Shutter Speed (Technical)

[prodigy2k7]

So, lots of cameras have a fastest speed of lets say 1/4000 or 1/8000.

Logically speaking, thats...pretty fast :\
How long does it actually take for the shutter to fully open? Obviously it has to be fast enough so the whole picture is exposed right instead of one side being under exposed and the other side being properly exposed, right?

 

[Yahoozy]

well i think it takes about half the time to fully open and then half the time to fully close, but it could also mean that the shutter is completely open for, lets say 1/4000 of a second and the time it takes to open and close fully arent really counted

 

[Steph]

At those speeds the shutter is never fully opened. The second curtain starts travelling before the first as fully opened. The gap between the two curtains then travels across the frame to expose the picture evenly. And you don't need a very fast shutter speed for the shutter to work that way. Anything shorter than the flash sync speed (that's around 1/125s for many current cameras) will result in the shutter not opening fully.

 

[Bifurcator]

Right. I guess it's always been about that tho. By listening to 25 year old cameras the 1/125 sounds identical to 1/4000. There's a noticeable difference between the sound of 1/60 and 1/125 though - as well as all slower speeds.

Electronic shutters can flash-sync much faster too. Mine syncs at 1/2000 . But ES are silent.

 

[Do'Urden's Eyes]

1/2000 Bifurcator :| thats seriously your sync speed? What are you shooting? because i believe not even high end Canons sync at that speed. the 1DS MarkIII i think is only 1/250 flash sync. i know however that Nikon generally has faster sync speeds but 1/2000!

Yeah so what are you using?

 

[Big Mike]

Cameras that sync that fast don't use a traditional mechanical shutter. As mentioned, it's 'electronic'...meaning that the sensor is 'activated' for that short period of time.

Also, old 'leaf' type shutters could flash sync at any of their speeds.

 

[Bifurcator]

Yup, right you are Mike. Actually I read somewhere that mine has both a mechanical and an electronic shutter but I dunno when or how it decides if it's mutually exclusive. I assume however, they are both always used and the ES opens before the MS and closes after it for long exposures (I dunno, less than 1/200?) and the opposite case for faster exposures.

I'm not entirely sure but I think most bridge cameras will sync at any speed like that.

Right you are about leaf (and curtain?) shutters also but sometimes they missed and the occasional odd shot on some cameras will come out black or gradated. hehehe...

 

[Sw1tchFX]

My D70 has a electronic shutter, where the actual mechanics only go up to 1/90th of a second, but the camera can shoot up to 1/8000th with a flash sync at 1/500th.

 

[MarcusM]

Does anyone have a good link to a graphic image or flash movie depicting how a shutter opens/closes? I've always wondered.

 

[kundalini]

Not sure of the actuation of the shutter, all I know is that at 1/8000s you can freeze a bumble bee's wings.

 

[MarcusM]

Not sure of the actuation of the shutter, all I know is that at 1/8000s you can freeze a bumble bee's wings.

hehe, wow, that's cool.

Evolution was not kind to those suckers...look how tiny those wings are in comparison to their body, no wonder they have to flap those things so fast.

[/end of thread hijack]

 

[Bifurcator]

Does anyone have a good link to a graphic image or flash movie depicting how a shutter opens/closes? I've always wondered.

Sure, you can search and find them.

http://electronics.howstuffworks.com/camera4.htm
http://electronics.howstuffworks.com/high-speed-photography2.htm
http://electronics.howstuffworks.com/digital-camera5.htm#

etc. You can find more by actually searching.

 

[MarcusM]

http://electronics.howstuffworks.com/digital-camera5.htm#

etc. You can find more by actually searching.

Thanks. Not sure if you're being condescending, kinda sounds like it but it's the net so I could be interpreting it wrong.

I actually did search but didn't find anything so I figured rather than waste 15 minutes searching and not finding anything I would check with the knowledgeable TPFers to see if anyone already knows of a good link.

 

[Bifurcator]

Oh sorry, didn't mean to sound condescending. I just meant search and you shall find. It was a bit of a nudge but not meant condescendingly. After all I reserve claim to the title "Most Lazy Man On The Planet!" And probably would have founded the procrastinators club but just couldn't be bothered.


If you're searching and finding nothing how about a tutorial on searching - where and how?

 

[Do'Urden's Eyes]

I know if your flash has high speed sync you can sync it to any speed but the actual cameras SYNC SPEED is different is it not? Its the fastest shutter speed where at one point both curtains will be open. beyond this speed (around 1/200 on alot of canon models) when the shutters open they open a little slit that shines the light across the sensor by sliding accross it. Like i said alot of Nikon models are alot faster with sync speeds as switch pointed out.