Red Dot finder on 8inch Dob

[Arcturus75]

Just wondering if I'll need to get a finder scope for an 8 inch dob that comes with a RDF.  Have other people struggled with just a RDF? If so what's a good, budget finder scope for the job?

TIA

[jimmyjamjoejoe]

I bought an RDF with a view to mount it alongside the finder... Instead, it just replaced the finder. 

RDF + Wide eyepiece was all I ever needed to find anything.

[JOC]

I use a dual mount with a RDF and a RACI - I have the RACI spot on and use this for fine tuning after I find something with the RDF.  With this combo I find anything I can physically see in the sky (RDF's are not normally magnified) in about 30 seconds flat.  If I had to pick a single finder I'd go the red dot one and I'm just using the el cheapo SW one - just a dot - no actual circles like the telrads have  

[Arcturus75]

1 hour ago, jimmyjamjoejoe said:

I bought an RDF with a view to mount it alongside the finder... Instead, it just replaced the finder. 

RDF + Wide eyepiece was all I ever needed to find anything.

That's something I've not considered, spend money on a wide eyepiece instead of a finder scope.  Out of interest, what size eyepiece would be best?

[RT65CB-SWL]

Hi  Arcturus75 and welcome to SGL.

Have you had a look at the Rigel Quickfinder ---> https://www.firstlightoptics.com/finders/rigel-quikfinder-compact-reflex-sight.html  or Telrad finder ---> https://www.firstlightoptics.com/finders/telrad-finder-astronomy.html ? 

[Arcturus75]

3 minutes ago, Philip R said:

Hi  Arcturus75 and welcome to SGL.

Have you had a look at the Rigel Quickfinder ---> https://www.firstlightoptics.com/finders/rigel-quikfinder-compact-reflex-sight.html  or Telrad finder ---> https://www.firstlightoptics.com/finders/telrad-finder-astronomy.html ? 

Thanks for the welcome,

I already own a Telrad that I have on a smaller scope, I may swap the RDF and the Telrad as the Telrad will probably be better suited to this.  I'm still wandering if a Magnified finder would be useful too?

[RT65CB-SWL]

If it helps, I use a small RDF along with the 6x30 finderscope on my C6/SCT.

[Ricochet]

The finder you want to accompany a red dot finder is the skywatcher 9x50 RACI. Even the widest 2" eyepieces are too narrow in an f6 8" dob to replace the finder in my experience. 

[rockystar]

I'm the same as @Ricochet I use a telrad to start me in the right place, then a RACI to hop a bit nearer, a bit of may and aperture show a few more stars, or even the brighter objects, then hone in with a 24mm 82° EP - some objects I know well, I can get there bypassing the RACI, but most of the time, that is my route

[Arcturus75]

Thanks for the replies everyone.  Can anybody recommend a decent budget 9x50 RACI?

 

[Buzzard75]

My scope came with a RDF. It was absolute junk and I wouldn't recommend one to anyone. I now use a Telrad and am much more pleased with it. I've considered a dual setup with a RACI finder as well, but with the Telrad and a GoTo I haven't found an occasion where I've felt I absolutely needed it yet. Assumming a perfect alignment with the scope though, I can see how it would be convenient to use the RACI to center the object and not have to swap out eyepieces repeatedly in the scope itself.

[John]

2 hours ago, Arcturus75 said:

Thanks for the replies everyone.  Can anybody recommend a decent budget 9x50 RACI?

 

You can pick up the Skywatcher or Orion branded ones for around £40 on the used market. Keep an eye on the UK Astro Buy & Sell website (assuming that you are in the UK) or even place a "wanted" advert.

After trying a few combinations I've found that a 9x50 RACI next to a Rigel Quickfinder (similar to a Telrad) is a very potent combination on my 12" dobsonian.

[Louis D]

I had a home brew 60mm finder with interchangeable diagonals and eyepieces, and still couldn't find small, faint objects like Uranus, Neptune, and PNs.  In desperation, I added Sky Commander DSCs and found everything in 30 minutes I'd been struggling for months to find and never looked back.  On my dob, I use a Telrad or QuikFinder (have both mounts on it), a green laser sight, a 40mm Meade SWA 5000 for widest field views, and Sky Commander DSCs to find objects.  I don't always align the DSCs if I'm observing easy to find objects.  From experience, I know where to place the guide circles or laser point relative to bright stars for familiar targets.  I just never found a good use for a finder scope.

[JOC]

Serendipity reminds me that I posted a picture of my set-up and I've just sorted out how to find it.  This is what I use on my 8" Dob, and I find it's brilliant.  Another advantage is, if I need to once I am on things in the RACI, I can still use this to move from star to star if I need to.  Even with a goto I find that I need to be able spot things in order to calibrate it and its good for checking targets and using on the occasions I just want to view a single easy to see with the naked eye object (like Saturn) and don't want to run up the goto unit.  Interestingly I have noticed that I don't always put the two finders on this way around sometimes one way seems easier and other times the reverse is true.

[Luna-tic]

On ‎10‎/‎20‎/‎2017 at 06:23, Buzzard75 said:

My scope came with a RDF. It was absolute junk and I wouldn't recommend one to anyone. I now use a Telrad and am much more pleased with it. 

The thing I've found with RDF's is they occlude dim stars when you aim at them with it. A telrad uses a circle to center the object in and doesn't hide it.

On ‎10‎/‎20‎/‎2017 at 06:52, John said:

After trying a few combinations I've found that a 9x50 RACI next to a Rigel Quickfinder (similar to a Telrad) is a very potent combination on my 12" dobsonian.

I bought a Rigel Quickfinder for my C6 and Edge 8. They come with two mounts so they can be multi-purposed. I liked it better than a Telrad for an SCT as they take up less space on the tube, and the sighting reticle is elevated more, but it does the same thing as a Telrad. I hardly ever use the finderscopes for either telescope now.

[Louis D]

18 hours ago, Luna-tic said:

but it does the same thing as a Telrad

Almost.  It has a 2 degree circle as the largest circle.  The Telrad has a 4 degree circle.  I have both, and prefer the Telrad on my dobs where the size isn't such a big deal.  On my Mak and frac, it's definitely the QuikFinder.  The circles are also a bit easier to see in the Telrad.

[JOC]

Maybe I don't miss the circles of some of these finders because I have a goto that (in theory ;-)  ) should be working !

[Luna-tic]

2 hours ago, JOC said:

Maybe I don't miss the circles of some of these finders because I have a goto that (in theory ;-)  ) should be working !

Yeah, hopefully. I sometimes have to find it in the Quickfinder so I can center it in the EP during the first or second star in the alignment. Seems like the AVX 'sort of' remembers better as you go along, because the alignments seem to get more precise each time.  And now and again, instead of bothering with an alignment if I'm not going to be out long, I'll manually skew and use the Rigel. I'm really satisfied with it, and sometimes surprised how accurate it stays because it gets removed each time I take the scope apart.