First light - a lot harder than I expected

[rkc]

A lovely night tonight for stargazing, perfect for trying out my new mount (AZ-EQ6) and scope (80ED). I'd been practicing in the daytime (getting finder scope aligned, etc), read everything I could find to read, and was looking forward to zipping around the cosmos selecting objects to view from the list on the SynScan ...

First problem: I set the tripod at a height that worked for my 11-year-old son, but that meant I needed to be a contortionist to look through the finderscope (the main scope was a little easier thanks to the right-angle diagonal)

Second problem: finding the alignment stars. I could pick them out easily enough with the naked eye, but once you are viewing through the finder, there are a lot more stars visible, and a lot less context, so identifying (say) Aldebaran is not so simple.

Third problem - goto accuracy. I think I managed to center al the requested alignment stars ok, but the accuracy of the gotos was not great - nothing I tried to go to ended up in the finder (thouhg it did at least put me in the right general part of the sky.

Fourth problem - unreliable connection on SynScan. I think the cable may be faulty. I swapped it for a standard network cable, and it seemed better. Sadly did not seem to improve the goto performance though.

So some questions:

1. Will my back ever recover from tonight's contortions?

2. What affects the accuracy of the goto performance. It occurred to me after I cam inside that perhaps in alt-az mode it's fairly critical to get the time right (I was guessing it - probably correct within 20 minutes or so). Anything else I might have been doing wrong? Is levelling the mount precisely important in alt-az mode?

I did get some lovely views of Jupiter (wow, it is beautiful), and managed to locate the Pleiades and the Orion nebula.

Richard

[ronin]

On all goto's the setting up of the initial position is fairly critical. The software has to assume a perfect initial set up then it will go to the first alignment star from that assumed position. So if the start is wrong the first star is wrong.

It is worth spending a little time getting it as good as possible.

An ED80 should have a fairly wide field of view but start with the low power eyepieces for the wider views.

Bit puzzled by identifying Aldebaren, it may sit in or by the Hyades cluster but they are faint and Aldebaren is big and orange. If it is in the view of the scope it would stand out by quite a bit.

Think there is a method of improving the accuracy of the goto. I think that the scope always refers to the original position when moving - so if that was a bit questionalbe then everything is. If you goto a star, centre is then hold down something like the Enter key the system then uses this "new" position as the reference. Trouble is I am fairly sure it is on one of the makes but not sure which, also the software changes often enough thay may have dumped it. Worth reading the manual.

No the back will not generally recover - you always bend over and it is generally cold, so making it worse.

As said for goto accuracy everything is important - time, location, levelling. Even if the scope can compensate for the errors it is better to have small errors to be compensated for rather then large ones.

[majapala]

Get a Telrad finder. You won't look back. Also, I find that the goto set up works best if you use 2 star alignment, using stars nice and far apart and where possible at different sides of the sky, say, Sirius and Dubhe.

Ive had a great night here too, crystal clear skies. Now I'm indoors looking at some new thermal boots online!

[Daniel-K]

making sure your finder is aligned well is important and them your home position. the more accurate your home position the more likely the star your trying to goto will be in the finder and easier to align your mount

[jimbooz]

What I find useful is looking through the finder with both eyes open. You can line up the cross on the finder with the star in question much easier.

Hope this helps

Jim

[rkc]

I fond a thread which gives a lot of good advice on how to get SynScan working and common mistakes. I wonder if I had the date backwards.

[rkc]

No, date looks like it was set right. I'll try again tonight (clouds permitting) and be more careful with the levelling and the time setting. On reflection, in alt-az mode it does need to be pretty sure of the time (in EQ mode, less so, I think)

[jason.p]

I know what you mean about correlating a magnified image (even binoculars) with the naked eye view. As in previous post I would recommend a "zero mag" finder like a Telrad, and if finances allow, a right angle correct image finder (if you haven't already got one). One of these is on my wish list as I'm finding most of my observing lately is directly overhead, and I seem to be spending most of my time on my knees

[SnakeyJ]

Time is pretty critical - prob more so than absolute precision with latt & long. Try and set it to the correct minute or consider the gps puck. Should be able to raise the mount a little for comfort and level. Do recommend the Telrad or a right angled finder.

[glowjet]

You could try swapping your finderscope for a right angle one, such as the RACI that will give you the same view that you see with your naked eye, easier to use in conjunction with your star maps, and possibly help with your back problem, you could invest in a 1mW- 5mW Green laser that you can shoot through the finderscope to see where your pointing and finally, as has been suggested, you can invest in an RDF such as the Telrad or some of the other popular makes. sorry can`t help with your GOTO problems, but there will be other members who can I am sure, enjoy your Astronomy

John.

[Chris Rowland]

Get a chair, preferably one that's adjustable. I use a cheap typist's chair. It helps to get you low enough to see through the scope.

Choose stars that aren't too high, Rigel and Betelgeuse are easier. Aldebaran should be easy at the moment because it's the bright star close to Jupiter - the really bright object in the South.

One trick I use with a finder is keeping both eyes open. I can then see the naked eye star through one eye and the finder view through the other. Move the naked eye star to the finder cross hairs and you should see it appear in the finder view from the opposite direction. I haven't described this well but try it.

Chris

[rkc]

Thanks everyone.

I've ordered a telrad so will see how that helps (I don't quite understand how it works though - seems that it would depend on where you put your eye as to which part of the sky it shows the target on).

I did wonder about right angle finder - seems like it would involve less contortion but make it rather harder to align since you can't look down the tube with the other eye at the same time. The issue with the finder scope is not just the low height, but the limited options of angle of approach without the main scope being in the way.

I've also updated the synscan to latest firmware, and reset it to factory settings (there were suggestions that it remembers the results of previous alignments - in which case the 'fake' ones I did while waiting for clear skies could have confused it?)

I have confirmed (using a network cable tester) that the handset cable I got is faulty - I guess I'll have to talk to FLO about getting a replacement (though I'm actually finding I prefer the ergonomics of my 6" network patch cable replacement...)

Here's hoping for clear skies tonight so I can play some more. I think I'll put the tripod higher, and bring some steps for the little-un to use if needed.

[SnakeyJ]

I have confirmed (using a network cable tester) that the handset cable I got is faulty - I guess I'll have to talk to FLO about getting a replacement (though I'm actually finding I prefer the ergonomics of my 6" network patch cable replacement...)

Here's hoping for clear skies tonight so I can play some more. I think I'll put the tripod higher, and bring some steps for the little-un to use if needed.

I hadn't got around to testing the pinout of the synscan cable, but if it is straight through I should be able to locate a good source for nice rugged curly leads as alternatives to SW's own.

Good choice on the Telrad, certain you will find this a whole lot easier, and with extra base plates an accessory that should prove future proof as your scope collection grows.

Jake

[rkc]

I hadn't got around to testing the pinout of the synscan cable, but if it is straight through I should be able to locate a good source for nice rugged curly leads as alternatives to SW's own.

Good choice on the Telrad, certain you will find this a whole lot easier, and with extra base plates an accessory that should prove future proof as your scope collection grows.

Jake

Seems to be straight through, but (on my cable) only 2,5,6,7,8 were actually connected (meaning no ground connection, if I am reading the pinouts correctly).

[Astro_Baby]

Some things that improve accuracy of the GoTo......

1 good polar alignment, my expetience has been a good polar alignment imprves the GoTo, very rough polar alignments result in very rough GoTo performance.

2 good centreing of alignment stars. Its very hard to judge when an alignment star is centred in almost any eyepiece unless your using something like a 5mm ortho in which cas its hard to get the alignment star into the eyepieace at all. Soooooo use the finder, it has crosshairs so you can be sure its centred. So long as the finder and main scope are well aligned this will help a lot.

3 when centering the alignment stars ALWAYS keep the approach method the same for ALL stars. Ie approach the star from left and below, or right and above, it doesnt make that much difference but whatever you do do it the same dor all alignment stars.

4 be positive, the mount hatess going to alignment stars as id your on the Golden Shot...up a bit, left a bit, right a bit, down a bit, left a bit etc.

A Telrad will help Id the bright stars without thefinder being cluttered but it wont help much with GoTo alignment. To locate the bright stars against the star background with a straight through finder you need both eyes open, one through the finder and one not. With some practice you can see both images merged with a big sky with the dinders ceosshairs merged over it.......sort of. Its an odd view. This woeks well with any straight theough sighting device, telrad, red dot or finder scope.

It doesnt help if your finder ends up in an odd position on an EQ mount and thats where a RACI finder can come in. Be aware that when using an EQ mount there is always the chance whateverfinder you have becomes tough to use. This seems to me to be more of a headache with scopes that have the finder mounted at the back like fracs and maks. Newts dont suffer this as the nose of the scope is always closest to the sky and as the finder is on the nose of the scope all is well. With a frac or Mak the finder is on the back end so closer to the ground ( newt owners might see some symbolism there...i cant comment . )

Hope thats some help.

[rkc]

Very helpful advice from all - thanks. And a much more successful night tonight, with all my goto's getting in the eyepiece.

Not sure whether it was the more careful levelling, the handset firmware upgrade, the careful setting of the time, or all of the above that made the difference, but I am now a very happy camper.

Richard

[CSM]

For really accurate alignment you need to start off with a low power eyepiece, centre that and then defocus it so that you have a large circle - much easier to centre. Then take that out and put in your highest power eyepiece and repeat. That way you can be pretty certain that you have actually centered it. And yes, try to choose something like Aldebaran or Betelgeuse - nice red stars so that you know that you are looking at the right object. A 9 x 50 right-angle finderscope will give you a 5 deg field of view and if you use that with a red dot finder - maybe a Telrad - that should help your back.

[dmahon]

As above. A reticule eyepiece (i.e. crosshairs) helps even more.

Or just connect up a camera and use plate solving software.

[rkc]

For everyone that recommended a Telrad above - thanks again. I ordered one last week but only got a chance to try it today (from inside through a window - too cold to go out) and it was an absolute revelation. Every star I could see with the naked eye, I could get in the eyepiece first time, every time. So much easier than the finder scope, and much less contortion required.