AE Lock on 5D mk 2

[Lon Howard]

Yesterday I started trying to use the AE Lock button on the 5D mk 2. The primary purpose (for now) is to prevent skies from being blown out when the main subject is in a darker portion of the frame. I will say that the function works marvelously - but only when it works!!

What I mean by that is that when I get the exposure locked (shown by the * icon in the viewfinder), most of the time it unlocks itself before I can get the image recomposed and re-focused. Sometimes it works but most of the time it will unlock.

Am I just not fast enough? It's not so bad when handholding but if on a tripod it's very hard to meter the sky, recompose and refocus on your subject, all in about 3-4 seconds. It's further complicated by the fact that I like to use the two second timer so I don't shake the camera; and even more so when I'm on my knees and trying to look up through the viewfinder. It gets real tiring, real fast; especially for these old joints .

In some places I've read, it says to keep the shutter button halfway down after you've metered the sky (or where ever), but it seems to me that if you've pointed the camera at the sky and pressed the shutter button halfway down, and never re-focus, then your subject will be out of focus, so I don't see how that helps. As I said, I just started this adventure yesterday and so I don't have a lot of images to look over - just trying to use (gasp ... ) LOGIC.

By googling around, I did find one solution that seems to work. In Av (my normal mode), meter the sky and remember the f stop and shutter speed. Then switch to manual mode and apply those same settings, focus and frame normally and take the shot. All the shots I've taken using this method seem to have turned out wonderfully, and I must say it's much more user friendly than trying to make AE Lock work for me.

But I know I'm missing some REALLY important here, and I'd love to know what it is.

Sleepless near Seattle ...

[Colin Southern]

But I know I'm missing some REALLY important here, and I'd love to know what it is.

Hi Lon,

Between you and me (and everybody else reading this), I NEVER use AE Lock - I find it far easier to just move the quick control dial a few clicks to dial in a little bit of negative exposure compensation - take the shot - and if the screen is still blinking (to indicate blown highlights) (in important areas) then I just dial in a bit more.

The 1Ds3 has a setup option to change the length of the various timers, but not sure if the 5D2 has that option.

[Lon Howard]

Hi Lon,
Between you and me (and everybody else reading this), I NEVER use AE Lock - I find it far easier to just move the quick control dial a few clicks to dial in a little bit of negative exposure compensation - take the shot - and if the screen is still blinking (to indicate blown highlights) (in important areas) then I just dial in a bit more.

I just tried that Colin, and it works equally as well.

The 1Ds3 has a setup option to change the length of the various timers, but not sure if the 5D2 has that option.

I don't see that in the 5dmk2 manual. Under Live View you can apparently lock exposure for 16 seconds, but it doesn't apply if using the viewfinder.

Thanks Colin! The AE Lock thingy is de-mystified, at least a little.

[inkista]

Try reading this article. I suspect that you're using the half-press on the shutter button to get focus lock, and thereby losing the AE lock. After you hit *, you have to hold the shutter half-press if your buttons are set up the default way. This is another reason I like back-button autofocus--putting the AF function on to the back button then frees up the shutter halfpress to be used solely for AE lock, instead of doing AE/AF lock double-duty.

[Lon Howard]

Try reading this article. I suspect that you're using the half-press on the shutter button to get focus lock, and thereby losing the AE lock. After you hit *, you have to hold the shutter half-press if your buttons are set up the default way. This is another reason I like back-button autofocus--putting the AF function on to the back button then frees up the shutter halfpress to be used solely for AE lock, instead of doing AE/AF lock double-duty.

Thanks very much for this, Kathy. A real coincidence but the article you linked to was what gave me the idea to just press the shutter halfway to meter the sky and then change to manual mode, using the same aperture and shutter speed settings, which then allowed me to re-focus without changing the exposure. But after you posted the link I did go back to the article and then moved on to another article by Mr. Winston on back-button AF. After that I moved back and forth between the two articles, trying to digest and reconcile the two of them. Very heavy reading, I will admit for one with no real background. I am ready for some shut-eye but I'll be out there with the camera tomorrow to see if I really understood what I read. Thanks for the shove. Cheers!