Why a pier?
Posted 16 July 2009 - 02:14 PM
Posted 16 July 2009 - 03:18 PM
Posted 16 July 2009 - 04:23 PM
Ok, so this may seem like a dumb question, but why would anyone prefer a portable pier? Most heavy duty tripods (G11, CGE etc) seem like a better idea to me. They're stable, low vibration, easy to transport and easy to level. A pier on the other hand is not as easy to set up, transport and level. It might look more "pro", but are there any practical advantages to a portable pier over a heavy duty tripod?
The two tripods you mention are not as easy to carry and set up as my Astro-Physics Portable Pier. The CGE is much heavier and the G11 doesn't have folding legs. Don't get me wrong, these two tripods are excellent and work very well, but the 6 inch Portable Pier is lighter, easier to handle, and carries just as much load.
My pier has been used with Atlas, Losmandy, and A-P mounts. I consider it to be very versatile and it's easy for me to haul around. It's no problem to pick it up one-handed and carry it out the door.
BTW - it doesn't cost any more than either of those tripods, either. A G-11 tripod runs about $675, my 42 inch Portable Pier is $605. I don't know if you can buy the CGE tripod separately. The downside to my pier is the fixed height, but I do have a couple extra center posts.
I'm certainly not a "pro" in this hobby. I bought mine simply because it works better for me. YMMV
Posted 16 July 2009 - 04:28 PM
I also have portable Parallax pier for my AP1200.
Posted 16 July 2009 - 05:19 PM
Posted 16 July 2009 - 07:19 PM
Posted 16 July 2009 - 08:44 PM
Can you level the pier? I have never used/seen one up close, but it looks like you can't adjust the height of individual legs so it would have to be used on a flat, level surface.
I'm not going to use it on the side of a cliff, but the pier doesn't have to be level. That's the beauty of a GEM - it doesn't care. I still shake my head when I see all these people with carpenter's levels and GEMs.
The only thing your GEM cares about is polar aligning the RA axis. "Level" doesn't matter much.
The only concern I have with level is the whole setup should not tip over when I load up the OTA and weights. So I'll look for a reasonable spot and have fun.
Posted 16 July 2009 - 09:56 PM
Jade, yes the legs can be extended quite a bit for leveling and various heights.
Posted 17 July 2009 - 07:38 AM
That is true Ron, and I argue this too. But having it close to level helps with drift aligning. If only using the polar scope then set it and go.
Yes, I use the polar scope and achieve very good tracking results that way. I am mostly a visual guy, but can get short to medium length images with just the polar scope.
In my mind, a level piece of ground is more important to the astronomer than to the tripod (or pier). I've set up on some angled patches and some rocky patches of earth. The telescope was fine - but the astronomer wasn't so happy after a while. It's uncomfortable and I keep spilling my wine.
Posted 17 July 2009 - 06:47 PM
I haven't seen an AP 3200 GTO on a tripod yet either.
Portable piers make no sense to me either. I had a G11 and the tripod was rock stable.
Posted 17 July 2009 - 06:53 PM
As for the levelling thing, I used to work as a surveyor, back in optical equipment days. For land survey work, we were completely neurotic about the transit being TOTALLY level. We mostly used one-piece leg tripods because they were stiffer, and just got the head somewhere close to level and over our turning point, then used the screws on the transit to level it. I agree that, for drift alignment, pretty close is handy, but nearly all mounts come with alt-az adjustments (that I've never actually seen anybody but me use) that allow perfect polar alignment, regardless of hub position. I think those little bubble levels are silly, that they are there mostly just to make the mount look "professional".......right up there with microscopic setting circles.......and just generate extra set-up time and discouragement. http://www.cloudynig...cons/tongue.gif
Posted 18 July 2009 - 02:17 PM
Someone told me that with a pier you wouldn't have to worry about your scope clipping the tripod legs. They are also very useful for people who have long FL refractors so they do not have to lay on the ground to view through their scopes. I choose the pier route because I have an inferior mount (LXD55) and the tripod is just not stable enough. A pier shouldn't have vibration issues as a tripod would. These are just things I have been told and thought about when I was deciding pier or tripod. I hope that helps! Clear skies.
LOL So I am not the only one who has a LXD55 mount that is not nearly stable enough even for a visual observer like me to use....at least not at the height I have to set the tripod to avoid viewing sitting on the ground...
In my case a CHEAP 150 buck Antares Portable pier
is much more stable PLUS being much easier to "push" out the door of my garage with the scope and mount attached and ready to use..then when I used the tripod...
My pier can be leveled as each of the legs have a nice large leveling screw built in...much easier to use then adjusting the legs of a tripod BUT then again my observation area is not on the side of a mountain its pretty level ... My only complaint is that the "wheels' are smaller then I would like as I can't honestly push it over the lawn...have to drag it slower then I would like
And did I mention I now have a lot more foot room around the scope and the extra knee room allows me to position my observation chair where I want it and not where a tripod leg gets in the way...
For me it was a "Never look back purchase" that just plain works and works better then the tripod...
Posted 18 July 2009 - 03:50 PM
I have the best of both, G11 tripod/pier. Legs are fixed at an angle for max rigidity but yet extendable for leveling on very rough ground. Plus it has a pier top which hold it up away from possibly hitting the legs.
I also have portable Parallax pier for my AP1200.
Have you compared the Parallax and AP portable piers? I have a D&G 8" f/12 on order, sometime in the few months I'm going to need to buy something ....
Posted 18 July 2009 - 11:10 PM
I have a short pier, 36" and like that the Parallax has a slightly small footprint but on a taller pier the wider AP might be better? Again never did a test.
There are so many AP piers being used I can't imagine any of these things are real issues but different strokes for different folks. Nice to have options.