How can I get consistent exposure while allowing aperture changes on Fujifilm X-T2?

Question

I'd like to change aperture and keep the exposure consistent while taking multiple photos of one scene. I am aware of the exposure triangle. I know I need to increase ISO or decrease shutter speed by a stop if I decrease aperture by a stop.

I would meter for exposure and set it in a way that I like. For example ISO 200, F/2.8 and a shutter speed of 1/4000. Now, the scene changes and I want to use a smaller aperture, so I stop down to F/5.6, two stops down. I'd need to change my shutter speed to 1/1000 to keep the same exposure.

The scene sometimes changes very rapidly, so I want to do this in as little actions as possible. I'd like the shutter speed to automatically adjust when I twist the aperture wheel.

What I've found so far:

• I can set ISO, aperture and shutter time on a value using the dials, which is manual mode, but then I need to change both aperture and shutter time. The goal is to change just one and keep similar exposure.
• Program mode activates if I put ISO, aperture and shutter speed on A for auto, but this keeps metering for individual photos on. I would like to achieve a consistent look for all my photos and for ISO not to change (unless I want it to for HDR shots, but I can limit auto ISO to 800, so that's not an issue).
• ISO priority actives if I put the ISO on a value (for example 200). This gets me closer to the effect I want, but metering is still on.
• If I flip the aperture switch to manual and keep shutter speed on auto, the shutter speed will adjust, but I still do not have the same consistency in exposure throughout my photos.

(How) can I achieve consistent exposure through a shoot, with the camera automatically adjusting shutter time if I adjust aperture?

Answer 1

Sounds like you want exposure lock (AE-L).

On my Sony, if I am in A (aperture priority mode) and with ISO not set to Auto, as the scene changes the camera adjusts the shutter speed to maintain a "correct" exposure. If now I lock the exposure, the camera does not change any of the exposure settings even as the scene changes (that's what exposure lock is for). And if I change the aperture while the exposure is locked, the camera adjusts the shutter speed so that the exposure is unchanged. Of course, unlocking the exposure will again allow the camera to adjust the shutter speed so that the exposure is again "correct".

Answer 2

Based on a cursory look at the Fuji XT-2 Owner's Manual, I'd suggest trying the following:

• Place the camera in 'Mode P: Program AE' (p.60 of the Manual)
• Set the [Exposure Compensation] dial to 'C' so that you can use the front command dial to select up to +/-5 stops of EC. (p.89 of the Manual)
• Half-press the shutter button to meter the scene. Use the front command dial to adjust EC to the exposure you want (p.89), then use the rear command dial to "shift" the same exposure value to your desired aperture (p.61).
• Once you have the desired aperture and shutter time, press the [AE-L] button.
• Use the rear command dial to "shift" the Av and Tv at the same exposure value as desired.

If your camera has an option for the [AE-L] button to hold until pressed again, you can release the [AE-L] button and you're set until you press it again.