If I understand your question correctly...

The two choices the photographer has is where to stand and when to press the shutter. There are however technical details to consider... such as your metering and focus point choices.

Metering options... The Fuji X100T has the following options, which will be slightly different by make and model.

01) Multi: automatic scene recognition is used to adjust exposure for a wide range of shooting conditions.

01) Spot: measures the lighting conditions in the selected focus area or center of the frame

03) Average: exposure is set to the average of the entire frame

04) Face Detection: exposure is set to the face area (or other)

05) White Balance: not strictly a metering option. How automatic WB settings are arrived at can be a complicated process. I am not sure which method the X100T uses, but you can find some general information here: Auto White Balance and a Digital Camera - July 30, 2015.

AutoFocus... I really like using face detection to focus when people or animals are in the scene, but on many cameras you can select the auto focus point(s). I tend to use only the center point, set the focus, and recompose. Zone focus is also an option that works well for street photography. For the film equipment that I have, I use manual focus. Some cameras also have a focus tracking option.

The on-board computer will determine the exposure etc. based on the above. Why a digital camera in auto mode chooses a specific f-stop, aperture, WB, and ISO is the magic algorithm of each mfg ; ). The photographer can take manual or partial control by fixing one or more of the choices (e.g. aperture priority).

I hope that answers your question...
Casey

A look at exif metadata...

By: cshimokita : February 17th, 2017-06:52

If you represent f-stop, shutter speed, ISO, luminance (reflected light), and illuminance (incident light) as a Base 2 log value, you can simplify the exposure calculation process... The "Additive System of Photographic Exposure (APEX)" is explored in a p...

I love it when you get so technical. It keeps me humble. ;) [nt]

By: fernando : February 17th, 2017-18:44

hahaha... A low light example... (photo included)

By: cshimokita : February 17th, 2017-21:24

Here is a look into the exif data from a low light photograph. It's a January 2017 photo of Aomori City walking back to the hotel after dinner. Ref 01 : a lone taxi in Aomori City after dark (c) CLH - January 2017 Ref 02 : Exif and APEX reference data We ...

Casey.....

By: watercolors : February 18th, 2017-04:01

when your camera is on automatic , low light setting or any other setting aside from manual , those are the calculations your on board computer makes based on the amount of light it measurers, distance , focus etc.? Sophisticated and interesting , thank y...

If I understand your question correctly...

By: cshimokita : February 18th, 2017-14:54

The two choices the photographer has is where to stand and when to press the shutter. There are however technical details to consider... such as your metering and focus point choices. Metering options... The Fuji X100T has the following options, which wil...

That is it....

By: watercolors : February 19th, 2017-01:08

so much sophistication in a tiny aluminium box , optics in conjunction with electronics. It's like an art in itself someone must of done all the possible calculations or at least came up with the mathematical formulas. Thank you very much for this reflect...

Yes to mfg testing...

By: cshimokita : February 19th, 2017-05:12

and each maker has their own approach and their own idea as to what makes the "best" photo