Digital vertical shift and masking - why isn't it more common?

DLxP

Well-known Member
I've been wondering lately why digital vertical shift isn't more widely available. Partly because its lack of availability means, as far as I can see, I'm somewhat locked into using Kodi.

By digital vertical shift I mean the ability to shift the active video content up or down. Kodi allows one to adjust the position of scope content within the projected image. One can then use this feature to shift scope video to the bottom of a 16:9 drop down projector screen, such that both black bars are at the top, instead of at the top and bottom.

The main benefits of this:
  • The bottom of the scope image is closer to the centre speaker (assuming it's not an AT screen) and typically better aligned with eye level. This means audio from the centre is better locked on to the action and the image is more visually immersive.
  • Being as both black bars are at the top of the projected image, light overspill can easily be masked. This massively improves perceived contrast, especially if you're using a white screen.
On the latter point, I made some magnetically-attached masking for my screen that takes about 5 seconds to attach or remove. It profoundly improves scope content and means the image has a crisp black border. Now that I've tried this, there is no way I'd be without it when using a drop down screen.

1616755334436.png


I'm using a grey screen, so the black bars weren't too bad, but still this is a huge improvement. For a white drop down screen the improvement would be so significant that everyone should do it if they can. Making the masking is relatively easy. The only problem is hardly any media players support the feature and I don't know of a single Blu-ray player that does.

As far as I'm aware, digital vertical shift can be achieved via Kodi and Lumagen (one's free, the other's many thousands of pounds). I think I recall that Dune players have it too, but I'm not sure. That's it, as far as I know.

Am I missing something? Is there some reason why this functionality isn't more popular? It's made such a massive improvement to my image I'm just really surprised more projector users aren't doing it.
 

Isco 3

Active Member
I personally ended up going with a scope screen 15+ years ago. I used to do what you are describing with an HTPC back then. I suppose people are used to having black borders and learned to live with them...
 

DLxP

Well-known Member
Yea, I was on the fence about a scope screen and ended up going 16:9 mainly as I watch a lot of Netflix etc. on the projector. The masking approach means I can switch back and forth between aspect ratios, but if I had a dedicated cinema room I'd probably go with scope too.

I suspect one of the reasons more people don't do this is it's a fairly niche feature, so I doubt many people are aware of it and the masking options it affords. It's a shame though because it's a bit of a revelation once you get it set up properly.
 

Isco 3

Active Member
That should be a single button on all projectors really. Like airbags... :D
 

Wull

Well-known Member
I've been wondering lately why digital vertical shift isn't more widely available. Partly because its lack of availability means, as far as I can see, I'm somewhat locked into using Kodi.

By digital vertical shift I mean the ability to shift the active video content up or down. Kodi allows one to adjust the position of scope content within the projected image.

That's interesting. Does Kodi allow for 'masking' like used on JVC PJ's. I think Sony calls this 'Blanking'.
 

DLxP

Well-known Member
That's interesting. Does Kodi allow for 'masking' like used on JVC PJ's. I think Sony calls this 'Blanking'.
Blanking is a bit different. Blanking is a feature on projectors that essentially blanks off video content, rather than moving it. The blank area still projects light, in the same way that the black bars on scope movies project some light.

I've never had much use for blanking with a 16:9 screen, but I think it can be useful for people with scope screens, for watching slightly different ratios.
 

ggr2k5

Active Member
I've been wondering lately why digital vertical shift isn't more widely available. Partly because its lack of availability means, as far as I can see, I'm somewhat locked into using Kodi.

By digital vertical shift I mean the ability to shift the active video content up or down. Kodi allows one to adjust the position of scope content within the projected image. One can then use this feature to shift scope video to the bottom of a 16:9 drop down projector screen, such that both black bars are at the top, instead of at the top and bottom.

The main benefits of this:
  • The bottom of the scope image is closer to the centre speaker (assuming it's not an AT screen) and typically better aligned with eye level. This means audio from the centre is better locked on to the action and the image is more visually immersive.
  • Being as both black bars are at the top of the projected image, light overspill can easily be masked. This massively improves perceived contrast, especially if you're using a white screen.
On the latter point, I made some magnetically-attached masking for my screen that takes about 5 seconds to attach or remove. It profoundly improves scope content and means the image has a crisp black border. Now that I've tried this, there is no way I'd be without it when using a drop down screen.

View attachment 1482753

I'm using a grey screen, so the black bars weren't too bad, but still this is a huge improvement. For a white drop down screen the improvement would be so significant that everyone should do it if they can. Making the masking is relatively easy. The only problem is hardly any media players support the feature and I don't know of a single Blu-ray player that does.

As far as I'm aware, digital vertical shift can be achieved via Kodi and Lumagen (one's free, the other's many thousands of pounds). I think I recall that Dune players have it too, but I'm not sure. That's it, as far as I know.

Am I missing something? Is there some reason why this functionality isn't more popular? It's made such a massive improvement to my image I'm just really surprised more projector users aren't doing it.
That's similar to what I do.
My screen consists of ProGrey Screen material from Home page - PSM Screens - Projector Screen Material UK stapled to the wall surrounded by DeepBlack Border tape from the same place. I glued a couple of metallic rulers to the wall to the left and right of the screen before covering them with the border tape.
For the masking panels I use Black speaker cloth wound round a wooden batten with small magnets at either end.
When watching 21:9 content, I just unfurl the masking panels and clip the magnets on to the covered metal border.
Takes less than two minutes to switch between 16:9 and 21:9. The rulers are large enough for me to accommodate other aspect ratios too.

Its not the most elegant solution, but the total cost was less than £60
 

iamsludge

Active Member
Perhaps projector manufacturers tend to think in terms of fixed frame screens?
i.e. my projector is setup so the middle of the screen is at eye height irrespective of aspect ratio. I certainly wouldn’t want my scope image higher or lower in any event.
 

Donnacha

Distinguished Member
A lot of projectors have motorised lens shift which allows the image to be shifted down so it ends up positioned where Kodi positions the scope image. The main difference is, as you say, there is still light projected from the projector off the screen, even if you use the digital masking/blanking feature.

Its probably the closest you get to what Kodi can do, and if you can add black out masking top and bottom of the screen then it would be a reasonable compromise.
 

Russ 66

Well-known Member
A lot of projectors have motorised lens shift which allows the image to be shifted down so it ends up positioned where Kodi positions the scope image. The main difference is, as you say, there is still light projected from the projector off the screen, even if you use the digital masking/blanking feature.

Its probably the closest you get to what Kodi can do, and if you can add black out masking top and bottom of the screen then it would be a reasonable compromise.
This is exactly what I do, I use the lens shift to move scope films to the bottom of my screen. I really can’t see the light projected below the screen.
 

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