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Originally Posted by va1erian
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I can only assume your comments are based on speculation from looking at the pictures, not from seeing the chair in person, picking one up, or using one?
Whilst I can't comment on the SkyWatcher Chair, as I haven't seen one, I can comment on the Bintel Chair. I own one of the originals bought from Scott Mitchell (wavelandscott) long before Bintel started importing them.
I have had mine for about 8 years and it is in as good a condition as when I picked it up. As Scott says these are made in Japan and are a high quality product. They are not flimsy and are in fact extremely solid, made of very thick tubular steel with a good wall thickness. If they can hold Houghy (sorry big boy
) they can hold most people. Mine is in perfect condition and shows no rust marks anywhere after 8 years of use.
When Scott Mitchell started importing these they were sold under the name of "Stellar Seat" in Australia. They have been sold in other countries under different names. In the USA they are sold under the name of "StarDust Astronomy Chair". In 2003 it was awarded a "Hot Product Award" by Sky and Telescope Magazine.
While the SkyWatcher Chair from Andrews is only $10 cheaper, I believe there are some important differences well worth paying an extra $10 for. The Skywatcher chair will be made in China to a price point and I would guess somewhat less sturdy in construction than the Stellar Seat sold by Bintel. Importantly, the Skywatcher chair uses a friction system to lock the seat at a given height, which over time could be prone to fail. The Bintel Chair uses a pair of very strong locking hooks which hook over the steel rails and the system can never fail or move in any way.
In terms of timber chairs I have used a number of them over the years and I still prefer the "Stellar seat" I purchased off Scott a few years ago, it is a high quality product in every respect. Including the nicely padded vinyl seat which has shown no signs of cracking after 8 years use. Timber seats are prone to knocks and dings which can then lead to splinters. Due to weathering they can also warp out of shape a little over time. The only advantage I see of a timber chair is that they are better suited to observing in extremely cold weather <0 degrees C, as a steel chair can get very cold, if you need to adjust it, or move it and you don't have full finger gloves on.
I highly recommend the Stellar Seat from Bintel. You will probably upgrade the telescope several times, before you need to upgrade the chair.
Quote:
Originally Posted by va1erian
Is there anything else ? Do you use something else, like a step ladder ?
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Not that does the job properly IMO.
Chairs designed for other purposes (like Drum stools etc) do not have a great enough height adjustment range for astronomy. At the moment you only have a 90mm refractor. A larger refractor 5" or 6" will require a greater height adjustment range than your 90mm refractor. Similarly, if you end up going with a larger dobsonian, it again requires a large height adjustment range. The Stellar seat has a height adjustment range of over 600mm and because of the "A" frame design stays stable on uneven ground at full height adjustment.
Quote:
Originally Posted by va1erian
To be honest, I find a need for a chair to be only mild.
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At the moment you are only learning. It takes time, in many cases years, to learn to observe properly and extract fine detail from an eyepiece view. An observing chair greatly increases your ability to keep your eye still, your head still, your body still and most importantly the telescope still. Most, if not all, serious visual lunar / planetary observers use an observing chair.
Quote:
Originally Posted by va1erian
I am not sitting while changing and manipulating eyepieces.
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At the moment it's a novelty to change eyepieces and get a different view of the same target. When you get more experienced you will find the tendency to change eyepieces can reduce dramatically, particularly as you start to use larger telescopes and hunt for dim threshold targets. My best effort is an 11 hour observing session with one eyepiece. I did add and remove OIII filters and UHC filters to the bottom of the focuser drawtube a few times throughout the night, but the one eyepiece stayed in the telescope the entire night, notwithstanding the fact that I own several cases full of premium eyepieces. That was with a 17mm Nagler T4 plus a paracorr in my 18" Obsession. This gives a true field of view of just over 1/2 a degree at 142X. Which frames the full moon at 142X. Similarly, my observing colleague Andrew Murrell can go most of the night using one eyepiece and only rarely changing the eyepiece; and then only for a specific reason like a larger FOV to fully frame a large target, or a higher power eyepiece to increase contrast and "pop" a threshold galaxy, or planetary nebula.
Quote:
Originally Posted by va1erian
Then I focus onto a planet or constellation, marvel at it for few seconds, and move on to the next item on my agenda. What am I doing wrong ?
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What you're doing wrong here is only spending a few seconds on each target. You need to spend a few minutes on each target even as your learn to observe. As I said earlier it takes time to learn to observe properly and extract the fine detail from the view. What I am trying to say here is that a newcomer will see a lot less while looking at "exactly" the same view as an experienced observer will see. You need to train yourself to observe which can take a few years of solid observing to become "highly skilled" and see detail that most observers miss. After a few months you will become skilled to the level where you see a lot of things that a beginner will miss. In addition to improving your observing skills by spending time on each target, it often can take several minutes to get a few seconds of steady air, which will give an improved telescopic view of what the previous few minutes just gave you. This gets more important as you start to use bigger telescopes as larger telescopes are more severely affected by variable seeing conditions than small telescopes.
Lets look at an example. Lets take the lunar crater "Plato" which is a favourite lunar target of a lot of people. It is located to the South of Mare Imbrium which is the top left corner of the FOV in a reflecting telescope.
Here are some images which try to explain what I mean. The original image is on the left and is an image taken by one of the worlds best lunar / planetary imagers, Damien Peach with a 14" Celestron SCT, under ideal seeing conditions.
For the purpose of this excercise forget about the detail in the terracing of the crater walls and just look at the little craterlets in the floor of Plato. In the original image there are a couple of dozen craterlets that are visible in the floor of Plato. Some are large and easy to see, some are tiny and impossible to see visually in a telescope. The number you see can often be very dependent on sun angle and seeing conditions
The image second to left is the view that a beginning observer might see through about a 10 inch or 12 inch telescope. They might see the 2 larger craterlets in the middle. They would probably miss the large craterlet tucked against the edge of the Eastern wall "almost in the shadow" and they would probably miss all the smaller less contrasty craterlets in the middle and near the walls.
The image 3rd to the left is what an intermediate level observer might see in a 10" to 12" telescope under good seeing conditions in a good telescope. They would see the four largest craterlets in the middle and they might get the large one tucked against the Eastern Wall.
The image on the right is what a highly skilled lunar observer might see in a very high quality 10" to 14" telescope on the very best nights of seeing. I have had similar views to this of Plato in my 14" SDM at powers up to 800X. I have also had views close to this (slightly less detail) at 600X in my 10" SDM. Irrespective of the advertising hype you read on the side of telescope boxes, it takes a very high quality telescope of at least 10" aperture (with tracking) and exceptional seeing conditions to get to 600X on any target, with a good quality detailed view. Some nights I have spent well over an hour just looking at Plato to extract the last of these tiny craterlets, that were going to reveal themselves, on a given night. I have also had dozens and dozens of nights where I struggled to see up to about 4 in my 14" SDM due to poor seeing conditions. There have also been plenty of nights I could only see 2 in my 10" scope. One night I could barely make out Plato in my 10" scope conditions were so bad.
The best way to improve your observing skills is to try and see detail within detail when you observe any target. In this case you don't just look at Plato, you start to look around the floor and the walls. Similarly when you observe Saturn or Jupiter, you look for detail within the detail, For example with Saturn the first thing to do is look for the Cassini Division within the rings, don't just look for the rings. The same applies to observing DSO's, You find a feature that reveals itself and then look for additional detail within that feature.
Cheers,
John B