Puzzled by the histogram

[tribal-warrior]

Today, I was experimenting with my G2's histogram which is actually the first time that Ive used a histogram (still fairly new to digital cameras!) From what Ive read on the internet, using the histogram seems like a viable alternative to taking light meter readings (which is what I'm used to doing with my film equipment.)

When using the histogram, I would expect that the display would change as I adjust the aperture or shutter speed. However, this does not happen. Say for example, I point the camera at a scene which the histogram has indicated underexposure. I open up the aperture (by one stop, two stops, even four and five stops) and there is no significant change in the histogram display. It looks pretty much the same.

Same deal when I point the camera at a scene which the histogram interprets as being correctly exposed. No matter how much I adjust the aperture or shutter speed, the scene will still be correctly exposed, according to the histogram.

Is there something that I'm missing here? By the way, the camera has been set to M.

 

[deejjjaaaa]

live histogram typically reflects what you see in EVF / on LCD and that is

1) jpg (not raw data) = set UniWB

and

2) lens settings and sensor reading parameters are adjusted by firmware so that you can see the scene as clear as possible, but not exactly as the shot will end up = so you need to force the camera to display the scene (and live histogram) as close to the real situation as possible instead as convenient as possible... that is achieved I guess by using "Constant Preview" and/or (depends on the mode M, A, etc) pressing some preview/display button - read the manual what your cameras has for that

 

[tribal-warrior]

read the manual what your cameras has for that

There is actually very little information about the histogram in the manual. There are some illustrations that indicate what underexposure, correct exposure and overexposure look like in the histogram and that's basically it. Though I did read on a forum that you can use the histogram to help review shots after they are taken so I might try that approach.

 

[Tullio]

Something does not sound right. The histogram is sensitive to changes in exposure (whether that's done by increasing/decreasing the exposure or by changing the aperture value. The only time the histogram will not change is when you actually lock the exposure via the AE lock button. So, make sure you are not pressing that button by mistake.