When is manual not really manual?

[C.J. Cookson]

I had an earlier thread about flickering in manual when using the xl1s. I finally received a response from technical support who confirmed that, even in manual, the camera does not function as a fully manual camera "for full manual control and total creative freedom"!

They suggested that I might try putting the ND filter on in manual which might be able to lock exposure to give me full manual control. Has anyone experimented with this and how successful is it? It seems mind boggling that manual means exposure can still go up and down on it's own!

[Dean Sensui]

With my XL1s setting the camera in manual always kept exposure properly locked and the audio levels consistent.

Holding focus during a zoom, however, was a different matter. I finally got a manual lens to solve that problem.

Dean Sensui
Base Two Productions.

[C.J. Cookson]

I asked Tech Support why, when in manual mode, the exposure bar appears in the top left of the screen, the same as in AV. They replies that manual is not fully manual, and that the camera, even when fixed on a tripod in constant lighting and no camera movement, will compensate up and down as required if the actors move a bit.

It seems strange that the only suggestion they could give for full manual control was to use the ND filter and then compensate for the darkness by adjusting the manual controls, especially if you are shooting in low light and don't have that much to play with! Do you have an exposure bar in the top left which goes up and down if you move something in front of the camera?

[Dean Sensui]

I also get that same exposure meter in the upper left corner. However, there's no change in exposure.

It shouldn't compensate at all, in fact.

Check to make sure that your gain is set at something other than "A", either to -3, 0, +6, etc. With the gain set on "A" you'll get some exposure compensation.

Hope this helps.

Dean Sensui
Base Two Productions.

[Don Palomaki]

The XL1 uses a lower center weighted averave metering system. Thus if bright/dark objects move within the image the exposure could change even if the overall scene content remains the same.

Zooming or panning could cause image changes that effect weighted average expsoure metering.

As Dean states, the gain setting is effective in manual mode. Thus you can have the gain in automatic mode while shutter and aperture are set manually.

[C.J. Cookson]

Thanks for the advise guys - it's a lot clearer than tech support!

For the record, no panning, zooming, light changes, autofocus nor gain were used, but the "lower center weighted average metering system" sounds a good explanation which, I assume means that the camera helps keep your manual settings by adjusting the exposure as needed.

So, back to my original concern, which was the exposure flickers now and again. If the camera's okay, I can probably put that down to mains-power fluctuations, and use just batteries, meaning my camera doesn't have to go in for repair!

Thanks again.

[Rob Lohman]

Don,

Isn't it so that the weighting alters the exposure METER ONLY!?!
I can't remember ever seeing my camera changing to compensate.
Ofcourse if a bright/dark object is moving your exposure will
change due to the light levels changing, and thus the meter will
change as well.

Or am I wrong in this?

[Don Palomaki]

With the camera image brightness is a product of aperture, shutter, and gain - just as with photography the density on film is a combination effect of aperture, shutter and processing (i.e., push processing).

If in totally manual mode, including manually set gain, the expsoure should hold. Zooming could cause a change if you get into the range where the minimum aperture of the lens changes.

With gain on Auto, there still is a degree of automatic exposure even through aperture and shutter are set manually, changes in image content brightness distribution might change the effective exposure via the automatic gain component due to the lower-centerweighting.