Orion 120ED Ad

Started by T.R., 07/23/2006 12:58AM
Posted 07/23/2006 12:58AM Opening Post
Orion's 120ED has a full page ad on the last page of Sept. S&T issue. F/7.5 and priced at $1999. I wonder if the orions are of the sky-watcher ed quality? Orion uses FPL-53, do the sky-watchers? I think its priced abit high, does 20mm more glass really more than double the price?(100ED is $899) Never quite understood the the jump in price for such a small difference in area. Maybe the price will "correct" after the newness wears off...it would then be a great buy if it can match the 80ED's quality.
Posted 07/23/2006 12:41PM #1
>>>Orion's 120ED has a full page ad on the last page of Sept. S&T issue. F/7.5 and priced at $1999. I wonder if the orions are of the sky-watcher ed quality? Orion uses FPL-53, do the sky-watchers? I think its priced abit high, does 20mm more glass really more than double the price?(100ED is $899) Never quite understood the the jump in price for such a small difference in area. Maybe the price will "correct" after the newness wears off...it would then be a great buy if it can match the 80ED's quality.
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Tim:

Here's some simple minded thoughts I have had regarding this scope.

1. Cost... For a similar design, one model suggests that the cost of a refractor is proportional to the cube of the aperture. This worked with the ED-80 to ED-100 projection. With a 120mm scope, and remmembering that the ED-100 was introduced at $999, would put the price of the ED-120 at $1726.

2. This scope is F/7.5, the Ed-80 is also F/7.5. Again my simple minded model suggests that to keep the same level of color correction with the same manufacturing tolerances and techniques, the ratio of the aperture to the focal ratio should be constant... Again this is true of the ED-80 to ED-100 comparision, but not true here... I think it would be a challenge to produce an ED-120 F/7.5 that would match the color correction of the ED-80, my thinking suggests that to do that, this scope should be around F/11.

When the Skywatcher versions of this scope came out, the reports I saw said that indeed there was significant false color, which is consistent with my simple minded analysis.

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I really hope Roland takes the time to comment on the difficulty of designing and manufacturing a 120mm f/7.5 doublet based on FPL-53 and what sort of color correction one might expect based on the ED-80 and ED-100....

Best to all...

Jon Isaacs
Posted 07/23/2006 03:52PM | Edited 07/23/2006 03:54PM #2
I'm with you Timothy - $1999 for a Chinese-made, ED apochromat OTA is astronomically high. Recall when Orion debuted the 100 ED it was priced at $999, then retreated to $899 after the novelty wore off. The same reduction will likely take place for the 120 ED, but even at $1799 I think it's an awfully high price for a sub-5-inch Synta OTA.

I have a 100 ED OTA and it's a wonderful scope optically, BUT mechanically it's only adequate. It lacks a collimatable cell, suffers from a crude Crayford focuser and has sloppily finished metal work such as a crude, unfinished edge on the dew shade. It's a good value at approximately half the price of a TeleVue 102 OTA.

I also have a Meade 127ED OTA. While that scope features an FPL-51 equivalent rather than FPL-53, and is therefore not as color free as a doublet made with FPL-3, mechanically the OTA is many fold superior to the Synta-made 100 ED's OTA. The Meade R&P focuser is excellent - as good or better than an Astro-Physics R&P unit I have on a D&G. The metal-work is far superior to the Synta as well and the scope has a collimatable cell. The Meade OTA was ~$1600 new from Anacortes and I've seen used examples for as low as $1275 on Astromart.

Given the above, to represent a "value" (at least to my sensibilities) the 120 ED would have to be priced at $1300-1400.

Put another way, I'd rather drop another $1000 on a Vixen ED115S than pay $1999 for a Synta 120 ED.

Regards,

Jim
Posted 07/24/2006 05:07PM #3
Timothy McDougall said:
Orion's 120ED has a full page ad on the last page of Sept. S&T issue. F/7.5 and priced at $1999. I wonder if the orions are of the sky-watcher ed quality? Orion uses FPL-53, do the sky-watchers? I think its priced abit high, does 20mm more glass really more than double the price?(100ED is $899) Never quite understood the the jump in price for such a small difference in area. Maybe the price will "correct" after the newness wears off...it would then be a great buy if it can match the 80ED's quality.

I don't know. As Jon mentioned, the cost goes up as the cube of the aperture--even more than that if you take into consideration the need for homogeneity over a greater volume of glass. But that only applies to the raw cost of the glass. The whole scope shouldn't go up as the cube of the aperture.

The problem is that there's just so much that could vary here. Even if you assume a given quality of color correction (whatever it might be), there's still plenty else that can affect the cost. You can spend a lot of time to make sure the optics are smooth, or you can just do a little touch-up off the machine. Either way, it still uses FPL-53 glass, but I bet you'd see quite a difference on low-contrast detail.

The bottom line is that the price will react to the market. If, after a few of these get looked through, the word is that the optics are only so-so, it'll come down. Personally, I wouldn't be in a rush to purchase one of these, and at that price, I suspect others won't, either.