The Manfrotto 400 is the bigger geared head for those of us who like manual control and these can handle a great deal of weight. I use mine on a Manfrotto 161MK2B tripod with adjustable column with my 20-pound, APM 120 binocs. I also love to use it with my little Meade 5" Mak OTA for a lovely evening of grab and go planetary viewing.
What do I mean by astro-modified? Well, this is a camera mount, by design and as cameras are generally used to point somewhat up and possibly all the way down to take pics of what's on your table in macro-mode, the gearing in this really nice geared-head is set-up to allow only that. You can use it for astro by mounting your scope or binocs on it "backwards", but that creates quite the inconvenience of having to reach around to the front in order to adjust altitude. Anyone who wants to track the heavens with this would certainly prefer the altitude control to be at the rear, not the front, but the mount is so good, astronomers still use it even with that inconvenience.
Well, mine was bought used (they go new for $800., but come up at much better, used prices at the -bay place), looks new and is probably at least 20 years old. Like many such items, the grease inside was drying out and turning to glue, binding the works and making it difficult to turn the knobs. So, I took it apart to clean it, re-grease it and adjust tension to get the lightest control feel while still having no play in the back and forth, up and down movement, since both axes are adjustable, spring-loaded niceness.
Darned if I didn't discover upon re-assembly that the big altitude gear can be reversed! Yup. So, now I have a 400 geared head with the altitude knob on the back where we astronomers want it and it allows movement all the way to from about -30 degrees down to fully 90 degrees at the zenith.
This mount head is pretty simple to disassemble with not too many small parts, but I recommend simply taking a pic at each step and just keep the bolts in the metal assemblies as you remove them, to make re-assembly simple. Now that I've done it, I could reverse the altitude gear in less than an hour, but getting off all the old grease, testing new greases and adjusting and re-testing took up a long evening, finishing at mid-night.
Honestly, if you have basic manual skills and a good set of metric hex wrenches or drivers, this is a pretty basic mod that requires no real modification as it was clearly designed by Manfrotto to allow for this reversal of the altitude gear.
I'll post a pic of the mod in action by Wednesday.
Edited by CharlesStG, 09 November 2020 - 12:12 PM.