Originally Posted by dougri
Yeah... got that. Lets see if I can explain correctly... I understand that when a scaler stretches the image to use the entire imager, that the projector is spitting out the full resolution (e.g. 1920x1080). I am talking about the 'resolving power' to borrow a term from photography. That is, if we project a test pattern that has alternating black and white lines down to single pixel width (or color which would be the worst case for CA), how close to the test pattern max detail can we get with a cheap DIY anamorphic?
Having actually tested this, I can honestly answer this part. The cheap 2 prisms (trophy lens) can only resolve a portion of the pattern.
The image will be clear in the centre but get progressively softer towards the edges as both CA and Astigmatism come into effect. The other key point is that the prism lens can only be focused in one direction at one time, so whist you will be able to focus the horizontal lines (vertical rez) all the way to the edges, the vertical lines (horizontal rez) becomes quite blured (even to the point of smear) from about the 1.78:1 area. This is a very demanding test and only the best anamorphic lenses can resolve this anyway. In some cases, the projector's lens can add artifacts as well which only get magnified by the anamorphic lens. My BenQ for example has quite a bit of CA, so the anamorphic lens simply magnifies this as it is already in the light path.
Yeah... I was talking about using a curved screen with an anamorphic lens, and wondering if it corrected some of the focus issues with prisms as well as pincushion.
ONLY a lens with fully adjustible astigmatism will allow true corner to corner focus on a curved screen. Allot of this actually is not the anamorphic lense's fault, but rather the fact the projector's lens is designed for a flat surface, but it can be made to work. HT projectors have their roots in data projectors where they are designed to work off a table at the base of the screen. Lens shift has allowed projectors to be moved closer to the centre of the screen, but their optics are not like film projectors that work off the centre.
people are so darned thin-skinned... the VAST majority of people appreciate helpful input from those involved in the trade. The disclaimer is enough for me... what? are we two years old?!
Thank you for the moral support
From what I know, CIH for video is about 7 years old now. This is the 3rd year for the Aussiemorphic Lens.