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Old 19-08-2014, 07:27 PM
issdaol (Phil)
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Join Date: Dec 2009
Location: Canberra
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Quote:
Originally Posted by rally View Post
You are not paying for aperture so much as you are paying for a higher level of chromatic correction and quality of optics.
The TOA is an acronym for Tak. Ortho Apochromatic Vs Tak Super Apochromat (TSA)
Have a look at a longitudinal aberration plots for these and you will see the difference.
The TOA series is highly corrected (near perfectly !) from well into the Infrared to well into the UV spectrum.

Like most things - if you want 50% of perfection - its cheap, if you want 85% its getting more expensive, if you want 95% its getting really expensive and if you want 97% it starts getting ridiculous.

For visual I think it would be hard to justify and difficult to discern.

Rally
Very well put

Just a visual inspection of the 2 scopes will also show the differences.

I use my Mewlon 300 for Deep Space and Planetary. The TSA-120 just cant keep up for deep space work.

But 1 very good reason for a refractor over a mirror/light bucket is Solar .

In terms of visual between the TSA120 and TOA130 you will not notice the difference. I had to make the same choice myself and went with the TSA120 saving the $1.5k and putting that money into a couple of nice EP's.
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