Total control over 'Shutter' speed 1/40 to 1/8000 and 'ISO' workaround.

Jon Fairhurst · December 6th, 2008, 01:51 AM

Quote:

Originally Posted by Tyler Franco

Somehow, I think there is a great possibly that you would have never gotten the shot had you had to have hauled around a monitor with a camera mounted on rails with a follow focus! Although, if you could have, I'm sure it would have looked great. :)

Too true!

Tonight I was thinking about the film, "The Spanish Prisoner." The 5D is the perfect high-quality stealth video camera for the undercover Japanese tourist. A RED ONE on rails just wouldn't cut it!

Lawrence Spurgeon · January 1st, 2009, 07:00 PM

Even with no physical first/second curtain, there is a limit to how fast the sensor can be read. I can't imagine it can go faster than 1/1000 sec. and probably more like 1/400 as a limit. I'm guessing part of it is camera is not reporting reality.

Andreas Neubert · January 2nd, 2009, 09:37 AM

Recording with the cam as much as is could - I don´t trust the displayed values eighter.

Using the (*) exposure lock, it even displays wrong apertures!!!
I just tried it on my 50mm f1,4 - and the cam displayed f2.0 when wide open and vice versa!

The displayed values are at least not reliable!
And I the feeling that shutter values are complete nonsense - you get even longer shutters than 1/30!!!
Gives you the impression that it diaplays just what it would use if you took a photo during video.

Daniel Lipats · January 2nd, 2009, 09:59 AM

You are right about longer shutter speeds than 1/30. I believe 1/20 is the lowest it can do. It will let you dial values even lower (up to 30 second long shutter) but it won't make any exposure difference in video mode.

It still does not make much sense. It may be slowing down the framerate to allow longer exposures.

I really have not taken the time to measure but I believe the shutter values are accurate down to 1/30 at least.

Mathieu Kassovitz · January 2nd, 2009, 10:08 AM

Quote:

Originally Posted by Andreas Neubert

Gives you the impression that it diaplays just what it would use if you took a photo during video.

Is this find totally accurate?

Jon Fairhurst · January 2nd, 2009, 12:40 PM

Check this thread for a shutter analysis. Watch the video to see the results:
http://www.dvinfo.net/conf/canon-eos...r-exposed.html

We didn't test 30fps or lower, but posted our findings for 1/40 to 1/500.

In summary
* 1/40 and 1/50 yield 1/45 or so.
* 1/60, 1/80, and 1/100 all yield 1/80, with the 1/100 setting becoming artificially darker.
* 1/125, 1/250 and 1/500 were accurate.

All tested with a Nikon lens at 100 ISO.

Andreas Neubert · January 3rd, 2009, 12:09 AM

Quote:

Originally Posted by Daniel Lipats

You are right about longer shutter speeds than 1/30. I believe 1/20 is the lowest it can do. It will let you dial values even lower (up to 30 second long shutter) but it won't make any exposure difference in video mode.

With 30p, an exposure longer than 1/30s is impossible.

Quote:

It still does not make much sense. It may be slowing down the framerate to allow longer exposures.

No it doesn´t, audio & movements clearly show that.

Daniel Lipats · January 3rd, 2009, 12:59 AM

Just took the time to do some quick tests. I don't have any charts here so I just printed something. Its only meant to demonstrate exposure with different shutter values.

There is something strange is going on for sure. It must be manipulating the framerate or the values are wrong. I did not try any movement test. One other possible explanation is that past 1/30 it only adjusts gain.

ISO value remained at 3200.

Jon Fairhurst · January 3rd, 2009, 02:15 AM

You might be right about only manipulating gain. From my tests of 1/60, 1/80 and 1/100, the smear is the same for all three, but the gain varies.

Bernard Racelis · January 3rd, 2009, 05:56 AM

Quote:

Originally Posted by Daniel Lipats

One other possible explanation is that past 1/30 it only adjusts gain.

ISO value remained at 3200.

The LCD display only shows up to 3200, but according to the instruction manual (page 123):

Quote:

For movie shooting, the ISO speed is set automatically. ISO 100 is set as standard, then it can increase up to ISO 6400 (expandable to H1: 12800) for low-light conditions.

When you enable ISO expansion and shoot in low light, you'll see that the image brightens even more (as the LCD shows slower than 1/30 speed) but becomes noisy.

If the LCD shows around 1/15, it's 6400.
If it's 1/8, it's 12800 (if ISO expansion is on).
But the actual shutter speed is 1/30.

Anything above 3200 becomes noisy, so I try to keep my shutter speed (indicated on the LCD) not dip below 1/30 (by underexposing using the exposure compensation dial).

January 1st, 2009, 07:00 PM	#32
Lawrence Spurgeon Regular Crew Join Date: May 2006 Location: Honolulu, HI Posts: 31	This can't work... Even with no physical first/second curtain, there is a limit to how fast the sensor can be read. I can't imagine it can go faster than 1/1000 sec. and probably more like 1/400 as a limit. I'm guessing part of it is camera is not reporting reality.

January 2nd, 2009, 09:37 AM	#33
Andreas Neubert New Boot Join Date: Dec 2008 Location: Munich, Germany Posts: 23	I don´t trust shutter display too! Recording with the cam as much as is could - I don´t trust the displayed values eighter. Using the (*) exposure lock, it even displays wrong apertures!!! I just tried it on my 50mm f1,4 - and the cam displayed f2.0 when wide open and vice versa! The displayed values are at least not reliable! And I the feeling that shutter values are complete nonsense - you get even longer shutters than 1/30!!! Gives you the impression that it diaplays just what it would use if you took a photo during video.

January 2nd, 2009, 12:40 PM	#36
Jon Fairhurst Inner Circle Join Date: May 2006 Location: Camas, WA, USA Posts: 5,513	Check this thread for a shutter analysis. Watch the video to see the results: http://www.dvinfo.net/conf/canon-eos...r-exposed.html We didn't test 30fps or lower, but posted our findings for 1/40 to 1/500. In summary * 1/40 and 1/50 yield 1/45 or so. * 1/60, 1/80, and 1/100 all yield 1/80, with the 1/100 setting becoming artificially darker. * 1/125, 1/250 and 1/500 were accurate. All tested with a Nikon lens at 100 ISO. __________________ Jon Fairhurst

January 3rd, 2009, 12:59 AM	#38
Daniel Lipats Major Player Join Date: Feb 2006 Posts: 260	Just took the time to do some quick tests. I don't have any charts here so I just printed something. Its only meant to demonstrate exposure with different shutter values. There is something strange is going on for sure. It must be manipulating the framerate or the values are wrong. I did not try any movement test. One other possible explanation is that past 1/30 it only adjusts gain. ISO value remained at 3200. Attached Thumbnails

January 3rd, 2009, 02:15 AM	#39
Jon Fairhurst Inner Circle Join Date: May 2006 Location: Camas, WA, USA Posts: 5,513	You might be right about only manipulating gain. From my tests of 1/60, 1/80 and 1/100, the smear is the same for all three, but the gain varies. __________________ Jon Fairhurst

January 2nd, 2009, 09:59 AM	#34
Daniel Lipats Major Player Join Date: Feb 2006 Posts: 260	You are right about longer shutter speeds than 1/30. I believe 1/20 is the lowest it can do. It will let you dial values even lower (up to 30 second long shutter) but it won't make any exposure difference in video mode. It still does not make much sense. It may be slowing down the framerate to allow longer exposures. I really have not taken the time to measure but I believe the shutter values are accurate down to 1/30 at least.