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#271
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Sat, 12 Jan 2019 11:22:31 -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. what's inherent is that the adc is the limiting factor, unless the sensor is crap, which is not the case in a d800. It only affects the scaling of the DR. 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. yes, so why bring up a non-existent camera? What makes you think I have? -- Regards, Eric Stevens |
#272
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Sat, 12 Jan 2019 09:27:17 -0500, Alan Browne
wrote: On 2019-01-11 18:34, Eric Stevens wrote: On Fri, 11 Jan 2019 11:15:19 -0600, Bill W wrote: On Fri, 11 Jan 2019 21:30:23 +1300, 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. Already explained to you: compression does not improve DR without consequences in quality elsewhere. Well, if you don't compress it, you have to chop off one or both ends. -- Regards, Eric Stevens |
#273
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Sat, 12 Jan 2019 11:22:32 -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. the only thing that's lost is *spatial* *detail* above nyquist (and a little below since this is the real world). below nyquist, there is no effect, and a grey card or other test target has essentially no detail, so it's *well* below nyquist. if they were shooting resolution test charts or scenes with fine detail, there would be a difference, as one would expect, but they're not, at least not in this test. All of this is irrelevant. The point is no solid is perfectly transparent. Certainly the material of the AA filter will not be. 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. actually, i am reading what you say, which is well beyond ludicrous at this point. Nowhere did I say they used a grey card. I compared their method to using a grey card. DxO have described their method in one of the URLs I have posted. It is now obvious you have not properly read or understood their description. Nor have you properly read and understood the sections of their descriptions which I have quoted. You have not even properly read or understood my paraphrasing of what DxO have written. As you so often have been accused, you have been arguing for the sake of arguing but without even paying proper attention to what you have been arguing about. --- snip --- -- Regards, Eric Stevens |
#274
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Sat, 12 Jan 2019 09:31:44 -0500, Alan Browne
wrote: On 2019-01-11 20:06, Eric Stevens wrote: On Fri, 11 Jan 2019 12:42:13 -0500, Alan Browne wrote: On 2019-01-10 22:52, Eric Stevens wrote: On Thu, 10 Jan 2019 07:39:32 -0500, Alan Browne wrote: On 2019-01-10 04:05, Eric Stevens wrote: 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. Please read what I am about to write and give it deep consideration before you reply. _There_is_no_such_thing_as_a_14_bit_sensor_! Or a 12 bit for that matter. The sensors which we are considering are *analog* devices which are not digital in their operation. 12 or 14 bits only come into it after the analog signal is stripped from the sensor and (only then) passed through an analogue to a digital convertor (ADC). Now you're being silly. The whole point of the ADC is to sample the analog sensor. Constrain that to 14 bits and that's all you get. The whole point of "more bits" in the ADC is not to find "bright" signal, but to sample down deep in the very smallest shreds of the darkest part of the signal. All of which is completely true. But how deep down are the shreds of the darkest part of the signal. And how bright is the brightest part of the signal before it overflows into blooming? It is the difference If the photographer exposed correctly, other than some (acceptable for esthetics) hotspot here and there, then it's pretty moot. Blooming is more than a hot spot. Its a general overflow. The physical truth of the matter is that deep down at the shreds lies noise. Usually a lot more noise than signal. Yep. An interesting point: according to DxO, when the test uses a paper target, some of the noise may actually be the texture of the paper of the target. between these that determines the dynamic range of the sensor. The fact that the DR is scaled to 14 bits is of secondary consideration. If 14 bits is all that ammters why go to all the trouble and expense of developing high DR sensors? Let's have a cheap sensor and hang it on a 14 bit ADC. As I pointed out several times engineers will usually "right size" the ADC to the sensor if maximum signal performance is desired. So if they put in a 14 bit ADC, there is likely less than 14 bits of honest-to-goodness signal. IOW: You're peddling hard to fit 7 pounds of **** into a 5 pound bag. True, but fortunately DR is compressible. -- Regards, Eric Stevens |
#275
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Sat, 12 Jan 2019 11:22:33 -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. yes i have. at least you got that part right. I knew that. You always have already explained. -- Regards, Eric Stevens |
#276
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Sat, 12 Jan 2019 09:32:43 -0500, Alan Browne
wrote: On 2019-01-11 20:20, Eric Stevens wrote: On Fri, 11 Jan 2019 12:44:39 -0500, Alan Browne wrote: On 2019-01-10 23:04, Eric Stevens wrote: On Thu, 10 Jan 2019 07:44:43 -0500, Alan Browne wrote: 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.jpg 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. You're being willingly and deliberately obtuse. No, I am attempting to use language with precision. I find it essential in technical matters. -- Regards, Eric Stevens |
#277
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Sat, 12 Jan 2019 11:22:34 -0500, nospam
wrote: 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. For what ISO and speed? No, no. No ISO or speed. The lens calibration is equivalent to stop settings according to nospam so it must be possible to set a lens to a particular EV. I picked 20 as an example. by picking 20 (or any number), you demonstrate you don't understand it. Now if I said, for example f/11 you would understand it. But that is not an EV. as i said, you don't understand it. here's a hint: what's the difference between f/8 and f/11 ? You are fortunate. I happen to have a lens on my desk. I've just measured the difference is about 4mm. -- Regards, Eric Stevens |
#278
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Sat, 12 Jan 2019 12:11:32 -0500, Alan Browne
wrote: On 2019-01-12 11:22, nospam wrote: In article , Eric Stevens wrote: Now if I said, for example f/11 you would understand it. But that is not an EV. as i said, you don't understand it. here's a hint: what's the difference between f/8 and f/11 ? a) f/3 b) 1 stop c) 1 EV d) a and b. e) b and c. C'mon _E_ric! I'm rooting for you! Try (8*f - 11*f)/88 or (-3*f)/88 -- Regards, Eric Stevens |
#279
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Sat, 12 Jan 2019 09:33:13 -0500, Alan Browne
wrote: On 2019-01-11 20:29, Eric Stevens wrote: On Fri, 11 Jan 2019 12:50:41 -0500, Alan Browne wrote: On 2019-01-11 03:46, Eric Stevens wrote: On Fri, 11 Jan 2019 00:18:28 -0500, nospam wrote: 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. For what ISO and speed? No, no. No ISO or speed. Willingly obtuse. I think that applies to all parties in this argument. -- Regards, Eric Stevens |
#280
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Finally got to the point where no new camera holds my interest(waiting for specific offering)
On 1/12/2019 9:52 PM, Eric Stevens wrote:
On Sat, 12 Jan 2019 09:33:13 -0500, Alan Browne wrote: On 2019-01-11 20:29, Eric Stevens wrote: On Fri, 11 Jan 2019 12:50:41 -0500, Alan Browne wrote: On 2019-01-11 03:46, Eric Stevens wrote: On Fri, 11 Jan 2019 00:18:28 -0500, nospam wrote: 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. For what ISO and speed? No, no. No ISO or speed. Willingly obtuse. I think that applies to all parties in this argument. Captain: ... What we've got here is failure to communicate. Some men you just can't reach. [ Cool Hand Luke ] -- == Later... Ron C -- |
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