The picture taken by Pentax k-x in M file is very dark.

I suspect that this is caused by the photographer's ignorance of exposure. The exposure combination in a scene is wrong, resulting in inaccurate exposure.

The exposure combination is influenced by ISO value, aperture value and shutter value. In a certain scene, these three values must be matched correctly to get the correct exposure.

When shooting in M files, always pay attention to the position of exposure compensation. 0.7 is acceptable, but it is higher than 1, which proves that your current exposure combination is not suitable. Generally, the scene is dark, and the exposure compensation display will be-1 or even lower.

In sunny and well-lit scenes, you can shoot with a low ISO, a small aperture and a shutter that tells you, but in a less bright environment, you need to adjust the exposure combination (increase ISO, increase aperture and reduce shutter speed).

According to your description, the dark images in a shutter are mostly caused by the following reasons.

1, the ISO value is too low. If the light in the scene is not good, or it is already in the evening and indoor environment, it is necessary to appropriately improve the ISO(800 or even 1600 can cope).

2, the aperture is not large enough, hand-held shooting in a dim environment, the aperture should be as large as possible. (F3.5 is the maximum value and F22 is the minimum value)

For photographers who started shooting directly with a SLR at the beginning, I suggest not shooting with M-files at the beginning, because if you are not sure about the exposure combination, using M-files with full manual exposure will reduce the film yield, or waste time and lose fleeting shooting opportunities because of taking time to set the exposure combination. It is recommended to use Av gear or Sv gear at first, and the fuselage of these two gears will be exposed automatically.

In addition, if you encounter a dark field (evening, night scene, indoor shooting), you should slow down the shutter speed and then fix the camera (for example, use a tripod) to shoot. When shooting at close range in a dim environment, you can also use a flash to fill the light.

If the Av file, Sv file, P file is still dark, press the light compensation key to see if the exposure compensation is accidentally set below -0.7.