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Seben 6x30 RA finder


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At the moment I'm using the stock 9x50 straight through finder on my 250px.  I've been wanting to upgrade to the 9x50 RACI, but yesterday I came across these Seben 6x30 RA finders for £13.99 (!!!!) brand new from Seben themselves.  Has anyone got any experience of these?  Would a 6x30 RA be better to use than a 9x50 straight through? 

Also, forgive my ignorance, but does an RA finder always show a corrected image or would it be identified as RACI rather than RA?

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I have not used this finder myself, but Seben seem to get mixed reviews with some products getting good reviews whilst others getting dire reviews.  I have the Seben 8-24mm zoom eyepiece myself which is actually really quite good considering the low price tag.

Regarding the finders, a RA finder will show an image that is the correct way up but that is still mirror reversed (L & R are the wrong way around).  As you said above, RACI finders will show a fully corrected view (right way up and correct L & R).

You used to be able to pick up the Skywatcher 6x30 finders really cheap (£16 incl postage) from Astroboot, but now that their postage costs have increased they come in at about £20.

Hopefully someone will be along shortly that has experience of this finder. 

Ade

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Seben don't generally get good reviews but it might be OK for that price. I use 6x30 RACI's (Skywatcher) on my smaller aperture refractors and they do a decent job but for a larger aperture scope I think the 50mm aperture is strongly preferrable, if you can get one. I prefer RACI which shows the sky as my eye sees it and as my star maps show it. I can cope with the inversion / reversal when I look through the eyepiece of the scope !

The trouble with realy cheap finders is that they can have poor, non-achromatic objectives and also can be stopped down to an even smaller aperture !. So it could be a false economy, if you see what I mean.

A half decent 9x50 raci is going to cost around £40 on the used market.

Faced with having to do something to improve the useability of the scope for £15 I'd probably go for a low cost red dot finder in place of the 8x50 straight through, get it really well aligned with the main scope, and manage with that until I had the funds for what I find is the ideal setup on a medium to large dob which is a 9x50 RACI partnered with a Telrad or Rigel Quickfinder.

 

Edited by John
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I have both an RA finder and RACI finder on different scopes and use these in conjunction with a Telrad/Red Dot Finder (RDF).  I use the Telrad/RDF to point at the right area of sky and then zero in with the RACI/RA finder.

If there is only one finder on the scope I personally find a straight through finder easier to use as you can keep one eye open and get a target star into the field of view which you can't do with a RACI/RA as you're looking directly at the tube.  However, getting yourself into a suitable position to use a straight through finder can be tricky.

I agree with @John that for a low cost a Red Dot Finder is probably a better investment than a cheap/low quality straight through finder. 

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Thanks for the replies everyone, I'll hold off for the 9x50 RACI.  It'll be my next purchase anyway so it'll be Christmas or earlier, and my Rigel and 9x50 are perfectly fine for now.

I realised also that the views through finders in my books are always illustrated using a 9x50, so it makes sense to not step down as it'd only confuse me ;-)

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I bought the finder you're talking about recently and it's terrible. If you've got a standard Synta 6x30 finder then you can unscrew the objective cell and replace the one on the Seben. The threads aren't quite right, but it seems to work. Image quality is far better than the stock Seben and you get the benefit of RACI, but personally I'd save your pennies for a "proper" RACI finder.

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  • 3 years later...

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