Tricks of controlling 5D mark II + EF lenses exposure manually

[Charles Wu]

I fonund some tricks to select the ISO, shutter speed, and aperture manually.

1. Setting to M mode. Use your hand to cover the lens, controlling the amount of light income. You would see the ISO going up and the aperture, shutter going down.

2. Remove your hand in bright light, you would see the ISO going down and the shutter going up quickly within 1 second. Press the AE lock "*" immediately. Because of the AE adjustment order is ISO, followed by shutter speed, followed by aperture. If you can press the AE lock within 1 second, you can lock the changing ISO, shutter, and aperture in certain values.

3. If you can seize the timing of pressing AE lock, you may lock the exposure values you want. Combine with the control of light income, you can get almost every exposure values you want. Just like controlling the exposure manually, althouth it may be troublesome.

This method can reserve all functions of 5D mark II, including contrast-based AF and shooting pictures during recording.

I am from Taiwan and my English writting ability is not good. I have written detailed description in Chinese. I hope someone can translate it and post here.

The full article:
http://www.hd.club.tw/thread-17068-1-1.html

Best Reguards.

Charles Wu

[Jon Fairhurst]

Hello Charles,

I think 1/30 shutter is the slowest possible speed when shooting video.

At 30 fps, if the shutter is open 100% of the time (360 degrees), the result is 1/30 seconds.

This assumes that the sensor is reset to 0 after each frame.

You can simulate longer than 1/30 in post with motion blur (blending frames.)

[Christopher Witz]

I've seen it dip down to 1/20th....

[Jon Fairhurst]

Originally Posted by Christopher Witz

I've seen it dip down to 1/20th....

I wonder if this is real though, unless the camera is dropping frames. =8-o

1) The shutter opens and the sensor starts collecting light.
2) 1/30th of a second later, the information is read from the sensor
3) The sensor is reset.
4) Go back to step 1 and repeat.

You can fake a longer shutter by not resetting all the way to black in step 3 above, but that's not really a 1/20th shutter. It's a frame blend, and you can do that with much better control in post.

The bottom line is that you can't really expose longer than your frame to frame interval. 1/30th on a 30fps camera is already 360 degrees, and that's as far as it goes.

That the screen says something longer than 1/30th is another story. :)

[Don Miller]

I haven't seen any value I want. On fast ef lenses, I typically see: wide open, f2, f 5.6, fully stopped down.
What are you guys seeing?

[Don Miller]

Originally Posted by Christopher Witz

I've seen it dip down to 1/20th....

Well, we are almost certainly seeing shutter speeds much higher than specified.

But I do think the shutter speed momentarily reported may be some sort of intermediate value before the actual value is set. Clearly the code setting movie auto exposure is not refined.

Is there any other way to see exposure value other than for several seconds after AE lock?

[Don Miller]

Originally Posted by Charles Wu

4. I found in M mode, the lowest shutter speed is 0.8 sec. In Tv and Av mode, the lowest shutter speed is 1/5 sec. Quite different from previous articles.

I'm sorry to say I'm skeptical. I believe you are seeing the camera value that are changed when you press record. The only way I've found to set exposure values is with the camera actually recording.

[Chris Hurd]

According to Canon, shutter speed during video mode is limited to a range between 1/30 and 1/125.

[Charles Wu]

Originally Posted by Jon Fairhurst

You can simulate longer than 1/30 in post with motion blur (blending frames.)

Yes, I really see the blending frames. I konw that is simulate effect. But it can incresae the exposure.

Originally Posted by Jon Fairhurst

I believe you are seeing the camera value that are changed when you press record.

Yes, you are right. I just mean the camera value when I recording. I'm sorry for the misunderstanding.

I think I should delete the item 4. "I found in M mode, the lowest shutter speed is 0.8 sec. In Tv and Av mode, the lowest shutter speed is 1/5 sec. Quite different from previous articles." to prevent out of focus.

Item 1.~3. is uesful and proven by other 5D2 uses in Hong Kong and China who read my detailed prescriptions of Chinese version. I suggest 5D2 owners can try it.

Thanks for all replies and corrections. And sorry for the limitation of my English expression.

[Don Miller]

Originally Posted by Chris Hurd

According to Canon, shutter speed during video mode is limited to a range between 1/30 and 1/125.

I'm satisfied that shutter speeds go much higher.

[Don Miller]

Originally Posted by Charles Wu

This method can reserve all functions of 5D mark II, including contrast-based AF and shooting pictures during recording.

Anyone able to keep exposure values when doing AF? I find this resets exposure.

[Charles Wu]

I think this is because the camera's AF system need large aperture to help focus.

If you lock the camera with the largest aperture, it may not change the exposure values.

[Don Miller]

Originally Posted by Charles Wu

I think this is because the camera's AF system need large aperture to help focus.

If you lock the camera with the largest aperture, it may not change the exposure values.

Thanks, I'll keep working on it.
Maybe I'll need to learn Mandarin to properly use my camera :)

[Mathieu Kassovitz]

Anyone for translation? For resume?

Merci

[Luis de la Cerda]

One thing I've noted is that even if you lock exposure, if you change the focal length of the lens during the recording the shutter speed and iso will change. The lens unlock technique should be able to overcome this, but the zoom ring tends to be so tight that you either end up completely unscrewing the lens or snapping it back on.