Tal 100RS...So, come on. Just how good are they?

[Trumpetnut]

I'm a newby to this esteemed centre of conversation and in all the posts I've read there seems to be a real hard core of tal 100rs followers. So, how good are they? Comments on build are welcome, but as a prospective frac jack what are thoughts on the view? Star tests? Chromatic aberration (I refuse to abbreviate)? The more comments on the experience of actually looking through one the better.

[nightfisher]

They are total rubbish, badly made glass in a rough and ready tube........................and im a total liar 

The Tal 100 in good condition gives superb views of Luna surface, excellent views of Saturn and pretty good on Jupiter, not so good on Mars, i think this is a common issue with Achromats and Mars.

Very good on globulars and some deep sky objects pus lets not forget double stars, the crayford focuser is a simple but well made unit, some people feel the overall build is a little "agricultural" but mine is well made, a lot of tals get modded into Solar scopes so a good alrounder

There is some thing about the Tal that just "appeals"

[John]

The one I had (an early one) was an excellent 10cm achromat. It showed a little false colour around bright objects as you would expect from an F/10 achromat but the objective lens seemed well figured and it matched the performance of the very good Japanese made Vixen 4" F/9.8 that I'd owned before it. That was pleasing because the Vixen was quite a bit more expensive than the TAL 100 was.

I then moved on to a Skywatcher ED100 which cost more (again used) but showed no false colour at all.

The TAL's I've had and used have had a slightly "agricultural" finish compared to, say, the Vixen, but everything worked as it should and the engineering was robust and bullet proof.

I think they have some character which is probably what appeals - to me they seemed like a 1950's / 1960's scope but with more modern coatings on the lenses.

[alan potts]

I been told by a friend that goes to Russia a lot and once lived there that many of these objectives are made to very high standard in military factories, when they have nothing to do they make telescopes, I think the place that makes Tal is in Siberia he did tell me the town, so should be good in the cold. Only what I have been told, I have not research this reply. For someone that never has had a scope he knows a lot about Lomo and Lzos.

Alan

[Bubbles82]

I have one and love the industrial feel although I've never looked through it

[Roy Challen]

They're not the best 100mm out there, but they are very good. And cheap. And interesting.

There is very little chromatic aberration on Jupiter or Saturn, slightly more (not at all excessive) on the Moon and Sun. I haven't really gone for splitting difficult doubles but Castor, Polaris, Epsilon Lyrae all easy. Airy discs are good although not quite as good as an ED70 I had in the past. I would go for one with the 2" Crayford simply because it's the best focuser that Tal 100s came with. The rack and pinion fitted to the 100 R has an almost useless travel of just over an inch, although this scope has the better lens coatings and (in my opinion) a much nicer aluminium tube.

I need a Tal 100 in my life, but it's like cars- if you can afford a Porsche or a TVR and you don't find TVR interesting/appealing then you're better off with the Porsche!

That probably doesn't help you, but that's my 2p worth!

[Trumpetnut]

What is the best 100mm achromatic then, Roy? And I'm only talking about functional seeing experiences here. Given the amount that people grumble about the limits of achromats I find it difficult to understand why anyone would not go for an ED or APO. In other words, what's the point of achromats?

[nightfisher]

They're not the best 100mm out there, but they are very good. And cheap. And interesting.

There is very little chromatic aberration on Jupiter or Saturn, slightly more (not at all excessive) on the Moon and Sun. I haven't really gone for splitting difficult doubles but Castor, Polaris, Epsilon Lyrae all easy. Airy discs are good although not quite as good as an ED70 I had in the past. I would go for one with the 2" Crayford simply because it's the best focuser that Tal 100s came with. The rack and pinion fitted to the 100 R has an almost useless travel of just over an inch, although this scope has the better lens coatings and (in my opinion) a much nicer aluminium tube.

I need a Tal 100 in my life, but it's like cars- if you can afford a Porsche or a TVR and you don't find TVR interesting/appealing then you're better off with the Porsche!

That probably doesn't help you, but that's my 2p worth!

Roy, please dont think i am taking any issue, but which 100mm do you think is best, its always interesting to get other peoples feelings on this type of question

[Earl]

Does 106 count ?

[Roy Challen]

I seem to have dug myself into a little hole!

Well, to answer the question, I simply don't know because I haven't experienced any 100mm refractors other than my pair of Tals. The fact that there are many more ED100s, triplet apos etc on the market used by many satisfied and experienced observers implies to me at least, that the Tal is not the optical equal of some of these scopes.

I conclude then (with tongue in cheek) that the best 100mm refractor is the one with the least optical aberrations.

Or the one/s you use the most, which for me means my two Tals. Oops, the hole has now turned into a pit!

[Earl]

from my limited experiance i did like the revelation 100mm f6 doublet, it was a nice scope and have always regreted upgrading from it, it was a keeper really.

http://telescopehouse.com/acatalog/Revelation_100mm_Apochromatic_Refractor-1-1.html

this is the TS one

http://www.teleskop-express.de/shop/product_info.php/info/p7549_Long-Perng-S600H-F-ED-Apo---Aperture-100-mm--f-6---2-7-Inch-Fokuser.html

[Stu]

Keep digging Roy, this is fun

[Trumpetnut]

Well, could someone perhaps guide me to some image examples of what chromatic aberration looks like then, please? I think I might be getting achromat block that is preventing me from dipping my toe in. If anyone has done astrophotography with an achromat I'd love to see some of the pictures (unprocessed) with perhaps a nod to the make and model of telescope. And again, what is the point of achromats?

[Earl]

, what is the point of achromats?

Price, at long focal lengths they perform well for that price.

[Roy Challen]

What is the best 100mm achromatic then, Roy? And I'm only talking about functional seeing experiences here. Given the amount that people grumble about the limits of achromats I find it difficult to understand why anyone would not go for an ED or APO. In other words, what's the point of achromats?

My analogy with the cars explains how I view the achro/apo situation. If you can afford either, and optical quality is the priority then you should buy the ed/apo, no question about it. But if you want a good quality achro with character, then a Tal 100 is a good choice. You could also go for a Unitron ( if you can find one for sale) or any one of the quality long f/ratio scopes from Japan that were made in the 70s-90s.

[nightfisher]

I seem to have dug myself into a little hole!

Well, to answer the question, I simply don't know because I haven't experienced any 100mm refractors other than my pair of Tals. The fact that there are many more ED100s, triplet apos etc on the market used by many satisfied and experienced observers implies to me at least, that the Tal is not the optical equal of some of these scopes.

I conclude then (with tongue in cheek) that the best 100mm refractor is the one with the least optical aberrations.

Or the one/s you use the most, which for me means my two Tals. Oops, the hole has now turned into a pit!

Roy, please dont feel you have dug a hole  (if you want to do some digging i have a pier to put in soon  )

Even though i rate the TAL as one of the finest 4" refractors, i would be the first to agree that a 4" ED should out perform the TAL

I bought a Starwave 102 f11 thinking i would sell my TAL, nothing wrong with the 102 but i guess it just did not have the TAL appeal, though other people might find the starwave more "appealing" than a TAL

[Jim Steele]

I'm a newby to this esteemed centre of conversation and in all the posts I've read there seems to be a real hard core of tal 100rs followers. So, how good are they? Comments on build are welcome, but as a prospective frac jack what are thoughts on the view? Star tests? Chromatic aberration (I refuse to abbreviate)? The more comments on the experience of actually looking through one the better.

They are a cracking scope for the money, they have a look, smell and feel all of their own.

Sure they are better (more expensive) scopes out there but they hold their own against most, at F10 they are easy on eye pieces so the perfect beginners scope, no cool down and minimal aberration.

Sure a Takahashi would give better performance, but for less than £250 they are a no brainer for any budding frac fan.

They are also a lovely white light scope with baader film or a wedge

Ben

[Roy Challen]

Well, could someone perhaps guide me to some image examples of what chromatic aberration looks like then, please? I think I might be getting achromat block that is preventing me from dipping my toe in. If anyone has done astrophotography with an achromat I'd love to see some of the pictures (unprocessed) with perhaps a nod to the make and model of telescope. And again, what is the point of achromats?

Chromatic aberration arises because the lens brings only two wavelengths of light to focus. This manifests in the eyepiece as a blue/violet fringe around bright objects. Apochromatic lenses bring three to focus and are essentially 'free from colour'. My gallery has a picture of M42 and nearby stars show a blue halo around them.

[Steve Ward]

Pretty much unbeatable given the price ... sure there are better (on paper) 100mm f/10 achromats out there but at the best part of three times the green ... 

[Roy Challen]

Roy, please dont feel you have dug a hole (if you want to do some digging i have a pier to put in soon )

Even though i rate the TAL as one of the finest 4" refractors, i would be the first to agree that a 4" ED should out perform the TAL

I bought a Starwave 102 f11 thinking i would sell my TAL, nothing wrong with the 102 but i guess it just did not have the TAL appeal, though other people might find the starwave more "appealing" than a TAL

Well, I guess that's what I'm trying to say too. To certain people Tals have appeal that goes beyond it's optical abilities. The ED I was referring to earlier was a Starwave, cracking little scope with seriously good build quality.

[Earl]

my experiance fo starwave optics would lead me to try out a Tal to be honest.

[Stu]

my experiance fo starwave optics would lead me to try out a Tal to be honest.

Not impressed Earl?

[Earl]

I was not, everything else was great for the price but the optical performance for what was labled an "astrograph" at the time was very disapointing.

[Trumpetnut]

So it's just a cost issue? Different achromats offer different qualities of colour correction? And the Tal 100rs offer a better level of colour correction and sharper views than other achromats of a similar price?

[Earl]

So it's just a cost issue? Different achromats offer different qualities of colour correction? And the Tal 100rs offer a better level of colour correction and sharper views than other achromats of a similar price?

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