Talk:Shutter speed

message: There are too many pictures, it is crowded, I think some can go. Any suggestions on which ones? Shoeshirt 23:39, 7 June 2007 (UTC)
replies: text: I voted with my delete key. Dicklyon 00:45, 8 June 2007 (UTC)
thread_title:  Too many pictures 

message: I've rewritten this accordingly to emphasize the actual duration x intensity = exposure formula. (Why isn't this even mentioned on exposure?) When people talk about shutter speed, they are not actually discussing the speed of the shutter opening and closing (which is designed to be as close to instanteous as possible) they are discussing the actual exposure time. We use the length of time (duration) and the intensity (aperture) to control the exposure itself, and the sensitivity of the film or sensor then reacts to that exposure within its range. Keeping the concept clear is essential. Girolamo Savonarola 06:19, 4 September 2007 (UTC)
replies: text: I took another whack at it.  I think the concept of total exposure needs to be in the opening paragraph, since controlling that is one of the main things the shutter speed is about.  And in the next paragraph, the duration x intensity thing really needs to menion the scene luminance to be complete; so I added a bit about that, since aperture itself does not determine intensity.  The Exposure (photography) article does say that total exposure is measured in lux seconds, which is intensity (focal plane illuminance) times duration.  It also points out that the EV (shutter speed and aperture combination in stops) needs to be combined with scene luminance to figure the total exposure.  It might be worth trying to further clarify all this. Dicklyon 06:40, 4 September 2007 (UTC)
replies: text: I'm not certain I totally agree about the scene luminance - that will affect the image rendering, based on the sensor/film response, but it has no bearing on the physics of the exposure. The equation defines exposure as any shot, regardless of its artistic merit or ability to fall within exposure latitude. In other words, any shot will have an exposure equal to intensity times duration. Whether or not it renders (exposes) decently is a function of the sensor/film, which is a completely separate consideration. Girolamo Savonarola 07:10, 4 September 2007 (UTC)
replies: text: It agree it's not about the rendering, and is independent of the ISO speed, but if the scene is dark, the total exposure will be zero no matter what the exposure time and aperture.  You need to get an intensity into the formula to get to the lux-seconds of exposure. Dicklyon 15:06, 4 September 2007 (UTC)
replies: text: You're missing my point - all photos are technically exposures, regardless. It may be zero lux-s, but it's still an exposure. Any case, is it even true? There's not much true black that won't expose something given a long enough exposure time. Girolamo Savonarola 15:35, 4 September 2007 (UTC)
replies: text: Yes, and the "EV" (exposure value) is a measure of what you're talking about.  But that's not the "total exposure", which as you point out is intensity (focal plane illuminance) times duration.  You can't substitute one for the other. Dicklyon 16:15, 4 September 2007 (UTC)
replies: text: A total exposure which is zero is still an exposure. It's run through the camera and was exposed to the sensor. My point is that you can consider the exposure a measurement of everything which will hit the sensor, measured just before it hits the sensor. Girolamo Savonarola 16:40, 4 September 2007 (UTC)
replies: text: But you need to be clear about what measurement you're referring to.  An exposure of 10 EV corresponds to f/32 for 1 second or f/1 for 1/1000 second, but doesn't say anything about how much light you're measuring.  A measurement of 1 Lux-second, on the other hand, is an amount of light, proportional roughly to so many photons per pixel or whatever.  The latter is known as total exposure, and requires an intensity input such as scene luminance. Dicklyon 16:52, 4 September 2007 (UTC)
replies: text: Perhaps I'm not being clear- the aperture controls the intensity, but the intensity itself is an amount of light (lux or ft-cd). Intensity times time equals exposure. Girolamo Savonarola 17:10, 4 September 2007 (UTC)
replies: text: Yes, it controls the intensity by how much of the light from the scene it admits.  I get that.  But it does not determine the intensity; you still need the scene luminance if you want to connect to the total exposure in lux-seconds. Dicklyon 20:49, 4 September 2007 (UTC)

text: While I'm thinking about all this, is there really a good reason why this article should be separate from shutter (photography)? It just seems kind of absurd that the two are split from each other. Girolamo Savonarola 17:12, 4 September 2007 (UTC)
replies: text: "Absurd" is a bit of a stretch.  The contents hardly overlap.  One is about the mechanisms, the other about how the time is uses as a parameter.  Having leaf shutter as a separate article is a bit silly, though.  The division of content between aperture, f-number, diaphragm (optics) is perhaps a bit much, too, but not as bad as "absurd." Dicklyon 20:47, 4 September 2007 (UTC)
replies: text: Much as we're debating definitions, don't take my diction in that comment too literally! :) I'm just pointing out that it probably makes more sense (in the view of a long-term goal of eventual FA) to combine the shutter theory with the physical shutter. Girolamo Savonarola 21:22, 4 September 2007 (UTC)
replies: text: Feel free to make a merge proposal. I might oppose it, but I'll think about it. Dicklyon 21:32, 4 September 2007 (UTC)
thread_title:  intro rewrite 

message: There seem to be several problems with this section:
# The symbol E surely refers to “exposure time” rather than “exposure”.
# The formulas are the reciprocal of the formula in Rotary disc shutter (i.e., the first formula gives the reciprocal of exposure time); either the symbol definitions or the formulas should be revised.
# The stated exposure times for shutter angles of 165° and 180° appear to be given in reverse order, and the value for 165° does not match that given by the first formula even if the formula is corrected.
JeffConrad (talk) 00:51, 19 October 2008 (UTC)
replies: text: S = \frac{E * 360^\circ}{F}
WYarde (talk) 09:53, 18 May 2009 (UTC)
replies: text: As Jeff mentioned, the problem is that the formula is for shutter speed (reciprocal seconds), not exposure time; I clarified.   Dicklyon (talk) 14:43, 18 May 2009 (UTC)
replies: text: Isn't this definition of shutter speed at odds with the one in the lead paragraph (shutter speed = exposure time)? Would it not be better to invert the formula and use the common definition? There's also the matter of the result for a 165° shutter angle; if it gives an exposure time of “about” 1/50 s, then so does a 180° shutter angle. JeffConrad (talk) 07:33, 19 May 2009 (UTC)
thread_title:  Cinematographic shutter formula 

message: Guys, someone should change the format of the "Creative utility in photography" as that huge white space in the middle of the page is quite annoying! Ty!  — Preceding unsigned comment added by 194.81.223.66 (talk) 08:27, 9 August 2013 (UTC)
thread_title:  Format 

message: This is a good article as the subject discussed and photos shown directly relate to the topic - which is shutter speed.Johnscotaus (talk) 06:11, 28 November 2015 (UTC)
thread_title:  Good article