Originally Posted by rekbones
An A lens was never really about increasing resolution as the data fed to projector is still the same. Scaling of any kind all most always introduces some artifacts as you no longer have one to one pixel mapping. A lenses have generally fallen out of favor because their main advantage was a brighter picture and with todays projectors this is not nearly as much of an issue. They also introduced some keystone that required a curved screen to correct not to mention the high cost. One to one pixel mapping I think is more important then # of pixels used on the projector. I do agree a 2:40 mode that compresses 16:9 content is a great option but was implemented in very few entry level projectors but anyone who cared about the best PQ from their 16:9 content would never use it.
True an A-lens doesn’t make more data but it does use more of the pixels a projector has and it does it thru a scaling process. The question always will be does the resulting more pixels and of course brightness outweigh any problems the scaling causes? I will say scaling is a very small issue anymore.
For four years I used a WXGA projector mostly as a 720 projector and I feed it constant diet or both DVD and BD thru a BD player outputting a 1080p version of everything so DVD was being scalled up to 1080p in the player and back down to 720p by the projector and the outcome was perfectly beautiful every time. The reviewer at PC went as far as saying don’t even worry about doing some keystone adjustments as it is scaling but so will almost everything else you will ever be watching on it and it all looks great.
We had a nice relationship for a while in the age of 1080p projectors and 1080p BD media and 1080 TV as things matched up. Now 4k comes along and people have vast amounts of 1080 media still so we are back to scaling again.
If I am watching a movie on my PC and I grab the corner of the media player window and resize the window the movie scales on the fly and no matter where I size it looks perfect. My screen resolution is so good I can’t see pixels and that doesn’t change if I size it super small. If I’m watching say a music video of Hank Williams from the 1930s someone captured on film and it didn’t weather time well it actually looks better when it is less immersive even with the pixels size not changing.
I’m not an advocate for A-Lens in any way and there are drawbacks you mentioned with distortions the lens can cause. My cheap 1080p projector even has scaling features that would help with them as I have 4way keystone and even can manipulate each corner of the image correcting pincushion and barrel distortions to some degree. Even though I don’t use these features as I have a flat screen and square and level setup, I have played with them and they seem to work without artifacts.
My point more is of course power zoom, focus and shift are nice features and if they are programmable its even better and they do appear more on the upper tier machines. Another budget friendly option for CIH or better CIH+IMAX especially in the 4k world could be scaling. The thought process would be is it more important to live with poor presentation and CIW or enjoy proper presentation with CIH or CIH+IMAX doing it with scaling.
For a few months with my 1080p projector I did the scaling method with my laptop based HTPC and PQ wise I had no issues. My PC was limited as I didn’t have a TV tuner and it only has a DVD player, but for Netflix and such scaling things thru the PC and leaving the projector set to IMAX size wasn’t an issue and none of my family members noticed except they didn’t like not knowing how to run it. After that I went to the inclined projector slide method for zoom, shift and focus and that’s been working good for CIH+IMAX for over a year now. They like the simplicity of just moving the projector.
It would be great IMO if the scaling could be done in the projector though and then it wouldn’t matter what was feeding it. I think scaling has surpassed optics in terms of a entry level proper presentation method.