3D LUT for the GUI color viewer

Not to beat a dead horse, yet is there any reason to create a 3D LUT for the GUI color viewer if I have an external monitor hooked up via DeckLink ?

I am using DisplayCAL which can create a lut for both my GUI Display and my external Display via DeckLink

I would think it would be nice if both of them were close.

Not to beat a dead horse, yet is there any reason to create a 3D LUT for the GUI color viewer if I have an external monitor hooked up via DeckLink ?

To me? No. I run with both GUI displays a little bit desaturated and dark and tell clients to disregard them. The only monitor to believe is the calibrated hero (Viewing) display going though a color-managed BMD output. To me, insert software LUTs for monitor compensation can lead to problems, particularly if the session is used on somebody else's system at some point. We have "ballparked" the GUI monitors so they're not terrible, but it's just a cheap $250-$300 display (even the Dell UltraSharps we use).

There's value in owning monitors that can store internal 32x32 LUTs, or using an external LUT box right before the monitor itself.

My gui is kind of bright and calibrated for when I need to do editing, then I have a neutral density sheet that I drop on when I need to do color.

There's value in owning monitors that can store internal 32x32 LUTs, or using an external LUT box right before the monitor itself.

Worth a quote to repeat, wish there were more monitors that can take internal LUTs and prefer monitors that can connect directly to the measuring tool to make that LUT.

So is the takeaway from this topic is
Building a software based 3D monitor lut for the viewer display is pretty much pointless?
Would it just be better to use the built in REC709 if one is available on the display

So is the takeaway from this topic is
Building a software based 3D monitor lut for the viewer display is pretty much pointless?
Would it just be better to use the built in REC709 if one is available on the display

I will personally try to calibrate the monitor as close as rec709 as possible.

So don’t trust the built in REC709 profile?
I am using a Benq SW271 for my viewer

My gui is kind of bright and calibrated for when I need to do editing, then I have a neutral density sheet that I drop on when I need to do color.

I did that in the old days when I was confronted with monitors that couldn't get dark enough. We can dig deep enough into the Dell UltraSharp menus that we can get them down pretty low, but you have to pretty much hammer it.

So don’t trust the built in REC709 profile?
I am using a Benq SW271 for my viewer

Monitors calibration "drifts" as components age, or as conditions in the work environment change. Hence the reason why people serious about color buy a colorimeter and regularly calibrate their screens.

I have a monitor calibrated to Rec709 and another one calibrated to sRGB for other purposes.
Honestly, I don't see huge differences between the built in and the external calibration profiles, though I agree about the drifts you write about...

My gui is kind of bright and calibrated for when I need to do editing, then I have a neutral density sheet that I drop on when I need to do color.

I did that in the old days when I was confronted with monitors that couldn't get dark enough. We can dig deep enough into the Dell UltraSharp menus that we can get them down pretty low, but you have to pretty much hammer it.

Because main video standard in 2020 is 30 years old

My gui is kind of bright and calibrated for when I need to do editing, then I have a neutral density sheet that I drop on when I need to do color.

I did that in the old days when I was confronted with monitors that couldn't get dark enough. We can dig deep enough into the Dell UltraSharp menus that we can get them down pretty low, but you have to pretty much hammer it.

Because main video standard in 2020 is 30 years old

Not sure about this reply: I don't use the gui monitor for color and it is annoyingly bright, so instead of going in a menu effort time I want it dark, I just dimm it with an ND.

O don't want the client to look at it either.

Well having more than 2 monitors is always a problem. I know big VFX house which simply never has 2 monitors on when client is in, otherwise you will get annoying questions

Some places just don't go for things like eg. Sony X300 + big OLED for "client". They see it rather as bad practice. They always have only main screen on and this is the reference for the client.