EOS 70D Video manual settings ISO limitations for sunlight

[moonlight33]

Working with EOS 70 D. 18-55mm lens, shooting at 55. Shooting field/scenic video in very bright conditions (not directly facing the sun). Trying to keep aperture between F8-F11 to maintain sharpness/depth of field (previously had problems with F32.) 24 FPS. In manual setting, working with 50 shutter speed, and was unable to set exposure correctly, had to utilize F16 to even come close (which was outside my goal of F8-F11) and it was still over exposed. This is because the ISO would only go to 100, not any lower. However, when I did a video test on Automatic, the exposure was perfect. Info from the camera shows it was shot also at 24 fps. Manual and Auto both sRGB. I can only assume that the auto system increased the shutter speed. It is hard for me to decipher if this impacted the movement in the video (of the waves), if there was jumpy movement, because the wind had picked up and was bouncing the camera around on the tripod. I am trying to use manual to keep the ss at 50 for this reason. How do I shoot manual in high light conditions? Thanks!

[p4pictures · Accepted solution]

Using the "correct" shutter speed to follow the 180 degree shutter angle rule often means that you will need to use some kind of neutral density filter on the lens to reduce the available light. Most popular are the variable ND filters, these are effectively two polariser filters in the same mount, and by adjusting the angle of one to the other you make the filter darker or lighter. This allows you to set the shutter speed, aperture and ISO you need and in bright light you can the reduce the ambient light with the ND filter to get the correct exposure. Do take care with choosing a variable ND filter, inexpensive ones often have a point where the angle between the two polarisers results in a cross shaped effect over the image as you approach maximum darkness of the filter.

This image below is an example of the cross over effect you with a cheap variable ND filter. 

Note: 

The 180 degree shutter rule is the one that says the shutter speed should be double the frame rate, so for 30fps you use 1/60th and for 25fps you use 1/50th. This 180 degree shutter angle is claimed to give the most effective looking movement of the subject. 

[stevet1]

moonlight33,

As Brian said, a lot of people will use an ND filter to cut down on the light to prevent overexposure in bright sunlight. I've never used a variable ND filter myself, but I have read of people using a 3 stop and it seems to work pretty well, I think.

Steve Thomas

[moonlight33]

Thank you for the very helpful response and image above.  As a previous film photographer, I have a skylight filter on that camera lens--how does a skylight filter translate to my digital system and will it help with this video problem? RE: the ND filter, if I purchase a variable one, which is a great suggestion, will I see this cross over effect before starting to film so I can readjust it? Or, will it appear solely with replay of the footage? Thanks!

[moonlight33]

Thanks! Most appreciated.

[p4pictures]

Typically skylight filters were used as a lens protection filter and to slightly warm up images on film. They can still be used for protection but the warming effect is not needed with modern auto white balance on a digital camera. 

To avoid the risk of vignetting at the edge of wide angle shots I would remove the skylight filter and only use the variable ND. 

With a variable ND you will be able to see the cross as per my photo on the camera LCD. This means you can turn the filter a little until the cross disappears and maybe small adjustment of aperture will be needed. 

[moonlight33]

Thank you for the expertise, very much appreciated.👍