If I set my f-stop to f1.8 and my shutter speed to 1/125th of a second and my ISO is maxed at 6400, yet my image is coming out dark. What is the problem and what can I do? Why?

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    \$\begingroup\$ Did you shoot in an unlit cellar or on a glacier under a blue sky? Those values are quite meaningless without knowing the scene. \$\endgroup\$
    – ths
    Commented Feb 22, 2017 at 8:38
  • 1
    \$\begingroup\$ Why are you unwilling to use a shutter speed longer than 1/125 sec? Are you trying to freeze some kind of motion, or just trying to avoid camera shake? Have you considered using a tripod? \$\endgroup\$
    – osullic
    Commented Feb 22, 2017 at 10:41
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    \$\begingroup\$ Post an example, it is impossible to guess what are you doing. \$\endgroup\$
    – Rafael
    Commented Feb 22, 2017 at 14:38
  • \$\begingroup\$ Possible duplicate of What is the "exposure triangle"? \$\endgroup\$
    – thebtm
    Commented Feb 22, 2017 at 20:06
  • \$\begingroup\$ We need more information to pinpoint what your issue could be. Are you sure you took off the lens cap? What camera are you using? Are you using a pinhole lens? What lens are you using? Does your camera have a built-in ND filter that's been activated? What are you shooting? When you say "coming out dark" is it completely black? Or underexposed? etc. etc. An example image would be useful. \$\endgroup\$
    – inkista
    Commented Feb 23, 2017 at 23:11

2 Answers 2


If your image is coming out dark you need to increase the exposure. You can do this in 3 ways:

  1. Allow more light to enter the lens - You state that your aperture is set to f1.8, I will assume that this is the maximum aperture, so we will move on.
  2. Record more of the light hitting the sensor - You state that you are already at the highest ISO setting for your camera, again we will move on.
  3. Increase the time the sensor is exposed to light - Increasing the shutter speed will allow for more light to hit the sensor, resulting in a brighter image.

The other option is to add more light to the scene, for example by using flash, but this would be out of the scope of a question about "Exposure triangle".


What is the problem and what can I do?

Whenever you have too dark image:

  • decrease F number
  • increase exposure time
  • increase your ISO number
  • use flash

or use automatic exposure mode (A, P, S or auto) instead.

If you cannot record image of well lit scene in automatic exposure mode or camera sets too unusual settings compared to other cameras you might have a problem with your equipment. Let me know if it is the case.


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