Hi Howard,
It's been a while since you posted your note, so I thought I'd give you a few of my impressions. You may know that I was a beta-tester for this version 5 of FocusMax, so I've been using it for fourteen months or so. There is a lot more to this version, to be sure, and it requires careful attention to the configuration and preferences. though in all respects it will also work like FocusMax 4 when it is set up in its preferences to the behave that way. As you see, you can have both versions installed and switch between them by using the "run as administrator" trick. With two system configurations, one could be set up like version 4, though I'm sure the intent was for two configurations to support two difference camera/telescope/focuser systems. I have myself all but forgotten about version 4.
What I like best about the new version is the MultiStar focus determination. There are two main advantages.
-- slew to the target and it focuses without moving away from the target. This is specially advantageous for me and my twenty-year-old Meade fork mount and my small FOV camera, because it avoids slewing away to a second or third sky location. Fewer slews means more stable (and quicker) image positioning for me.
-- statistically better focus determination, with multiple stars involved and several choices of how many images to capture at each stage of the process.
Because of my small FOV camera, one disadvantage is that longer focus image exposure times are necessary in the fainter fields I typically observe, so the total focusing time is often somewhat longer than what would have occurred using FocusMax 4.
I've also implemented FocusMax's temperature compensation for the first time. This is great. My OTA temperature expansion is very well characterized at -111 steps per degree C. With a total focus range of 7000 steps, this covers a temperature range of about 55 degrees C. This is adequate for my climate location. This capability is also in FocusMax 4, but I never thought to figure it out and use it. What a time saver - I focus at the beginning of the night and can run all night.
I'm now installing new LRGB filters along with an older H-alpha filter. This will require redoing the filter offsets. I believe Bob's FocusOffsets.vbs script will run without modifications and use FocusMax's MultiStar capabiliity to focus. I'm waiting for better weather to try this. I'll need new flats for calibration, too.