Lamp Life and Replacement
Panasonic is a little vague on specs for lamp life, but if you read the manual, the early warning light for the lamp (assuming full power) comes on at 1800 hours and then again at 2000, which would be its normal rating. Based on that, 3000 hours should be right on the money with low power lamp use all the time.
If you are ceiling mounting the projector, you will have to unmount it to change the lamp, as is true with most, but not all home theater projectors. The good news, is that many users will choose shelf mounting instead of ceiling mounting, and then all you have to do is turn the unit upside down, unscrew the lamp door change the lamp, and flip it back over, so you are back in business.
PT-AX100U Projector Screen Recommendations
Finally, an easy projector to talk about screens with. First, it looks great on all three screens I viewed it on, the Carada Brilliant White (106"), where it was blindingly bright in its brightest modes (Dynamic, Vivid Cinema, and Normal). I also used it with the Elite HC gray ezFrame. It worked very well there too, in fact I used the Elite for most of the image shots this time (just out of convenience).
Lastly, I spent hours watching movies, football and HDTV on my 128" Firehawk, an truly excellent, but expensive high contrast light gray surface. The Firehawk was an exceptional match. The projector had the lumens even in Cinema 1 mode to fill the Firehawk with the room darkened for movie watching. The aspects of the Firehawk matched well, the Panasoniic's black levels as noted are very good, but its also very bright. The properties of the Firehawk lowered the black levels, provided a rich viewing experience, and as noted, still was sufficiently bright. (The Elite is a similar screen, but a bit lower "high contrast" and less gain, so not as bright, but less than half the price for the same sized screen).
So, in summary: Sports fans, who need the brightest image around, a white surface with gain, like the Carada Brilliant White, would be an excellent choice. A super wide viewing angle, a virtually non-existant "hot spot", and a blinding image on the screen. Movie watchers can appreciate such a screen as well, especially if you can't fully darken the room.
For purists, a surface like the Firehawk (some gain, some high contrast, but lowers black levels) is ideal. It will also reject a fair amount of side lighting (that isn't too far back). The only downside is the Firehawk (and similar screen's) narrower viewing cone - they say 28 degrees either side of center.
A screen like the Elite HC gray, Da-lite's HC Cinema Vision and other similar surfaces, can't quite match the Firehawk but do it for much less, more of an economy thing, similar but not quite as bright.
Lastly, a dark gray HC surface will also work - haven't recommended that recently. This will give you the blackest blacks, good contrast, but a narrow viewing angle, and will gobble up lumens. In this case, however, although the Panasonic PT-AX100U already has good black levels, it has more than enough horsepower to let you choose the dark gray surfaces, if you really want to knock down the blacks to their darkest, and if you are not going large on your screen (I still wouldn't recommend this type of screen if you are going much over 100" diagonal).
Gee, a projector that will work great with most screens, in most rooms. As you can see, your viewing preference (movies, vs. mixed (movies/sports/HDTV)), will be part of your choice, as well as your level of fanaticism regarding blacks. For me, I enjoyed the Firehawk the most, but each screen really worked with this projector. Consider your viewing preferences, your ambient light issues, and your seating positions, and make your best call. By the way, I particularly favor those screens with some high contrast properties of your walls are light colored, and you are by far most critical when watching movies.
On the other hand, with the 106" Carada Brilliant White, and the PT-AX100U set to Dynamic, you might find yourself looking for a pair of sunglasses! Go figure!
I really don't enjoy calibrating projectors. It takes time, and I'm not an expert, but can handle brightness, contrast and gray scale color balance. Problem is, that different controls overlap their effects, to to get a great neutral gray/white, from full white to dark levels, can take some time. Worse, not every projector gives you all the user controls you need without entering their "forbidden" service menus, where serious ISF professional calibrators play. I avoid service menus like the plague, sticking with the controls users can work with, with a basic calibration disk.
This small section is mostly for those who live to play around with their projectors.
OK, here's the interesting stuff. The Panasonic has a tendency to be cooler (color temperature) in the whites and light grays (favoring blue) and warmer (favoring red, in the darker grays). To give you an idea, the goal was to get a perfect 6500K color temperature across the board for ideal movie watching from DVD. Out of the box, in Cinema 1, the projector was overall a little too cool