Finderscope frustration!

[ramstar]

I know it will seem a really dopey question to nearly everyone but I have to ask or I'll end up giving up even before I've started! To set the finderscope, do I point the scope at a distant fixed object (preferably in daylight) then make the adjustments on the finderscope until the cross hairs are more or less central in the viewfinder and with the same object visible? I've had my first ever scope (Dob 200) out twice and am struggling to make any progress. At this rate I'll end up just looking through the eyepiece and chasing things across the sky!

[Bizibilder]

That's the usual way to do it. If the Moon is about you can use that as it is quite easy to find in the main scope before you adjust the finder - and line up on a crater like Copernicus that is easy to see in both.

[autonm]

Hi ramstar,

I also have the Dob 200 - 2 options

At night - aim the scope with the EP at say the centre of the moon or a real bright star. Then without touching the scope look through the finderscope. Next using the screws align the crosshair to be the centre of the object.

That should get you near enough, then as your using the scope more - tweak the crosshair slighty to improve accuracy.

Or during the day - aim the scope at a building / tree as far away as possible - 2miles + ? ... then again set the finderscope crosshairs to be on the centre of that object.

Hope that all makes sense.

[ronin]

Dead right.

What you end up doing is pointing scope, play with finder, check scope and recentre object then readjust finder.

Don't rush it, them clouds will be around for a while.

[ramstar]

Thanks - I'll follow your advice at the next opportunity then keep my fingers crossed!

[crazyjedi]

I usually use a fixed terrestrial object during daylight or a bright star at night. I wouldn't use the Moon though as it moves relatively quickly across the sky and will lead to lots of fiddling and frustration. The stars move very slowly by comparison and so is better. If possible use polaris.

A fixed land based object is good to use (the more distant the better)

[Scott]

+1 for doing it during the day. find an object in your lowest power eyepiece (highest number). when centred put in your highest power eyepiece (lowest number) and recentre. now adjust your finderscope so that the crosshairs are on the centre of your target. once centred, check that you still have the target centred in the scope (you may have bumped it). try to be as accurate as possible as it will make it easier to find things in the sky later. hope this helps.

Scott

[crazyjedi]

Good call on using your high power ep for fine tuning Scott I forgot to include that bit.

[cosmojaydee]

Just make sure the rubber band is placed around the finder scope, then pass the scope into the holder ensuring the rubber band sits inside the finder holder, without it you will not be able to make the adjustments

[Herbig]

A cross hair reticle EP is also useful for centering the object illuminated one for using at night.

[petecj]

Treated myself to a SW200p for Xmas and have spent the time since setting up etc (as no decent oppos for first use in anger yet!). Interested in cosmojaydee's comment about a rubber band on the finderscope? On mine there was one hooked over one of the adjusting screws and the pillar of the holder but no mention of its purpose in the manual?

Have been aligning (more or less successfully) on a daytime distant object.

All information gratefully received,

Pete

[cotterless45]

Chuck the finder scope away, get a red dot finder or a Telrad. You"ll learn the sky quicker and won't be confused about what is upside down or around the wrong way.

By using a 40/30 mm ep you should get most targets in the fov,

Nick.

[CSM]

A red dot finder is ok if you can see what you are trying to find, but if light pollution is bad then it can be difficult. And it can be difficult to actually center the object properly. Yes - a Telrad could be the answer, used with the finderscope.

[LeeB]

I use a red dot or telrad to find everything, even if you can't see it, you know where it should be (from charts) in relation to the bright stars, and a low power eyepiece will give a large enough field of view to fine locate through the main scope. I use either a 35mm or 43mm eyepiece for this.

[Dunkster]

Ditto the Telrad / Rigel sentiment ... I don't get on with my finder scope... prefer to use the Telrad and a nice wide EP

[crazyjedi]

Treated myself to a SW200p for Xmas and have spent the time since setting up etc (as no decent oppos for first use in anger yet!). Interested in cosmojaydee's comment about a rubber band on the finderscope? On mine there was one hooked over one of the adjusting screws and the pillar of the holder but no mention of its purpose in the manual?

Have been aligning (more or less successfully) on a daytime distant object.

All information gratefully received,

Pete

The rubber ring is supposed to be slipped around the outside of the finder before pushing the finder through it's holder ring. It will act as the point of cantact between the finder and it's holder. This allows the adjustment screws further back on the holder ring to make fine adjustments while the rubber ring acts as a sort of pivot point. It is a little hard to describe really

[autonm]

noob question (I have a 200p Dob) - whats a telrad?? and can any one post a link for one which would work on the 200p so I get the idea?

thanks

[Nibor]

noob question (I have a 200p Dob) - whats a telrad?? and can any one post a link for one which would work on the 200p so I get the idea?

thanks

Try:-

http://www.firstlightoptics.com/finders/telrad-finder-astronomy.html

They appear to out of stock but someone, somewhere should have one.

[muttley]

As another beginner with a 200p, I will chime in with my thoughts: it is fairly straightforward to line up the finder scope if you take it slowly. Definitely set it up during the day, as it is too dark and cold to be fiddling with alignment at night in the winter. Remember that everything is upside down & reversed, which takes time to get used to. I lined up on something large & close to start with (like a chimney a few hundred yards away with a low power eyepiece). Once that was OK, I picked something further away to fine tune. Repeat until you are happy.

I don't think there is any reason to choose between a finder scope & a telrad. I recently bought a telrad, and simply fixed it onto the main tube next to the finder. I now have the best of both worlds, as each has its advantages & disadvantages.

The first night I went out I struggled to find the moon in the finder(!!) but you get used to it quickly, so do persevere.

Simon

[Herbig]

I use both, I find the red dot/telrad is easier to use wearing specs

[LeeB]

A good point Herbig, it also stops your glasses getting scratched , as the telrad is viewed from a distance whereas im always banging in the finder.

[Josh Wilson]

Come on guys! What's the only star that hardly moves at all? Polaris! :D I always use Polaris to align my finder, because it hardly moves at all in the time you need to align it!

For focusing, I take it off the mount and focus on a bright star or planet (not the sun though!) or, if it's out, I use the moon. But once you get the focus, it pretty much stays locked unless it's dropped, in which case, focus isn't going to be the biggest issue.

Josh

[ramstar]

Having sorted out the finderscope issue from earlier in the week, i had my first proper viewing tonight. In the absence of a sighting of the moon from my patio, Jupiter was the obvious target. As a complete novice, it still took me a while to actually get it in the eyepiece but got there eventually before cloud put a stop to it. Were the moons the 4 objects to the left? Amazing to think how far away it is!

[Patrice Lanteigne]

Those were the Galilean moons. You have met Callisto, Ganymede, Io and Europa, lovely but shy ladies. Their other 60+ sisters are very shy and seldom seen from down here.

[emadmoussa]

That's what I would do. Sometimes I use the moon as a target.