Starwave 102mm f11 - first impressions

[CraigT82]

Having had this scope a couple of weeks now and having used it a couple of times I can offer some thoughts.  Though there's not much I can write about this scope that hasn't been written before. 

Very first impression is how nicely it's built. The paint finish is a lovely high quality pearlescent white, with the brushed aluminium look trim and nicely anodized focuser and tube rings, it's a really good looking scope up close. The long dew shield moves up and down smoothly and has a locking screw.  The tube has nicely blackened baffles and the inside of the dew shield has a nice matt black paint too.... Coupled with the excellent AR coatings it makes it difficult to see anything down the tube. A Cheshire eyepiece test reveals only one reflection from the objective lenses, I can only assume this is because both reflections are on top of one another, so the lens cell appears to be nicely engineered with well aligned lenses. 

The focuser itself is very well engineered with a smooth action and lots of travel. Using a laser in a HG parallizer the spot exits the front bang in the centre  showing that the focuser is properly aligned with the optical axis. Though using the supplied 2" to 1.25" adapter the spot is slightly off,  nothing to worry about though. Annoyingly my 30mm vixen NPL won't focus without pulling the adapter and diagonal out a little (1mm each), Maybe the tube was shortened sometime in the past!? Again nothing to worry about really, just a minor annoyance. 

In use the scope is easy to balance and the long length makes pointing and tweaking the view very easy on the az4, the length of the tube providing a nice lever with which to move around the sky. I haven't seen much through it but What I have seen I'm pleased with. Mars tonight showed a faint hint of dark seas and some evidence of a south polar cap* at 224x though the disc is getting pretty small now, and the moon showed crisp detail with only a hint of CA around the limb (see pic straight off the phone with no edits other than a crop) though It was a bit hazy which dimmed the image somewhat which could have toned down the CA a bit. Turning to the double double and working up through the mags I achieve a dark line between each pair at approx 140x. My f7.5 newt will achieve this split at 90x, though the image of the stars is more aesthetically pleasing in the frac. Snapping smartphone pics ain't too easy as even with long fl eyepieces the f11 ota means the exit pupil is small, compared to the faster newt.

It's really nice not having to worry about cooling and collimation! Just plonk it down and away you go. Compared to my big long newt this frac is so simple and user friendly that I can tell it's going to get a lot of use both at home and away, and with outreach.  It takes literally 2 mins to get it out the garage and start observing. Using it on  the AZ4 is fine in still conditions, I've had it up to 224x without too much vibration, though I expect the wooden tripod helps with that, a bit of wind catching the long tube though and the image starts trembling. 

That's about the sum total of my thoughts so far, will add more to this thread as I get more usage out of the scope. 

*EDIT: having looked at s couple of Mars images in the imaging section the polar cap has shrunk to a dot now, so it seems I was imagining it when I was observing! 

 

[johninderby]

Lovely scope.  ?

Had the Lyra version a few years ago and it did perform very well with minimal CA. Looks like a proper scope as well and a good buy.

Only sold mine after building Big Red the Carton 100 f/13.

[Ben the Ignorant]

1 hour ago, CraigT82 said:

Though using the supplied 2" to 1.25" adapter the spot is slightly off,  nothing to worry about though. Annoyingly my 30mm vixen NPL won't focus without pulling the adapter and diagonal out a little (1mm each)

At f/11 the corrected field is so wide that small misalignment doesn't matter, as you say.

The 2mm lack of backfocus probably occurs because the scope was designed with a 2" diagonal in mind, which has a longer optical path.

The coating and blackening are indeed very dark, as seen in the last pic.

[SIDO]

Nice setup and report, sounds like you are pleased with it, the most important measure...

[ASSA]

Nice report, may I ask You a question?. This Takahashi diagonal is prism or mirror? Mine 102/1100 is TS brand. Using bino Wo and pair of WO 20 mm 66 eyepieces (~55x) I couldn't split Double Double. Adding Wo 1.6x barlow at ~90x magnification one of pair splitted with dark tiny lane. Second pair won't co-op with me this night and that time i didn't have any more pairs of eyepieces to check how it perform.

If it's not a problem, maybe I'll hook up to your topic about this telescope? When I was looking for information about that scope, there were not so many of them, maybe in this way we will help others in choosing their first refractor  

[Fozzie]

These 102 F11 are a great package, I looked at the TS version before coming across the AA version.. Wouldn't be without mine, after her performance during the cold snap in feb this year.. obviously seeing was superb but it showed how well put together and figured these scopes are!!

When I first got mine I had a 1.25" diagonal, revelation branded, and although my 32mm plossl focused I swear I could see vignetting to the edge of field, upgraded to a 2" diagonal and I've had no such issues... Im tempted by a Tak Prisim for lunar work as I belived them to be better/less light scatter, thought they would match the lower FL SLV's very nicely, so good to know I might struggle with high FL and focus on this, although I do have an extension tube if required.

Hope you enjoy the new scope...

Ta

Fozzie

[CraigT82]

44 minutes ago, ASSA said:

Nice report, may I ask You a question?. This Takahashi diagonal is prism or mirror? Mine 102/1100 is TS brand. Using bino Wo and pair of WO 20 mm 66 eyepieces (~55x) I couldn't split Double Double. Adding Wo 1.6x barlow at ~90x magnification one of pair splitted with dark tiny lane. Second pair won't co-op with me this night and that time i didn't have any more pairs of eyepieces to check how it perform.

If it's not a problem, maybe I'll hook up to your topic about this telescope? When I was looking for information about that scope, there were not so many of them, maybe in this way we will help others in choosing their first refractor  

I'ts a prism diagonal, sounds like you just need a little more magnification to get a convincing split of the narrower pair. I need quite a lot of magnification here as I'm city centre and my local seeing is pretty poor (also my eyes aren't that sharp!) No problem about the linking ?

[ASSA]

Prism... so there is a problem with Vixen NPL  with mirror diagonal 1,25" it would focus without any doubts. I heard rumors that prism better co-op with achromats "reducing" AC. It would be Great to check that out under dark skies.

I have a plan to compare that scope with Old Gold series ED 100/900 side by side on planetary and lunar work. On M42 there was no differences between them. Sharp trapezium, superb contrast on both scopes.

Double clusters in Perseus, magnigicent view. Ofcourse less detailed than from 12" Newtonian but it was pleasure.

On Moon with pair of TV zoom 8-24 set on 8 mmn there was no even hint of CA. Great colours, medium shaprness but propably because Moon was low on sky, maybe 1.5h after rising. Important thing, with 20 WO erfles added to Binoviewer set there was easily visible CA, yellowish little glare!!! Thats why erfles Goes away and i'm waiting for package from FLO with BST ED's pairs. Best view of Moon i have with 25 mm e-lux Plossl, superb sharp and no CA. 

I would be able to make more reports when sky will be clear.

Sorry for english.

Regards

Luke 

[Stu]

11 hours ago, CraigT82 said:

I achieve a dark line between each pair at approx 140x

Nice write up Craig. I always wanted to try one of these, have had a few looks through other people's and the views are very nice indeed, crisp and will little CA.

My Tak will split the DD clearly down at x70 and below so I don't see any reason why your scope shouldn't be managing similar levels. Perhaps seeing was not so good??

[CraigT82]

5 hours ago, Stu said:

Nice write up Craig. I always wanted to try one of these, have had a few looks through other people's and the views are very nice indeed, crisp and will little CA.

My Tak will split the DD clearly down at x70 and below so I don't see any reason why your scope shouldn't be managing similar levels. Perhaps seeing was not so good??

Yes I'm in the middle of an estate and surrounded by houses on all sides, so my local seeing is pretty bad in winter when everyone has their heating on.

I just need to pull my finger out and get away to a decent observing site

[Stu]

2 hours ago, CraigT82 said:

Yes I'm in the middle of an estate and surrounded by houses on all sides, so my local seeing is pretty bad in winter when everyone has their heating on.

I just need to pull my finger out and get away to a decent observing site

That's quite a challenge, I know from experience what you face! Particularly bad when it is very cold.

I am also the same, need to find the motivation to get out to better sites, but it is pretty challenging with all the other pressures of life isn't it. At least we managed a few hours as a group last night which was fun, if cold!

[John]

Good report Craig. I've seen these scopes a few times at shows but I've not had the chance to use one. Difficult to justify purchasing one with 2 ~100mm refractors already in my "fleet" !

Pity about the 30mm NPL not coming to focus easily. That might be a result of using the 1.25" prism diagonal - I believe their light path is shorter than a mirror diagonal of the same size.

Otherwise all good stuff from the 102mm F/11

 

 

[CraigT82]

On 14/12/2018 at 08:19, Fozzie said:

Im tempted by a Tak Prisim for lunar work as I belived them to be better/less light scatter, thought they would match the lower FL SLV's very nicely, 

I can't detect any scatter at all using the Tak prism, which is great for me as scatter is the one abberation I hate! I think it would go very well with the SLVs and really let the scope do it's thing.