Why are Synta OEM refractors such good value?

In recent years I have owned or had pass thru my hands these Synta-sourced refractors from Celestron, Orion, Skywatcher:

150mm F8 achromat
120mm F8 achromats, 2 good, 1 returned
100mm F10 achromat
100mm F10 triplet prototype (yes has more color than the ED below but much better than the achromat above)
100mm F9 ED doublet
80mm F 7.5 ED doublet, 2 good
70mm F10 achromat, 1 mediocre

I know its not a good idea to generalize, and 8 out of 10 certainly isn't perfect, but the 8 are actually excellent in star testing. I've certainly seen crummy Unitrons and other legendary makers, so I think we live in interesting times when even inexpensive optics can deliver results out of line with cost.

I'm not a fan of star tests because there is so much that can be done wrong with them. At least, speaking for myself. I'm more comfortable with "that's a good view of Jupiter or it isn't." Certainly you can have ten scopes that seem to star test well and half of them prove to be defective under other kinds of testing (such as quality of image).

But I don't think a 20% defect rate is anything to brag about. You are right, however, that even top names often mess up. Speakng from my experience, I've had not-so-good-luck with mainland China products (which incidentally is getting a lot of press on other issues: lead paint, defective heparin, contaminated food exports, etc.) in astronomy and have gotten more satisfaction by paying more and getting equipment that is all-around better built.

I freely recommend the mainland Chinese Newts to beginners, not because I think they have a better qc/qa than the refractors, but because I do think they are the best deal out there for newbies who might otherwise suffer from sticker shock. I guess I avoid recommending the refractors because you're paying more (as with any refractor design for qc/qa that appears to be no better than what you can get with the Newts.

I'm somewhat sorry to see some of the inexpensive Japanese achromats having lost out to the mainland Chinese. The Omcron (maybe similar to Antares) was a pretty good achro in its day.

regards
Greg N

I would agree that Synta refractors are a
good value -- reasonable quality for what you pay.

150mm F8 achro -- 3 very good; 1 returned
80mm F7.5 ED -- superb

4 out of 5 were quite good in star testing; 1 of 5
had terrible coma -- something gone wrong with the
lens spacers I suspect.

I had the same impression too!

150mm F8 achromat - Very Good

8" F4.9 Newtonian - Superb!

2, 4.5" F8 Newtonian - Good

120ED - Superb!

Sold my TV102 after seen a 4.5" F8 Newtonian. Not enough visual difference to justify the cost difference.

Clear Skies,
Gu

PS. Attached is a jupiter photo from a $45 used 4.5" Newtonian

Attached Image:

Reason is that achromats are relatively easy to make, glass is quite inexpensive, so if someone gears up to make thousands of them, the cost can be very low.

Rolando