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#241
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
In article , Eric Stevens
wrote: EV's are equivalent to stops for any purpose related to exposure. I can change exposure value without changing the stop setting. No ****. That's sort of the point. It's my point. Stops aren't exposure values. Exposure values are not stops. they are. Lets leave it at that. ok, but you saying so doesn't make it correct. Allright then. Please explain to your readers how you set a lens to an EV of 20. asking such a question shows you do not understand the topic. I do understand the topic. nothing you've said so far indicates that you understand anything about the topic. I understand the mistake you are making. I also understand that you will never admit to being wrong and will never explain to your readers how you set a lens to an EV of 20. that describes you, where it's been explained why you're wrong, yet you refuse to admit it. The problem is that you have somehow conflated the square root of 2 with the term 'stop'. also wrong. on the other hand, i understand your confusion, which i've explained in other posts, and it has not helped at all. |
#242
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
In article , Eric Stevens
wrote: My lenses are not calibrated in EVs. actually, they're calibrated in 1/3 evs, unless they're old, when it wasn't possible to be that accurate. Further, lenses do not determine EVs on their own. It is also necessary to set a shutter speed. and iso. You say that my lenses are calibrated in EVs and then agree there are factors additional to the lens which determine EV. Is my lens somehow prescient or are you an idiot? ad hominem. You mean there is another choice? yes. If I accept what you say its got to be one or the other. no. |
#243
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
In article , Eric Stevens
wrote: dxo is reporting the dynamic range of various *cameras*. and even if you ignore the 14 bit issue, their numbers are highly suspect. the nikon d800 and d800 are identical cameras, the only difference being the lack of an anti-alias filter on the d800e, something which does not affect dynamic range (only aliasing). thus, the results should be *the* *same* (other than alias artifacts on high frequency content). Light passes through the filter which affects the spectrum detected by the sensor. Of course this will affect the dynamic range. nonsense. an aa filter has *zero* effect on dynamic range. You know that do you? yes. Show me the data. show me the data that it does. Google shows that a hell of a lot of work has been done on the spectral properties of anti-aliasing filters. You should write to all the authors and tell them they are wasting their time. spectral properties aren't the issue. you claim that dxo is shooting grey cards in their testing, which does not have detail anywhere close to nyquist, therefore the presence or absence of an aa filter will have no effect whatsoever. dxo claims that the d800 has 14.4 stops dynamic range and the d800e has 14.3 stops. Even ignoring error bars, this is not at all surprising. it's very surprising that two identical sensors (other than an aa filter, which has no effect except for aliasing) in identical cameras with identical electronics have different results, without any explanation as to why. That it has no effect except for aliasing is classic nospam. no, it's classic signal theory 101. It reminds me of the discussion when you assumed that in Windows the 'print' function sent a file straight to the printer without anything going on in between. In fact all kinds of things may be going on as well the one thing that you have in mind. diversion, lying about what i actually said and irrelevant. you're *really* grasping at straws. |
#244
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
In article , Eric Stevens
wrote: But the digital DR of the output of the ADC is not the same as the analog DR of the sensor. Nor is there any reason why it should be. Well that's exactly what I said. If they are publishing the DR of the sensor, why would any photographer care about that, if the DR is then limited by the ADC? The usable output of any camera we buy is all we care about. There is no reason why the DR of the sensor should not be compressed to make it fit within the limits of the ADC. actually there are several reasons, but the only one that matters is that the sensor data *isn't* compressed or altered in any way prior to the adc. arguing about a non-existent camera, one which is likely to never exist at all, is pointless and actually, rather bizarre. After all, in processing it's going to be further compressed (and probably clipped) for viewing on a screen and even further compressed (and probably clipped) when output to a display device or printer. I presume the intention is that the original information be preserved as much as possible as far down the processing stream as is possible. no. DXO's results are at best misleading, whether it's malicious or not. I suspect that the problem is that they are working in an area which few people properly understand. plenty of people understand it. the problem is you're not among them. e.g.: https://corp.dxomark.com/wp-content/...rmationCapacit y.pdf and https://corp.dxomark.com/wp-content/...titative-measu rement-of-contrast-texture-color-and-noise-for-digital-photography-of-high-dyn amic-range-scenes_small.pdf or http://tinyurl.com/yaaf4o6s not relevant, and use on urls so they don't break. |
#245
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
In article , Eric Stevens
wrote: The problem is clearly DXO's testing methods. No matter how you look at this, you have to be able to imagine all kinds of sources of inaccurate measurements, especially if they are slight. I have to agree with nospam and Alan. You can't get DR outside of the limits of the ADC because that is the output you see, but you can certainly get test results outside of that limit. But the digital DR of the output of the ADC is not the same as the analog DR of the sensor. Nor is there any reason why it should be. nobody said it was, however, it's always going to be limited by the adc. The recorded output of the ADC is limited by the capabilities of the ADC. But these have no effect on the capabilities of the sensor. again, nobody said the adc would alter the sensor's capability. what you still fail to grasp is that whatever the sensor can produce will always be limited by the adc, unless the sensor itself is the limiting factor, which is not the case in a d800 class camera. If the sensor can discriminate between luminance levels from 'c' to 'q' it will always retain that ability irrespective of the capabilities of the ADC. How the ADC encodes it is another matter, and how that image is decoded by RAW decoder is another matter again. There is enormous scope for fiddling and adjustments. except that no fiddling or adjustments are being done. and if it really *is* the sensor they're measuring, then it should be the *same* for the *same* sensor, and it is not. Not when you shove another piece of glass in front of one of the sensors. no effect on dynamic range. Nor when you realise that not all sensors will be identical and all measurements are subject to errors. especially when the methodology is itself an error. if they're supposedly measuring the sensor's dynamic range, explain why the nikon d50 & d70 differ by a half-stop, both of which used the same popular 6mp sony sensor (as did pentax). other results also differ. I have no way of knowing but the first thing I would suspect is the circuitry between the sensor and the ADC. then you'd be wrong. there is nothing between the sensor and adc, in those two or any other camera under discussion. the d50 & d70 are basically the same camera, with minor feature differences, such as the d70 having two control wheels versus one, compact flash versus sd card, slightly faster frame rate, wired remote option, flash commander mode and some minor other things i don't remember, none of which have *any* effect on the dynamic range. |
#246
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Fri, 11 Jan 2019 23:21:51 -0500, nospam
wrote: In article , Eric Stevens wrote: The problem is clearly DXO's testing methods. No matter how you look at this, you have to be able to imagine all kinds of sources of inaccurate measurements, especially if they are slight. I have to agree with nospam and Alan. You can't get DR outside of the limits of the ADC because that is the output you see, but you can certainly get test results outside of that limit. But the digital DR of the output of the ADC is not the same as the analog DR of the sensor. Nor is there any reason why it should be. nobody said it was, however, it's always going to be limited by the adc. The recorded output of the ADC is limited by the capabilities of the ADC. But these have no effect on the capabilities of the sensor. again, nobody said the adc would alter the sensor's capability. You have been strenuously arguing that it will limit it. I have been pointing out that that is not necessarily the case. what you still fail to grasp is that whatever the sensor can produce will always be limited by the adc, unless the sensor itself is the limiting factor, which is not the case in a d800 class camera. It depends by what you mean by 'limited'. The sensor will always do do whatever it can do and it's DR can be scaled up or down to fit the output bandwidth of the ADC. It is because of the scaling that you can have the output of a sensor with a 14.8 stop DR scaled down to to suit a 14 bit ADC. It's not a big deal. If the sensor can discriminate between luminance levels from 'c' to 'q' it will always retain that ability irrespective of the capabilities of the ADC. How the ADC encodes it is another matter, and how that image is decoded by RAW decoder is another matter again. There is enormous scope for fiddling and adjustments. except that no fiddling or adjustments are being done. You would know that if you worked for the right section of Nikon. Or perhaps you have reverse engineered a D800? You will also have to know what goes on in the Nikon RAW decoder. So I don't actually believe you know. and if it really *is* the sensor they're measuring, then it should be the *same* for the *same* sensor, and it is not. Not when you shove another piece of glass in front of one of the sensors. no effect on dynamic range. So you keep saying. That doesn't make it true. Nor when you realise that not all sensors will be identical and all measurements are subject to errors. especially when the methodology is itself an error. How can it be an error when they make clear what they are testing and how? if they're supposedly measuring the sensor's dynamic range, explain why the nikon d50 & d70 differ by a half-stop, both of which used the same popular 6mp sony sensor (as did pentax). other results also differ. I have no way of knowing but the first thing I would suspect is the circuitry between the sensor and the ADC. then you'd be wrong. there is nothing between the sensor and adc, in those two or any other camera under discussion. Do you know whether the ADC is pipelined, or perhaps Nikon use one ADC per column of pixels? In any case, do you know whether the voltage divider resistors all have the same value? That the sort of thing which Nikon's competitors would like to know. For that matter, is the ADC the same in each camera under discussion? I'm afraid I don't share your confidence in your certainty. the d50 & d70 are basically the same camera, with minor feature differences, such as the d70 having two control wheels versus one, compact flash versus sd card, slightly faster frame rate, wired remote option, flash commander mode and some minor other things i don't remember, none of which have *any* effect on the dynamic range. If you examine first https://imaging.nikon.com/lineup/dslr/d50/index.htm and then https://imaging.nikon.com/lineup/dslr/d70/ you will see that the D70 boasts of: "New Nikon DX Format CCD image sensor for 3,008 x 2,000-pixel images New advanced digital image processor to optimize image quality, control auto white balance, auto tone and color control" I would expect the D70 and D50 to have different characteristics. -- Regards, Eric Stevens |
#247
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Fri, 11 Jan 2019 23:21:50 -0500, nospam
wrote: In article , Eric Stevens wrote: But the digital DR of the output of the ADC is not the same as the analog DR of the sensor. Nor is there any reason why it should be. Well that's exactly what I said. If they are publishing the DR of the sensor, why would any photographer care about that, if the DR is then limited by the ADC? The usable output of any camera we buy is all we care about. There is no reason why the DR of the sensor should not be compressed to make it fit within the limits of the ADC. actually there are several reasons, but the only one that matters is that the sensor data *isn't* compressed or altered in any way prior to the adc. It is inherent in the operation of an ADC that the full DR of the sensor is incorporated in the bit band-width of the output. arguing about a non-existent camera, one which is likely to never exist at all, is pointless and actually, rather bizarre. I thought we were arguing about what DxO have done when measuring the DR of the various Nikon cameras you have cited. After all, in processing it's going to be further compressed (and probably clipped) for viewing on a screen and even further compressed (and probably clipped) when output to a display device or printer. I presume the intention is that the original information be preserved as much as possible as far down the processing stream as is possible. no. Oh! I'm surprised. Are you saying that they are happy to lose it? DXO's results are at best misleading, whether it's malicious or not. I suspect that the problem is that they are working in an area which few people properly understand. plenty of people understand it. It's clear that you don't, you can't as you haven't even read their technical papers. the problem is you're not among them. e.g.: https://corp.dxomark.com/wp-content/...rmationCapacit y.pdf and https://corp.dxomark.com/wp-content/...titative-measu rement-of-contrast-texture-color-and-noise-for-digital-photography-of-high-dyn amic-range-scenes_small.pdf or http://tinyurl.com/yaaf4o6s not relevant, and use on urls so they don't break. -- Regards, Eric Stevens |
#248
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Fri, 11 Jan 2019 23:21:49 -0500, nospam
wrote: In article , Eric Stevens wrote: dxo is reporting the dynamic range of various *cameras*. and even if you ignore the 14 bit issue, their numbers are highly suspect. the nikon d800 and d800 are identical cameras, the only difference being the lack of an anti-alias filter on the d800e, something which does not affect dynamic range (only aliasing). thus, the results should be *the* *same* (other than alias artifacts on high frequency content). Light passes through the filter which affects the spectrum detected by the sensor. Of course this will affect the dynamic range. nonsense. an aa filter has *zero* effect on dynamic range. You know that do you? yes. Show me the data. show me the data that it does. Google shows that a hell of a lot of work has been done on the spectral properties of anti-aliasing filters. You should write to all the authors and tell them they are wasting their time. spectral properties aren't the issue. Of course it is, unless the AA filter has none. The light which determines the RGB image has to bass through the filter and some must be lost on the way. you claim that dxo is shooting grey cards in their testing, which does not have detail anywhere close to nyquist, therefore the presence or absence of an aa filter will have no effect whatsoever. You are not even reading what I say! I said nothing of the sort but I have several times stated what it is that DxO do. Now you seem to be arguing without having read or understood what it is you are arguing about. dxo claims that the d800 has 14.4 stops dynamic range and the d800e has 14.3 stops. Even ignoring error bars, this is not at all surprising. it's very surprising that two identical sensors (other than an aa filter, which has no effect except for aliasing) in identical cameras with identical electronics have different results, without any explanation as to why. That it has no effect except for aliasing is classic nospam. no, it's classic signal theory 101. So if it's not in the equation it doesn't exist? The map is not the territory. It reminds me of the discussion when you assumed that in Windows the 'print' function sent a file straight to the printer without anything going on in between. In fact all kinds of things may be going on as well the one thing that you have in mind. diversion, lying about what i actually said and irrelevant. It's typical of what you do. you're *really* grasping at straws. You don't even seem to have the right straws. -- Regards, Eric Stevens |
#249
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Fri, 11 Jan 2019 23:21:48 -0500, nospam wrote: In article , Eric Stevens wrote: My lenses are not calibrated in EVs. actually, they're calibrated in 1/3 evs, unless they're old, when it wasn't possible to be that accurate. Further, lenses do not determine EVs on their own. It is also necessary to set a shutter speed. and iso. You say that my lenses are calibrated in EVs and then agree there are factors additional to the lens which determine EV. Is my lens somehow prescient or are you an idiot? ad hominem. You mean there is another choice? yes. If I accept what you say its got to be one or the other. no. Excellent. What is it? Oh I know. You have already explained. -- Regards, Eric Stevens |
#250
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Fri, 11 Jan 2019 23:21:46 -0500, nospam
wrote: In article , Eric Stevens wrote: Do your lenses have stops? Yes. Exactly. So they are indeed calibrated in EV. ([1] above). No. EVs can be deduced. See https://en.wikipedia.org/wiki/Exposure_value "In photography, exposure value (EV) is a number that represents a combination of a camera's shutter speed and f-number, such that all combinations that yield the same exposure have the same EV (for any fixed scene luminance)." Finding some convenient words doesn't obviate the facts. Your camera and lenses are calibrated in EV. What words are used (stops for example) do not matter at all. Dear me! I can change the EV to which my camera is set without changing the lens aperture. My lenses are not calibrated in EVs. Further, lenses do not determine EVs on their own. It is also necessary to set a shutter speed. Wow! You could pass Photography 101, chapter 3 (Basics of exposure). CONGRATS! Now you have followed me that far, you may be interested to see https://upload.wikimedia.org/wikiped..._Ib_with_EV.jp g Notice how the bottom of the shutter speed ring has a pointer with which you can set the EV. That enables the aperture ring (dimly seen behind the pointer) to be moved in synchronism with the shutter speed ring so as to maintain constant the preset EV. This is an early pre-prescient camera. According to nospam modern cameras don't need the EV to be set. The aperture ring knows the EV all on it's own. i never said any such thing. stop lying. I take it back. It was Alan Browne. -- Regards, Eric Stevens |
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