16 bit intensity really 8 bit?

[Neil Macmillan]

I have some 16 bit capable fixtures which have channel 1 and 2 for intensity. I hoped to get some nicer smoother slow fade ups (at least to the capability of the fixture) by switching to 16 bit mode, but I don't seem to be getting a true 16 bit. So to follow, I bring the fader for the fixture to 100% then store to a playback. I then go into the setup for the playback, raise and lower tab then change the raise time to, for example, 255 seconds.

When I watch the dmx output, I would expect to see the 1st channel stay at zero while the 2nd channel goes through 0-255 in 1 second, then the 2nd channel would reset to zero as the 1st channel increments to 1 and so continuing till in 255 seconds they both read 255 and 255.

Instead, they increment as 0,0; 1,1; 2,2; 3,3; 4,4 and so on till 255,255 - in effect, only 8 bit duplicated over two channels as far as I can see.

Am I missing something?

I understand that the board only allows 0-100% control via the faders, in 1% increments, so it can never achieve even 8 bit control from a fader, but was hoping it may be able to automate it via raise time.

For reference, I am on the latest version 8 firmware (build 8), running a FLX S24.

[kgallen]

Have you patched a fixture profile that has the intensity channels defined as 16-bit? i.e. the exact same correct 16-bit mode on the fixture and on the desk? Otherwise most fixtures have the intensity MSB as the "intensity" channel and you'll get 8-bit dimming as the "fine" LSB will just stay at 0.

I think I might have the odd fixture with 16-bit intensity, maybe I could play sometime if I can find which one it is...!

[Neil Macmillan]

On 1/11/2025 at 12:59 PM, kgallen said:

Have you patched a fixture profile that has the intensity channels defined as 16-bit? i.e. the exact same correct 16-bit mode on the fixture and on the desk? Otherwise most fixtures have the intensity MSB as the "intensity" channel and you'll get 8-bit dimming as the "fine" LSB will just stay at 0.

I think I might have the odd fixture with 16-bit intensity, maybe I could play sometime if I can find which one it is...!

Sorry for the slow reply! It's rising the two numbers simultaneously, so it is making some attempt at playing across the two channels. Just the two numbers duplicate each other. Perhaps the S24 is purely an 8 bit intensity setup and it just fakes being 16 bit to support the profiles. I do see on other channels, such as pan/tilt etc. it does use the full range.

Something I'll need to try perhaps is to make a profile which has a 16 bit setting which isn't intensity (some other option such as a beam setting) and try to see if it is able to move those settings on a 16 bit fade. Just makes it a bit inconvenient that the fader wouldn't really do anything beyond selecting the light.

[kgallen]

15 minutes ago, Neil Macmillan said:

Perhaps the S24 is purely an 8 bit intensity setup and it just fakes being 16 bit to support the profiles. 

I doubt it (but I need to do the research to substantiate that, so will endeavour to find "my light")! Being able to define intensity as 16-bit has been in the "old" fixture editor from well before FLX series desks were designed and I doubt they would have not written the software to support that on their latest range of consoles. If it was just 8 bit it would just use the MSB channel and leave the LSB at 0.

Needs some more investigation unless another user already knows the answer (you never know, Edward or Jon might answer as they are still lurking 😉

[kgallen]

Hi @Neil Macmillan

I had a play with my FLX (ZerOS 8.0) and a Cameo Q-Spot 40 which has 16-bit dimmer. The fixture definition was written by myself.

I use the Z key to access the DMX Outputs tab to look at the DMX values sent to the fixture on addresses 1 and 2 where the fixture MSB and LSB intensity channels sit.

If I use the channel fader to manually play with the intensity, at 0% I see 0/0 (MSB/LSB). As I move the fader up the LSB goes to 128 and the MSB increments. When I get to 100% I see 255/255.

Instead, making the desk do the dimming, I set Programmer Time on at 10:00 (10 minutes) and type syntax 1@@. I now see the LSB incrementing from 0-255 and the MSB increment when LSB is 255. Similarly if I do clear-clear I see the LSB count down from 255 to 0 then the MSB decrement then the LSB 255 to 0 again. All the way down to 0/0.

So when the desk does the dimming, true 16-bit dimming is performed. When the fader is used, the dimming is understandably simplified - that fader doesn’t have 16-bit resolution!

Conclusion - 16-bit intensity dimming works as expected. 
 

Hope that helps. 

[Davidmk]

Interesting and makes sense. Did you try the intensity wheel by any chance?

[kgallen]

10 minutes ago, Davidmk said:

Did you try the intensity wheel by any chance?

No, but I have now! The Intensity Wheel indeed works as 16-bit - although it's stepped so it's not smooth but certainly the LSB/MSB behave as a 16-bit 'pair'.

[Davidmk]

I think a lot of fixtures with "16 bit" parameters ignore the a few of the least significant bits. Presumably they are limited by the steps on their stepper motors.

We live and learn. 😊

[Neil Macmillan]

On 1/23/2025 at 8:41 PM, kgallen said:

Hi @Neil Macmillan

I had a play with my FLX (ZerOS 8.0) and a Cameo Q-Spot 40 which has 16-bit dimmer. The fixture definition was written by myself.

I use the Z key to access the DMX Outputs tab to look at the DMX values sent to the fixture on addresses 1 and 2 where the fixture MSB and LSB intensity channels sit.

If I use the channel fader to manually play with the intensity, at 0% I see 0/0 (MSB/LSB). As I move the fader up the LSB goes to 128 and the MSB increments. When I get to 100% I see 255/255.

Instead, making the desk do the dimming, I set Programmer Time on at 10:00 (10 minutes) and type syntax 1@@. I now see the LSB incrementing from 0-255 and the MSB increment when LSB is 255. Similarly if I do clear-clear I see the LSB count down from 255 to 0 then the MSB decrement then the LSB 255 to 0 again. All the way down to 0/0.

So when the desk does the dimming, true 16-bit dimming is performed. When the fader is used, the dimming is understandably simplified - that fader doesn’t have 16-bit resolution!

Conclusion - 16-bit intensity dimming works as expected. 
 

Hope that helps. 

Thanks for this. Had to get storm damage out the way before getting a look at this. I can confirm that you are correct - the board is capable of doing this as I've done the same on the Phantom FLX S24 (and I assume it will work with my board too).

As this is the case, it looks like there is a bug in the raise / lower times.

I put in 600 seconds to the raise time on a playback channel, and did everything as per what you described above (fixture etc.)

As you'll see, it is raising the MSB and LSB simultaneously. I have also checked on the Phantom FLX and it also does the same so this isn't an S24 issue.

I've created a screen capture of everything I'm doing so you can see the issue. If I'm missing something, I'm delighted to be put straight on what I'm doing wrong. I can't see any reason it shouldn't be doing exactly what it does when you do what you described in your post. This should just be an automated recording of that operation.

You can see the screen capture here:
 

 

[Davidmk]

If you've got sufficient evidence you should mail support as it doesn't look as though anyone at VariLite ever looks at the forum.

[Neil Macmillan]

2 hours ago, Davidmk said:

If you've got sufficient evidence you should mail support as it doesn't look as though anyone at VariLite ever looks at the forum.

Thanks David. Yes, I do intend to shortly. Was pretty much just sense-checking that I'm not being an idiot and missing something before I do mail support. It's been good to see that it does operate as I expected when you use the programmer timer (which I didn't think of trying) so it adds to the likelihood that something is indeed not right in the software for the raise / lower times.

[Simon]

Raise lower effectively emulates moving the faders, which are limited to 8bit.

All other calculations for fades etc, are 16bit.

I have raised this as issue ZOS-12581 for future consideration.

 

[Neil Macmillan]

9 hours ago, Simon said:

Raise lower effectively emulates moving the faders, which are limited to 8bit.

All other calculations for fades etc, are 16bit.

I have raised this as issue ZOS-12581 for future consideration.

 

Pretty much what I thought. For the kind of work that I do in film and television, it would be a huge bonus to be able to programme 16 bit intensity changes. Often I have a fairly powerful LED filming light at perhaps 5% in a scene and I'm asked to bring it smoothly up from black. Those 12 jumps over a 4 second rise are really noticable on camera.

Your wording has made me realise that the get-around for this would be to have a lit cue and a black cue which would allow me to go from black to lit or lit to black with 16 bit fading. Fair bit more work in time-sensitive situations, but I've just checked and I get 16 bit intensity changes between cues. That'll work for now in certain circumstances where I have a bit of time.

I don't see any benefit to the raise/lower being 8 bit rather than 16 bit, so it would be great if that could be sorted for a future update. Makes it a very quick way to make timed rises and falls for a saved scene.