Altair Astro Starwave 102ED vs 102ED-R

[badgerchap]

Good afternoon all,

 

I've been thinking about a 4" refractor for purely visual for some time. For various reasons I'm drawn to Altair's Starwaves - cost of course being a factor as well as just a liking for the company.

I'm inexperienced when it comes to fracs, having spent most of my time behind mirrors, so I'm unsure as to whether or not the extra three hundred quid is a worthwhile investment for the 102ED-R over the 102ED. They're both F7 doublets, but the ED-R seems to have an FPL53 element whilst the plain ED is said to carry lanthanum/FCD100. I've been out of the game a while and haven't even heard of FCD100. I did read a review which said that this was an upgrade over the previous FPL51, but there was also a debate over whether or not the listing was correct, and the scope may indeed still come with FPL51.

The website doesn't give much detail on coatings, other than the ED-R is STM coated and the ED is multicoated. 

Apart from this and some minor details, I think they're pretty equivalent, so for purely visual work is there anything that can justify the extra 300 quid? Has anyone used both or owned both and noticed a difference?

Also, whilst I'm here, does anyone have a recommendation for a good Alt/Az mount for one of these 4-5kg setups?

[Dave scutt]

I have a sightron mount, which I plan on using with a skywatcher 100 ED pro.

Can't comment on what it will be like as still waiting for the tripod to be delivered but there are good reviews on here about them.

Dave .

I think there's one on abs for sell

[Louis D]

Even in my 72ED, there is noticeable violet fringing at high power with FPL-51 glass.  It's absolutely fine at lower powers.  I would think the violet fringing would just get worse with the larger objective.

In my 90mm APO FPL-53 triplet, there is little to no fringing at high powers.  I think most of the improvement comes from the glass and not the triplet.  Based on that, I would recommend the FPL-53 version.  The purple fringing in my 72ED was driving me nuts having been a reflector guy for 20 years prior.

[badgerchap]

29 minutes ago, Dave scutt said:

I have a sightron mount, which I plan on using with a skywatcher 100 ED pro.

Can't comment on what it will be like as still waiting for the tripod to be delivered but there are good reviews on here about them.

Dave .

I think there's one on abs for sell

Interesting, I'd not spotted that option. Another one to add to the shortlist, thanks!

[badgerchap]

26 minutes ago, Louis D said:

Even in my 72ED, there is noticeable violet fringing at high power with FPL-51 glass.  It's absolutely fine at lower powers.  I would think the violet fringing would just get worse with the larger objective.

In my 90mm APO FPL-53 triplet, there is little to no fringing at high powers.  I think most of the improvement comes from the glass and not the triplet.  Based on that, I would recommend the FPL-53 version.  The purple fringing in my 72ED was driving me nuts having been a reflector guy for 20 years prior.

Hmmmm yes, that's what I'm worried about - zero CA to any CA at all is going to feel disappointing, for all the other benefits of looking through glass.

 

Ah well, looks like my bank manager might like me a touch less....

[Elp]

The EDR is pretty much the same scope as the Starfield 102 which I've got, it's excellent.

I use it on a Tecnosky Cubo mount.

Don't ignore the tripod, it's more important than the mount in my opinion, sturdy ones provide a better experience.

[Ratlet]

I went for the 102 fpl53 equivalent on the basis that if I got the fpl51 and could see issues I'd be kicking myself till the end of time.

With regards to the bank manager I'd suggest you start looking at 120 triplets or Takahashi's and then do the old bait and switch.  They'll be delighted you're only spending £900 on the scope.

[John]

Personally I'd go for a scope with an FPL-53 element, or equivalent, if possible. Once you have seen CA around brighter targets it's impossible to "unsee" it, unfortunately. 

On alt-az mounts, I've found that single arm mounts such as the AZ-4 can handle up to F/7 100/102mm refractors pretty well but somehow struggle when the focal ratio of the scope gets towards F/9. Tripod choice can help with this to some extent but a good 4 inch ED refractor can sustain pretty high magnifications on the right targets and it's a pity if the mounting arrangements can't quite keep up with the scope's capability.

 

Edited August 22 by John

[Highburymark]

I haven’t used either of the scopes you mention, but FPL-53 and FCD100 are basically equal in terms of suppressing false colour. Some top performing apos used FCD100. So in this case, what’s more important is how the two scopes are figured, and how the ED element combines with the mating glass. FPL-53 does not necessarily mean you are buying the best scope.

[Louis D]

2 minutes ago, Highburymark said:

FPL-53 does not necessarily mean you are buying the best scope.

However, all else being equal in this case (mechanicals, polish, coatings, figure, etc. because it's the same scope company making both in the same price range), then you can safely look at the glass type for comparison.

[Bivanus]

My 2c: Been using in paralel  FPL53/Lanthan Photoline doublets from TS and the ubiquios SW72ED which is also a doublet with "mistery" ED glass.

I have yet to see any CA in the TS while the SW72ED clearly displayed it ( as LouisD already told , depends of loight intensity and I also think spectrum ) 

Please note , I am using the Photoline for visual too both cyclop and bino 😁 so I am talking  about eye-centric stuff , when the camera enters the talk there is simply NO comparison between FPL53/Lanthan and SW stuff

EDIT: Forgot the conclusion - get the FCD100/Lanthan as FCD100 is simply HOYA's FPL53

Edited August 22 by Bivanus

[Highburymark]

24 minutes ago, Louis D said:

However, all else being equal in this case (mechanicals, polish, coatings, figure, etc. because it's the same scope company making both in the same price range), then you can safely look at the glass type for comparison.

I don’t think everything is necessarily equal here though - for example the pricier scope seems to have a better focuser.
£595 for a 4” FCD-100 seems incredibly cheap though. I’d be suspicious at that price. There are different grades of super dispersion glass - maybe that’s what’s happening here. But we can infer nothing from the fact that one scope is FPL-53 and the other FCD-100 - both are super-dispersion glasses.

[Elp]

Prob best to go to an astro meet or something, people will state their preferences for both types all day long. A good longer f ratio scope will also provide good correction.

[Nicola Fletcher]

I have the 102 ED-R. It’s a really super apochromatic refractor that has given me fantastic views and I definitely recommend it.

I don’t know if iim right, but I thought the focuser on the ED-R was better than the ED but I could be wrong. The focuser is great on the ED-R with loads of travel, two speed and you can mount two finders on it which I like very much.

If it wasn’t for this forum, I honestly would have been happy with this scope forever, but then I found out about Takahashi scopes and have been bankrupted. However, I haven’t sold my Starwave as I think it’s a super scope that stands up to the premium brands very well.

I haven’t compared the ED to the ED-R but I can definitely recommend the latter as a fantastic 4” refractor that you won’t be disappointed with.

Edited August 22 by Nicola Fletcher

[badgerchap]

53 minutes ago, Nicola Fletcher said:

...and you can mount two finders on it which I like very much.

This is something I really hadn't thought of until today, but it keeps nudging my brain. It seems really useful! What finders do you use in those slots?

As for Taks, they're still out of my price range until I can ship a few kids off to Uni...

[badgerchap]

3 hours ago, Ratlet said:

I went for the 102 fpl53 equivalent on the basis that if I got the fpl51 and could see issues I'd be kicking myself till the end of time.

This is why I'm umm-ing and ahh-ing so much! I'm sure they're both great, but I would blame my own tightfistedness if I wasn't super-happy with the plain ED.

 

Damn my foresight!

[bosun21]

2 hours ago, Bivanus said:

NO comparison between FPL53/Lanthan and SW stuff

The Skywatcher ED refractors apart from the 72ED were all FPL53 doublets. They have now begun using FCD100 the equivalent. My ED120 and ED80 show not a hint of CA even at high magnification. I have no idea why they decided to use lesser glass in the 72ED. Both my scopes are FPL53 and Schott glass. I also looked at the Altair 4" scopes and all the research I did showed that only the ED-R versions were FPL53 and the others were FPL51.

Edited August 22 by bosun21

[Nicola Fletcher]

17 minutes ago, badgerchap said:

This is something I really hadn't thought of until today, but it keeps nudging my brain. It seems really useful! What finders do you use in those slots?

As for Taks, they're still out of my price range until I can ship a few kids off to Uni...

I put a red dot finder (just a Celestron Starpointer pro which I use on all my scopes) with the lovely illuminated Altair 10 x 60 RACI which is a pleasure to use and also goes on other scopes including my 12” dob (https://www.altairastro.com/altair-10x60mm-raci-finder-scope-90-deg-erect-image-prism-variable-illuminator-eyepiece-2504-p.asp). I really like having both a RDF and finderscope as I  use manual mounts mostly.

I’ve attached a few photos - first the Starwave on the Skywatcher EQM35 mount with the RACI visible, then double mounted with an FC76 on a manual alt-az mount and then a side by side with an FC100DZ showing how robust and compact the Starwave is, and how nice the focuser is!
 

 

[badgerchap]

12 minutes ago, Nicola Fletcher said:

 

 

 

Oh dear, I think the dual mounting may have just pushed me over the edge. It was looking at such setups that got me thinking of a 4" f7 frac in the first place. I think the Starwave would be a treat next to my C8 SCT. Is that a Sky Tee? If not, what is it?

 

By the way, I think if I end up going down the ED-R route, I'm blaming you personally...

[Nicola Fletcher]

8 minutes ago, badgerchap said:

Oh dear, I think the dual mounting may have just pushed me over the edge. It was looking at such setups that got me thinking of a 4" f7 frac in the first place. I think the Starwave would be a treat next to my C8 SCT. Is that a Sky Tee? If not, what is it?

 

By the way, I think if I end up going down the ED-R route, I'm blaming you personally...

Oh yes, the frac and the C8 would be fantastic together! I mount my 4” with my Mewlon 180C which would be a similar setup to your proposed one and they are fantastic.

That mount is a Giro Ercole Mini which I use for travel but the Giro Ercole is a bigger version and can take larger scopes. I have an AZ75 on order from FLO (more bad influence from SGL!) which I think will be similar but more stable for the bigger scopes.. Double mounted scopes are great fun to use and look amazing together.

I wish you the best of luck with your choice but I can say you won’t be disappointed with the ED-R if you go for it. I’m sure the ED is a great scope too though. Good luck!

[IB20]

Have the Starwave 102ED-R and a StellaMira 125 FC100 and haven’t seen any false colour other than from atmospheric dispersion so it’s exceptional glass and has kept pace to my fluorite Tak.

The AZ4 and steel tripod handles the ED-R easy as pie.

Edited August 22 by IB20

[badgerchap]

@IB20 nice comparison. Does make me just think a moment about a Tak...

...but no, the Starwave is the aperture/fl combo I'm after. Still, maybe a Tak in the future!

[Louis D]

5 hours ago, Bivanus said:

EDIT: Forgot the conclusion - get the FCD100/Lanthan as FCD100 is simply HOYA's FPL53

I see where the ad for the 102ED specifies FCD100.  If this is really the case, it is truly a bargain.  However, if it ends up showing FCD1 (FPL-51 equivalent) levels of color correction, I'd be returning it on their dime for false advertising.

[heliumstar]

Go with ED-R. Doesn't really matter which of the clones. They are all superb. Get the cheapest one you can find. I had 80mm version and couldn't see any difference between Altair and Tak 76DCU. I still sold both and went with 127 Maksutov and now looking for 4" APO (again!).

[badgerchap]

7 hours ago, heliumstar said:

Go with ED-R. Doesn't really matter which of the clones. They are all superb. Get the cheapest one you can find. I had 80mm version and couldn't see any difference between Altair and Tak 76DCU. I still sold both and went with 127 Maksutov and now looking for 4" APO (again!).

I've been tempted by those 127 Maks many times but never gone for one - always ended up going for a longer FL in a larger Cat or wider FOV in something fraccy. One day maybe...