help with locking the exposure (I think)

[michaelherrick]

I just purchased a rebel t2i, mainly for video, but ive always wanted a dslr camera to shoot photos too, and ive been playing around with it and cant seem to figure it out, im in full manual mode, but for some reason, when i shoot in live view, i notice the screen will go dimmer or brighter, depending on the brightness of the object, even though every setting is in manual. so if i point it at a darker object, it will automatically brighten it up a bit, and if i point it at the a light or something, the image will become darker. i see a bar on the screen moving across a little number line, i think its a called like exposure compensation or something, and i thought i figured out how to lock it, with the AE lock button, but i press that and nothing different happens. can someone please help me with this problem? it would be greatly appreciated, thanks

 

[MrBarney]

I just had to go and get my camera to check that - what do you know, it does! It will be the LCD compensating for the brightness so that it can still give you something to look at. It will have no bearing on the resulting photo.

The bar moving across the bottom is the light meter. The camera thinks that the "correct" exposure for any given scene is when the moving line is in line with the mid-point. In manual mode, you are responsible for the exposure, not the camera. Therefore exposure lock is meaningless. To adjust the exposure, modify the iso, aperture and shutter.

In just about any other mode the camera sets at least one of those for you to get the meter as close to the centre as it can. This is where exposure lock would work.

(cue someone promoting Understanding Exposure )

Ok, I'll do it: [ame="http://www.amazon.com/Understanding-Exposure-Photographs-Digital-Updated/dp/0817463003"]Amazon.com: Understanding Exposure: How to Shoot Great Photographs with a Film or Digital Camera (Updated Edition)…[/ame]

 

[michaelherrick]

ok, so its only the lcd screen adjusting brightness? that makes sense, because i didnt think something would automatically change the picture like that in manual mode. I understand all exposure and all the settings (shutter, aperture, iso) i just thought the camera was making it brighter or darker for some reason.

 

[JasonLambert]

If it's like the XSI then there should be a rectangle on the LCD screen. This is the area that the cameras meter is using. It WILL change the outlook of the image and can be moved with the directional keys.

 

[KmH]

I bet that's all covered somewhere in the users manual.

 

[Josh66]

If it's like the XSI then there should be a rectangle on the LCD screen. This is the area that the cameras meter is using. It WILL change the outlook of the image and can be moved with the directional keys.

Read the manual again. Start with Section 5 on page 95. (That's in the XSi manual - Section and page numbers are probably different in other manuals.)

That rectangle has nothing to do with metering. That's where it is focusing.

When in live view, the only metering mode you can use is Evaluative - so there is no 'zone' that you can move around. It's metering the entire scene.

(That section also describes how the screen automatically adjusts brightness, and how to disable that feature.) <-- Or maybe not...

 

[michaelherrick]

i cant find anything in the user manual that talks about brightening just the screen, it talks about an auto lighting optimizer that brightens the image if its to dark i guess, but nothing about the lcd

 

[Josh66]

It said something about a custom function to turn the auto brightening off...

Let me try to find it again...

 

[Josh66]

Hmm... Maybe you can't turn that off. I think that custom function is something different.

 

[michaelherrick]

i honestly dont mind it if all its doing is making the lcd screen brighter to see the photo better, as long as its not actually effecting the photo.

 

[Josh66]

I can see how it could be annoying though. Personally, I think it should reflect the settings you have dialed in...

It would make the live view pretty useless if you were going for a low-key shot, for example. It would try to brighten it up to make it look 'normal'. Wouldn't affect the actual exposure, but it might make you think you have the wrong settings...

 

[MrBarney]

I can only tell you what the 50D does, but I have this:

Manual p129: "under low light conditions the Live View might not reflect the brightness of the captured image".

Manual p117: "Exposure simulation displays and simulates how the brightness of the actual image will look".

I have exposure simulation in the menu under the second spanner icon, then Live View function settings. It seems to do exacly what O|||||||O would like it to do.

 

[fokker]

Yeah, there's a custom function that you can change to make the LCD either automatically compensate to a 'normal' level of brightness (what you have turned on) or you can set it to show exactly how the photo will look.

 

[Josh66]

Yeah, there's a custom function that you can change to make the LCD either automatically compensate to a 'normal' level of brightness (what you have turned on) or you can set it to show exactly how the photo will look.

That's what I thought... I don't have that camera though, so I couldn't try it... I was just looking at the manual online.