Svbony 102ED F7 refractor, first light impressions (SV503)

[Nik271]

Hi all,

I recently bought this refractor and noticing there are very few reviews of it decided to start one.

When unpacked  I was pleasantly surprised by the manufacturing quality of the scope. The tube is aluminium and the OTA weighs just 4kgs. It comes without finder or diagonal, just tube rings with a vixen style dovetail and four screw holes on top of each ring for attaching plates for finders and guiders. It has a retractable dew shield and an excellent rotatable R&P focuser, with 2-speed adjustment knobs. Fousing this scope precisely is critical as it is not a true APO, the objective is two air-spaced elements using FPL-51 glass. So there is CA in and out of focus but the £650 question is how good is it in focus?

Well last night I pushed the magnification up to x180 on the Moon and pleased to report I didn't  see chromatic aberration when in focus. Inside of and out of focus there is  some red and blue halo. I understand this is normal for this class of refractor. The colour actually helps me with achieveing a perfect focus, just find the focus place where the fringing goes away and that's it. Similarly it is colour free on stars up to 1-st magnitude. I did see some colour in Sirius though, so it is not all quite perfect.

Obviously at 714mm this scope is for wide field and I tried it on Pleiades, Double Cluster and Andromeda with a 2 inch 32 Panaview EP giving me a 3 degree field. The views are good, but somewhat washed out because of the bright Moon. Then checked the Auriga clusters and some of Cassiopeia. It's definitely a step up from m y 20x80 binoculars -a lot more stars are visible and in the Panaview it is sharp up to 70%. I guess this is normal as the focus 'plane' is not flat at F7. Can't wait for a new moon clear night for proper testing.

To test the optics I tried splitting a few double stars at x180 with good results: Rigel was easy (as it should be with any decent refractor). In Sigma Orionis I could spot all the four components. Best of all I managed to split Alnitak, which often gives trouble to my Mak 127, so quite pleased. The colours of stars looked right, similar to the Mak view I'm used to but with tighter diffraction rings. I finished with Epsilon Mon, Beta Mon and S Mon, all split with ease at x180.

Conclusion for the moment: this seems a very good 4 inch budget ED refractor. Not in the APO refined league I'm sure but looks good enough for me. Actually when I think about it - it can do 90% of what my Maks do on an average night plus can also do widefield. I will add more reports here, as I spend more nights under the stars with it.

Clear skies,

Nik    

 

Edited February 11, 2022 by Nik271
typos corrected

[Zermelo]

Very interesting write-up, Nik.  Svbony seem to spreading their wings into new territory all the time. If I ever upgrade my achromat I'll take a long look at that one.

[ScouseSpaceCadet]

Looks about the same quality as the £495 Altair Ascent 102ED. In focus C.A. just isn't an issue except on the obvious - Sirius for instance. I've yet to see any fringing on the lunar limb.

 

[Nik271]

After a few more weeks and several clear nights of use here is an update:

I managed a new moon DSO session in my Bortle 5 garden. I focused on the Ursa Major part of the sky.

M81/M82 were showing nicely in the same field of view in the SVbony 15mm EP. The shapes of both galaxies were clearly defined, but not much detail of their structure was visible. I admit I have not seen anything beter in these from my garden even with a 6 inch reflector. Then Owl nebula M97: faint smudge against light polluted sky. It was much better with the OIII filter, the circular shape was obvious but no sign of the 'eyes'. Nearby the M108 was barely detectable, as was M109 lower down: from experience I know where to look and I could detect them with averted vision but they were very faint. I didn't expect anything more than that with 4 inch aperture.

Then I looked at the low clusters in the south: M41, M47, M46. This is where the wide field refractors excels, they were looking lovely indeed despite being low. With OIII filter I spotted the planetary NGC 2438 in M46, had to  use x90 with a 8mm Starguider for that.

I recently purchased a high power 3.2mm TMB planetary EP so I tried it on Theta Aurigaue and Rigel, but the views were disaapointing. The stars were easily split but  looked rather mushy with purple halo. I'm not getting this  in 6mm or 4mm EPs, so perhaps this is the limit of the scope, about x180. Fair enough as I have my Maks which are more suitable for high powers.

I started using the scope as a quick grab and go on a photo tripod and AZ5 deluxe. A bit wobbly in the wind but definitely light and ready for action in seconds when there is a gap in the clouds. Recently managed a bried look at the first quarter moon in a 10 minute cloud gap spell and the view was lovely.

A side note: I don't like where the finder screws are located near the focuser as this is too low for me. So I glued a small finder shoe to the tube directly behind the dew shield. Perfect location for a RDF. Here is a picture.

[Mr Spock]

Good reports. Sounds like a really nice scope.

56 minutes ago, Nik271 said:

I recently purchased a high power 3.2mm TMB planetary EP so I tried it on Theta Aurigaue and Rigel, but the views were disaapointing. The stars were easily split but  looked rather mushy with purple halo. I'm not getting this  in 6mm or 4mm EPs, so perhaps this is the limit of the scope, about x180.

Not evident in the fpl53 102mm f7 ED I have. I suppose this is the difference between fpl51 and fpl53 - and of course the extra cost.

[Paz]

I think these 102mm f7 scopes are great, whether fpl51 or 53 they are really practical and flexible. I've had one for a couple of years or so and I initially compared mine to a 127mm Mak and a 120mm f5 achromat which it was intended to replace. Whilst it could not beat those scopes at their specialities and suffered an aperture disadvantage it gives super clean views and is more flexible and easy to use and that has what made it become my most used scope.

[Sunshine]

Nice write ups, it seems you have found a scope which will keep you busy for a long while!

[OK Apricot]

Great report, loads of detail and a lovely read, nice one Nik. AZ5 looking very suitable 👍

[ScouseSpaceCadet]

On 12/03/2022 at 11:24, Nik271 said:

After a few more weeks and several clear nights of use here is an update:

I managed a new moon DSO session in my Bortle 5 garden. I focused on the Ursa Major part of the sky.

M81/M82 were showing nicely in the same field of view in the SVbony 15mm EP. The shapes of both galaxies were clearly defined, but not much detail of their structure was visible. I admit I have not seen anything beter in these from my garden even with a 6 inch reflector. Then Owl nebula M97: faint smudge against light polluted sky. It was much better with the OIII filter, the circular shape was obvious but no sign of the 'eyes'. Nearby the M108 was barely detectable, as was M109 lower down: from experience I know where to look and I could detect them with averted vision but they were very faint. I didn't expect anything more than that with 4 inch aperture.

Then I looked at the low clusters in the south: M41, M47, M46. This is where the wide field refractors excels, they were looking lovely indeed despite being low. With OIII filter I spotted the planetary NGC 2438 in M46, had to  use x90 with a 8mm Starguider for that.

I recently purchased a high power 3.2mm TMB planetary EP so I tried it on Theta Aurigaue and Rigel, but the views were disaapointing. The stars were easily split but  looked rather mushy with purple halo. I'm not getting this  in 6mm or 4mm EPs, so perhaps this is the limit of the scope, about x180. Fair enough as I have my Maks which are more suitable for high powers.

I started using the scope as a quick grab and go on a photo tripod and AZ5 deluxe. A bit wobbly in the wind but definitely light and ready for action in seconds when there is a gap in the clouds. Recently managed a bried look at the first quarter moon in a 10 minute cloud gap spell and the view was lovely.

A side note: I don't like where the finder screws are located near the focuser as this is too low for me. So I glued a small finder shoe to the tube directly behind the dew shield. Perfect location for a RDF. Here is a picture.

Nice, detailed write ups thanks. Pretty much echoing my own experience with an ED102 f7. Similarly I do find 180x to be a higher mag sweet spot. Having owned four budget eps previously, the Vixen SLV 4mm has so far proved to be excellent and I've absolutely no plans to change it.

Regarding the 'mushy' view above 180x I cannot say the Altair ED102 suffers with this so much. The view is 'less crisp' but not mushy. On lunar especially I can up the mag well past 200x while maintaining sharpness.  There's also no false colour halos. The only star I noticed this on was Siruis however that in itself is not unusual. To go higher than 180x a quality GSO 2.5x ED barlow is used. Maybe give that a try rather than a TMB planetary II. I've owned a couple of those inc. a 4mm and did not rate them at all in any of my scoped to be honest.

 

[bosun21]

On 11/02/2022 at 14:44, ScouseSpaceCadet said:

Looks about the same quality as the £495 Altair Ascent 102ED. In focus C.A. just isn't an issue except on the obvious - Sirius for instance. I've yet to see any fringing on the lunar limb.

 

They are always out of stock for the 102ED at Harrison’s . 

[ScouseSpaceCadet]

On 01/06/2022 at 17:08, bosun21 said:

They are always out of stock for the 102ED at Harrison’s . 

I bought mine direct from Altair after requesting a stock notification. 18 months on, the scope is still a cracker for the price imho. I imagine the Svbony is just as good. Nik has given his a good workout. 👍

 

Edited June 2, 2022 by ScouseSpaceCadet
has

[bosun21]

1 minute ago, ScouseSpaceCadet said:

I bought mine direct from Altair after requesting a stock notification. 18 months on, the scope is still a cracker for the price imho. I imagine the Svbony is just as good. Nik had given his a good workout. 👍

 

Yes it was the Altair I was looking at in Harrison’s Telescopes. I may contact Altair direct.