Canon 7D Mark II - some questions

[Valvebounce]

Hi Neuro.
Why are you confused, in AV the top dial will change the shutter speed as the camera will try to keep the 'ideal' exposure by adjusting the shutter speed when one changes the aperture using the top wheel! : ;D ;D
Ok tin hat on and nearly finished the fall out shelter! ;D

Cheers, Graham.

This is how my 7D2 was set up by Canon and I have not changed it. In Av mode:
- the top dial changes shutter speed

???

 

[Don Haines]

Funny, I have a 7DII in my hands right now, and in Av mode, the top dial changes aperture, and in Tv mode the top dial changes shutter speed.

Mikehit, in Av mode, The aperture has priority and the camera adjusts the shutter speed to try to match the aperture for best exposure. Note that as you click the wheel left, the aperture drops down step by step to the smallest number the lens will support, and the opposite occurs when you click the wheel to the right. It may look like you are changing the shutter speed, but you are not. What you are doing is changing the aperture and the camera recalculates the shutter speed to match it.

To prove the point, try this..... With the wheel set in one position, move the camera towards a brighter light source and see how the shutter speed becomes faster, and how it drops as you go towards a darker light source. The aperture does not change, but the camera is recalculating the shutter speed for the changes in light levels.

 

[hbr]

Funny, I have a 7DII in my hands right now, and in Av mode, the top dial changes aperture, and in Tv mode the top dial changes shutter speed.

Mikehit, in Av mode, The aperture has priority and the camera adjusts the shutter speed to try to match the aperture for best exposure. Note that as you click the wheel left, the aperture drops down step by step to the smallest number the lens will support, and the opposite occurs when you click the wheel to the right. It may look like you are changing the shutter speed, but you are not. What you are doing is changing the aperture and the camera recalculates the shutter speed to match it.

To prove the point, try this..... With the wheel set in one position, move the camera towards a brighter light source and see how the shutter speed becomes faster, and how it drops as you go towards a darker light source. The aperture does not change, but the camera is recalculating the shutter speed for the changes in light levels.

Hi Don,
Thought I'd learn something so I got mine out too. What you are saying is correct. But now see what happens when you half press the shutter button and turn the dials. The top dial will adjust both the shutter speed and aperture and the EC display stays in the center while the back button will adjust the shutter speed thus changing the EC setting. Neat. Pretty smart camera.

 

[Mikehit]

Funny, I have a 7DII in my hands right now, and in Av mode, the top dial changes aperture, and in Tv mode the top dial changes shutter speed.

You are correct - my typo

 

[Don Haines]

Funny, I have a 7DII in my hands right now, and in Av mode, the top dial changes aperture, and in Tv mode the top dial changes shutter speed.

You are correct - my typo

I made the same typo writing my response Fortunately, I noticed it before posting....

and then HBR posted.... and I learned something new.... One of the reasons why I like this forum....

 

[neuroanatomist]

Thought I'd learn something so I got mine out too. What you are saying is correct. But now see what happens when you half press the shutter button and turn the dials. The top dial will adjust both the shutter speed and aperture and the EC display stays in the center while the back button will adjust the shutter speed thus changing the EC setting. Neat. Pretty smart camera.

Not exactly.

In Av mode, the main/top dial controls aperture....only (and similarly in Tv mode it controls only the shutter speed). In Av or Tv, the quick/rear dial controls EC. Av and Tv are autoexposure modes, so for example, in Av when you change the aperture value, the camera will adjust the exposure to compensate and achieve the metered exposure. If you have selected an ISO setting other than auto, the only parameter the camera can adjust is shutter speed. But in auto ISO, as you stop down the camera will leave the ISO at 100 and lengthen the shutter speed until 1/FL (for FF, 1/1.6*FL for APS-C), then ramp up the ISO until it hits whatever the maximum setting is, then it will start using longer and longer shutter speeds.

EC is slightly different – there, you are telling the camera to achieve an exposure offset from the meter reading. Still, again using Av as an example, with a specific ISO set the camera must change the shutter speed as you change aperture, but with Auto ISO it can vary that instead.

 

[hbr]

Thought I'd learn something so I got mine out too. What you are saying is correct. But now see what happens when you half press the shutter button and turn the dials. The top dial will adjust both the shutter speed and aperture and the EC display stays in the center while the back button will adjust the shutter speed thus changing the EC setting. Neat. Pretty smart camera.

Not exactly.

In Av mode, the main/top dial controls aperture....only (and similarly in Tv mode it controls only the shutter speed). In Av or Tv, the quick/rear dial controls EC. Av and Tv are autoexposure modes, so for example, in Av when you change the aperture value, the camera will adjust the exposure to compensate and achieve the metered exposure. If you have selected an ISO setting other than auto, the only parameter the camera can adjust is shutter speed. But in auto ISO, as you stop down the camera will leave the ISO at 100 and lengthen the shutter speed until 1/FL (for FF, 1/1.6*FL for APS-C), then ramp up the ISO until it hits whatever the maximum setting is, then it will start using longer and longer shutter speeds.

EC is slightly different – there, you are telling the camera to achieve an exposure offset from the meter reading. Still, again using Av as an example, with a specific ISO set the camera must change the shutter speed as you change aperture, but with Auto ISO it can vary that instead.

Thanks Neuro,
For the past 8 years I have only used the "M" mode. I have never used the "P," "AV," or "TV" modes. Currently I have the "Highlight Tone Priority" set from my last shoot. That automatically sets the ISO to 200. What I was trying to say was that after I half pressed the shutter button in these two modes was that the EC (?) bar remained at 0 and both the aperture and shutter speed both moved when I used the top dial. That surprised me. Using the back button worked as I would have expected, only changing the shutter speed in the AV mode and the aperture in the TV mode and the EC (?) bar moved accordingly, allowing me to darken or lighten the results from what the camera had automatically selected.

Make any sense? I sometimes have trouble writing what my mind is thinking. I think that agrees with what you said in your last sentence.

 

[hbr]

So right now I am in my study in not so great light. I have the 50 mm f/1.8 on the camera. I am in the AV mode. Using the back button I set the aperture at f/1.8. The camera selected 1/20 sec. Moving the camera slightly will automatically change the shutter speed. Half pressing the shutter release button will not change these settings. If I take this shot now I should have the proper exposure.
But, if after half pressing the shutter release button I turn the top dial, to the right and select an aperture of, say, f/32 the shutter speed will change to keep giving me the proper exposure, let's say it changes to 1/13 sec. By turning the back button I can increase or decrease the shutter speed and the point on the EC bar will now move either up or down, (which is changing the shutter speed).

I don't know if there is any value to knowing this except that if I am using either of these modes, I can compensate for an overly bright or dark picture.

 

[neuroanatomist]

For the past 8 years I have only used the "M" mode. I have never used the "P," "AV," or "TV" modes. Currently I have the "Highlight Tone Priority" set from my last shoot. That automatically sets the ISO to 200.

HTP limits the lowest available ISO to 200, but doesn't automatically set it there. You can change the ISO to higher values with HTP. ISO 100 isn't available because the camera is actually exposing at a 1-stop lower ISO than it's set to (e.g. if you set ISO 800, it exposes at 400), then it applied a tone curve to push everything but the highlights up a stop).

What I was trying to say was that after I half pressed the shutter button in these two modes was that the EC (?) bar remained at 0 and both the aperture and shutter speed both moved when I used the top dial. That surprised me.

That's the whole point of Av – you pick the aperture and let the camera worry about the rest to give you a metered exposure. As I said, in Auto ISO, that may change and not the shutter speed.

Using the back button worked as I would have expected, only changing the shutter speed in the AV mode and the aperture in the TV mode and the EC (?) bar moved accordingly, allowing me to darken or lighten the results from what the camera had automatically selected.

Exactly how EC works. But as above, depending on settings shutter speed may not change.

 

[weixing]

Hi,
Summary:
P Mode
Main Dial (Top Dial) let you change a different set of Shutter Speed and Aperture values.
Aperture and Shutter Speed will change accordingly. ISO might also change if in Auto ISO mode.
When adjust EC using Quick Control Dial (Rear Dial), Aperture or Shutter Speed will change accordingly. ISO might also change if in Auto ISO mode.

Av Mode
Main Dial (Top Dial) let you set desired Aperture.
Shutter Speed or ISO (if in Auto ISO) will change accordingly.
When adjust EC using Quick Control Dial (Rear Dial), Shutter Speed or ISO (if in Auto ISO) will change accordingly.

Tv Mode
Main Dial (Top Dial) let you set desired Shutter Speed.
Aperture or ISO (if in Auto ISO) will change accordingly.
When adjust EC using Quick Control Dial (Rear Dial), Aperture or ISO (if in Auto ISO) will change accordingly.

M Mode
Main Dial (Top Dial) let you set desired Shutter Speed.
Quick Control Dial (Rear Dial) let you set desired Aperture.
ISO (if in Auto ISO) will change accordingly.
When adjust EC (only available in Auto ISO), ISO will change accordingly.

Have a nice day.