Hello All,
I'm evaluating an Astro Tech 106LE for purchase. I don't know a lot about them. It will be my first high end refractor purchase and I have some questions:
-Is a field flattener a good thing to have for a visual refractor or is it primarily a benefit for astrophotography?
Mainly for astro imaging.
-Does the AstroTech 106LE have a flattener.
No, aftermarket only, but AT makes a decent flattener for it on their website.
-What does the LE suffix stand for in AT106LE?
Limited Edition. AT made 50 price point 106LE. Same glass as the AT106 with a less robust focuser at 2" vs 2.7", capable of carrying about 3 maybe 4 lbs. I heard from one source the aluminum tube might be slightly thinner, I don't know about that, but AT did put the AT106 on a "diet" in the last year or so. What they did I have do details, but likely made the OTA thinner among some other things. The move to make the instrument lighter was a good move on Astro Tech's part. In all of the information comparing the AT106 with the AT106LE, the only issue to crop up was the focuser. If an owner felt the stock focuser on the LE didn't suit their needs they would replace it with either the Moonlight or FeatherTouch. But then you are back up to the same price as the AT106. However, its apples and oranges comparing a stock AT106 to the Moonlight, which I installed on my C80ED. You buy a MoonLight and it makes the AT106 focuser feel cheap, thats just me though. I'm even at the point where I would like to upgrade the focuser on my AT106 based on my experience using one. I also like the fact they are pre-drilled for their auto focus package, whether DC or stepper design. Since I'm involved in imaging, its important to have a excellent quality focuser with equally excellent carrying capacity. Speaking of focusers, one of the reasons why I want to switch out the focuser is the fact the compression ring is held "tight" by only one thumbscrew. I don't know why Astro Tech went this route with such a fine instrument. Having only one securing screw for the imaging train doesn't instill confidence in my opinion. But for imaging, the focuser is more than adequate for the job.
My target refractor is a Williams Optics GTF-102, is this a better scope for a first higher end refractor? Is it worth holding out for a used one to appear on the market. The scope will be mounted on a new iOptron ZEQ25 with a 27lbs capacity. I'm setting a limit of weight at ~15lbs.
I can't provide any opinions here, I haven't had the opportunity to look through the WO scope, nor do have I read much about it. I like the fit and finish of WO products, always have. I like bling and cool machined parts and WO supplies all that. The WO brand catches my eye for sure. However, there was a period of time they were getting hit with QC complaints, I don't know if all that has been resolved. As you know the WO GTF-102 has a built in flattener. First of all and I don't know if this is even relevant, I read a comparative review sometime ago that involved three different FF. The WO flattener came in last and the images posted you could see why. Stellarvue had the best performing FF, but considering it's high price you would expect that. Personally, if the FF gives you edge to edge round stars and doesn't degrade the brightness of the image, thats all that counts with me. Most flatteners won't give you exactly middle image flat stars, but you would expect at least close to that. Furthermore, before buying a FF obviously you have to evaluate your views to even justify the purchase in the first place. The requirements are tighter when imaging and I went ahead and bought a FF even though I haven't had a real chance to determine the edge performance of the AT106. Chances are it will need a flattener, most scopes in the price point do and is understood. The fact WO did it at the plant and placed it internally is a convenience for sure, but I don't know what the majority opinion would be from imagers about this feature, again, it all depends on the cost and performance of the upgrade.
The AT106 has a pot load of favorable reviews to it's credit, I would imagine the AT106LE, sans the focuser should be as well accepted as it's brother is. In fact the AT111 also receives glowing reviews and that scope was on my wish list equal to the AT106 even though the center element is configured out of FPL-51 glass instead of the more expensive FPL-53 glass. However, there are variables between the two glass elements other than comparing one to another. It has to do with the manner the glass was configured, even TEC uses FPL-51 glass in some of their scopes and they are considered very high end instruments. The AT111 apparently has been configured correctly because it performs like the AT106 with well corrected glass and no hint of spurious color.
Its a tough choice, I know about the AT106 to more of a degree than the WO product, but I'm sure you would be happy with either one fitted to the ZEQ25GT mount. Good luck to you.
Sincerely,
John