Well, that's all of this project until now. After spending some time with this system. I have some notes about my DIY lens performance here.- Geometry Distortion
By not using curved screen and using near max zoom of the projector. I got image distortion on all 4 sides of the screen, especially on the left side of the screen . I decided to zoomed in and loose some area of the picture. And by image adjustment that try to make the center screen's proportional most correct. I got horizontal stretched image on the left and right side of the screen.- Chromatic Aberration (CA)
This is full screen of test grid.
Here's CA on the left, center and right side.
Even though in the image show kind of serious CA on the left side but in real life i can tell it's not that serious. The grid is about 2.5 cm in width. It hardly see the CA from viewing distant.- Reflection (Ghost image)
Ghost image is the reflection which we could see in some overexposed scene (very bright object/text on very dark background -: ending credits). I got very less reflection/ghosting. It's very hard to see on my DIY Lens so i can't get the picture of it - Brightness and color saturation
I can notice both of them slightly decrease when using lens comparing with lens removed.- Picture sharpness
Due to CA previously mentioned. It also decrease image sharpness. I'd like to say that it make the picture more soft, not blur. Here's sample picture
Grid pattern without lens comparing to grid pattern on the center of screen when using lens in CA section above.
Sample movie image, Without lens.
The sample above is cartoon image which have sharp drawing. In normal movie the difference is less noticeable.- Focus Shift
I got slightly difference focus when using and not using lens. So i have to adjust image focus on the projector every time i put lens in and out for best picture quality. That's little annoying. Luckily i didn't remove lens so often - Horizontal Screen Position Shift
When using Lens, the image position will shift to the left side a little. At first i think this my fault alignment. But i just later read Aussie Bob's Omni-CIH Calculator sheet and found that it seems to be normal issue. It's hard to notice this glitch so i leave it that way.
That's all i can tell about my lens performance for now. Even though it looks like so many artifact and disadvantage using lens. But most of them are aware so i didn't worry about them much. So far i'm very happy with it's price/performance and enjoy using it very much