If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#31
|
|||
|
|||
The base ("native") ISO of a sensor
Alfred Molon wrote:
In article , Floyd L. Davidson says... Alfred Molon wrote: Once again: explain why at ISO 64 the exposure time is THREE times the exposure time at ISO 200. The DXOMark site you are referring to claims that both at ISO 64 and ISO 200 the real ISO is 83. But if the real ISOs at ISO 64 and 200 really both were 83, the exposure times should be the same. They are not, so DXOMark and you are wrong. You don't understand sensor characteristics, ISO, or exposure; and should not be saying others are wrong. DXOMark is not wrong. Consider that the design target for maximum output from a sensor, in terms of linearity, may not be the actual maximum output. Also consider that a "correct" exposure level might be 2.7 fstops below whatever is chosen as the "maximum output", or it might be 1.3 fstops! All of that is totally independent of when whites actually do clip, which is a function of the ADC, not the sensor. And all of that makes what you believe to be how it works just a little bit the other side of a fantasy too. Floyd, please explain why at ISO 64 the exposure time is three times the exposure time at ISO 200. DXOMark claims that at both ISO settings the true ISO is 83. For the reasons already stated above! -- Floyd L. Davidson http://www.apaflo.com/ Utqiagvik (Barrow, Alaska) |
#32
|
|||
|
|||
The base ("native") ISO of a sensor
In article , Floyd L. Davidson says...
Alfred Molon wrote: In article , Floyd L. Davidson says... Alfred Molon wrote: Once again: explain why at ISO 64 the exposure time is THREE times the exposure time at ISO 200. The DXOMark site you are referring to claims that both at ISO 64 and ISO 200 the real ISO is 83. But if the real ISOs at ISO 64 and 200 really both were 83, the exposure times should be the same. They are not, so DXOMark and you are wrong. You don't understand sensor characteristics, ISO, or exposure; and should not be saying others are wrong. DXOMark is not wrong. Consider that the design target for maximum output from a sensor, in terms of linearity, may not be the actual maximum output. Also consider that a "correct" exposure level might be 2.7 fstops below whatever is chosen as the "maximum output", or it might be 1.3 fstops! All of that is totally independent of when whites actually do clip, which is a function of the ADC, not the sensor. And all of that makes what you believe to be how it works just a little bit the other side of a fantasy too. Floyd, please explain why at ISO 64 the exposure time is three times the exposure time at ISO 200. DXOMark claims that at both ISO settings the true ISO is 83. For the reasons already stated above! Again a non-answer to a simple question. The claim was made that the ISO 3200 of the E-M1 II is not a real ISO 3200, and to back up this claim the data on DXOMark was referenced. But this DXOMark data is obviously wrong - DXOMark measure the same ISO 83 at both ISO 64 and ISO 200, when in reality the exposure times are vastly different. -- Alfred Molon Olympus E-series DSLRs and micro 4/3 forum at http://tech.groups.yahoo.com/group/MyOlympus/ http://myolympus.org/ photo sharing site |
#33
|
|||
|
|||
The base ("native") ISO of a sensor
In article ,
Alfred Molon wrote: In article , Floyd L. Davidson says... Alfred Molon wrote: In article , Floyd L. Davidson says... Alfred Molon wrote: Once again: explain why at ISO 64 the exposure time is THREE times the exposure time at ISO 200. The DXOMark site you are referring to claims that both at ISO 64 and ISO 200 the real ISO is 83. But if the real ISOs at ISO 64 and 200 really both were 83, the exposure times should be the same. They are not, so DXOMark and you are wrong. You don't understand sensor characteristics, ISO, or exposure; and should not be saying others are wrong. DXOMark is not wrong. Consider that the design target for maximum output from a sensor, in terms of linearity, may not be the actual maximum output. Also consider that a "correct" exposure level might be 2.7 fstops below whatever is chosen as the "maximum output", or it might be 1.3 fstops! All of that is totally independent of when whites actually do clip, which is a function of the ADC, not the sensor. And all of that makes what you believe to be how it works just a little bit the other side of a fantasy too. Floyd, please explain why at ISO 64 the exposure time is three times the exposure time at ISO 200. DXOMark claims that at both ISO settings the true ISO is 83. For the reasons already stated above! Again a non-answer to a simple question. The claim was made that the ISO 3200 of the E-M1 II is not a real ISO 3200, and to back up this claim the data on DXOMark was referenced. But this DXOMark data is obviously wrong - DXOMark measure the same ISO 83 at both ISO 64 and ISO 200, when in reality the exposure times are vastly different. Extended low ISO are been explained to you earlier in this thread. You just don't want hear nor learn. mFT sensors are silly small only a quarter of the size of fullframe ones. It's close to fraud comparing them... Bigger is better! :-ppp -- teleportation kills |
#34
|
|||
|
|||
The base ("native") ISO of a sensor
In article , Me wrote:
[ ... ] You don't believe that if something tests better than the laws of physics dictate is possible, then some trickery or deception is going on? Sure it could be "error" by the manufacturer - but they seem to always err on the side of making the camera seem to perform better than it really does rather than worse - it is deliberate. In the link I posted above, then the plot for "ideal 4/3" format assumes that every pixel is captured and recorded and there's no read noise / electronic noise degrading the dynamic range. Yet that camera appears to perform better than is possible - better than "ideal". The loss of dynamic range as ISO increases is inevitable "shot noise" - there's nothing that can be done to avoid it. Olympus and Fuji are nortorious for cheating with ISO: http://www.photonstophotos.net/Chart...M1%20Mark%20II |
#35
|
|||
|
|||
The base ("native") ISO of a sensor
On 2017-05-30 18:19:55 +0000, nap said:
In article , Me wrote: [ ... ] You don't believe that if something tests better than the laws of physics dictate is possible, then some trickery or deception is going on? Sure it could be "error" by the manufacturer - but they seem to always err on the side of making the camera seem to perform better than it really does rather than worse - it is deliberate. In the link I posted above, then the plot for "ideal 4/3" format assumes that every pixel is captured and recorded and there's no read noise / electronic noise degrading the dynamic range. Yet that camera appears to perform better than is possible - better than "ideal". The loss of dynamic range as ISO increases is inevitable "shot noise" - there's nothing that can be done to avoid it. Olympus and Fuji are nortorious for cheating with ISO: http://www.photonstophotos.net/Chart...M1%20Mark%20II The issue I find disturbing is those DxOMark ISO numbers are all over the place, and not just problematic in the areas of extended ISO. Then there is your tagging Fujifilm in this group of questionable ISO numbers. It is worth noting that the last Fujifilm camera evaluated was the X100 which is the last of the Fujifilm CMOS sensored cameras. None of the current, or recently aged, X-Trans, X-Trans II, or X-Trans III sensored Fujifilm X-Series cameras have been evaluated by DxOMark. There has yet to be any sort of report regarding where the current crop of Fujifilm X-trans sensored cameras (X100S, X100T, X100F, X-Pro1, X-Pro2, X-E1, X-E2(s), X-T1, X-T2, X-T10, or X-T20 are regarding proven ISO ratings which might, or might not support your accusation of ISO cheating. Unless you are aware of another lab testing sensor ISO performance that we are not aware of. If that is the case please cite. -- Regards, Savageduck |
#36
|
|||
|
|||
The base ("native") ISO of a sensor
In article , nap says...
http://www.photonstophotos.net/Chart...M1%20Mark%20II ISO 83 measured at both ISO 64 and ISO 200. But in reality the exposure time at ISO 64 is three times the exposure time at ISO 200. That diagram contains wrong data. -- Alfred Molon Olympus E-series DSLRs and micro 4/3 forum at http://tech.groups.yahoo.com/group/MyOlympus/ http://myolympus.org/ photo sharing site |
#37
|
|||
|
|||
The base ("native") ISO of a sensor
Alfred Molon wrote:
In article , nap says... http://www.photonstophotos.net/Chart...M1%20Mark%20II ISO 83 measured at both ISO 64 and ISO 200. But in reality the exposure time at ISO 64 is three times the exposure time at ISO 200. That diagram contains wrong data. -- Alfred Molon Olympus E-series DSLRs and micro 4/3 forum at http://tech.groups.yahoo.com/group/M...myolympus.org/ photo sharing site It does not. You don't appear to be able to comprehend sensor characteristics, ISO specifications, ISO gain, ADC characteristics and how they relate to each other and to SNR or Dynamic Range. You have a rigid fixed idea of relationships that in fact are not fixed at all. If that is not within your grasp you will just have to accept the word others who do understand it and tell you the chart is accurate. Rest assured that both Bill Claff and DXOMark understand it well! -- Floyd L. Davidson http://www.apaflo.com/ Utqiagvik (Barrow, Alaska) |
#38
|
|||
|
|||
The base ("native") ISO of a sensor
In article 2017053012243459901-savageduck1@REMOVESPAMmecom,
Savageduck wrote: On 2017-05-30 18:19:55 +0000, nap said: In article , Me wrote: [ ... ] You don't believe that if something tests better than the laws of physics dictate is possible, then some trickery or deception is going on? Sure it could be "error" by the manufacturer - but they seem to always err on the side of making the camera seem to perform better than it really does rather than worse - it is deliberate. In the link I posted above, then the plot for "ideal 4/3" format assumes that every pixel is captured and recorded and there's no read noise / electronic noise degrading the dynamic range. Yet that camera appears to perform better than is possible - better than "ideal". The loss of dynamic range as ISO increases is inevitable "shot noise" - there's nothing that can be done to avoid it. Olympus and Fuji are nortorious for cheating with ISO: http://www.photonstophotos.net/Chart...%20OM-D%20E-M1 %20Mark%20II The issue I find disturbing is those DxOMark ISO numbers are all over the place, and not just problematic in the areas of extended ISO. Then there is your tagging Fujifilm in this group of questionable ISO numbers. It is worth noting that the last Fujifilm camera evaluated was the X100 which is the last of the Fujifilm CMOS sensored cameras. None of the current, or recently aged, X-Trans, X-Trans II, or X-Trans III sensored Fujifilm X-Series cameras have been evaluated by DxOMark. There has yet to be any sort of report regarding where the current crop of Fujifilm X-trans sensored cameras (X100S, X100T, X100F, X-Pro1, X-Pro2, X-E1, X-E2(s), X-T1, X-T2, X-T10, or X-T20 are regarding proven ISO ratings which might, or might not support your accusation of ISO cheating. Unless you are aware of another lab testing sensor ISO performance that we are not aware of. If that is the case please cite. The conclusions are for you to make... http://www.photonstophotos.net/Chart...%20EOS%205D%20 Mark%20IV,FujiFilm%20X-T2,Olympus%20OM-D%20E-M1%20Mark%20II,Sony%20ILCE-7 RM2 http://www.photonstophotos.net/Chart...205D%20Mark%20 IV,FujiFilm%20X-T2,Olympus%20OM-D%20E-M1%20Mark%20II,Sony%20ILCE-7RM2 You should notice, however the foot and shoulder of the curves... I'm kinda busy right now so don't expect prompt comments. -- teleportation kills |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Sony's new sensor. "white" pixel filtering? | nospam | Digital SLR Cameras | 0 | February 9th 12 05:50 PM |
Sony Exmor R ("back illuminated") sensor in production | Alan Browne | Digital SLR Cameras | 31 | August 21st 09 08:40 AM |
"Corset-Boi" Bob "Lionel Lauer" Larter has grown a "pair" and returned to AUK................ | \The Great One\ | Digital Photography | 0 | July 14th 09 12:04 AM |
Nov Foveon wants the..."pill" camera sensor market.....no jokes! | RichA | Digital SLR Cameras | 1 | November 17th 07 06:02 PM |
Question for J. Theakston -- "Third Base"?? | Radium | Film & Labs | 2 | October 9th 06 04:01 AM |