Stellamira 125 ED F7.8

[Marian M]

On 26/08/2023 at 15:47, Paz said:

The SM125mm does go deeper than the 102mm refractor on DSOs. I didn't measure it empirically but I would describe the improvement as obvious but not epic. I think a bigger jump in aperture would be necessary for the difference to be epic.

I also have the 120/600 f5 achromat and still use it from time to time but I use the 102mm f7 more because the quality-to-effort ratio is better and because the 102mm f7 is a more general purpose scope. I found the 120/600 does better on dark extended objects at low magnifications, but on less extended targets, and targets that resolve into stars and bright targets and as magnigication goes up the 102edr catches up and pulls ahead.

I haven't looked through a 152mm achromat to be able to compare it to a 125mm apochromat. If weight is not an issue and only observing DSOs at low magnifications is the task then it sounds like a bit of a conundrum as to which to go for.

One thing I would say is to check if the 152mm can use binoviewers without having to barlow it.  You can shorten the ota on the TS Optics125mm scope for binoviewing at low magnifications, but if the 152mm has to have some barlowing, then you may find that (for binoviewing at least) you can't get the lowest magnifications in the 152mm scope.

It's difficult as all those scopes are good for their design purposes, it's just making choices about which compromises you give and take on.

Many thanks for the quick revert!

 

I had a quick session of observations last weekend where I had the chance to compare my 102 TS FPL53 with my SW120/600 achro. Most time spent on Double Cluster and Moon, with my binoviewer eyepieces- having 2 of each, I just dropped them in the 2 scopes, a little bigger magnification on 102 because of the longer F (714 vs 600).  On Double cluster, up 67x (Morpheus 9), the image was brighter in achro, but the same was visible in apo as well, just a little more darker. Any single star I tried to look for in achro, was visible also in apo. Above this magnification (using some barlows and GPCs), the image started to break down in achro. Probably above this magnification, it was the other way around- any star visible in apo, if you know where to look for, was visible in achro as well. I am not an experienced person and most of my time I spent enjoying what I see and less comparing, but most likely a more experienced person would have seen probably a bigger difference. Also between 60x- and probably 120x, the image in achro was reminding me my already sold Mak127 view, the stars weren't single points like in apo but much more "unfocused" with "a visible diameter" 

 

Regarding the TS 152 5.9 achro, TS give very clear data on backfocus. It has a slightly bigger backfocus from 2" thread compared with my 102 apo, which I have adapted for bino without ang GPC. By removing the M68 to 2" adapter and replacing with the short M68 to T2 adapter, about 25 mm will be gained, which will increase the backfocus bigger than 150mm requested (110mm for MB2 and 40 mm for T2 Baader prism)

 

Now coming back to 125 APO, still I am trying to read as much as possible here. The quality seems very good (very happy with the smaller brother, 102), it will take the binoviewer without any other change, directly with the 2" diagonal, which also will shorten the length and do it much solid and rigid. Probably up to 60x-100x, the 152 will be above or similar, while above this magnification, 125 will start shining- talking here about DSO only, for the rest, 125 will outperform

 

Which one to take, I yet have to figure out, think, debate...

 

Many thanks again!

[FLO]

On 11/08/2023 at 00:12, Paz said:

I checked mine closely and I could see marks where the paper was in contact with the OTA under the tube rings, the same as some others have mentioned. In my case it was very slight and I don't think I would have noticed if I had not gone looking hard for it. I could not get it to show up in a photo. I am ok with the finish of the OTA

A couple of owners have reported the same. We checked our stock at the warehouse and found they are the same (if viewed under a particular light, at a specific angle). We contacted the manufacturer. They say minor blemishes can be polished with two polishing pastes. 

We bought the pastes and tried them. The result is excellent, so we will do the same for all our current stock.

For future batches, we have asked the manufacturer to pack the tube rings separately. 

@Paz , I understand you don't consider the blemishes a problem, but if someone reading this does, they are welcome to contact us. We will then collect their telescope, polish its carbon fibre, and then redeliver it to them. All free of charge. (This assumes the owner has the original box and packaging for safe transport. If not, we'll email them details of the paste so they can polish their telescope's carbon fibre at home). 

Thank you to all those who have posted photos and observing reports. It is good to hear owners are pleased 🤗 

Steve 

[ScouseSpaceCadet]

1 hour ago, FLO said:

A couple of owners have reported the same. We checked our stock at the warehouse and found they are the same (if viewed under a particular light, at a specific angle). We contacted the manufacturer. They say minor blemishes can be polished with two polishing pastes. 

We bought the pastes and tried them. The result is excellent, so we will do the same for all our current stock.

For future batches, we have asked the manufacturer to pack the tube rings separately. 

@Paz , I understand you don't consider the blemishes a problem, but if someone reading this does, they are welcome to contact us. We will then collect their telescope, polish its carbon fibre, and then redeliver it to them. All free of charge. (This assumes the owner has the original box and packaging for safe transport. If not, we'll email them details of the paste so they can polish their telescope's carbon fibre at home). 

Thank you to all those who have posted photos and observing reports. It is good to hear owners are pleased 🤗 

Steve 

Steve

I noticed mine has those blemishes but so slight I only noticed at a certain angle and in a certain light... 🙄

Is the paste cheap and the polishing process stress free and easy?

[Louis D]

I've got a CF tube with some scratches I plan to fill with clearcoat and polish out.  What polishes did the manufacturer recommend?  There are dedicated CF polish kits out there, but they're not cheap.  I've got metal polishing compounds for jewelry, but I'd hesitate to use them on clearcoat paint.

[fireballxl5]

Although I'm lucky and my SM125 is not affected, I'd like to know which polish is recommended should maintenance be required in the future.  Not that I abuse my scopes lol, accidents do happen when you're tired early in the morning🙃

[Cleetus]

I would imagine Autoglym Super Resin Polish would be a safe bet in this instance. Available everywhere.

 

 

"The famous bottle can be found in garages all over the world, and has been lovingly applied on everything from hyper cars and priceless classics to family cars. It will not only restore gloss to dull surfaces, but is also ideal for removing small scuffs and scratches on new or old paintwork.

Use every few months as needed to maintain a superb shine.

The undefeated, 4 time winner of Detailing World’s Polish of the Year award."

Edited September 1, 2023 by Cleetus

[Elp]

If someone wants to try it out on a different product first, a very high grit (higher the number the smoother less gritty it is) wet and dry paper with water might achieve the same. If it works on car lacquer, no reason it can't work on this.

[moriniboy]

FLO have offered a return to base solution and they will undertake the polishing, I will be taking them up on this offer. Thanks FLO.

[Cleetus]

1 hour ago, Elp said:

If someone wants to try it out on a different product first, a very high grit (higher the number the smoother less gritty it is) wet and dry paper with water might achieve the same. If it works on car lacquer, no reason it can't work on 

I wouldn't have the courage to try that.

Edited September 1, 2023 by Cleetus

[FLO]

7 hours ago, Louis D said:

I've got a CF tube with some scratches I plan to fill with clearcoat and polish out.  What polishes did the manufacturer recommend?  

 

3 hours ago, fireballxl5 said:

Although I'm lucky and my SM125 is not affected, I'd like to know which polish is recommended should maintenance be required in the future.  

My colleague in the workshop is currently at the Herstmonceux Astronomy Festival, but I'll ask him when he returns Monday. 

I don't want to casually recommend people polish their telescope's carbon fibre. It is possible to over-polish. If the telescope is one of ours, please contact us first. 

Steve 

[Elp]

Just a thought regarding route cause @FLO, if packing future batches with rings separately, in general use with rings would the issue re-present itself? Are the rings causing it? Does it affect the 90ED which I assume is manufactured the same, same supplier etc.

Edited September 1, 2023 by Elp

[Stu]

1 hour ago, Elp said:

Just a thought regarding route cause @FLO, if packing future batches with rings separately, in general use with rings would the issue re-present itself? Are the rings causing it? Does it affect the 90ED which I assume is manufactured the same, same supplier etc.

It almost seems that the rings are fitted before the finish has completely cured if they are leaving impressions on the surface?

[Elp]

That's a good call, but again, would it also affect the 90EDs? Unless if the way they process them are different, or these were processed quicker to meet a delivery schedule. Often such things are attributed to change in process, especially on new product.

Edited September 1, 2023 by Elp

[Louis D]

My frac's CF tube is military grade (from a US company that makes them for the aerospace industry).  No blemishing from the rings on it.

[Elp]

I'm sure they'll get to the cause, considering how popular they've been they'll have to restock soon.

[FLO]

4 hours ago, Elp said:

That's a good call, but again, would it also affect the 90EDs? 

We have not experienced this with any other CF telescope, and we don't expect to see it again with this one. This minor cosmetic blemish appears to be a one-off. 

4 hours ago, Stu said:

It almost seems that the rings are fitted before the finish has completely cured if they are leaving impressions on the surface?

We are not sure. It might be as you say, and/or a chemical reaction with glue in the tube-ring felt. I suspect we won't know for sure. The blemish is minor, easy to solve, and won't happen again. 

4 hours ago, Louis D said:

My frac's CF tube is military grade (from a US company that makes them for the aerospace industry). 

I suspect 'military grade' and 'aerospace' are American-style marketing speak. (Please don't mention who makes these claims; I don't want my mugshot on a dartboard) 🙂 

All CF telescopes we have experienced (regardless of brand) have sturdy tubes with ample wall thickness. 

HTH, 

Steve 

[Louis D]

8 hours ago, FLO said:

I suspect 'military grade' and 'aerospace' are American-style marketing speak

No, the dude I bought it off of actually works for an aerospace company that makes CF tubing.  Being the head tube maker, he was able to make an appropriately sized tube to replace the original aluminum tube off hours.  It's not hyperbole that he made it to the same spec as the stuff going to various aerospace contractors.

[The60mmKid]

It's good to maintain perspective on such matters... Minor blemishes on a tube are minor blemishes on a tube. I commend FLO for swiftly and thoughtfully addressing things, which is far more than I can say for a few of the astronomy outfits (including the American ones) I've dealt with. I wish I was in the market for a 5" refractor...

Edited September 2, 2023 by The60mmKid

[Elp]

1 hour ago, The60mmKid said:

I wish I was in the market for a 5" refractor...

You probably are, you just don't know it yet...

[The60mmKid]

5 hours ago, Elp said:

You probably are, you just don't know it yet...

Nope. Already have one 👍 Some things I know well enough.

[Seme]

Hi Everyone

I'm now a happy owner of the 125mm club. No.0043

But i've lost myself with all the numbers I have the sm125 and the 2" 0.8x Reducer/Flattener the Starlight xpress  filter wheel and the old sx-825 (black camera). I'm hoping this will work ok.

Dave at Flo said i need 55mm spacing if any one could tell me where does the 55mm start and finish.

Many Thanks

Darren 

[Elp]

Usually backspacing starts from the bottom of the reducer/flattener thread to the camera sensor. I've used all sorts of lenses, flattener and reducers and this distance to distance has always been the case. Add in around 1/3 of filter thickness to the 55mm or work within +0.33-1mm typically.

Edited September 11, 2023 by Elp

[Paz]

Here's my final update, I've checked everything out that I wanted to and all is well. I've had some good views of Saturn and Jupiter, not in perfect conditions but good enough to be able to tell that the scope is ok. The focuser has also stood up to everything I've tried in it including a 31mm Nagler and Binoviewers with a pair of 17.3mm Delos. One other thing on the focuser, I think this has very slightly more available in-focus than my 102mm f7.

The main challenge I have noticed is just getting used to the dimensions of it, it's the longest scope I've used (on a tripod) so the eyepiece moves around a lot and balancing different eyepiece weights is more of a thing than on shorter scopes, but it is just a case of getting used to it. I have found I prefer to use an extension pier with this scope for a higher eyepiece position which means a heavier/bulkier mount to take out, and it means slightly more vibes, but I have found that it is fine having got used to it. Heavier eyepieces also raise the eyepiece position as the scope has to be further forward to stay balanced.

I have taken off the handle as I didn't find that I really needed it in the end and I would rather be able to mount a finder shoe on the front tube ring. 

I got myself a slightly longer dovetail bar (a More Blue 220mm instead of 200mm - but it weighed less than the original bar despite being longer) to have enough room to be able to balance with light or heavy eyepiece set ups just by sliding the dovetail forward or back in the clamp. However I think this does not give quite enough adjustability and I think I may get a 300mm bar.

I ended up getting an ADM saddle for my Skytee 2 as I was starting to worry about if/when the standard saddle might give out with this scope (not because I was worried myself, just from reading so many other people worrying about it with other scopes!). To be fair now I've got one it is obviously more robust and I'm glad I got it.

When solar observing the scope performs well as I would expect, but it does catch the heat of the sun very quickly if you leave it at all broadside to the sun. I try to set it up and get it balanced as quickly as I can and then point it at the sun with the cap on so it is collecting a minimum of heat while I do the rest of setting up. I tried it with a quark on the sun and the views were fine, but it's a lot of magnification, I think the quark is better suited to smaller scopes unless the conditions are amazing.

I don't know how this would compare to the established top end brands when it comes to squeezing out the last fraction of a percentage of performance but I find myself enjoying the views and not wondering about whether anything else out there might better, which is a good sign. I don't think there is anything lighter and that was an important consideration for me.

I'll be using this as my main scope this winter, and I aim to check out how it compares to the C8 in particular.

I am interested to hear reports from other owners, please share some comments if you've got one of these.

[Saganite]

Thanks Paz, very enjoyable reading and it looks like a very fine scope.  I shall watch for your reports through the winter....👍

[ScouseSpaceCadet]

On 23/09/2023 at 23:33, Paz said:

Here's my final update, I've checked everything out that I wanted to and all is well. I've had some good views of Saturn and Jupiter, not in perfect conditions but good enough to be able to tell that the scope is ok. The focuser has also stood up to everything I've tried in it including a 31mm Nagler and Binoviewers with a pair of 17.3mm Delos. One other thing on the focuser, I think this has very slightly more available in-focus than my 102mm f7.

The main challenge I have noticed is just getting used to the dimensions of it, it's the longest scope I've used (on a tripod) so the eyepiece moves around a lot and balancing different eyepiece weights is more of a thing than on shorter scopes, but it is just a case of getting used to it. I have found I prefer to use an extension pier with this scope for a higher eyepiece position which means a heavier/bulkier mount to take out, and it means slightly more vibes, but I have found that it is fine having got used to it. Heavier eyepieces also raise the eyepiece position as the scope has to be further forward to stay balanced.

I have taken off the handle as I didn't find that I really needed it in the end and I would rather be able to mount a finder shoe on the front tube ring. 

I got myself a slightly longer dovetail bar (a More Blue 220mm instead of 200mm - but it weighed less than the original bar despite being longer) to have enough room to be able to balance with light or heavy eyepiece set ups just by sliding the dovetail forward or back in the clamp. However I think this does not give quite enough adjustability and I think I may get a 300mm bar.

I ended up getting an ADM saddle for my Skytee 2 as I was starting to worry about if/when the standard saddle might give out with this scope (not because I was worried myself, just from reading so many other people worrying about it with other scopes!). To be fair now I've got one it is obviously more robust and I'm glad I got it.

When solar observing the scope performs well as I would expect, but it does catch the heat of the sun very quickly if you leave it at all broadside to the sun. I try to set it up and get it balanced as quickly as I can and then point it at the sun with the cap on so it is collecting a minimum of heat while I do the rest of setting up. I tried it with a quark on the sun and the views were fine, but it's a lot of magnification, I think the quark is better suited to smaller scopes unless the conditions are amazing.

I don't know how this would compare to the established top end brands when it comes to squeezing out the last fraction of a percentage of performance but I find myself enjoying the views and not wondering about whether anything else out there might better, which is a good sign. I don't think there is anything lighter and that was an important consideration for me.

I'll be using this as my main scope this winter, and I aim to check out how it compares to the C8 in particular.

I am interested to hear reports from other owners, please share some comments if you've got one of these.

Thanks for your thoughts...

I've taken advantage of FLO's offer to polish the ota to remove the (very minor in my case luckily) tube ring imprints and it's being picked up tomorrow.

Otherwise I've been very happy with the Stellamira's performance, although the scope has only had three outings due to poor weather and work. The ota was taken to Astrocamp unfortunately that long weekend was a washout.

The combination of aperture, focal ratio and low weight combined with the nice optics and focuser is perfect for my needs. There's absolutely no need for me to keep more than one telescope now, so I'll very soon be selling my Altair 102ED, Skymax 127, AZ5 and AZGTI. 

Sometime next year the AVX will go too as I aim to simplify observing and replace that with an alt az mount. 

Hopefully the weather will be kinder at Kielder Star Camp in October. I really want the Stellamira 125 to render me speechless under those dark skies. 🧐