102 mm F7 ED Refractor. Which Brand should I choose?

[Guest]

I have enjoyed using ED refractors over the years. Some have proven to be too long physically for me personally. They all give great views though.

But in recent times I have noticed several 102 mm F7 ED refractors available under different brands.

TS Services, William's Optics,Altair & Technosky.

These are all advertised as having FPL 53 glass as one of the objective elements.

But TS Services also mention that Lanthanam glass is used with FPL 53 glass. They all look super refractors.

Alright yes, I am looking for an ED refractor that I can own and enjoy into my tender years. Maybe buy the reducer aswell and finally get into astro photography.

But with what appears to be the same refractor but different branding. Which one would I be better off buying?

Does anybody own one or know anything about these ED refractors?

Edited March 7, 2021 by Guest

[RobertI]

I have bought the Altair Astro 102ED F7 and have been extremely happy (actually amazed) with the results I got during the Mars opposition and more recently Lunar and Solar. Very good for doubles too. I find the 714mm focal length considerably easier to use than my 1000mm achro. My scope is the same as the TS Optics Photoline and the Tecnosky 102ED. The optics are made by United Optics (Kunming). As for the Lanthanum, I have the same question - TS make a big deal of it, the Tecnosky website (Italian) refers to it but the UK Tecnosky retailers don’t mention it! Altair Astro don’t mention it and when I asked the question on their Facebook page......nothing. I’m not at all bothered but would like the mystery cleared up! A number of people on SGL have bought these scopes recently, covering all three brands, and the quality control seems to be very good. I’m sure any of the three brands would be fine. The build quality by the way is top notch, a very hefty and well engineered rotating focuser and sliding dewshield. Would definitely work for imaging as well as visual. 👍
 

 

Edited March 7, 2021 by RobertI

[KP82]

Afaik these are essentially the same scope from the same source in China. But each of these brands have their own minimum specs for the optics, focuser and the tube, carry out their own QA and include different accessories (e.g. bahtinov mask). My own experience tells me they are usually about the same quality wise, so I'd go for the cheapest although I'd probably exclude TS Optics due to possible custom charges. 

[mikeDnight]

I'd be very surprised if there's any difference between the glass types in these refractors if they are in the same price bracket. My friend paulastro recently bought a Technosky 102ED and is very happy with it.  I must say that although I haven't used his scope yet because of the lockdown restrictions, it looks a very impressive telescope. I can't imagine the manufacturer making an FPL53 & Lanthanum objective for one brand and an FPL53 using a different type of mating element for another brand, it wouldn't make economic sense. I strongly suspect the only difference, if any, will be purely mechanical. 

I recently watched a Utube video by Ed Ting, where he compared one of the 115mm Technosky or similar brand ED with a Takahashi FS102. He said he had to keep checking which scope he was looking through. He also said that "in focus" the Technosky star test was almost indistinguishable from that of the Tak. 

[johninderby]

Tecnosky bench tests the scopes before shipping and if you buy from Astrograph Rupert also checks the scope and makes sure collimation is perfect. 

http://astrograph.net/Tecnosky-102/700-F7-FPL-53-Double-APO-with-25-RP-Focuser

[david_taurus83]

I had the Altair 102EDR. Was a very nice scope. I bought it for visual but inevitably stuck a camera on the back lol. It got good praises about how sharp the views were when I brought it to the astro club one night. Also had a 70mm quad from Altair and currently now use the 80EDR for imaging. The only niggle I have with them is the locking ring for holding 2" nosepieces. It can be very hard to tighten without turning the focuser as well. But it's just a personal niggle. Can always stick a Clicklock or thumbscrew adapter on there. Altair are UK based and cheaper than WO and TS as far as I can tell from browsing.

[Deadlake]

8 hours ago, johninderby said:

Tecnosky bench tests the scopes before shipping and if you buy from Astrograph Rupert also checks the scope and makes sure collimation is perfect. 

http://astrograph.net/Tecnosky-102/700-F7-FPL-53-Double-APO-with-25-RP-Focuser

Agree, if you have the dealer in-between you and the manufacture then these scopes are good value. 

[vlaiv]

I've seen color fringing on a few occasions when this scope was used for imaging with OSC sensor. I was surprised on how bad it looked.

It was so bad that I thought scope was mistaken for FPL-51 model. Don't know if this is general thing or those particular models were suffering for some reason.

Also don't know what the performance is like when doing mono + filters. I'm sure that for visual it is very good and color free scope.

[paulastro]

10 hours ago, johninderby said:

Tecnosky bench tests the scopes before shipping and if you buy from Astrograph Rupert also checks the scope and makes sure collimation is perfect. 

http://astrograph.net/Tecnosky-102/700-F7-FPL-53-Double-APO-with-25-RP-Focuser

I second this.  I bought this scope through Astrograph, taking delivery just before Christmas.  In fact,  mine was the last one in stock at Tecnosky in Italy or anywhere else as far as I'm aware at that time.  Rupert is great to deal with and as promised, the scope arrived in perfect collimation, and in fine condition.

Of course, though I have no experience of them,  other 102ED F7 FPL53 doublets are available 😁.

Edited March 8, 2021 by paulastro

[Carl Au]

16 hours ago, Grumpy Martian said:

I have enjoyed using ED refractors over the years. Some have proven to be too long physically for me personally. They all give great views though.

But in recent times I have noticed several 102 mm F7 ED refractors available under different brands.

TS Services, William's Optics,Altair & Technosky.

These are all advertised as having FPL 53 glass as one of the objective elements.

But TS Services also mention that Lanthanam glass is used with FPL 53 glass. They all look super refractors.

Alright yes, I am looking for an ED refractor that I can own and enjoy into my tender years. Maybe buy the reducer aswell and finally get into astro photography.

But with what appears to be the same refractor but different branding. Which one would I be better off buying?

Does anybody own one or know anything about these ED refractors?

I concur, what he said. I own one of the forementioned scopes, mine is from Altair Astro, a ED 102 ED-R, absoultely cracking scopes. 

[Carl Au]

6 hours ago, Deadlake said:

Agree, if you have the dealer in-between you and the manufacture then these scopes are good value. 

They very good value for money indeed, the build quality is really very good also. 

Edited March 8, 2021 by Carl Au

[mikeDnight]

There's an unboxing and first impressions video of the Technosky 102ED on Utube that's worth watching. The lunar surface is exquisite, with only a fine colour fringe to the lunar limb. Not sure what camera or eyepiece he was using, but the CA could be introduced or added to by either, especially if it was a phone camera. Visually, the CA wouldn't be anywhere near as evident.

[Neo_uk]

I also own the altair 102mm f7 triplet..great scope both visually and for astrophotography...here's my latest image taken with the 102mm although it being my first narrowband image .

Really pleased with the scope and would recommend it to anyone .

 

[Nicola Fletcher]

I also have the Altair 102 ED-R and I think it’s fantastic. I use it for visual only and I’m absolutely delighted with it.

[Carl Au]

On 09/03/2021 at 19:18, Nicola Fletcher said:

I also have the Altair 102 ED-R and I think it’s fantastic. I use it for visual only and I’m absolutely delighted with it.

I can not beleive how much I like my scope, I have sort of fallen back in love with astronomy again and I'm just getting out more, finding more gaps between the clouds , getting half an hour in with the moon. I use my scope using a Badder zoom and barlow. I can get down to 3.5mm easily giving me superb sharp detail across the lunar surface, better than any of the dobs I have previously owned. I highly recomend the Hyperion zoom/barlow combination with a good refractor, it's very handy for some jobs. I hate changing eyepieces to be honest and since the Hyperion Zoom is such a good eyepiece (as good as a TV Radian IMHO) I don't see myself going back to having a big collection again. The 2 inch ED30 I bought from TS fills the rich field gap at the other end of the spectrum. 

Edited March 11, 2021 by Carl Au

[Basementboy]

Great thread, thanks – does anyone have experience with the FPL-51 glass, for viewing (not astrophotography)? They're almost half the price of the 53 and I'm not sure I'd tell the difference just for visual. Any thoughts?

Also : are any of these in stock anywhere? Altair didn't answer an email I sent them, and I'm wary of buying anything from the EU (still waiting on a shipment of cork from Portugal ordered six weeks ago)

 

[Carl Au]

19 minutes ago, Basementboy said:

Great thread, thanks – does anyone have experience with the FPL-51 glass, for viewing (not astrophotography)? They're almost half the price of the 53 and I'm not sure I'd tell the difference just for visual. Any thoughts?

Also : are any of these in stock anywhere? Altair didn't answer an email I sent them, and I'm wary of buying anything from the EU (still waiting on a shipment of cork from Portugal ordered six weeks ago)

 

 

No, Altair are notoriously poor communicators sadly, they do however sell very good telescopes. If it says they are in stock they are in stock in my experince. TS are all out of them. This shop: https://www.teleskop-spezialisten.de/shop/Telescope/ED-APO/100-115mm/TS-ED-102mm-f-7-APO-Refractor-telescope-with-2-Crayford-Focuser::489.html?language=en says they have the crayford version in stock from a google search. Everyone else in europe is giving June as to the arrival of the next batch. Both types seemed to have sold out very quickly after I bought mine. TS told me they had 13 of the FPL 51 version when I asked 2 months ago, they have all gone now. I don't have any experince using the FPL 51 version, but I am told that you can tell the difference, however FPL 51 glass is still very good. Which ever you buy you would be buying a nicely built traditonal looking refractor with excellent optics, better than the ED100 or ED 120's I previously owned, but that's just my opinion.

 

Edited March 11, 2021 by Carl Au

[Adam J]

On 08/03/2021 at 00:34, mikeDnight said:

I'd be very surprised if there's any difference between the glass types in these refractors if they are in the same price bracket. My friend paulastro recently bought a Technosky 102ED and is very happy with it.  I must say that although I haven't used his scope yet because of the lockdown restrictions, it looks a very impressive telescope. I can't imagine the manufacturer making an FPL53 & Lanthanum objective for one brand and an FPL53 using a different type of mating element for another brand, it wouldn't make economic sense. I strongly suspect the only difference, if any, will be purely mechanical. 

Actually it is possible as the miss understanding that most people have in this thread is that Lanthanum is not a type of glass. Lanthanum is a material used to dope or coat the flint and provides an effect similar to a minus violet filter. 

So in theory it is possible that some have specified this coating and some have not. However, it is more likely that some simply do not mention it and they are all the same as you say.

Its just not impossible.  

Adam

[vlaiv]

2 minutes ago, Adam J said:

Lanthanum is a material used to dope or coat the flint and provides an effect similar to a minus violet filter. 

Does it act like filter or simply changes refractive index when added to certain type of glass?

[Adam J]

 

Just now, vlaiv said:

Does it act like filter or simply changes refractive index when added to certain type of glass?

I seem to remember that in the case of doping the effect depends on the type of glass that you add the Lanthanum Nano particles to and in the case of coating it is more like a filter. But if they don't specify how can you tell what they are doing with it? From a quick search in some glasses (at least) it acts to increase refractive index. But its also possible that it has two effects one on refractive index and a second on transmission of violet light. 

More research required if you want to know the exact answer and you probably need to know what the flint glass is made from too. 

 

Adam 

 

[johninderby]

In camera lenses it is used to reduce dispersion and improve the clarity of the image .

Edited March 11, 2021 by johninderby

[Adam J]

13 minutes ago, johninderby said:

In camera lenses it is used to reduce dispersion and improve the clarity of the image .

It might be that it is allowing the lens element to be made thinner in the case of doping.  Such a reduction in thickness would have that effect. 

Edited March 11, 2021 by Adam J

[johninderby]

An interesting read on Lanthium and Leica lenses. 

https://lhsa.org/2018/09/rare-earth-glass-leica-lenses-a-quick-and-quirky-overview/

[Nicola Fletcher]

2 hours ago, Carl Au said:

I can not beleive how much I like my scope, I have sort of fallen back in love with astronomy again and I'm just getting out more, finding more gaps between the clouds , getting half an hour in with the moon. I use my scope using a Badder zoom and barlow. I can get down to 3.5mm easily giving me superb sharp detail across the lunar surface, better than any of the dobs I have previously owned. I highly recomend the Hyperion zoom/barlow combination with a good refractor, it's very handy for some jobs. I hate changing eyepieces to be honest and since the Hyperion Zoom is such a good eyepiece (as good as a TV Radian IMHO) I don't see myself going back to having a big collection again. The 2 inch ED30 I bought from TS fills the rich field gap at the other end of the spectrum. 

I completely agree Carl, It's such a step up from my last scope and an absolute joy to use. I was looking at Bode's twin galaxies last weekend and was so impressed with how much I could see. I'm looking forward to seeing Jupiter and Saturn. I also use the Baader Hyperion MKIV mainly, and I agree it is great. I'm using a 1.25in Altair dielectric diagonal, and I do find that it is very difficult to tighten it properly in the focuser, which means the eyepieces slide around especially with the weight of the Hyperion. But it's a minor gripe - the convenience of the Zoom is great. I saw you got the barlow - I am glad you find it works well with your setup. I use my scope on the EQM-35 Pro or else a Giro Ercole mini mounted on the SW tripod if I just want to have a look without the bother of setting up the goto. 

@Basementboy, I just rang Altair a few weeks ago when I was buying accessories for the Starwave and wanted to ask some questions. They were really helpful, and I wonder if it's a better idea to ring rather than email? Both the telescope and the accessories arrived really quickly, and I must say I have had a very good experience with Altair. 

[Louis D]

4 hours ago, Basementboy said:

Great thread, thanks – does anyone have experience with the FPL-51 glass, for viewing (not astrophotography)? They're almost half the price of the 53 and I'm not sure I'd tell the difference just for visual. Any thoughts?

It depends on the magnification used.  At low powers, you're not likely to see any difference except perhaps on the brightest objects.  Where you will see it is at high powers where there will be a slight violet violet fringe around bright objects with FPL-51 that is much more subdued with FPL-53, especially in triplet form.  However, even the most APO refractor still has some fringing compared to a Newtonian at high powers.  If you've always used pure reflectors as I have, it's a bit of a surprise that the term APO doesn't equate to absolutely false color free, especially on either side of best focus as you find that best focus.  I would equate APO to very well tamed false color.  In a reflector, a white star is always white no matter which side of focus you're on by comparison.