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

[Don Miller]

Originally Posted by 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.

There is the option of taping the contacts after setting aperture. Or using a non-canon zoom.

[Bernard Racelis]

Originally Posted by Charles Wu

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

This is incorrect.
While the 'normal' phase detection AF operates at max aperture, the camera's contrast detection AF only needs -- contrast. It doesn't necessarily need a large aperture if there is enough contrast.

If you have a lens with max aperture of 2.8, and hit the AF button while shooting at 5.6 (regardless of whether the exposure is locked or not), it will stay at 5.6 if there's enough contrast, or by brightening the image by upping the ISO. It will only change to 2.8 if it's still too dark.

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

This is also incorrect.
If you lock the camera at the largest exposure, and there is not enough contrast (too dark), it will still brighten the image by upping the ISO.

The AF button is useful and accurate for pre-focusing before shooting.
But not useful while shooting.

[Mathieu Kassovitz]

Originally Posted by Bernard Racelis

This is incorrect.
While the 'normal' phase detection AF operates at max aperture, the camera's contrast detection AF only needs -- contrast. It doesn't necessarily need a large aperture if there is enough contrast.

If you have a lens with max aperture of 2.8, and hit the AF button while shooting at 5.6 (regardless of whether the exposure is locked or not), it will stay at 5.6 if there's enough contrast, or by brightening the image by upping the ISO. It will only change to 2.8 if it's still too dark.

Do you mean it keeps your previous setting (aperture) in any case?

Originally Posted by Bernard Racelis

This is also incorrect.
If you lock the camera at the largest exposure, and there is not enough contrast (too dark), it will still brighten the image by upping the ISO.

Does it keep the aperture? And the shutter speed?

Originally Posted by Bernard Racelis

The AF button is useful and accurate for pre-focusing before shooting.
But not useful while shooting.

Does it change the exposure values? In this case, which ones?

Merci.

[Bernard Racelis]

Originally Posted by Charles Wu

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

Another thing I tested is that if you lock the aperture at max aperture and there's not enough contrast because the area within the AF focus square is too bright (instead of being too dark), it will stop down the lens to increase contrast.

[Bernard Racelis]

Originally Posted by Mathieu Kassovitz

Do you mean it keeps your previous setting (aperture) in any case?

Does it keep the aperture? And the shutter speed?

Does it change the exposure values? In this case, which ones?

Merci.

If you have exposure lock on, then it will return to the locked aperture after the AF locks in.
For example, if the exposure is locked at 5.6 and it's too bright, it will stop down to a smaller aperture (ex 16) and change it back to 5.6.
If it's too dark, it will open it up to max aperture (ex 2.8) and return to 5.6.
If there's enough contrast, then it will stay at 5.6 while the AF is working and after.

The info display (aperture/speed/ISO) does not update while the AF working.
I cannot confirm what values the ISO or shutter (if any) are being changed to.
But you can hear the click as the aperture is stopped down or opened up, and another click when it returns to the locked setting.

[Mathieu Kassovitz]

Originally Posted by Bernard Racelis

Another thing I tested is that if you lock the aperture at max aperture and there's not enough contrast because the area within the AF focus square is too bright (instead of being too dark), it will stop down the lens to increase contrast.

Originally Posted by Bernard Racelis

If you have exposure lock on, then it will return to the locked aperture after the AF locks in.
For example, if the exposure is locked at 5.6 and it's too bright, it will stop down to a smaller aperture (ex 16) and change it back to 5.6.
If it's too dark, it will open it up to max aperture (ex 2.8) and return to 5.6.
If there's enough contrast, then it will stay at 5.6 while the AF is working and after.

Does it mean that the aperture changes only while the AF is working and returns to the initial locked aperture that we had chosen before?

Originally Posted by Bernard Racelis

The info display (aperture/speed/ISO) does not update while the AF working.
I cannot confirm what values the ISO or shutter (if any) are being changed to.
But you can hear the click as the aperture is stopped down or opened up, and another click when it returns to the locked setting.

I'd actually like to have information about the possibility to set and lock any aperture and shutter speed (1/50th).

Merci.

[Bernard Racelis]

Originally Posted by 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.

Right, when you go into movie mode, it will try to select a shutter at or near 1/focal length (example 1/80 with an 85mm lens), then select the aperture (example 5.6) and ISO.

When you you point the camera to a darker area (and the exposure is not locked), it will try to increase the ISO first, then pick a slower shutter speed -- but only up to a point -- it will still try to stay near 1/80 (say up to 1/50 but not slower), then select a larger aperture (example 2.8) and the shutter speed goes up back to or near 1/80) and adjust the ISO accordingly.

Now if you mount a 24mm lens, it will try to select 1/30 which is the minimum shutter speed. Therefore, you want to stay away from wide angle if you don't want too much motion blur. It will only select a higher shutter speed if it's already at or near lowest ISO (100) and the smallest aperture.

And, as Luis mentioned, with a zoom lens, it will adjust the speed to or near 1/focal length as you zoom in and out and adjust the ISO accordingly.

Now with a non-EF lens where the camera doesn't know the focal length, it seems to default to 1/40 or 1/50 -- for some people this may be close enough to the commonly used 1/60 setting for 30fps.

And it will go down to the minimum (1/30) when it's too dark and already at the max 3200 ISO. The LCD could show 1/10, but I don't think it actually goes down below 1/30 because the 'look' is the same between 1/30 and "1/10" -- there are no dropped frames, the exposure is the same, and it's not combining multiple frames into one blurred image (like the 'slow shutter' mode in other video cameras).

As already mentioned in another thread, it will go faster than 1/125. Unlike with minimum speed (where it shows a false 1/10 speed), you can actually see the exposure being adjusted as you point the camera at a brigher area and the speed goes faster than 1/125 and the ISO already at min 100 (the aperture is obviously not changing because it's a non-EF lens).



Then here's the kicker -- I mounted an EF 300mm lens and it's showing 1/320 (even while recording) which contradicts what's being said about the 1/125 limit ! Same thing with a EF 70-200 -- it goes up to 1/200. I've only done this indoors (pointing the lens at a flourescent light) -- I have yet to test this outdoors to confirm if the exposure is actually changing (between 1/125 and higher). It's more difficult to test this with an EF lens than with a non-EF lens (where you can manually select a larger aperture to force it to minimum ISO 100 and faster than 1/125 just by pointing it at a light. With an EF lens, I would need to shoot outside where it's really bright, with the lens (automatically) stopped down to F32 and minimum ISO 100 before it would go higher than 1/125.

[Mathieu Kassovitz]

What a mess . . . Isn't there any solution for simple control over aperture (no manual lenses) and over shutter speed?

[Tyler Ginter]

I have explained these steps in a little more detail here: How To Use Video Mode on the Canon 5D MK II on Vimeo

Please refer to Note 3. It is working perfectly on my camera to get manual control over my ISO and Lock my aperture to wide open. Once again the only way you can get your shutter to change is if you are in plenty of light (outside during the day) and you get your ISO locked to 100 then when you move the exposure compensation wheel you have manual control of your shutter... It's working perfect for all my tests and I'm happy with the results: http://tylerginter.smugmug.com/galle...34710937_p2uiT Your results may vary so sorry... :(

[Luis de la Cerda]

Tyler,

I watched your video and it's interesting. One thing I'd like to mention thoug is that you can lock settings in exposure simulation, as long as you use Av or Tv mode. What's frustrating though is that exposure simulation is nothing more than a simulation... You can change the aperture and it'll simulate the exposure level you'd get at that aperture, but actual lens aperture remains constant. :( Bummer!
One last thing I'd like to share is that auto exposure seems to skip several aperture options when it seeks the perfect exposure. For example, on my sigma 24-70 2.8 the apertures it seems to want to stick to are 2.8, 5.6, 16 and 32. This is also a pain because sometimes 5.6 is still too shallow and 16 is way to deep DOF-wise. Sometimes I find the camera wanting to shoot 1/30th f32 iso3200 in broad daylight, WTF!

Canon should be ashamed of themselves.

[Tyler Ginter]

As for the Av and Tv modes I figured that out and included those steps in Note 3 which you can read below the video. Those steps are working perfectly for me and here is an example to prove it. I shot these two examples at 1/30, ISO 1000 and F 3.5

Still frame extracted from video:
www.comcamdaily.com/5dmkii/still from video.PCT

Photo shot in manual mode:
www.comcamdaily.com/5dmkii/still photo.JPG

As you can see the DOF and Exposure are identical on both of these. This was all done under exposure simulation and I had complete control of my ISO and Aperture wide open. I do not have control of Shutter unless there is enough light to get my ISO down to 100 but in this case there wasn't enough light...

[Mathieu Kassovitz]

Originally Posted by Tyler Ginter

I do not have control of Shutter unless there is enough light to get my ISO down to 100 but in this case there wasn't enough light...

Perhaps pointing it to a light no?

[Tyler Ginter]

Originally Posted by Mathieu Kassovitz

Perhaps pointing it to a light no?

I think I need to do another video tutorial... This is so hard to explain without actually showing people how it works...

[Bernard Racelis]

Originally Posted by Tyler Ginter

It is working perfectly on my camera to get manual control over my ISO and Lock my aperture to wide open.

Originally Posted by Tyler Ginter

was all done under exposure simulation and I had complete control of my ISO and aperture

If I'm using an EF lens with a max aperture of 1.4, does the method allow you to select an aperture or are you required to use max aperture (1.4) only ?
Can you clarify ?

Also, does your method take into consideration that the camera defaults at or close to 1/focal length shutter speed, and that the shutter speed changes as you zoom ?

[Tyler Ginter]

Originally Posted by Bernard Racelis

If I'm using an EF lens with a max aperture of 1.4, does the method allow you to select an aperture or are you required to use max aperture (1.4) only ?
Can you clarify ?

Also, does your method take into consideration that the camera defaults at or close to 1/focal length shutter speed, and that the shutter speed changes as you zoom ?

Yes this method only works with the aperture wide open and yes the shutter speeds do play a roll in your zoom. Once again this is just a way to lock down your aperture so it is wide open and have manual control of your ISO. It is far more consistent than other methods I have tried. It isn't complete control but at least you can trust that your exposure won't change and your ISO won't go above what you want it to and your aperture can be locked to wide open so you can get the most out of your lens. When you are outside in daylight you also have the luxury of adjusting your shutter speed once your ISO drops to 100. Not perfect but it works for me and gives me all the control I need! :)