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#151
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Tue, 8 Jan 2019 08:31:05 -0500, Alan Browne
wrote: On 2019-01-08 03:54, Eric Stevens wrote: On Mon, 07 Jan 2019 23:42:07 -0500, nospam wrote: In article , Eric Stevens wrote: But a moot point IMO. I doubt the sensor mentioned has 14 bits of DR in the first place. Esp. once you account for noise. Well, DxO measure 14.3 but what exactly that means is unknown. But if they made that specific statement then I would expect they must have grounds. it means their test methodology is worthless or they're intentionally lying. Or that you have failed to understand what they are doing. Your other post ends with a statement to the effect that DxO don't say what their algorithms are doing, so nospam certainly didn't fail anything. nospam will fail to understand what they are doing if he doesn't know what they are doing. That applies to everyone. In the end physics is physics and there is no way they are getting more DR than the sensor offers. Not even the bit depth of it. According to nospam they are claiming a DR of 14.3 for the sensor of the D800. As they said in the link that I posted which has somehow got snipped "Maximum dynamic range is the greatest possible amplitude between light and dark details a given sensor can record ...". -- Regards, Eric Stevens |
#152
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Tue, 8 Jan 2019 08:29:29 -0500, Alan Browne
wrote: On 2019-01-08 04:02, Eric Stevens wrote: Theey do not specify their algorithms in the article. Exactly. So? -- Regards, Eric Stevens |
#153
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Tue, 08 Jan 2019 10:28:26 -0500, nospam wrote: In article , Eric Stevens wrote: This is DxO's own account of the situation at: https://www.dxomark.com/dxomark-came...ol-and-scores/ "Dynamic range corresponds to the ratio between the highest brightness a camera can capture (saturation) and the lowest brightness it can capture (which is typically when noise becomes more important than the signal Ð that is, a signal-to-noise ratio below 0 dB). A value of 12 EV is excellent, with differences below 0.5 EV usually not noticeable. Dynamic range is an open scale." This appears to confirm that the situation is as I deduced: they are not testing the dynamic range as recorded in a raw file. They are testing the range that a camera can capture. i.e. it is the dynmaic range of the sensor. It is not the dynamic range of the raw file. no, it doesn't confirm that, nor does it explain how they get numbers that are greater than the theoretical limit of the camera. If you read the whole of the article you might get to understand their methodology. It starts off with measurement and finishes with: "We measure the luminance of each uniform area (patch) on the chart using a certified luminance-meter, and then input the values into DxO Analyzer software. Once we have measured the target and calibrated the DxO Analyzer software, we shoot test images of the noise target at different ISO settings, and measure the Noise for each color channel of the target image (R, Gr, Gb, B). We compute the mean gray level and noise values for each patch and for all images shot at different ISO settings, and finally interpolate these numerical values for all gray levels to calculate and plot signal-to-noise ratio (SNR) curves, from which DxO Analyzer extracts the SNR 18%, the dynamic range, and the tonal range." Theey do not specify their algorithms in the article. because their algorithms won't withstand scrutiny. That may or may not be true. without knowing what their algorithms are, they're worthless. You undoubtedly use a large number of algorithms without knowing what they are. Nevertheless you must find them useful, otherwise you would not use them. -- Regards, Eric Stevens |
#154
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Wed, 9 Jan 2019 08:36:24 -0500, Alan Browne
wrote: Its amazing what Google can produce. This is DxO's own account of the situation at: https://www.dxomark.com/dxomark-came...ol-and-scores/ "Dynamic range corresponds to the ratio between the highest brightness a camera can capture (saturation) and the lowest brightness it can capture (which is typically when noise becomes more important than the signal — that is, a signal-to-noise ratio below 0 dB). A value of 12 EV is excellent, with differences below 0.5 EV usually not noticeable. Dynamic range is an open scale." This appears to confirm that the situation is as I deduced: they are not testing the dynamic range as recorded in a raw file. They are testing the range that a camera can capture. i.e. it is the dynmaic range of the sensor. It is not the dynamic range of the raw file. It doesn't actually say that, however. How, specifically, are they bypassing the raw file to get the data? By measuring not the data in the file but the range of brightness that the camera can capture from their test set up. -- Regards, Eric Stevens |
#155
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Tue, 8 Jan 2019 08:32:40 -0500, Alan Browne
wrote: On 2019-01-08 04:04, Eric Stevens wrote: On Mon, 7 Jan 2019 16:57:44 -0500, Alan Browne wrote: On 2019-01-07 16:19, Eric Stevens wrote: On Sun, 6 Jan 2019 10:13:09 -0500, Alan Browne wrote: On 2019-01-04 18:58, Eric Stevens wrote: On Fri, 4 Jan 2019 16:16:05 -0500, Alan Browne wrote: On 2019-01-02 04:16, Eric Stevens wrote: On Wed, 2 Jan 2019 07:48:13 +0000, RJH wrote: On 02/01/2019 01:38, nospam wrote: In article , Eric Stevens wrote: You are obviously wedded to 1 stop per bit. Why is that? math. Why for example can you not have 2 stops per bit, or pi stops per bit? As long as you scale the entire brightness range with the available 14 stops. because it doesn't work that way. think about what a stop means. FWIW, I don't follow the linearity - in fact I've often wondered why aperture, ISO and shutter speed aren't infinitely variable, especially with digital. This article takes me closer to understanding: https://expertphotography.com/understanding-fstops-stops-in-photography-exposure/ The author of that article is using 'stop' when he should be using 'exposure value'. But lets not get into that in this thread. It's confused enough already. :-) There is no difference at all between an EV and a stop of any of the three independent variables of ISO, exposure period and aperture. It may be hair-splitting but none of my lenses are calibrated in EVs. They most definitely are, and probably 1/2 or 1/3 steps of EV as well, [1] --- or possibly very fine steps in speed priority or auto modes. I bow to your superior knowledge of my equipment. 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)." -- Regards, Eric Stevens |
#156
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Tue, 8 Jan 2019 08:38:02 -0500, Alan Browne
wrote: On 2019-01-08 04:12, Eric Stevens wrote: On Mon, 07 Jan 2019 23:42:08 -0500, nospam wrote: In article , Eric Stevens wrote: It may be hair-splitting but none of my lenses are calibrated in EVs. They most definitely are, and probably 1/2 or 1/3 steps of EV as well, or possibly very fine steps in speed priority or auto modes. I bow to your superior knowledge of my equipment. your equipment is nothing special. many people have the same stuff. for modern lenses, it's user selectable at 1, 1/2 or 1/3 stops. not all options may be available on all cameras. it appears that nikon no longer offers 1 stop anymore (there's no reason to) but older nikon slrs did. i assume canon, pentax, etc., are similar. examples: https://www.imaging-resource.com/PRODS/D7000/screens/DSC_0211.jpg https://1.img-dpreview.com/files/p/a...ages/Captures/ d1x_41.gif http://www.steves-digicams.com/2004_reviews/d70/d70_custom_menu2.jpg for older lenses with a mechanical aperture ring (manual lenses and early autofocus), the aperture ring will normally click at 1 stop increments, sometimes 1/2 stop. occasionally, it's both on the same lens, i.e., the widest and smallest are 1 stop, rest 1/2 stop. there is no point in 1/3 stops since the mechanics aren't good enough. some lenses, such as mirror lenses, have only one f/stop, with no adjustments to be made, although they sometimes accept an nd filter in the back. This illustrates the disadvantage of not using the language with precision. As I said, all my lenses make use of f/numbers which are a measure of stops. Your thoughts have jumped the rails and are now talking about the intervals of Exposure Value of which the camera is capable. The exposure value may be used to set lens aperture, shutter speed or ISO. They are not identical to stops. EV's are equivalent to stops for any purpose related to exposure. I can change exposure value without changing the stop setting. Whether selecting ISO, pushing/pulling exposure, pulling/pushing development, aperture, speed, lighting, filters, even scrimming if you want to push the use that far ... As an aside I used to use these charts when shooting with my 'blad. Didn't need a meter most of the time: http://www.fredparker.com/ultexp1.ht...ensity%20Chart http://www.fredparker.com/ultexp1.ht...%20CHA RT%20B Reciprocity rules! -- Regards, Eric Stevens |
#157
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Tue, 08 Jan 2019 10:28:28 -0500, nospam
wrote: In article , Eric Stevens wrote: It may be hair-splitting but none of my lenses are calibrated in EVs. They most definitely are, and probably 1/2 or 1/3 steps of EV as well, or possibly very fine steps in speed priority or auto modes. I bow to your superior knowledge of my equipment. your equipment is nothing special. many people have the same stuff. for modern lenses, it's user selectable at 1, 1/2 or 1/3 stops. not all options may be available on all cameras. it appears that nikon no longer offers 1 stop anymore (there's no reason to) but older nikon slrs did. i assume canon, pentax, etc., are similar. examples: https://www.imaging-resource.com/PRODS/D7000/screens/DSC_0211.jpg https://1.img-dpreview.com/files/p/a...ages/Captures/ d1x_41.gif http://www.steves-digicams.com/2004_reviews/d70/d70_custom_menu2.jpg for older lenses with a mechanical aperture ring (manual lenses and early autofocus), the aperture ring will normally click at 1 stop increments, sometimes 1/2 stop. occasionally, it's both on the same lens, i.e., the widest and smallest are 1 stop, rest 1/2 stop. there is no point in 1/3 stops since the mechanics aren't good enough. some lenses, such as mirror lenses, have only one f/stop, with no adjustments to be made, although they sometimes accept an nd filter in the back. This illustrates the disadvantage of not using the language with precision. As I said, all my lenses make use of f/numbers which are a measure of stops. Your thoughts have jumped the rails and are now talking about the intervals of Exposure Value of which the camera is capable. The exposure value may be used to set lens aperture, shutter speed or ISO. They are not identical to stops. they absolutely are. So I double the shutter speed. I have halved the exposure value but I haven't affected the stop setting. If you want to continue arguing to the contrary I will be happy to leave you to it. -- Regards, Eric Stevens |
#158
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Finally got to the point where no new camera holds my interest(waiting for specific offering)
On 2019-01-10 04:05, Eric Stevens wrote:
On Tue, 8 Jan 2019 08:31:05 -0500, Alan Browne wrote: On 2019-01-08 03:54, Eric Stevens wrote: On Mon, 07 Jan 2019 23:42:07 -0500, nospam wrote: In article , Eric Stevens wrote: But a moot point IMO. I doubt the sensor mentioned has 14 bits of DR in the first place. Esp. once you account for noise. Well, DxO measure 14.3 but what exactly that means is unknown. But if they made that specific statement then I would expect they must have grounds. it means their test methodology is worthless or they're intentionally lying. Or that you have failed to understand what they are doing. Your other post ends with a statement to the effect that DxO don't say what their algorithms are doing, so nospam certainly didn't fail anything. nospam will fail to understand what they are doing if he doesn't know what they are doing. That applies to everyone. In the end physics is physics and there is no way they are getting more DR than the sensor offers. Not even the bit depth of it. According to nospam they are claiming a DR of 14.3 for the sensor of the D800. As they said in the link that I posted which has somehow got snipped "Maximum dynamic range is the greatest possible amplitude between light and dark details a given sensor can record ...". 1. A 14 bit sensor cannot, possibly, record 14.3 DR. 2. DR must exclude noise as well. So what does "details" even mean above? I'm done with this. Absolutely pointless. -- "2/3 of Donald Trump's wives were immigrants. Proof that we need immigrants to do jobs that most Americans wouldn't do." - unknown protester |
#159
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Finally got to the point where no new camera holds my interest(waiting for specific offering)
On 2019-01-10 04:08, Eric Stevens wrote:
On Tue, 8 Jan 2019 08:29:29 -0500, Alan Browne wrote: On 2019-01-08 04:02, Eric Stevens wrote: Theey do not specify their algorithms in the article. Exactly. So? Not clear enough, huh? They don't show their algorithms (proprietary, I assume). OTOH, the claim of 14.3 DR in the face of a 14 bit sensor and no apparent accounting for noise is bad fish. That clear enough? EOD for me. -- "2/3 of Donald Trump's wives were immigrants. Proof that we need immigrants to do jobs that most Americans wouldn't do." - unknown protester |
#160
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Finally got to the point where no new camera holds my interest(waiting for specific offering)
On 2019-01-10 04:11, Eric Stevens wrote:
On Tue, 08 Jan 2019 10:28:26 -0500, nospam wrote: In article , Eric Stevens wrote: This is DxO's own account of the situation at: https://www.dxomark.com/dxomark-came...ol-and-scores/ "Dynamic range corresponds to the ratio between the highest brightness a camera can capture (saturation) and the lowest brightness it can capture (which is typically when noise becomes more important than the signal Ð that is, a signal-to-noise ratio below 0 dB). A value of 12 EV is excellent, with differences below 0.5 EV usually not noticeable. Dynamic range is an open scale." This appears to confirm that the situation is as I deduced: they are not testing the dynamic range as recorded in a raw file. They are testing the range that a camera can capture. i.e. it is the dynmaic range of the sensor. It is not the dynamic range of the raw file. no, it doesn't confirm that, nor does it explain how they get numbers that are greater than the theoretical limit of the camera. If you read the whole of the article you might get to understand their methodology. It starts off with measurement and finishes with: "We measure the luminance of each uniform area (patch) on the chart using a certified luminance-meter, and then input the values into DxO Analyzer software. Once we have measured the target and calibrated the DxO Analyzer software, we shoot test images of the noise target at different ISO settings, and measure the Noise for each color channel of the target image (R, Gr, Gb, B). We compute the mean gray level and noise values for each patch and for all images shot at different ISO settings, and finally interpolate these numerical values for all gray levels to calculate and plot signal-to-noise ratio (SNR) curves, from which DxO Analyzer extracts the SNR 18%, the dynamic range, and the tonal range." Theey do not specify their algorithms in the article. because their algorithms won't withstand scrutiny. That may or may not be true. without knowing what their algorithms are, they're worthless. You undoubtedly use a large number of algorithms without knowing what they are. Nevertheless you must find them useful, otherwise you would not use them. Since it doesn't pass a basic physics test, it's not trustable and should not be used. -- "2/3 of Donald Trump's wives were immigrants. Proof that we need immigrants to do jobs that most Americans wouldn't do." - unknown protester |
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