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TAL100RT vs TAL100RS?

twotter

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twotter

twotter

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Could anyone help me understand the differences between these two telescopes please?

I think it comes down to different coatings on the optics (purple on the RT and pale green on the RS) & a different focuser (1.25" on the RT and a crayford 2" on the RS), but I'm not totally sure. Also interested if I should choose one over the other?

Thanks.

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nightfisher

nightfisher

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Hi Twotter, you will only get the older 100r as a second hand scope, i think there might be one on ebay at the mo?

the focuser on the 100r is a rack an pinion, not all that good but usable and some say the 100r had slightly better lens

the newer 100 rs is a superb scope with a crayford single speed focuser 2" with 1.25 reducer, though in my strive for perfection i am looking into getting a dual speed focuser for my 100rs.......god knows what i will do with the original tal focuser, i heard of some one that created a 100rs with the older purple lens and claimed it was a stonker of a scope

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AndyH

AndyH

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Hi.

The 100R was the first 4" F10 Tal produced. Had a short metal dewshield and a 1.25" r&p focuser, similar to the focuser on the Tal newts and early Klevtsov's. I think the focuser had a range of about 25-30mm. Fine for std plossls, orthos etc, but problamatic if using eyepieces that required a lot of infocus. This was called the 'R'

Whilst the above was still rolling off the production line, a new ota with the same lens, but with a 2" r&p focuser, was brought out. Shorter tube to take the large focuser and large solid plastic dewshield. This was called the 'RS'.

Mid 2000's the 2" r&p focuser was changed to Tal's 2" crayford. Around this time, probably a bit earlier, Tal developed a new coating system for their lenses(and aluminising for their mirrors), hence the change in the colour of the coatings from a deep purple to a more 'greeny' hue. Designation was kept as the 'RS'.

The 100R was eventually phased out, not 100% sure when. Perhaps early to mid 2000's?

The talk of the purple lenses being better than the greener ones is one that Tal deny*. They say the newer coating tech is an improvement. Perhaps users that have tried the two side by side are seeing differences in the actual lens finish rather than the coating. Only more user reports could really decide this, I guess?

Whenever you see a 'T' in amongst a Tal designation, all this means is that that scope comes with a Tripod, rather than a pillar/pedestal.

So, if it were me, I wouldn't fret about the lens coating, but would be rather more interested about the mechanicals, of which the newer versions have superiority. Not that I wouldn't be very tempted if an old 100RT came up, in good nick, with mount, tripod and all accessories included. Something about these old girls that make me smile and feel warm n fuzzy :smiley:

Hope that helps a wee bit.

Cheers,

Andy

* I say deny, but really mean, they're saying nowt about the subject. I've only read them saying that the new coating tech is an improvement.

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Astro_Baby

Astro_Baby

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Older versions of the R versions are also reputed to have worse baffling inside the scope with gaps.

Something to bear in mind as well is no two RS units ever seem to be quite the same. Mine has a much shorter focuser block than some with the result it has more in focus than some scopes.

For the right money secondhand these scopes are a killer, the newer Rs version probably wins out over the older one as stated above because of ts superior mechanicals. Lightly loaded the focuser on mine is a dream. Stick some orthoscopics into it for planetary and its amazing, put a big widefield EP in it and you'll be surpised at how wide the view is and how sharp.

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nightfisher

nightfisher

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Thanks for the info. Mrs Twotter has just admitted that there was one on eBay :)

That sounds very interesting i have toyed with getting an older 100r and putting the better focuser on it, as its just 3 little screws to swap out, but i will stick with my 100rs and look forward to some more up grades

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Dodge

Dodge

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I've only had one EP that didn't come into focus with my 100RS, and that was my (huge) 28mm 2" Nirvana. With a 2" diagonal, I didn't have quite enough in-focus. Without the diagonal, it was fine.

I've not come across any 1.25" EP's that didn't come into focus either with or without a diagonal.

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Mr Fiery Jack

Mr Fiery Jack

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That sounds very interesting i have toyed with getting an older 100r and putting the better focuser on it, as its just 3 little screws to swap out, but i will stick with my 100rs and look forward to some more up grades

I almost think up-grading a TAL is a bit of a crime really, a bit like modding a moggy minor.

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nightfisher

nightfisher

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I almost think up-grading a TAL is a bit of a crime really, a bit like modding a moggy minor.

so whats wrong with a moggy minor gettinga V8 transplant :grin: :grin: :grin: :grin:

i really like my Tal and want the best from it :cool:

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AndyH

AndyH

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I am wondering if my Hyperions will come to focus but if they don't I've got a good range of plossls to try instead. Either way I'm looking forward to trying it out on the Moon :)

If you try out your hyperions along with any std plossls etc, on another scope, see how much more infocus the former need compared to the plossls. Hopefully very little(ie: less than 10mm), which might mean you'll have luck.

I've STILL to this day never had a better view of Saturn, than I had with my old RS. Stunning view. I literally had to drag my dad away from the eyepiece that night. A mixture of perfect seeing and great optics.

When santa arrives I beg for some pics.

Andy.

ps: Twotter - do not click on this link, unless you want santa to be annoyed and not to deliver your xmas present.

Everyone else - Here's the ebay 100R. Rather tidy. http://tinyurl.com/cd8wa8g

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AndyH

AndyH

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That sounds very interesting i have toyed with getting an older 100r and putting the better focuser on it, as its just 3 little screws to swap out, but i will stick with my 100rs and look forward to some more up grades

You'd need to shorten the 100R tube for the new RS focuser to reach focus though. I think the R tubes are about 2" or so longer?

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twotter

twotter

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I am informed that if (and it's a really big if, in fact the biggest if, in the history of ifs), if, the skies are clear from Friday night then Mrs Twotter may allow a test viewing....in the interests of science.

I did say if :)

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