The handful of settings that are painful to discover are wrong afterwards: date and time, file format, card formatting in the camera, and whatever the maker publishes about the current firmware version.
Nothing here is a secret setting. It is the list of things that cost a whole outing if they are wrong, and minutes if they are right.
The four that matter first
Date and time, because every file carries them and no later correction is as good as having them right.
File format, raw or rendered, because it decides what can be adjusted afterwards. White balance in particular becomes a development choice rather than a decision made at the moment.
Card formatted in the camera, per the maker’s own instruction.
Firmware, read before installed — the note states what changes, and the number states nothing.
The two worth a minute each
Image review, which drains the battery faster than most people expect, and the focus mode, which is the setting most likely to be wrong in a way that looks like a fault. A body that hunts in low light is usually a body reading a flat surface in a wide focus area.
What no setting fixes
A spare battery you did not bring, and a published shot count measured to a procedure that resembles nobody’s day. Both belong to the packing rather than the menu.
What people ask before they commit
Should I update the firmware before using it at all?
Read the release note first, then decide. A version note states what the version changes, and that is the only basis for updating — never the number alone. An update that fixes something you have never encountered and alters something you rely on is not an improvement for you.
Why format the card in the camera rather than on a computer?
Because the camera writes the directory structure it expects and clears anything it does not recognise. A card formatted elsewhere can work perfectly and still produce odd behaviour in a body that wanted its own layout, and the manufacturers publish the instruction for that reason.
Last reviewed 12 September 2026