Skip to main content

Timeline for What is "ISO" on a digital camera?

Current License: CC BY-SA 2.5

22 events
when toggle format what by license comment
Aug 18, 2019 at 20:53 comment added mattdm FWIW I think there's plenty of room for a full answer here which includes the distinction you are making and why it's important.
Aug 18, 2019 at 20:52 comment added mattdm Ugh I'll repost that comment with a fixed link once I get to a computer. Should go to photo.stackexchange.com/a/27588/1943
Aug 18, 2019 at 20:49 comment added Mark Ransom @mattdm your second link is broken. I think that misunderstandings about noise would be much less if we were all using a modern definition of exposure. I do understand the weight of tradition though.
Aug 18, 2019 at 20:42 comment added mattdm @Mark Depends on the sense of the word "exposure". At least for the last 50 years, at least one common use of the term definitely includes ISO. Your usage is arguably more technically correct, but that's really an uphill fight against common usage in the field. See this answer for more.
Aug 18, 2019 at 20:16 comment added Mark Ransom But ISO is not part of exposure. Rather it determines how the camera will react to the exposure it receives.
Aug 18, 2019 at 14:11 answer added user86453 timeline score: 1
Mar 22, 2019 at 16:40 answer added relatively_random timeline score: 3
Oct 23, 2014 at 13:43 answer added Iliah Borg timeline score: 1
Mar 4, 2011 at 14:23 history tweeted twitter.com/#!/StackPhotos/status/43677865694334976
Feb 8, 2011 at 16:47 history edited PearsonArtPhoto
edited tags
Jan 10, 2011 at 0:12 answer added jrista timeline score: 33
Jan 9, 2011 at 15:19 vote accept mattdm
Jan 9, 2011 at 1:26 answer added PearsonArtPhoto timeline score: 17
Jan 8, 2011 at 22:12 comment added Evan Krall See photo.stackexchange.com/q/2946/378 for a discussion of how digital cameras implement ISO.
Jan 8, 2011 at 19:26 answer added Matt Grum timeline score: 98
Jan 8, 2011 at 19:17 comment added lindes Fair enough; considering a lighting change to be a "change of scene", and thus "separate" from exposure value, seems a valid way to describe it. As such, whether lighting of a scene is an "exposure factor" is certainly arguable, though I like to think of it as one. :) It's certainly not one that you control from within the camera, though -- err, unless you're controlling the flash brightness from within the camera. :)
Jan 8, 2011 at 19:13 answer added lindes timeline score: 94
Jan 8, 2011 at 18:54 comment added mattdm Traditionally, EV is just Av × Tv. With sensor gain under easy immediate control, these days it's effectively: Av × Tv × Sv = EV. Then, EV / lighting = final exposure.
Jan 8, 2011 at 18:51 comment added mattdm That's a matter of where you place your terms. :) For any given scene, there is a certain Exposure Value which will record an image with a certain average brightness value. By adjusting aperture, exposure time, or sensitivity, you change the exposure value, and for a constant scene that changes the "exposure" of the resulting output image. By changing the lighting, you change the scene itself, meaning that a different exposure value will be required to record the same brightness in the resulting image.
Jan 8, 2011 at 18:41 comment added lindes There's a fourth exposure factor: Amount of light. ;)
Jan 8, 2011 at 18:18 comment added mattdm I realized we have great questions/answers on aperture, decent ones on shutter speeds, and nothing which really gets to the heart of this third exposure factor. So, here we go. :)
Jan 8, 2011 at 18:17 history asked mattdm CC BY-SA 2.5