richard plumb
Distinguished Member
Posted this in the c9 owners thread got it’d be useful as a standalone thread to get some discussion going
found this post while looking at options for tying to calibrate brightness without an expensive service or dedicated meter - using a DSLR. Has anyone tried something like this, and how were the results?
summary - set your camera to iso 100, f11, 1/8 shutter speed and adjust brightness until meter reads zero - should give you close to 128cd/m which is about what we should be looking for, right?
how does brightness change depending on room ambient light? If you’re only metering on a patch on the screen then won’t 120cd/m be the same brightness regardless of the room lighting> and therefore potentially look too dim in a bright room/bright in a dark room? Is that 120 target based on an assumption of a dark viewing environment?
edit: found this link referenced else which talks about viewing environment.
Viewing Environment and Calibration
Interesting read I think. 100 nits is only really relevant if you view in the same conditions - 5 nits surrounding lighting (pretty dark room) with some bias lighting around 5-10 nits. If you watch in a brighter normal room you’ll need to counter with higher brightness.
this expectation that most living rooms will be brighter - brighter than 100 nits SDR has a knock on impact to HDR too. HDR assumes standard white is 100 nits so can look dim if you’re using >100 nits for SDR viewing
I’m surprised there isnt a formula for brightness based on ambient lighting? I.e. if we have 100 nits in a 5nit ambient environment, how bright for a 20/40/60 nit environment? Such calculation should be possible as it’d be based on the display overcoming the ambient lighting enough to get back to the original mastering. Also surprised this still seems to not properly address HDR with some way to adjust the tone mapping to allow for brighter ‘normal’ whites to align better with the SDR setting for each individual
found this post while looking at options for tying to calibrate brightness without an expensive service or dedicated meter - using a DSLR. Has anyone tried something like this, and how were the results?
You can easily adjust the brightness using your camera as a light meter. Display a white screen on the monitor. An empty Word document or similar works just fine. Set the camera on full manual, ISO 100, f/11, 1/4 sec. Meter the screen using spot metering. Make sure the screen fills the entire metering area. Adjust the monitor's brightness until the camera's meter is on zero. That provides a brightness level of roughly 64cd/m^2. If you want something a bit darker go for 1/8 sec. which yields 128cd/m^2.
summary - set your camera to iso 100, f11, 1/8 shutter speed and adjust brightness until meter reads zero - should give you close to 128cd/m which is about what we should be looking for, right?
how does brightness change depending on room ambient light? If you’re only metering on a patch on the screen then won’t 120cd/m be the same brightness regardless of the room lighting> and therefore potentially look too dim in a bright room/bright in a dark room? Is that 120 target based on an assumption of a dark viewing environment?
edit: found this link referenced else which talks about viewing environment.
Viewing Environment and Calibration
Interesting read I think. 100 nits is only really relevant if you view in the same conditions - 5 nits surrounding lighting (pretty dark room) with some bias lighting around 5-10 nits. If you watch in a brighter normal room you’ll need to counter with higher brightness.
this expectation that most living rooms will be brighter - brighter than 100 nits SDR has a knock on impact to HDR too. HDR assumes standard white is 100 nits so can look dim if you’re using >100 nits for SDR viewing
I’m surprised there isnt a formula for brightness based on ambient lighting? I.e. if we have 100 nits in a 5nit ambient environment, how bright for a 20/40/60 nit environment? Such calculation should be possible as it’d be based on the display overcoming the ambient lighting enough to get back to the original mastering. Also surprised this still seems to not properly address HDR with some way to adjust the tone mapping to allow for brighter ‘normal’ whites to align better with the SDR setting for each individual