Red dot finder problem

[Adamchiv]

Hi guys, in pretty sure this will have been brought up before but here goes..... my skywatcher explorer 130m came with a red dot finder, and obviously some cutbacks had to be made to sell this set up at such a good price. Im fairly sure the red dot finder is one of them and is the most basic available (no problem with that at all). So when trying to point at a star with this finder I noticed that it was very hard to know with any degree of accuracy if it was lined up correctly. If I move my head ever so slightly then the dot will move away from the target, and since I cannot know if my viewpoint is dead central, it seems impossible to allign correctly with any certainty. So I was wondering whether to upgrade that straight away, and if so, what is a good upgrade? Also is it just me doing it wrong and are all red dot finders like this? Would a crosshair finder be more accurate? 

Thanks if you can help, adam

[cloudsweeper]

The RDF is OK if you line it up with something - get it in the centre of the EP, then adjust the RDF so it's right on it, as far as you can tell.  (Again, just judge as best you can with the dot in the centre of the view.)

And remember to adjust the brightness - it can blot objects out.

I soon went for a finderscope - the RACI types give a non-inverted image, and have a reticle.  But I still keep the RDF on the arm leading to the finderscope, and use that for a rough aim, then the finder, then the low power EP.  Others swear by the Telrad finder with red circles corresponding to angular measures.

Doug.

[Davey-T]

There are various designs of RDF some with crosses, some with a rotator to give you a choice of reticle, generally I've found them all a bit bright so they extinguish the star, especially dimmer ones, the Telrad isn't too bad but a bit big, the only real solution is to lash out on a right angle illuminated finder.

Dave

[ronl]

I use one of these http://www.firstlightoptics.com/finders/rigel-quikfinder-compact-reflex-sight.html it is very good, and very lightweight,

read the reviews, this will give you an idea what it would be like on your scope, I wouldn't be without mine.  

[Linda]

24 minutes ago, ronl said:

I use one of these http://www.firstlightoptics.com/finders/rigel-quikfinder-compact-reflex-sight.html it is very good, and very lightweight,

read the reviews, this will give you an idea what it would be like on your scope, I wouldn't be without mine.  

I have it too and used it for a month. When aligning it in daylight, I have noticed that the red circle can point slightly at a different place depending on where I hold my eye. But it is not quite as bad as with my el cheapo finder scope. Still I really find it very usefull for pointing the scope at the nearest naked eye star. After arriving there, I use the finder scope or telescope to find the object.

[Mak the Night]

A lot of reflex sights suffer from being too bright. I eventually acquired a TS Optics RDAC but it didn't totally alleviate the problem. For large bright targets, especially planets low in the plane of the ecliptic it's fine. 

It's well made and I have one for each of my telescopes, but inevitably I bought an RACI which is used on my Mak.

Basically, it's a modified NATO gunsight. I think a Telrad or similar are probably the best reflex sights but until they make one that can be attached to a Synta foot I'll carry on with the RACI.

http://www.teleskop-express.de/shop/product_info.php/info/p7892_TS-RDAC-LED-Red-Dot-Finder-for-astronomy-and-daytime-observation.html

[The Admiral]

I changed my el cheapo plastic device for one like Mak the Night has, but I got mine from 365 Astronomy. Yes, it is a bit bright, but it's a joy to use, seems rugged, and seems to retain its alignment after removal and replacement on the 'scope.

Ian

[Mak the Night]

16 minutes ago, The Admiral said:

I changed my el cheapo plastic device for one like Mak the Night has, but I got mine from 365 Astronomy. Yes, it is a bit bright, but it's a joy to use, seems rugged, and seems to retain its alignment after removal and replacement on the 'scope.

Ian

I agree the metal ones are rugged and will retain alignment well after removal. For me, they are ideal until I need to observe above an elevation of around 30° or anything near the zenith. But for lower targets the RDAC can make target acquisition and/or re-acquisition very easy.

[Astro Imp]

When using red dot finders keep both eyes open and align your finder so the red dot covers the target star. This way there is no problem getting your head/eye in the correct position.

[Riemann]

You could consider a Telrad finder.   Very easy to use and extremely accurate.   The best accessory I have bought for my scopes.   The red dot finder on the SW 130 is OK but the Telrad is in another league.

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

Peter

 

[Adamchiv]

Thanks everyone, plenty for me to think about in those responses. This forum is a total dream, helpful, informative and friendly. Dark skies everyone! Adam

[brrttpaul]

i love the telrad, if i had any gripe then its the size , pretty sure they could make that at least half the size

 

[jonboy51]

I'm an absolute beginner! My wife bought me a Celestron 130 SLT for my Christmas. Due to the weather I've only had it out nly once! I'm having problems lining up the red dot, the adjustment controls don't seem to work with no movement at all when attempting to line up. I'm desperate to get things working as I'm fascinated by the planets. Can anybody help?

[cloudsweeper]

51 minutes ago, jonboy51 said:

I'm an absolute beginner! My wife bought me a Celestron 130 SLT for my Christmas. Due to the weather I've only had it out nly once! I'm having problems lining up the red dot, the adjustment controls don't seem to work with no movement at all when attempting to line up. I'm desperate to get things working as I'm fascinated by the planets. Can anybody help?

Hi there - 

You don't get a huge amount of movement, but you certainly should notice something!  Get a distant object in the (low power) eyepiece, then see where the red dot is in comparison.  It shouldn't be too far off.  Keep the dot in view on whatever you see behind it, then slowly adjust the up/down and side-to-side controls.  The goal is to get it over what you see in the middle of the EP.  

If you get no movement of the dot, check if anything is loose.

They are quite simple devices, and I've not come across a faulty one yet!  (Others might have different experiences!)

Hope you manage it,

Doug.

BTW, that's a nice 'scope, what with the GoTo and the alt-az mount.  You'll find it easy to align and use, and should get good results from it as soon as the bloomin' skies clear.  Then it won't be long before you want extra bits for it.  Have fun!

 

[The Admiral]

I originally bought the Baader Skysurfer for my 'scope, and found that I wasn't able to align it with the 'scope axis. When I checked it out I reckoned that it had 'down' movement but wouldn't adjust above its centre line. The good folk at FLO replaced it, but I found it to be worse if anything. In the end, FLO reimbursed me. That's when I went for the Lacerta metal bodied device (http://www.365astronomy.com/365Astronomy-Deluxe-Multi-Reticle-Red-Dot-Finderscope-Metal-Body-RED-GREEN-LED-wide-base.html ), which as I commented above, has been great.

Jonboy51, don't forget that you can do the aligning in daylight! Focus on a distant object and use that.

Ian

[jonboy51]

Thanks guys, will try this afternoon and let you know how things go. Thanks for the advice, really appreciated.

[Mak the Night]

3 hours ago, jonboy51 said:

I'm an absolute beginner! My wife bought me a Celestron 130 SLT for my Christmas. Due to the weather I've only had it out nly once! I'm having problems lining up the red dot, the adjustment controls don't seem to work with no movement at all when attempting to line up. I'm desperate to get things working as I'm fascinated by the planets. Can anybody help?

I'm not sure what finder is supplied with your scope but it's not unusual for some of the mass produced plastic reflex sights to be faulty. I had similar problems with a Sky-Watcher sight supplied with my Skymax. The 'Y' axis was fine IIRC but it wouldn't move far enough in the 'X' axis (side to side) to accurately align it with the scope. 

Eventually I replaced it with an Orion EZ II.

The X & Y movement controls (shown) worked correctly on the Orion. It fitted into the telescope finder shoe as it has a standard Synta foot, although I believe Celestron telescopes have different finder shoes.