Changing from a RDF to an optical viewfinder?

[pipnina]

Since looking for a star chart, I figured a RACI optical viewfinder would make finding objects via star-hopping much easier compared to the RDF supplied with my Explorer 130. I did some googling and found this: http://www.firstlightoptics.com/finders/skywatcher-9x50-right-angled-erecting-finderscope.html

Does this look like a good finder to replace my red dot? The red dot has, so far, only been useful for getting very bright objects in view (e.g. the moon, M42, planets) and less so for anything else.

    ~pipnina

[knobby]

That's a decent finder, but not everyone gets on with them ... I've got one on my Dob but can't get used to it , I like to look at the sky with one eye and the other eye through the finder ... Not easy with a raci

[ronin]

Finders are something that suit a person or don't.

The one linked to is sort of a standard one and so you should be fine.

I say this as people say how good a telrad is, the time I used one it was about the worst thing I have ever looked through. I couldn't see anything in it or through it. To say it is not the finder for me is an understatement. I would rather just aim along the scope OTA and had better success.

So yes it may be an improvement and should be, but as I found some just do not suit a person.

What will happen with the one shown is that it will collect more light and so hopefully show the target object a bit more, it will also show a lot more stars and so could cause confusion.

RDF's simply put a dot in your view where the scope is pointed at. The idea is you put the dot where an object should be, even if you cannot see the object. You have to determine where it should be and just aim there, yes you are aiming blind but that is how they work. The Ring nebula is an easy example, you probably cannot see it by eye, but the location is fairly easy mid way between the 2 "lower" stars of Lyra. The other aspect of an RDF is you do not look at the RDF you look at the sky beyond it and ignore the RDF.

[laudropb]

Hi Pipnina. I use this finder on my Dob and have found it very good, but I also use Telrad with it. You have got to remember that this finder will give you a 9x image. You will see a lot more stars and you have to get used to this.

[pipnina]

Thanks guys, I think I'm gonna get it. If all else fails I still have my RDF, I guess.

Apologies for the cloudy skies!

        ~pipnina

[Tinker1947]

Save your money and buy a Telrad.......

[pipnina]

Save your money and buy a Telrad.......

I've looked at them and they look compelling... So much choice!

One note about the telrads, though: How do i fit it to my scope? The guy in a video I watched about them mentioned tape... sounds like a lot of time and effort and a big potential for screwups... Or does it fit some other way?

    ~pipnina

[knobby]

Double sided sticky pads ! I reckon though that the rdf and the raci together will work well, the rdf can get you close to an object then the raci can get you closer , good luck with your choice

[Tinker1947]

The telrad comes with sticky pads you roughly line it up with the scope centred on a bright star........then once attached adjust as required....

[pipnina]

I see many benefits for having both... I am honestly more tempted by the sight than the telrad...

Decisions decisions...

I'm thinking the only way to know for sure is to try both. But given as I'd probably like things to be magnified and not have to deal with replacing batteries (I always forgot to turn my RDF off and within a month the battery went flat) ... I think the RACI would be best for me... That is: If it has a crosshair of some sort (It does have one, doesn't it)

[astronymonkey]

Hi,

I use both a red dot and the 9x50 raci side by side and find that works well. You do need to fit an additional shoe to use both together but you can use the red dot to get close then use the raci to centre to object .... and yes, the raci has a cross hair built in.

Cheers

[Charic]

I have  a standard 9x50 finder scope and a Telrad.

I sold my first Telrad because of my requirement to have to wear prescription glasses to see the target reticules properly, yet do not need the glasses to see through the telescope. After I sold it, I bought another one, as it felt as if something was missing. I have never used the new one since due to the brightness of my observatory (garden). but away from the lights and into the darkness, I cant see the finder scope reticule against a dark sky, so the Telrad should be my better option. 

With my 9x50 I observe with BOTH EYES OPEN.

[inedible_hulk]

Hi,

I replaced the RDF on my Explorer 130p with one of these. It's very good, but I found it hard to use on its own, so quickly added a the Telrad's little brother, the Rigel Quick Finder: http://www.firstlightoptics.com/finders/rigel-quikfinder-compact-reflex-sight.html. They make a very effective combo and, being smaller, the Rigel is a better fit for the scope.

As previously stated, straight through finders are easier to use as you can keep both eyes open, but given the observing position on a newt, some contortionist-like manoeuvres would be required [emoji3].

Just a word of warning though: it's quite big and makes balancing the scope a bit tricky. This pic should give you some idea of the size.

Sent from my iPad using Tapatalk

[chiltonstar]

I use a combination of a RACI and an RDF as well as I find this gets me in the area very quickly (RDF) and then exactly to the spot with the RACI. Sighting along the tube is a bit more difficult with a MAK or SCT than a frac for obvious reasons.

I've got a dual mounting bracket, but it does raise the RACI a little too much (and I keep smacking my head on it) so I've dismantled the original, ultra-cheap RDF that SW supplied and fixed it to the RACI to get a more compact combination.

Chris

[astronymonkey]

Hi chris,

I haven't heard of combining the raci and rdf. Do you have pic you could post up and I wondered about how you still adjusted the aim of the raci independant of the rdf.

Cheers

[chiltonstar]

Hi chris,

I haven't heard of combining the raci and rdf. Do you have pic you could post up and I wondered about how you still adjusted the aim of the raci independant of the rdf.

Cheers

I originally used a plastic jubilee clip, but changed to simple black insulating tape so that I can remove it easily. I attach it to the front barrel (parallel sided) of the RACI once it is focussed and locked; the plastic rail of the RDF is also parallel sided, so it lines up well - just  a tweak with the lateral and vertical adjustments of the RDF to get both finders co-aligned.

Chris

[Astro Imp]

I use a Telrad together with the RACI you link to and find them a good combination.

[astronymonkey]

I originally used a plastic jubilee clip, but changed to simple black insulating tape so that I can remove it easily. I attach it to the front barrel (parallel sided) of the RACI once it is focussed and locked; the plastic rail of the RDF is also parallel sided, so it lines up well - just  a tweak with the lateral and vertical adjustments of the RDF to get both finders co-aligned.

Chris

Thanks chris.

Cheers

[pipnina]

After all of the posts on this thread, I've decided I'm going to get the RACI finder and use that in conjunction with my RDF until funds allow me to get a telrad to compliment it.

Once it arrives I'll say how I got on with it.

[laudropb]

Good choice !!! Best of luck.

[Night Hawk]

I love my Telrad. I couldn't get on with my FS by itself, however when both are used together they come into their own when hunting dso's.  Also  when re alligning my FS with polaris as I always manage to knock it when I move it at the end of my session!