Best refractor 120/140

[Stu]

45 minutes ago, SimonIRE said:

Although weight is perhaps a negative, the TOA130 is the best corrected refractor you can buy in my opinion. The only comparable scope that I haven't looked through is the AP130GTX which I expect is very very good too. 

TOA130 was very tempting for me, but the length/focal length put me off. Would love to try one in future as I’m sure they are fantastic. Try, likely not buy!! 🤣

[Deadlake]

4 hours ago, Stu said:

TOA130 was very tempting for me

I looked at it as well, but it was too slow for my use case and also it’s repudiation for cooling down relatively slowly. 

Edited September 12, 2021 by Deadlake

[SimonIRE]

2 hours ago, Deadlake said:

How does colour/contrast compare between your LZOS and TOA?

This isn’t easy to answer. On planets, the LZOS definitely wins both on colour and resolution (obviously) but the TOA is incredibly good. Colour correction to my eye on the TOA is slightly better. As an astrograph with the 67 flattener it produces and perfectly flat field across a IMX455 chip - something you might expect but I have failed to achieve in my FSQ106 for example (I am a pixel peeper to the nth degree). I’m going to change the focuser though - I have a FT arriving next week. My LZOS is now in Spain for imaging only. 

Edited September 12, 2021 by SimonIRE

[Andrew_B]

6 hours ago, Deadlake said:

Ageema already make them, however a long wait time and not that much lighter then many triplets.

Only produced in small numbers as well. They look superbly made to the point of being over-engineered although the weight does kind of remove one of the big selling points of having a high quality doublet in the first place.

In theory one of their scopes would be an option for the OP but waiting times and no availability secondhand pretty much rules them out.

[Highburymark]

At these apertures, scope size and weight really do increase quickly as the amount of glass rises exponentially with each 10mm jump (particularly when upgrading to a triplet). The TOA 130mm looked like a sizeable increase in bulk from TSA-120 - incredible telescope though. 
Just weighed my fully laden TSA-120 as 8.7kg - I can still use it on a carbon fibre Gitzo 4-series tripod rated for 25kg (with a Skytee mount), but must admit the 2 second vibrations are distracting, so I’ve just found a secondhand 5-series Gitzo rated for 40kg payload - and even more importantly, improved stiffness. Am hoping this will work well with the Tak.  I just don’t have the space for a bigger wood/steel astronomical tripod, so this scope is as far as I can go with a camera tripod. 
Never used one, but looks like the Rowan mount could probably handle all of these scopes, though.

[Highburymark]

30 minutes ago, Andrew_B said:

Only produced in small numbers as well. They look superbly made to the point of being over-engineered although the weight does kind of remove one of the big selling points of having a high quality doublet in the first place.

In theory one of their scopes would be an option for the OP but waiting times and no availability secondhand pretty much rules them out.

Agree they look and sound superb - but also pricey in Europe for a doublet - they cost the same as a TSA triplet fitted with FT focuser

[Space Hopper]

24 minutes ago, Deadlake said:

I looked at it as well, but it was too slow for my use case and also it’s repudiation relatively slow cool down. 

I looked at a TOA130 as well, and read the same. The 3 elements are pretty widely spaced apart.

 

[Fedele]

 

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Edited September 13, 2021 by Fedele