016, 04:00 AM
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This proves you don't understand DxO.
I hope you realise that the 'Print' stat DxO show you is not a real measurement like the 'Screen' one is.
It isn't fake as in 'faked moon landings', but it's close. :)
They did not actually check the SNR, dynamic and tonal ranges of a downsized JPG. How many people have looked at DXOmark over the years, even been influenced to buy something because of its ratings, and not realised that? Or you, in your arguments?
From a purely mathematical point of view they added 3dB advantage for every doubling in the number of pixels, to their 'Screen' results, assuming that everyone shoots a picture of a uniform monocolour background without a subject.
Nothing to do with FF or APS-C. The same amount is added if the additional pixels are on a phone or a medium format camera.
DXOmark's downsampling assumption will have the K-50 being better at this than the Sony A7S, and the K-3 downsampling equal to the Nikon D750 and better than the Canon 5D MkIII. It should not be treated seriously!
Stick to the 'Screen' measurements, though, and you won't go too far wrong.
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