The remote's controls are fairly typical of a well laid out business projector remote. I should start by pointing out that the EP1690 supports remote mousing, thus the large disk pad, and accompanying left and right mouse buttons.
At the top of the remote are Power controls, an A/V mute, and other short cut buttons, that allow you to do an Auto setup (re-sync), image Freeze, Keystone correction, Mode change, and aspect ratio change, without having to navigate through the entire menu system. Below the disk pad are digital zoom in and out, Page up and Page down buttons, and four arrow keys for navigation. You'll note that they also have numbers on those keys, and the rest of the 0-9 numerics are below. You use the numbers for setting Projector ID, and possibly (didn't work with it) security features.
Below the arrow keys are the Menu button a Clear button (escape), and Enter. If you are not in the Menu system, those buttons and those below directly select different sources (VGA, S-video, etc.) The Clear button doubles to toggle off/on the Source lock mentioned about.
Overall, an excellent menu, and it offered better range than many remotes (especially the remotes with some other Optoma's I have tested, which had very limited range (barely 20 feet).
Optoma EP1690 Manual
At this point, I'd like to comment on the EP1690's manual, just to say, it is one of the more impressive manuals I've read through lately. Easy to understand, and very well laid out, with plenty of good graphics. It could stand a little more detail relating to the "why's" of some of the controls, especially for those wanting to tweak image performance, but overall, one of the best manuals I've seen this year.
Lens Throw and Lens Shift
Lens shift is easy - the Optoma EP1690 does not have variable vertical nor horizontal lens shift. The built in lens shift places the projector below the bottom of the screen to get the ideal rectangular image on the screen. The amount of offset is more than most. I assume, since it uses the same layout as the home theater HD72, that for a 100" 16:9 screen, the center of the lens is going to be almost 17" below the bottom of the screen surface, and around 15 inches if you are working with a 16:10 image instead of 16:9.
The lens throw is about average for a business projector (though some would call say it has a short throw lens, but since most projectors have moved toward shorter throw lenses in the last few years, I'd say the EP1690 is fairly typical. To fill that 100" 16:9 screen, the closest you can position the projector (measured from front of the lens) is from approximately 11.24 feet or you can place it as far back as 13.5 feet. The manual has a nice chart and data table - great for computing the screen size based on distance, but not as friendly if you know your screen diagonal and need distances, as I did.
Audible Noise Levels
The EP1690 is a pretty quiet projector as a business projector. In full power (Bright mode), noise is more typical of home theater projectors than business ones. Even in a small room, you should find the noise level to be fine. In low power modes it quiets down further, not as good as the best home theater models, but more than acceptable for almost all movie type viewing. Officially Optoma claims 30 db at full power and 27 at low. If I had to guess (I do not have the tools to measure, I would believe the 27 db rating, but the noise difference between the two modes is definitely more than 3db, so I'd make that guess around 33 db, still very acceptable. To give you an idea, the Panasonic LB60 business projector claims about 36 db in full power, and the Epson Powerlite 760, a whopping, and noisy 41 db.
Optoma EP1690 Lamp Life
Anyone care to guess? Unlike Sanyo, who never publishes lamp life specs, Optoma does. The problem here is conflicting information. On the Optoma Datasheet it only says 2500 lumens in Eco-mode (low power) and doesn't list a full-power rating (not uncommon). The problem is, that in the manual, it says 2000 hours in full power, and 3000 hours in Eco-mode.
I emailed the product manager at Optoma (right before the Labor Day weekend started)for clarification, but have not heard back yet. I will presume the 2000/3000 hour spec because it lines up with the other projectors Optoma has using this chasis, lens, and lamp.