Exposure changes in Full Manual Mode(Creative MM).

B

BhambuNath

Well-known member
Hello Friends,

In Creative Movie Mode with full manual controls and Manual focus when I zoom in I see the exposure changing as image gets brighter with the zoom in. I think the image should become darker as the aperture closes but it is happening opposite.

Just to make sure that the aperture is locked in as I zoom, I set the aperture to 6.3. With this aperture when I zoom in , the image still starts to get brighter without any change in aperture.

Is this way it is suppose to happen or I'm doing something wrong?

Thanks.
 
I was wondering the same thing. Everyone is saying to go into Creative movie mode, and to the M setting. But when i do this, i cant lock the exposure! I can only change the aperture and shutter speed. How do you lock exposure in M setting.
When i change the setting to S, then i can lock the exposure, but why not in M mode.

thanks :)
 
Thanks Ben, did not know about this property of zoom lenses.

Chris, you lock the exposure with aperture, shutter and ISO. If you set these things to their respective values and do not zoom, your exposure will stay put(if the light conditions stay consistent).
 
Isn't it supposed to get darker as you zoom in, like the OP said?

In addition to being in creative mode, you have to set what type of exposure metering in the menu to full manual instead of priorities.
 
Yes, but as Ben said that it's the property of zoom lenses, so it will happen in any mode if you are zooming in or out...

In Creative movie mode you have to set the exposure to M mode for full manual control.
 
BhambuNath said:
Chris, you lock the exposure with aperture, shutter and ISO. If you set these things to their respective values and do not zoom, your exposure will stay put(if the light conditions stay consistent).
Click to expand...


what if you are in a situation where the light does change? being outside for example, I dont want the exposure to change as i move the camera.
 
This has been discussed at some length in more than one thread.

As you zoom in the image should darken (due to optical laws), unless the camera compensates by widening aperture during the zoom, if the aperture isn't full open already. It does seem to compensate to maintain a constant effective aperture, not necessarily in totally smooth steps. With the original firmware it also seemed to compensate even when aperture was wide open, presumably by changing ISO. With the upgrade firmware, that no longer seems to happen.

So what's the firmware version?
 
As for exposure lock in full manual - well, it's locked already at the settings you've set, so you wouldn't expect exposure lock to work.
 
i have the updated firmware 1.1.

I get the fact that the lens compensates with light by changing its aperture, but when you are in the M setting, it only lets you lock the shutter speed and aperture. Not the exposure, but in other modes such as the S setting, it lets you lock the shutter and exposure settings, but not the aperture.
 
Exposure consists of aperture, shutter speed, and ISO. In full manual mode you are setting all three. There's nothing else to lock.
 
sorry for the miss understanding, you are correct. I got thrown off, when the exposure levels started to change, but i guess its locked
 
Exposure consists of aperture, shutter speed, and ISO. In full manual mode you are setting all three. There's nothing else to lock.
Click to expand...
Getting a bit off topic now we've sorted that out, but I guess one could go further and say that it's not just aperture, shutter, and ISO, but also it's light transmittance of the lens (variable by ND filters on the front) and the illumination applied to the scene (eg additional lighting). If you're going to be using the GH1 in broad daylight especially sunlight, you're likely to need an ND filter or two, or a variable one, so you set aperture shutter and ISO to your requirements, then cut down the incoming light if the metering shows overexposure at those settings, by using an ND filter. Or if in poor light, you set aperture shutter and ISO then add lighting to get the exposure correct.
 
It is very difficult to get totally "bumpless" zoom with the 14-140, it must be something to with the design, you can get some bumpless zoom, but from 14-140 in one go, doesnt matter how much you stop down, what you lock, what firmware, you seem to get a bump. IMO, its better to lock exposure in s or a cmm and zoom, seems to bump less, not sure why!
 
chrismagicc said:
sorry for the miss understanding, you are correct. I got thrown off, when the exposure levels started to change, but i guess its locked
Click to expand...

I was confused by this too. Wasn't expecting the exposure meter to indicate changing levels when the AE lock was engaged in manual mode. But it makes sense that it does -- helps in setting aperture, shutter and ISO to get proper exposure.
 
Yeah this has been discussed a couple of times already. And I even conducted a test to show that the stepping people are seeing is only in the preview and goes away when it is recording.
 
And I conducted one that showed it was there in the recording - but after upgrading the firmware, I can no longer see the problem (and obviously, having seen the problem clearly before, I know what I'm looking for).

I still think there should be auto ISO as an *option* in full manual mode. I know I want this shutter speed, I know I want this aperture, now I want the GH1 to compensate any modest scene illumination changes by smoothly varying the ISO, coupled with exposure compensation setting so that if I want, I can have the scene over-exposed a little by a constant amount as the light changes. Seems an obvious thing to have, which wouldn't affect anyone wanting to do the job 'properly' with fixed ISO of their choice.
 
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