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#301
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Finally got to the point where no new camera holds my interest(waiting for specific offering)
On 2019-01-12 21:19, Eric Stevens wrote:
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. If you chop off the lowest bits nobody cares. It's noise. (Prefer rounding than truncation but that's a quibble). Indeed on a system I worked on the long past the signal was encoded for transmission to another system on the aircraft with the upper bits being signal values (a voltage) and the information status bits and parity in the lower 3 bits. That way if any "client" system erroneously used the status bits as signal it would simply be noise in the destination system's computations. This could introduce bias (since status bits didn't change often) but it was way deep in the noise... -- "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 |
#302
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Finally got to the point where no new camera holds my interest(waiting for specific offering)
On 2019-01-12 21:44, Eric Stevens wrote:
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. Doesn't matter to the esthetics of the image (it's either a good, neutral or bad esthetic, but that's all it is...) 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. That's not noise. To claim it's noise absurd. It's part of the image being recorded. 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. Geez. Again. Compressing DR = increased quantization noise. TANSTAAFL. -- "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 |
#303
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Finally got to the point where no new camera holds my interest(waiting for specific offering)
On 2019-01-12 21:51, Eric Stevens wrote:
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 The correct reply was e). But thanks for playing. -- "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 |
#304
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Finally got to the point where no new camera holds my interest(waiting for specific offering)
On 2019-01-12 22:39, Eric Stevens wrote:
AS you say, they (probably) have to take it from an image file. Although they could tether the camera. Tethering the camera is just getting the image file w/o storing it on the camera's memory card. I'm done. Really. This is pointless. You have no knowledge of electrical engineering from what I can see. I'm not an engineer (but worked for many and many worked for me) and what I and nospam have been pointing out to you is pretty basic systems engineering reality. TANSTAAFL. Look that up. It really embodies the entire thing. snipped the rest because it's just blather that doesn't address the issue at all. Icing to disguise a bad cake, really -- "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 |
#305
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Finally got to the point where no new camera holds my interest (waiting for specific offering)
On Jan 13, 2019, Alan Browne wrote
(in ): On 2019-01-12 22:39, Eric Stevens wrote: After 313 posts to this mind numbing thread without any end in sight, can you guys just pick up your cameras, and shoot something, anything? -- Regards, Savageduck |
#306
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Finally got to the point where no new camera holds my interest(waiting for specific offering)
On 13/01/2019 15:48, Savageduck wrote:
On Jan 13, 2019, Alan Browne wrote (in ): On 2019-01-12 22:39, Eric Stevens wrote: After 313 posts to this mind numbing thread without any end in sight, can you guys just pick up your cameras, and shoot something, anything? Can you see the bird at this MID? And/or this MID? -- David B. |
#307
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Finally got to the point where no new camera holds my interest(waiting for specific offering)
On 2019-01-13 10:48, Savageduck wrote:
On Jan 13, 2019, Alan Browne wrote (in ): On 2019-01-12 22:39, Eric Stevens wrote: After 313 posts to this mind numbing thread without any end in sight, can you guys just pick up your cameras, and shoot something, anything? I've given up. And you can kill threads if you're not interested. -- "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 |
#308
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Finally got to the point where no new camera holds my interest(waiting for specific offering)
On 1/13/2019 11:38 AM, Alan Browne wrote:
On 2019-01-13 10:48, Savageduck wrote: On Jan 13, 2019, Alan Browne wrote (in ): On 2019-01-12 22:39, Eric Stevens wrote: After 313 posts to this mind numbing thread without any end in sight, can you guys just pick up your cameras, and shoot something, anything? I've given up. And you can kill threads if you're not interested. The show has been slightly entertaining .. only slightly. Here's a nutshell recap of the thread as described by lyrics from the "Missing Persons" song "Words" ~~ ~~ You look at me as if you're in a daze It's like the feeling at the end of the page When you realize you don't know what you just read What are words for when no one listens anymore What are words for when no one listens What are words for when no one listens it's no use talkin at all I might as well go up and talk to a wall 'cause all the words are having no effect at all It's a funny thing am I all alone Something has to happen to change the direction What little filters through is giving you the wrong impression It's a sorry state I say to myself What are words for when no one listens anymore What are words for when no one listens What are words for when no one listens it's no use talkin at all Do you hear me Do you care Do you hear me Do you care ~~ ~~ [ YMMV ] :-) -- == Later... Ron C -- |
#309
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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 23:10:27 -0500, nospam
wrote: In article , Eric Stevens wrote: 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. that would be a flaw in their testing. Yep. Which is one of the reasons that DxO do it the way they do. 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. so is ****. -- Regards, Eric Stevens |
#310
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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 23:10:23 -0500, nospam
wrote: In article , Eric Stevens wrote: 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. good work! since we now know that 1ev = 4mm, it's a very simple calculation to set a lens to your desired ev 20: simply zoom the lens to 80mm, or alternately, choose a fixed focal length 80mm lens. Oh no. You have it wrong. It's 4mm netween the f/8 mark and the f/11 mark on the lens ring. The diameter of the lens ring is 60mm which gives it a circumference of 188mm. using your calculatios, 8omm is 152 degrees of rotation of the ring. I've just tried that but the ring won't rotate that much so I have concluded that my 105mm Micro Nikkor will not do an EV of 20. math is fun. Especially when it is disconnected from reality. -- Regards, Eric Stevens |
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