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 |
#11
|
|||
|
|||
dpreview also tries to teach the trolls about ISO/aperture :)
In article ,
Sandman wrote: In article , PeterN wrote: snip Sandman: Furthermore, EV+5 on one camera is NOT the same as EV+5 on another camera, like ISO is trying to be. Because adaptation of methods of exposure varies, ISO should not be considered an absolute measurement of sensitivity, but merely a reasonable guideline. That is one of the reasons a lot of us bracket exposures. But the point is, ISO *was* an absolute measurement of sensitivity, meaning that one film of ISO400 and another film of ISO400 was equally sensitive to light, that was the entire point of ISO. Youpp! An gave us Ansel Adams zonesystem even though he used ASA, me thinks... Now, when digital rolled around, they adopted ISO to mean sensor amplification, but the problem was that ISO is sensitivity over a unit area, not over the exposed area (since that was pretty much the same back in 135 days), but digital cameras can't use a standard that is relevant to unit areas when each camera had different amount of such unit areas Which is rather useless compared to the above, but gives some sort of reference for what middle grey should look like... -- teleportation kills |
#12
|
|||
|
|||
dpreview also tries to teach the trolls about ISO/aperture :)
On 10 Sep 2017 07:27:26 GMT, Sandman wrote:
In article , PeterN wrote: snip Sandman: Furthermore, EV+5 on one camera is NOT the same as EV+5 on another camera, like ISO is trying to be. Because adaptation of methods of exposure varies, ISO should not be considered an absolute measurement of sensitivity, but merely a reasonable guideline. That is one of the reasons a lot of us bracket exposures. But the point is, ISO *was* an absolute measurement of sensitivity, meaning that one film of ISO400 and another film of ISO400 was equally sensitive to light, that was the entire point of ISO. Now, when digital rolled around, they adopted ISO to mean sensor amplification, but the problem was that ISO is sensitivity over a unit area, not over the exposed area (since that was pretty much the same back in 135 days), but digital cameras can't use a standard that is relevant to unit areas when each camera had different amount of such unit areas They can, when what matters is not the total amount of light falling on the entire sensor but the amount of light which falls on a unit area of sensor. Those pixels in the unit area don't care what is happening in the neighbouring unit area. All that matters to them is the amount of light which falls upon them. -- Regards, Eric Stevens |
#13
|
|||
|
|||
dpreview also tries to teach the trolls about ISO/aperture :)
On 10 Sep 2017 07:23:32 GMT, Sandman wrote:
In article , Eric Stevens wrote: Sandman: https://www.dpreview.com/articles/2666934640/what-is- equivalence-and- why-should-i-care It's funny, this article contains pretty much the exact same key points and examples I showed the trolls here a couple of years ago, where you need to adjust the aperture *AND* the ISO to get similar end-result when it comes to sensor amplification. The example shows a MFT sensor having to adjust its aperture by the crop factor and the ISO by the crop factor squared to receive the same amount of total light as the FF sensor to produce an image with the same light intensity and the same sensor amplification. Now, where have I heard this before? :-D Sandman How to measure ISO 11/28/2015 "FF: 1/250, f5.6, ISO 800 MFT: 1/250, f2.8, ISO 200 The above is the same *amount of light* on the sensor, which creates as identical image as possible using different sensor technologies. Also, you adjust the ISO by the crop factor squared to match the signal amplification of the larger sensor, so you will get very equivalent noise." In the dpreview article they used the exact same ratios: FF: f5.6 ISO 3200 MFT: f2.8 ISO 800 And the end result was similarly amplified images. Go figure Eric Stevens: Go figure indeed. If only the man applied the mathematics of the situation from beginning to end he would not have reached the (erroneous) conclusion he has. Sandman: Take it up with dpreview, same math, same examples, same conclusions. Go figure Same logical errors. Same hot air from the trolls of rpd I could explain it but it requires diagrams which I can't put on rpd and it requires algebra which is too complicated to be published in a text news group. One day I might produce it as a PDF, but it's quite a lot of work. -- Regards, Eric Stevens |
#14
|
|||
|
|||
dpreview also tries to teach the trolls about ISO/aperture :)
In article , Eric Stevens wrote:
PeterN: Because adaptation of methods of exposure varies, ISO should not be considered an absolute measurement of sensitivity, but merely a reasonable guideline. That is one of the reasons a lot of us bracket exposures. Sandman: But the point is, ISO *was* an absolute measurement of sensitivity, meaning that one film of ISO400 and another film of ISO400 was equally sensitive to light, that was the entire point of ISO. Now, when digital rolled around, they adopted ISO to mean sensor amplification, but the problem was that ISO is sensitivity over a unit area, not over the exposed area (since that was pretty much the same back in 135 days), but digital cameras can't use a standard that is relevant to unit areas when each camera had different amount of such unit areas They can, when what matters is not the total amount of light falling on the entire sensor but the amount of light which falls on a unit area of sensor. Incorrect on several accounts. First, the amount of light that falls on a unit area is never "the matter" to the photographer. The end result is. Secondly, when you have different amount of unit areas in play, whatever "iso" one unit area may or may not be in relation to is irrelevant. Thirdly, ISO for digital cameras does NOT means X amount of light gathered per unit area, that's the *film* usage of ISO. "ISO" for digital cameras is an arbitrary value to match the *lightness* of the film-equivalent of that ISO setting. So when you talk about "ISO" in digital cameras, it has absolutely nothing to do with light per unit area other than the camera trying to emulate the result of a ISO analog film. Which, depending on your sensors size means you have to amplify it more or less than another camera. Those pixels in the unit area don't care what is happening in the neighbouring unit area. All that matters to them is the amount of light which falls upon them. They are also not more "sensitive" depending on your ISO settings. They are fixed. With less total light, the signal needs to be amplified more to match the brightness of the film ISO emulation step. -- Sandman |
#15
|
|||
|
|||
dpreview also tries to teach the trolls about ISO/aperture :)
In article , Eric Stevens wrote:
Eric Stevens: Same logical errors. Sandman: Same hot air from the trolls of rpd I could explain it but it requires diagrams which I can't put on rpd and it requires algebra which is too complicated to be published in a text news group. One day I might produce it as a PDF, but it's quite a lot of work. Like I said - more hot air from the trolls. :-D And it's also ironic that Eric, in a photography usenet group, seem to want to claim there is no way to convey something other than text here :-D -- Sandman |
#16
|
|||
|
|||
dpreview also tries to teach the trolls about ISO/aperture :)
In article .com,
Savageduck wrote: Sandman: ISO is irrelevant. Camera makers should just have a setting for amplification. So you set the camera to EV+X to have the signal amplified x amount of times. And high-end cameras can have it pushed to EV+8 or EV+10 while more normal cameras maxes out at EV+6 or something. Furthermore, EV+5 on one camera is NOT the same as EV+5 on another camera, like ISO is trying to be. RichA: That's actually not a bad idea. Problem is, camera makers are still pandering to old film shooters, hence ISO which is the ASA of digital. Same reason perhaps we still have F-stops and not T-stops for still shooting, though that's probably as much about marketing as functionality. One of the interesting features with my X-T2 is the EV adjustment dial option. It has the typical +3/-3 EV dial settings. However, it also has a “C” setting which passes control to the front control wheel and extends the EV adjustment to +5/-5 EV. and acts very much like an amplification gain adjustment to the base sensor generated signal. Are you sure? Can't say anything about that particular camera, but usually the EV setting is for auto-compensating the *exposure*, not the sensor amplification. I.e. if you have the camera set in aperture-priority mode and it decides on 1/250 for f5.6, then moving the EV to EV+1 would just set it to expose at 1/125 f5.6 for instance, i.e. the "ISO" setting, or rather the sensor amplification remains the same. Is the -5/+5 setting different in your camera, or is the entire EV function different? -- Sandman |
#17
|
|||
|
|||
dpreview also tries to teach the trolls about ISO/aperture :)
In article ,
Sandman wrote: [---] Like I said - more hot air from the trolls. :-D Nice autumn day today: A tad chilly but the sky is clear and it ain't that windy... Are you going hot air ballooning today? You do seem to have all the toys! :-)) http://www.dmi.dk/uploads/tx_dmidata.../1/c/59b50265c 1486.png -- teleportation kills |
#18
|
|||
|
|||
dpreview also tries to teach the trolls about ISO/aperture :)
On 2017-09-10 09:50:58 +0000, Sandman said:
In article .com, Savageduck wrote: Sandman: ISO is irrelevant. Camera makers should just have a setting for amplification. So you set the camera to EV+X to have the signal amplified x amount of times. And high-end cameras can have it pushed to EV+8 or EV+10 while more normal cameras maxes out at EV+6 or something. Furthermore, EV+5 on one camera is NOT the same as EV+5 on another camera, like ISO is trying to be. RichA: That's actually not a bad idea. Problem is, camera makers are still pandering to old film shooters, hence ISO which is the ASA of digital. Same reason perhaps we still have F-stops and not T-stops for still shooting, though that's probably as much about marketing as functionality. One of the interesting features with my X-T2 is the EV adjustment dial option. It has the typical +3/-3 EV dial settings. However, it also has a “C” setting which passes control to the front control wheel and extends the EV adjustment to +5/-5 EV. and acts very much like an amplification gain adjustment to the base sensor generated signal. Are you sure? No I am not sure. I am just relaying what seems to be happening. Can't say anything about that particular camera, but usually the EV setting is for auto-compensating the *exposure*, not the sensor amplification. That is my expectation of normal function. However, when in manual, or shutter priority, I see changes made to EV comp in reaction to speed adjustments. I.e. if you have the camera set in aperture-priority mode and it decides on 1/250 for f5.6, then moving the EV to EV+1 would just set it to expose at 1/125 f5.6 for instance, i.e. the "ISO" setting, or rather the sensor amplification remains the same. ....and that is what I experience when using Aperture priority. Is the -5/+5 setting different in your camera, or is the entire EV function different? All I can tell you is how using the Custom, "C" setting on the EV dial expands the EV range from +3/-3 to +5/-5, and moves control to the front control wheel, and how making various exposure adjustments in different exposure modes effects what I see to change with the EV comp settings. https://www.dropbox.com/s/g2pph9alnfwz3ot/screenshot_168.png In Aperture priority mode that EV compensation acts as you would expect, but with the expanded compensation range (+5/-5) controlled via the front control wheel rather than the EV dial. In Shutter priority the behavior is different. Using the EV compensation in the normal +3/-3 operation I see only the expected, and normal EV indicator/scale on the LCD/EVF regardless of speed setting. However, if the Custom “C” EV is selected, when speed is adjusted the EV can be seen to move without touching the EV adjustment. https://www.dropbox.com/s/lf4szsegb14pldk/screenshot_169.png In full Manual mode the same movement of the EV compensation indicator/scale in the LCD/EVF is shown regardless of using normal or “C” for EV comp. It just seems a bit odd to me when compared with what I had been used to with my Nikon DSLRs. It might just be a Fujifilm mirrorless thing. ;-) -- Regards, Savageduck |
#19
|
|||
|
|||
dpreview also tries to teach the trolls about ISO/aperture :)
In article 2017091007015440977-savageduck1@REMOVESPAMmecom, Savageduck
wrote: Sandman: Is the -5/+5 setting different in your camera, or is the entire EV function different? All I can tell you is how using the Custom, "C" setting on the EV dial expands the EV range from +3/-3 to +5/-5, and moves control to the front control wheel, and how making various exposure adjustments in different exposure modes effects what I see to change with the EV comp settings. https://www.dropbox.com/s/g2pph9alnfwz3ot/screenshot_168.png Yeah, that seems to suggest that it is used to set aperture and shutter (exposure) compensation, not sensor amplification. And the extended range is probably due to the front dial is stepless while the EV dial has printed steps. It just seems a bit odd to me when compared with what I had been used to with my Nikon DSLRs. It might just be a Fujifilm mirrorless thing. ;-) Yeah, few Nikon DSLR's have a EV dial to begin with, most have a EV button and then you use the command dial to set it. I think my D800 has a range of +/- 4 steps if I remember correctly. Both my Nikon Df and my Sony A7 have a EV dial that goes from -3 to +3 -- Sandman |
#20
|
|||
|
|||
dpreview also tries to teach the trolls about ISO/aperture :)
In article ,
Sandman wrote: In article 2017091007015440977-savageduck1@REMOVESPAMmecom, Savageduck wrote: Sandman: Is the -5/+5 setting different in your camera, or is the entire EV function different? All I can tell you is how using the Custom, "C" setting on the EV dial expands the EV range from +3/-3 to +5/-5, and moves control to the front control wheel, and how making various exposure adjustments in different exposure modes effects what I see to change with the EV comp settings. https://www.dropbox.com/s/g2pph9alnfwz3ot/screenshot_168.png Yeah, that seems to suggest that it is used to set aperture and shutter (exposure) compensation, not sensor amplification. And the extended range is probably due to the front dial is stepless while the EV dial has printed steps. It just seems a bit odd to me when compared with what I had been used to with my Nikon DSLRs. It might just be a Fujifilm mirrorless thing. ;-) Yeah, few Nikon DSLR's have a EV dial to begin with, most have a EV button and then you use the command dial to set it. I think my D800 has a range of +/- 4 steps if I remember correctly. Both my Nikon Df and my Sony A7 have a EV dial that goes from -3 to +3 Do you intend to get the Sony AIII by Christmas? -- teleportation kills |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Teach dullish Brit police how to do their own jobs | George Kerby | Digital SLR Cameras | 0 | July 21st 10 07:24 PM |
What a Greek Wedding Can Teach You About Relationships | es8zzp3j | 35mm Photo Equipment | 1 | January 26th 08 11:18 PM |
What a Greek Wedding Can Teach You About Relationships | [email protected] | Photographing People | 0 | January 26th 08 07:20 PM |
What a Greek Wedding Can Teach You About Relationships | [email protected] | Digital Photography | 0 | January 26th 08 07:19 PM |
In-camera aperture vs. In-lens apertu What's the difference? | LooksLikeRain | Digital SLR Cameras | 22 | May 10th 07 05:52 AM |