Timeline for Why can't I set a partial ISO stop?
Current License: CC BY-SA 3.0
5 events
| when toggle format | what | by | license | comment | |
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| Jul 19, 2011 at 12:17 | comment | added | Matt Grum | Partial stops have to be part of the auto-ISO function in order to get the correct exposure when using auto-iso with fixed shutter and aperture speeds. However they are implemented in software not hardware so the ISO150 you get in auto mode is "fake", I think the partial stops are unavailable when auto-iso is not on in order to simplify operation of the camera. | |
| S Jul 19, 2011 at 11:41 | history | suggested | Jari Keinänen | CC BY-SA 3.0 |
googled it and added link
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| Jul 19, 2011 at 10:55 | comment | added | Matt Grum | Ah but there is a need of sophisticated hardware / extra electronics to implement partial ISO stops properly. Canon cameras with fractional ISOs or hacked firmware just fake the intermediate stops by fiddling the numbers in the raw data, which is bad (see my answer). With auto ISO in M mode you actually need partial ISO stops to get the right output levels in a JPEG. But if shooting Tv/Av without auto-ISO you can always adjust shutter and aperture in third stops to get the right exposure when using a whole stop ISO. | |
| Jul 19, 2011 at 9:58 | review | Suggested edits | |||
| S Jul 19, 2011 at 11:41 | |||||
| Jul 19, 2011 at 7:55 | history | answered | fahad.hasan | CC BY-SA 3.0 |