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I would like to find an inexpensive alt-az head to go on a conventional
photographic tripod. It will carry an Orion ST-80. The telescope is likely to spend more time pointed at Himalayan peaks from a roof with a view than at the sky but it will get pointed at the sky for a reasonable amount of time. Astronomical use will probably be quite casual. The tripod has a removable head, with a standard threaded stub on which the alt-az head will presumably go. The Orion AZ-3 is way too much in the context. I am really looking for something in the same range as a moderately priced photographic tripod head. Failing that, I suppose a moderately priced photographic head will serve reasonably well. It is just not as intuitively obvious a way to point a telescope. I could manufacture one but I have a years long stack of things I could manufacture and am "in the process of making". I think I should accept that "can" will not translate into "will". I would appreciate any suggestions anyone might have. The Orion AZ-3 is way too much in the context. I am really looking for something in the same range as a moderately priced photographic tripod head. - Shankar |
#2
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![]() "Shankar Bhattacharyya" wrote in message ... I would like to find an inexpensive alt-az head to go on a conventional photographic tripod. It will carry an Orion ST-80. The telescope is likely to spend more time pointed at Himalayan peaks from a roof with a view than at the sky but it will get pointed at the sky for a reasonable amount of time. Astronomical use will probably be quite casual. The tripod has a removable head, with a standard threaded stub on which the alt-az head will presumably go. The Orion AZ-3 is way too much in the context. I am really looking for something in the same range as a moderately priced photographic tripod head. Failing that, I suppose a moderately priced photographic head will serve reasonably well. It is just not as intuitively obvious a way to point a telescope. I could manufacture one but I have a years long stack of things I could manufacture and am "in the process of making". I think I should accept that "can" will not translate into "will". I would appreciate any suggestions anyone might have. The Orion AZ-3 is way too much in the context. I am really looking for something in the same range as a moderately priced photographic tripod head. Seriously, the AZ-3, is about as cheap as you'll get. Remember it has 'slow motion' drives on both axes. There are similar photographic heads, but they cost _more_ (Manfrotto for instance do one, which starts at about twice the AZ-3's price). The cheaper photographic tripod heads, lack the slow motion adjustments (which is why they are cheaper). Versions with the slow motion gears, from any reasonable photographic supplier will be at least as expensive, getting even more expensive if they are reasonably rigid (for instance The MN400 photographic head, goes for about £400...). The problem is that once your magnification goes above perhaps 30*, having the finer pointing accuracy becomes important. I don't know what price you are seeing for the AZ-3, but on it's own (without a tripod), it is not expensive (in the UK about £99). However you also have to remember that many of the cheaper photographic tripods, have the same problems as cheaper astronomical designs, of not really being stiff enough. That all being said, have you considered secondhand?. Quite a few scopes (like the Skywatcher 120), are sold on the AZ3 mount, which for such a large scope, is really 'undersized'. Hence a number of these mounts do appear secondhand on Ebay, and AstroAds, and could be a good way of getting one at a sensible price. In general, you will need the adapter plate, to fit a normal tripod, unless the AZ-3 you buy already has this fitted. HandsOnOptics, do the Celestron Alt/Az mount, for $129, while Kendrick, list The AZ3 for $117. Best Wishes |
#3
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Shankar Bhattacharyya wrote in message . ..
I would like to find an inexpensive alt-az head to go on a conventional photographic tripod. It will carry an Orion ST-80. The Orion AZ-3 is way too much in the context. I am really looking for something in the same range as a moderately priced photographic tripod head. I would appreciate any suggestions anyone might have. The Orion AZ-3 is way too much in the context. I am really looking for something in the same range as a moderately priced photographic tripod head. - Shankar Avoid ANY photographic pan-tilt heads & tripods with any telescope. I very occasionally use a large & very heavy double-legged Bogen #3047 tripod with its own pan-tilt head for my 90mm f/11 Vixen refractor. Putting it as mildly as possible: It's a complete disaster at any power! Use a proper telescope tripod with an altaz head (preferably with slow motions) designed for the purpose. Or put an altaz head on a firmly fixed pipe or rigid pier. You will not regret it for a moment. A photographic tripod is only suitable for binoculars in my opinion. How birdwatchers ever see anything through their telescopes is beyond comprehension. It's no wonder they're twitchy! I envy you your view. Even if it is upside down. grin Chris.B |
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#6
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#7
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I would appreciate any suggestions anyone might have. The Orion AZ-3 is
way too much in the context. I am really looking for something in the same range as a moderately priced photographic tripod head. - Shankar This is what I can offer. Jon's Side Saddle Mount. I have been using a Bogen 3040 tripod with a 3047 head for several years as a mount for a variety of scopes including a C5, a Pronto, an Apogee ST-80 clone and an Orion Space Probe 130 ST. I like this setup, it has some problems with the larger scopes but I have still been able to get the Space Probe 130ST up to 500X on the double-double. Some comments. 1. I have described this before, not sure anyone shares my my positive opinion of this technique. I am also not sure anyone has actually understood how this works either. 2. I have been doing this for several years and it is second nature to me. I think to make it work one really needs to understand the basic mechanics of the balance. 3. The basic trick here is to use a three axis photographic head and flip the top axis 90 degrees so the scope is along side the mount rather than on top of it. Here is a link to a photo of my ST-80 clone mounted this way. http://members.aol.com/jonisaacs/bik...s/poglidsk.jpg By mounting the scope "Side Saddle", it turns the photographic head into a single side fork mount and if you look carefully in the photo you can see that the altitude pivot axis comes close to passing through the center of balance of the scope. What this means is that the scope is balanced about the pivot, it does not try to overturn as is normal with a photographic head pointed at a high altitude. It works in a similar fashion to a DOB mount or an Upswing mount. With a normal "on top of a photo tripod" mounting, as the altitude increases, the scopes center of gravity moves towards the back and it is more and more off center. The only way to handle this is either with gears, balance weights or by tightening the bearing so they do not move. The Side Saddle Mounting side steps this problem because the scope is alongside the bearing and aligned with the altitude pivot rather than above it so it can remain balanced at most any altitude. The main problem with the Side Saddle mount is that it puts an off-center load on the azimuth bearing and with a heavier scope it is not as smooth as I would like. This Side Saddle Mount also works nicely for terrestial viewing, bird watching and such. 4. Cost: I cannot recommend an inexpensive tripod/head that is capable of doing this. I have two Bogens, a 3051 with a 3030 head that cost $40 used and the 3040 with a 3047 head that was $35 used. Both work well for this but both probably cost somewhere between $250 and $300 complete. These are available on Astromart at times. 5. Anyone interested in learning more about the Side Saddle Mount, Email me privately, I have some more photos and would like to see others try it and see how it works for them. My experience is that it is a great improvement over mounting the scope on top of the tripod in the normal manner but probably not as nice as a Televue Telepod. Best wishes, jon isaacs |
#8
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3. The basic trick here is to use a three axis photographic head and flip the
top axis 90 degrees so the scope is along side the mount rather than on top of it. Here is a link to a photo of my ST-80 clone mounted this way. http://members.aol.com/jonisaacs/bik...s/poglidsk.jpg By mounting the scope "Side Saddle", it turns the photographic head into a single side fork mount and if you look carefully in the photo you can see that the altitude pivot axis comes close to passing through the center of balance of the scope. Hi Jon, Interesting to see your technique. I've wondered why I don't see it more often since I've also found it works well. I'm always on the lookout for a photo head that would lend itself especially well to this but often find the right one being quite costly. More recently I acquired a Manfrotto 486 ballhead with a built-in quick release plate. The quick release plate allows for the camera mounting screw to be removed so that a short bolt can be put in its place that's long enough to also go through the Celestron 80f5 plastic tube holder. With the ball head's plate tilted 90* to one side (into one of the grooves in the head's body), the entire arrangement acts 'side saddle' and is smooth, light and solid. Only improvement I've made is to add a slim strip of teflon or other smooth material around the shaft that connects the plate to the ball, so when that shaft sits in the body's groove it rotates even more smoothly. Added bonus is the quick release - I can pop the scope off and have the whole thing folded up in seconds. Or, if walking through doors and around fences with the whole setup, the single lock lever prevents the scope from flopping around. Works like a dream. Shooting myself in the foot here, but it works as well for the 80f5 as the Giro Mini I now have for sale. Bought the Giro Mini for a 6 lb. scope but it looks like 6 lbs. is too heavy without a counter weight. In my opinon, counter weights defeat the purpose of a light alt-az. When the 6 lb. scope didn't work, I used the Mini for the 80f5 but found no major performance gain, no quick release and an extra lb., so went back to the ballhead. Kirk |
#9
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(Jon Isaacs) wrote in
: I would appreciate any suggestions anyone might have. The Orion AZ-3 is way too much in the context. I am really looking for something in the same range as a moderately priced photographic tripod head. 3. The basic trick here is to use a three axis photographic head and flip the top axis 90 degrees so the scope is along side the mount rather than on top of it. Here is a link to a photo of my ST-80 clone mounted this way. http://members.aol.com/jonisaacs/bik...s/poglidsk.jpg That's an ingenious approach to the zenith problem. Thanks for the idea. It seems like a very plausible way to handle a small scope. I'll try that for a bit to see how the ST-80 handles. - Shankar |
#10
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Try the Bogen micro? fluid video head.
smooth and steady and cheap. |
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