Talk:Shutter speed

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[edit] Speed measured in seconds?

Speed is normally measured as something per second. Taka 20:14, 14 September 2006 (UTC)

Shutter speed is the conventional misnomer for exposure time; it's measured in seconds. Dicklyon 00:45, 8 June 2007 (UTC)
The terminology is confusing. I would expect speed and time to have an inverse relationship - when something is done with more speed (faster), it takes less time and vice versa. If shutter speed is a misnomer as Dicklyon says, it should be noted and explained in the article. --Imroy 14:14, 23 August 2007 (UTC)
What I say is irrelevant. Find a book that talks about it if you want to put it in the article. You can't just go around saying things are confusing in an encyclopedia. Dicklyon 01:00, 28 August 2007 (UTC)
Also just to note that speed normally measures distance divided by time. Since this isn't actually a measurement of distance, it fails the "normally" qualifier anyway. Girolamo Savonarola 07:44, 2 September 2007 (UTC)
I'll have a crack at this. Red herrings aside:
  • The shutter speed is the time taken for the shutter to open and close.
  • Shutter speed is the time set for the shutter to remain open after pressing the shutter release.
  • ... to travel to the open position and return to the closed position.
    • We have time, and distance if you like.
    • 1/100 (a hundreth part of a) second is faster(longer) than 1 (one) second. The time it takes to travel ...
    • This could be viewed as a cycle, and the time taken to complete it is the speed.

Hope I'm helping to find a simple explanation for the apparent confusion. I made a start by editing the other side

← Cygnis insignis 15:56, 2 September 2007 (UTC)

Sure, that's an OK explanation of speed. It's not how it really works, though. The shutter mechanisms generally snap open at a constant fast speed, then wait, then snap shut at a constant fast speed. So taking "speed" literally as distance per time is misleading, and not what's intended. There's also lens speed and film speed, where no such strained analogy would be attempted. Dicklyon 16:01, 2 September 2007 (UTC)
The first part of your statement is not in conflict with what I wrote. There is no analogy to a normal use of speed given, it is speed. The couple of minutes you took to read my reply was fast– there is no need to find distance, though it can be found. That we set the amount of time before it shuts is irrelevant to the action/event. And the rate that a shutter can return is pertinent in high speed photography, modern cameras are faster. Cygnis insignis 17:07, 2 September 2007 (UTC)

← Manamarak 17:38, 1 December 2007 (GMT)

I agree, shutter rate would be a more accurate description, but the general usage refers to shutter speed, so we are stuck with it.

[edit] Too many pictures

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)

I voted with my delete key. Dicklyon 00:45, 8 June 2007 (UTC)

Ahh, it looks much less cluttered now. Shoeshirt 02:08, 8 June 2007 (UTC)

[edit] rewrite

Some of it's OK, but the last edit seemed like it messed up the lead paragraph pretty good, so I reverted it. I'll try to work on it a bit later. Dicklyon 01:33, 3 September 2007 (UTC)

1/8000 s is not an extraordinary claim. You should be actively improving the page, not camping out and making unilateral decisions about the content. Cygnis insignis 07:47, 3 September 2007 (UTC)
No, 1/8000 is not at all unusual, but it's not from the list given in the referenced source; and it already says that the series is commonly extended on both ends. If you'd like to change to a different source to support your edit, that would be fine. Dicklyon 16:24, 3 September 2007 (UTC)
I apologise to you, as you regarded my insinuation as uncivil. I was annoyed, it was an intentional comment. Please, don't alter people's posts, it will get up their nose and is an example of what I implied. Moving along ... My last EC was confession that it might have muddled things. However, I think that you, and I, have improved the page - if only a little. I notice that In photography, shutter speed ... is at the start again. If there is another kind, can we disambiguate that? I think that this articles difficulties may arise in attempting to make in one in a series of– . I tried to make reference to other concepts from the POV of shutter speed. The article now explains shutter speed in a clearer way, but can we add something about the limitations of speed. By the way, are you sure that it is internationally accepted. Cygnis insignis 21:20, 3 September 2007 (UTC)
I figured you'd be happier to have your intentional insinuations removed than see them lead to a less civil discussion, but I take your point. Anyway, yes, camera standards are very international, since the manufacturers all target global markets, but there will still be come variations, too; I believe these numbers can be traced to an ISO standard of around 1960 (the APEX system), though they were in use much earlier, too. It is conventional in wikipedia articles to introduce the topic with the field that it is part of, hence the "In photography..." even though there may not be other interpretations. Dicklyon 23:15, 3 September 2007 (UTC)
The only convention, I am aware of, is having the title as close to the beginning as possible. It gets back to my 'article series' statement; it gives the reader an explanation of shutter speed, and restricts us to explaining only that. The tricky bit is explaining it within the context of photography, but also the mechanics of it. 5 'W's, to be trite.
  • "[The] Shutter speed [of a camera; in photograpy; is when] ..." - Maybe I'm being petty.
Is there another kind of shutter speed? –it should be mentioned. I thought the use of camera, in the first line, helped place the concept in context. Photography does that as well. Cygnis insignis 00:08, 4 September 2007 (UTC)

[edit] intro rewrite

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)

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)
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)
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)
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)
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)
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)
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)
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)
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)
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)
"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)
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)
Feel free to make a merge proposal. I might oppose it, but I'll think about it. Dicklyon 21:32, 4 September 2007 (UTC)

[edit] New sections proposed

I propose to add links to relevant external sites where shutter speed is explained. Examples are http://www.illustratedphotography.com/photography-tips/basic/shutter-speed and http://www.ephotozine.com/article/Camera-Shutter-Speeds-explained

I furter propose a section discussing the creative usage of shutter speed in photography, specifically discussing the visual effects which can be obtained through manipulating shutter speed. ← Manamarak 17:38, 1 December 2007 (GMT)

Be sure to read up on WP:EL, and see if you can include content in the article, with those sites as sources, rather than using external links per se. Good idea on the new section. Dicklyon 18:05, 1 December 2007 (UTC)
Thanks Dicklyon. I have added the above section, but I suspect I may have made a bit of a hash of the citation, if anybody can offer any suggestions, I would much appreciate it.
I will add another section relating to the difference between motion blur and camera shake when utilising slow shutter speeds unless there are any objections. Manamarak 21:35, 1 January 2007 GMT