correct based on available evidence F16 HUD delay

[Revientor]

in this video: (DCS ORIGINAL ONE)

 

 

You can see the HUD having updated inmediatly, you can see each knot that you increase, but real one have a delay (on porpouse???) I am not sure, but I think is around 20ms

 

 

here is a old youtube video where you can see that delay in the altitude and speed scale

ofcourse this is old and you will tell is a F16A, but for sure more youtube investigation could bring some light in this

[Swift.]

I'm confused the real life video you have provided shows the IAS being updated without noticeable lag.

[Geraki]

@Revientor you are correct must have a delay

 

let's see if it is fixed in feature beta release

[Tomsk]

I'm quite sure the HUD delay will be realistic to a F-16CM Block 50 aircraft :)

[Revientor]

Finally this was added, thanks

[Bjarned]

Video recorded at 145 fps (same as sim-fps). You see 7 frames of video for each HUD update. That gives about 20 fps for the HUD. This is way too low and makes the pitch ladder unreadable when maneuvering. In rl it must be smooth and readable of course. If it is impossible to reprogram this without rewriting the whole module i understand why you don't do anything about it

https://rumble.com/v63q8g7-dcs-f-16-hud-refresh-rate.html

[Hobel]

vor 1 Stunde schrieb Bjarned:

Video recorded at 145 fps (same as sim-fps). You see 7 frames of video for each HUD update. That gives about 20 fps for the HUD. This is way too low and makes the pitch ladder unreadable when maneuvering. In rl it must be smooth and readable of course. If it is impossible to reprogram this without rewriting the whole module i understand why you don't do anything about it

https://rumble.com/v63q8g7-dcs-f-16-hud-refresh-rate.html

Correct me, but wasn't it already 20FPS before? shouldn't it be more if the patch notes say that the refresh rate is now higher?

[Bjarned]

Yeah it has always been 20 fps. I think they only changed the update frequency on the numerical readouts for speed and height.

Edited December 28, 2024 by Bjarned
typo

[Heli Shed]

try fixing at 60fps and then record.....................................................

[Bjarned]

27 minutes ago, Heli Shed said:

try fixing at 60fps and then record.....................................................

Why?

[Heli Shed]

1 hour ago, Bjarned said:

Why?

TBH if you don't get why, then we're on to a non starter pal.  Good luck.

[pegasus1]

7 hours ago, Heli Shed said:

TBH if you don't get why, then we're on to a non starter pal.  Good luck.

Can you explain to the rest of us non starters why this would make a difference, or have you read it somewhere but dont understand yourself?

[TobiasA]

vor 40 Minuten schrieb pegasus1:

Can you explain to the rest of us non starters why this would make a difference, or have you read it somewhere but dont understand yourself?

Theoretically you should record at a multiple of that refresh rate.

However, the practical difference if you are already at a multiple of 7 is probably negligible. If you record on almost the double frequency, then your jitter is about 50%.

But we have three different framerates here... The HUD fps, the ingame fps, and the recording fps. And on top that of the screen. So... Difficult to say if frequcies overlap.

And, more important, the HUD refresh rate says nothing about the frequency in which the information on it is updated. See the Tomcat for example. There is usually some smoothing in sensor inputs, some delay in inputs being processed so you may display information with 20 Hz but the information might be refreshed in 10Hz.

[Bjarned]

Ok Tobias i got some minutes so ill try to argue with you.

1. Do you have the F-16 module?

2. If so, do you think the pitch ladder is readable when doing tight turns?

3. Do you understand what you are seeing in the video I posted?

[Bjarned]

Please disregard TobiasA. He has no clue of what he is talking about.

[TobiasA]

vor 25 Minuten schrieb Bjarned:

Ok Tobias i got some minutes so ill try to argue with you.

1. Do you have the F-16 module?

2. If so, do you think the pitch ladder is readable when doing tight turns?

3. Do you understand what you are seeing in the video I posted?

Yes, I do have the module and I am flying it a lot. Probably a few hundred hours by now.

Yes, I think the pitch ladder is readable to a realistic amount.

Yes, I understand what you showed in the video. 

No, I was not replying to you but to the one above me (whom I quoted). And it was about overlapping datapoints (or pictures, in this case) on different frequencies which is part of my daily work.

But since you want to discuss it... I think it is realistic even though probably not being perfect. A similar effect can be seen on this video during the GCAS pullup, you see the pitch ladder not being perfectly stabilized on the horizon. It always moves a bit as a result of HUD updating frequency. Also, the speed and altitude readings are updated slower than the pitch ladder is.

Also note that the Youtube video is at least one fourth the speed (no slower than that), probably recorded on the HUD itself, and your video is way slower than that and recorded in very high resolution. 20Hz is 50ms update rate, which would result in a 1 degree "jitter" at a 20deg/s turn. Which is about the same in that video I posted. Probably a bit faster, but as it is recorded on a tape, it is hard to tell. Also, GCAS tops out at like 8G so no full 20deg/s.

 

HUD videos showing pure pull-up or pull-down are pretty rare, and the VHS frequency of 24Hz doesn't really make it possible to claim the update frequency to be higher or lower. However, the amount of movement in the pitch ladder up or down in rapid and sharp pulls will allow for some guessing because of the jitter from one picture to another caused by the update frequency on the data displayed on the HUD, and based on that, I think 20Hz comes pretty close.

This video also shows a similar effect, watch the horizon line passing through as the nose passes through.

And then there is this one, showing the lag during pitch and roll (see the horizon line lagging behind)

 

You are free to explain why you think that the HUD update rate should be higher based on evidence supporting it.

The stage is all yours, I was just discussing frequencies when filming and displaying sensor data and as to why those aren't necessarily the same and why it is wise to record data matching a multiple of that frequency. But this is a complicated topic, English isn't my native language and I'll see myself out, leaving that material in here so you all might discuss that topic.