I posted a variation of this in the shootout thread, but thought I'd target the HW50 guys...
I've got the HW30. When I got it, I ran some simple test patterns and realized the left side of the screen wasn't as sharp as the rest. I did an exchange and the 2nd unit had the exact same behavior. After further reading back then, it became apparent that lens inconsistency is just an attribute of all HW30s. It seems this is also the case with the HW50. As I've written before, while this stuff shows up in test patterns I've never noticed it in real world video content. Even a year later, I wouldn't have purchased one of those other models for my usage pattern.
Last weekend, about a year after getting my HW30, I decided to revisit the lens. I took my HW30 down from the ceiling and using various shelving I repositioned the HW30. Close/Further/offset left/offset right/centered vertical/up vertical/down vertical/etc. All in an attempt to see what gives the most uniform sharpness.
I wanted some specific patterns to test this. I really wanted a projector primary color pattern to set focus and then the same pattern with the different RGB colors to see convergence. I wanted to test focus separately from convergence, so a green only pattern was appropriate. I couldn't find these on the web so I created some test patterns to help me out. You HW50 guys might want to try them out.
What I found with my HW30 is that every mounting location exhibited some unfavorable behavior. The position just moved the problem. I was most surprised to see that a smack center PJ location exhibited some focus issues closer to the center of the screen! When all was said and done, I decided to stick with my existing mounting position. This is ceiling mounted about 10% below the screen top and centered vertically. The distance is about 70% toward the furthest distance from the screen. This gives a pretty sharp image across all but the left 15% of the screen. FWIW, I found I could make it a little better by moving the projector all the way back and using horizontal shift toward the right a little. Ultimately I decided the benefit wasn't worth the effort to move the ceiling mount.
The lens on my HW30 has some significant chromatic aberration (perhaps?) in the areas that have soft focus. The single color dot test shows it quite well.
Here is the info on the test pattern... I'd be interested to hear what HW50 people see as I've read the HW50 has the same lens as the HW30.
1) Single pixels spaced every 5 pixels
2) "Plus" signs (10 pixels high / 10 pixels wide)
Each of these two patterns comes in 6 variations: Red only, Green only, Blue only, Red+Green, Green+Blue, Red+Green+Blue (aka White)
There are 12 buttons on the top to pick the appropriate pattern/color.
If you want to give your PJ a focus workout, do the single pixel green test and see if that dot is clear all over the screen. If it's like my HW30, in some areas you will see a solid dot and then a "smear" coming out of it at some angle away from the center of the screen.
You may also find the manual focus is quite sensitive. If you are trying to optimize, a 1 degree or less turn can make a noticeable difference.