How much does using lens shift and zoom affect projector image quality?

[admin_exported]

Some projectors seem to have huge positioning flexibility with lens shift and zoom capability. My question is, does a projector perform best when it's centred with the screen and at its closest operating distance, or can you use these zoom and shift features to the max without any detriment to the picture?

 

[Frank Harvey]

Genuine lens shift won't really affect anything (mine doesn't anyway), although you may run into issues if you're using it to it's maximum. As far as zoom is concerned, the more you zoom out, the softer the picture will become. Ideally, it's best to not use zoom if you can get away with it. The closer the projector is to the screen, the brighter the image, the further away it is, the duller it'll become. Obviously moving the projector closer to the screen will normally need the use of the zoom facility.
It is best to keep the projector as centred as possible.

 

[Anonymous]

So, when you say centred, you mean in the middle of its zoom range, therefore falling somewhere in the middle of the stated throw ratio range?

 

[The_Lhc]

No he means inline with the centre of the screen, ie not off to one side.

 

[Anonymous]

Ok, so centred with the screen makes sense. But what about distance to the screen? Closest is brightest, but you're saying closest is also softest? So farthest away is dullest and sharpest? Is it then best to have the projector somewhere in the middle of the potential "distance to screen" range?

 

[Frank Harvey]

Closest is brightest, furthest away is duller. The further away from the screen the projector is, the softer the picture will look compared to being closer and sharper (if you keep the same screen dimensions).

 

[Anonymous]

Ok. So the ideal scenario is to have the projector reasonably centred with the screen, and as close as possible to the screen, for your given screen size.

Thanks for the help.

 

[Andrew Everard]

For the given screen size and the throw ratio of the lens, yes.

This 'How To' video should give you some more pointers.

 

[Anonymous]

For the given screen size and the throw ratio of the lens, yes.

This 'How To' video should give you some more pointers.

Thanks for that. I'm getting some conflicting info, however, on the throw ratio calculation. I was under the impression that the calculation uses the screen width. The 'How To' video suggests it's the screen diagonal dimension that's used. Does it vary from manufacturer to manufacturer?