Telrad or Wixey

[peteftm]

Hi all

Some advice please for someone who has lost his "GO TO" capability ! I now have a dob and don't have a clue how to star hop

What do you think my best bet is to start finding objects quickly, a Telrad or the wixey and stellarium?

Thanks for reading

Pete

[themos]

Experienced observers swear by their telrad.

I have a wixey and it's helped me find many things. I haven't tried a telrad yet.

[Doc]

I have both on my scope.

[peteftm]

I've just ordered the wixey from FLO along with a laser collimator which i guess is most important!

So with the wixey , can i just check the altidude of objects from stellarium and get the dob somewhere near the target? First levelling off the ota with a spirit level i take it.

Thanks for the replies

Pete

[dlp]

I tried the iPhone app 'AppBox Pro', which includes a spirit/angle level, last night but couldn't make much sense of it. It'd be a lot cheaper for me than a wixey if I could get it to work properly!

[Doc]

Thats correct as long as your OTA is level and you zero your wixey you will be fine. Double check on Polaris and adjust until polaris reads the correct altitude.

Also your base needs to be as level as you can get it.

[peteftm]

Thanks gents for your help.As long as i can locate the brighter messier objects say with the wixey i'll be happy for now

[glowjet]

Star hopping is not easy to start with and both additions will have their uses, invest also in a copy of Illustrated Guide to Astronomical Wonders, its not expensive, but provides all the help by way of photos star maps and diagrams for each of the many DSO and other interesting subjects located in the Constellations.

[pvaz]

Star hopping became very easy for me once I developed a method.

I have a transparent scaled telrad sight overlay for my pocket sky atlas. It's as simple as putting the telrad overlay on the object, look closely for a few seconds to memorise the position and angle of the circles to the closest stars, then mimic it in the sky. To memorize the angle I find it useful imagining lines and triangles between those stars.

95% of the time I get it spot on in the EP FoV in less then a minute doing this process, most of that minute spent memorizing the telrad vs atlas image. I'm so confident about getting the area right that even on tiny DSOs that don't jump at me in the EP, I just leave the scope be in the initial position and use AV and tapping to find it within the FoV. So when I'm finding Herschel 400 objects, the "find the object in the FoV" part often takes longer then the star hopping part.

However, It gets trickier when there are no naked eye stars (or this are rather faint) near the object, as I can't really mimic what I see on the Atlas without, at least, 2 or 3 stars near the telrad circles. This are the only cases I need to use the optical finder as an aid, but I often do long sessions without even removing the caps from the optical finder.

Of course, under LP, this method won't work.

[omneferuss]

I must confess a certain ignorance on my part here.. but isn't a Telrad no more than a zero-power finder, much like a Red Dot Finder? ...or is there something I've missed ???

[Doc]

It has 0.5, 2, and 4° circles that project onto the sky, so it's very easy with a telrad overlay on your map to star hop.

[omneferuss]

Thanks Doc, I can see the virtue of that to a certain degree ..but to me, the zero-power end of "finding" was never the problem.. arm's-length fingers handspans n all that, easily judged by eye... in my polluted sky, it's been the step from finder to EP-view that has lost me.. the extra stars and reverse-from-RACI view and change of FOV... it's that intermediate step that matters to me.. between zero/10 times, and higher powers..

as for the OP... might be better knowing if we're talking 10" Dob or ED80 EQ mounted ???

[pvaz]

I can see your point, but that only happens if you do the finding at high power. If you point with the finder, then look in the EP and find the object sitting there then the reverse view and extra stars won't matter. The idea here is to use the finder alone to pin point the object and then observe, thus you need as many naked eye stars as possible to get it right. I probably see around 500 from my backyard, but I would have to count to be sure...

Using the map bellow, notice the 2 stars near the middle ring in the telrad sight. Now you point it at the sky till it matches and voyla, M57 will be in the FoV of your EP. You can't do the same with a standard RDF.

PS-> I know M57 is a very simple example but it serves to illustrate the idea.

BTW the telrad is built so the distance between the circles always matches the sky to scale even when you get closer or farther away from the sight. So a scale overlay for the atlas of your choice will match exactly what you then see in the sky.

[Doc]

It can be hard finding those little galaxies and planetaries, to find them I orientate Cartes du Ceil or Stellarium so that it matches exactly what I see through my eyepiece. Then I find the brightest star or asterism near to the object I'm searching for then I can and jump star to star until I reach my final destination, sounds harder then it is and it works really well.

[spaceboy]

Thanks Doc, I can see the virtue of that to a certain degree ..but to me, the zero-power end of "finding" was never the problem.. arm's-length fingers handspans n all that, easily judged by eye... in my polluted sky, it's been the step from finder to EP-view that has lost me.. the extra stars and reverse-from-RACI view and change of FOV... it's that intermediate step that matters to me.. between zero/10 times, and higher powers..

as for the OP... might be better knowing if we're talking 10" Dob or ED80 EQ mounted ???

I agree with omneferuss to a certain degree. I have the same problem but going from naked eye to optic finder. I prefer RDF's as this eliminates the whole reverse view issue. I have recently picked up a telrad ( which I am still waiting to try out ) in the hope to enhance the whole RDF experience.

Pvaz where do you get the telrad overlays from??

[pvaz]

The pocket sky atlas haves a drawing of a telrad sight to scale on the hard cover.

I just scanned it, removed the background, and printed over one of those transparent-projector-sheets (they must have a proper name in english but I have no idea what it is! ^^)

[spaceboy]

Thanks

In english OHP FILM

[brantuk]

Hi Pete - you may like to join the Dob Users social group. There's lots of ideas on dob mods and equipment and you may have something to post up as well. It's under Communities... Social groups on tabs at top - or click the link in my signature

[Albireo380]

Hi Pete,

You might also want to consider a Rigel Qwikfinder. It is much smaller and a bit lighter than a Telrad, so may fit more easily onto your Dob. I have used mine for years and it is a cracking piece of kit. You can get it for about £32 from FLO.

Tom

[Moonshane]

I use a Telrad on my large dob and a Rigel on my small dob. I prefer the Telrad as it seems more accurate but both are good. I usually find things with the combination of the Telrad / Rigel and right angle corrected finder (I have on both scopes) and even with reasonable magnification the target is usually in the EP. Never used a Wixey byt all that levelling business sounds fiddly - I just put mine down, cool and start! I find star hopping and using the 'geometric method' (using the shapes of stars and the target to form eg a diamond) to be a great way to locate things.

[peteftm]

Many thanks for all your replies , i think this must be the most active astro site i've ever used

Pete

[LukeSkywatcher]

I'd imagine that for a Dob that a wixey would be uuber handy. I have never used either a telrad or a wixey.

[pvaz]

The wixey, along with an azimuth setting circle on the base are like a goto system. However you will need to align the base with the north, then align the wixey and have an auxiliary system to tell you the current alt-az coordinates of the object you wish to see (this can be a laptop running CdC or Stellarium or some other software on your mobile). So it reduces the fast setup time you usually get with a dob, you'll need power supply for the laptop and, as it works like a goto, you'll not memorize the objects locations as easily as when you star hop.

I like to memorize the locations so I won't be dependent on gadget to find objects, no matter if I'm using the scope or binos. Besides once you know where something is and you don't even need a chart, you can be much faster then any GOTO system. It also impresses just about anyone you invite over to take a peek on your scope!

[LukeSkywatcher]

I like to memorize the locations as I become non dependent on gadget to find objects, no matter if I'm using the scope or binos.

I agree.

I have no gadgets to use. I dont want to use any. I decide on a target and find myself a starting point and star hop my way across the sky until i know i am in the general area and then i slowly narrow my search area by increasing the magnification of my EP's.

Its how i have always done things. I tried a SkyScout a couple of times to locate objects but found it very unrewarding.

[peteftm]

I'm going for a telrad.I've always relied on GO TO in the past so i think it will be more rewarding to find objects myself