Stellamira 125 ED F7.8

[omo]

Theres a few of these out in the wild now so please join in 👍

FLO's latest addition to their own line up is a very nice looking scope at 125mm with an ED element and Lanthanum to go with it, its a fairly well tried combination. At F7.8 it suits me as a visual observer and with additional flatners / reducers available caters to imagers as well.

Due to the carbon fibre tube it is really quite light weight. The 2.5" focuser feels nice and smooth.

 

The scope itself is packaged within a double wall cardboard box and then there is the Oklop custom bag. Its made up of sections of foam that are glued together,

The case:

 

@JeremyS the internal cutout for the scope is approximately 875mm long 145mm where narrow, 170mm wide otherwise and 185 deep.

 

 

Protects the scope nicely. The carbon is well lacquered - although that will only really matter to solar observers. UV will break down carbon fibre over time.

 

Compared to my 4" DZ the 125ED is a step up in size, I like that the red anodising is not too bright and there is not to much of it, I feel Williams Optics for example go a bit OTT on anodising.

 

My companion is a Spanish Water dog - Io, at least here no one is going to think he was named after a toothbrush......

The scope is shipped with a Vixen style bar, the Losmandy was fitted as I prefer them and more importantly being longer i can get safety stops to prevent a potential disaster should the mount slip in the clamp

 

The bino viewer will not focus without a GPC, which was to be expected. I like Baader click locks, there is not one at M63, instead you use an M68 click lock and a M63 to M68 adapter, both Baader and TS make these.

Due to the length this adds i will try the Baader short 2" clamp as well - pinch it from the DZ

Looking down the tube you can see the baffling and it is apparent in the focuser tube as well, nice deep green coatings on the optics

 

Not sure how it wears #42, there was 19 left when i bought it?

 

So far the only thing i have been able to look at is a pylon 500 yards away at 78x nice clear view with a bit of rust apparent, but i live in hope i can get some clear skies and astro darkness soon to point it upwards.

 

 

 

[JeremyS]

Thanks for the feedback on the Oklop case @omo

Does your DZ fit in? If so, any chance of a pic, please?

[BGazing]

Lovely. How is RST handling it?

Are you sure you have not posted this in a wrong forum, says sale/swap...

[omo]

The Oklop is huge for a DZ, more suited to a Tessa i would think, compared to my home made version:

 

 

[omo]

5 minutes ago, BGazing said:

Lovely. How is RST handling it?

Are you sure you have not posted this in a wrong forum, says sale/swap...

Should be in general scope etc, oops, can a mod help as other have replied - i dont think i can move the thread

 

For the first time i had the RST back driving when switched off, so unlike the DZ the longer moment arm needs a bit of balancing

Edited August 7, 2023 by omo
catching up

[BGazing]

1 minute ago, omo said:

The Oklop is huge for a DZ, more suited to a Tessa i would think, compared to my home made version:

 

 

I use one of their tripod bags for DZ, without extra padding. That is actually what Oklop guys gave me...

Tripod bag still has, I believe, 10mm padding.

[Cornelius Varley]

Moved

[YogSothoth]

Great looking scope. Hopefully you’ll have some clear skies soon.

Edited August 7, 2023 by YogSothoth

[moriniboy]

First problem (for me anyway) imprints of the tube rings in the tube CF. Not sure how to deal with this. The tube was covered in lightweight wrapping paper and the rings were on top of the paper.

 

Edited August 8, 2023 by moriniboy

[osbourne one-nil]

Tempting - I currently image with a Vixen doublet and flattener, and it's absolutely fine (rather good actually). I might try one of these and see if I prefer its simplicity compared to the similar focal lengthed R200SS I have. I know I'd be sacrificing speed and aperture, but I do find imaging with a Newt pretty stressful!

[fireballxl5]

Received mine today after ordering on Friday afternoon.  Close inspection found some glue on the tube from the felt liner on the rings after fitting and adjusting the rings, nothing major.  

Quick look at the Sun and very impressed by the view, showing fine surface detail and nicely resolved sunspots.

Will check nighttime performance over coming weeks.  Looking good so far👍

 

[Hans Joakim]

These Oklop “Styropacks” are pretty neat. I have one for my GEM45 mount that makes carrying and transportation much easier. Great looking scope too!

[WbRaDy]

22 hours ago, moriniboy said:

First problem (for me anyway) imprints of the tube rings in the tube CF. Not sure how to deal with this. The tube was covered in lightweight wrapping paper and the rings were on top of the paper.

 

I have just received mine this morning with the same problem, I thought it maybe residue from the felt on the rings but it's definitely an imprint, as if the laquer was tacky when they were closed, if the marks remained under the rings it wouldn't bother me so much but in my case the tube will have to be moved for imaging.

[ScouseSpaceCadet]

First the bad news. Full disclosure, my first SM125 had a bubble and swirls of scratches on the dew shield.

The whole telescope was swiftly replaced by FLO yesterday. On inspection I could not see any faults and last night I even managed half an hour under a clear sky. I was very impressed with the short session.  Albireo's yellow and blue colours really popped. The orange colour of Gamma Aquilae was strikingly obvious even at low mags.

I swung the ota up through Cygnus and was impressed with  how the star fields were rendered even under the light pollution. M29 popped right out at me.

A defocused Vega showed a tight even round circle and no false colour in the mix.

A very quick test but so far I'm very happy with the telescope despite the initial hiccup.

[fireballxl5]

After "first sunlight" yesterday afternoon the skies stayed clear for a regular first light last night. 

I had time for a reasonable session,  selecting mainly binaries, but also M13, M92, M27 and M57. The DSOs were a challenge owing to lack of proper darkness here at 53°N  so the binaries really showed off the performance of the scope.  Using a TV 3-6mm zoom,  stars were tight balls of light with nicely formed diffraction rings.  Star colours were obvious and reminded me why I prefer visual observation with a refractor🙂 The colours in Almach and Albireo in particular were rich and bright.  Lots of others gave similarly fine views. Excellent scope,  I'll be keeping mine👍

CS, Andy

[Paz]

I had mine arrive today, here's my comments so far...

Packaging - very good, it had evidently seen a bit of action in transit but a close fitting box around a soft scope bag looks like a good combination. Inside the scope bag there were a couple of dings where the tube rings were resting which is good, but also a couple of dings where the focuser knobs were resting which is not so good, it would be preferable if packaged so that the focuser knobs are not bearing any weight.

OTA Finish - 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 but I would say I imagine this kind of surface by its nature will pick up and show signs of use and wear over time more than a powder coated metal tube would. 

Weight - This is the thing that got me interested in going for a 125mm refractor after a long time holding off and not wanting to have to get a heavier and more expensive mount than my EQ5 or Skytee 2. With the tube rings/dovetail/handle on (i.e. without funders, diagonals, eyepieces, etc) I make it just under 5.6kg. This is very good and slightly lighter than advertised, I am guessing maybe because I am excluding the cap over the objective which is a chunky metal one. Here's some comparisons that I've weighed directly myself...

• C8 + dovetail + dewshield 5.9kg
• Stella Mira 125ED + dovetail + rings 5.6kg.
• Altair Starwave ED102R + dovetail + rings 4.1kg

Tube Rings / Dovetail / Handle - These are light and well made. At one place the felt under the tube rings was rucked up a little rather than being flush, it looked to me like maybe when it was closed around the OTA the paper underneath it bunched a little and drove the felt back a little, but this is minor, I've pushed the felt back into place and it is fine. The dovetail bar is quite short, I am hoping if I find the right compromise position that I can balance ok with a single light eyepiece or a heavy bino set up by just moving the whole scope and dovetail in the mount and not have to move the tube in the rings, but this will require testing in the field. I am not sure if I will leave the handle on or take it off to save some more weight, but I wonder if the handle helps with stability and therefore vibes, I will look out for this.

Objective - This looks super clean and reassuringly green, and lots of internal baffling is apparent inside the OTA.

Dew shield - This comes back a good way to reduce size and it goes forward a good way to provide protection. However I imagine sliding it back and forth is going to end up marking the OTA soon enough unless you keep the OTA and the felt under the dewshield super clean. The very end of the dewshield where the cap goes over is metal not carbon fibre.

Focuser - This is a standard 2.5" dual speed rack and pinion. The first observation is that there are no screws holding it to the OTA, it is either glued in or press fit or maybe screwed in or some combination. I am sure it is functionally fine but I'll probably be thinking about this a little when I'm in the freezing cold pointing at the zenith with a Terminagler hanging out of it. The focuser is the same fundamentally as the focuser on my Altair ED102R but the ED102R focuser somehow looks beefier, maybe it is or maybe it is just looks like that due to being the same size focuser on a smaller scope. The drawtube moves smoothly, with minor variations in tension through its travel that I would expect to some degree and I guess will iron out with use. The focuser rotates moves smoothly however the single speed focuser knob clashes with the thubscrew tensioner for the rotating focuser so I can't rotate the focuser past that point. The thumbscrew is a very nice one but quite fat and doesn't allow enough clearance. It's not necessarily a problem worth worrying about as long as the focuser is fundamentally straight, I can get a thinner thumbscrew or just rotate in the other direction to get to where I need to be. One other point - the draw tube tensioner screw applies tension very gradually, it feels to me like it is spring loaded or something like that - posh touch if this is what is going on. Other tensioners I have feel on-off in comparison.

Collimation - An indoor star test shows it looks straight/collimated and varying the rotation and position of the focuser suggests a square / straight focuser, but star testing in the field looking at stars at different altitudes and using different focuser rotations and positions and loads is required to be sure all is well and that it holds focus etc. I had a couple of scares though - I noticed what I thought was some image shift but thank goodness tracked it down to slop in the Skytee 2 axis letting the scope move around a little. Then I noticed some more movement and tracked that down me moving my weight slightly between my feet and this moving the floor slightly and that moving the mount!  

Vibes - On an un balanced Skytee 2 (i.e. no counterweighting) it vibes slightly more than the C8 (it is lighter than the C8 but it is longer and with the weight concentrated at each end). The vibes are within the realms of what is acceptable to me and slightly better than I was expecting/hoping for. It will vibe less if counterweighted, and less when on an EQ5 which is the other mount it will be used on. However I am guessing that in the field it will catch the wind more than smaller scopes.

That's as far as I have got. I have some field tests lined up for if I get a clear sky which will cover the remaining checks. I could have taken it out for some cloud-dodging solar looking just over the roof of my house this afternoon but I thought that would be unfair on the scope and end in disappointment due to the poor conditions so I didn't try. My main take away so far is that it is genuinely lightweight and easy to handle, it would make no difference to the set up effort required whether I was taking this or the 102mm refractor out. One is heavier than the other but not so much that it matters at all to me. Cool down time will be interesting to test, as alongside size and weight that is a major setting up factor for any scope, I wonder how it will do on that front.

[bosun21]

Great report? Did you miss out on the reduced price that ended on Saturday? I am seriously considering buying one of these for myself but I’m still waiting for some actual nighttime testing by an experienced observer to get a proper insight on the optics. (So I hope you get a few clear nights soon) The problem with large apochromatic refractors is their price. If I end up not buying one of these then it’s a case of keep saving for an alternative.

Edited August 11, 2023 by bosun21

[John]

That is a really good initial report on this telescope. Lots of detail and some "straight talking" where needed.

Thanks for posting it 👍

I will look forward to your reports on what observation with this instrument is like 🙂

[fireballxl5]

A brief chance to use the scope last night before the cloud rolled in and it gave some pleasant views of Saturn low in the SE at around midnight. I managed to capture some video and produce this image. A little noisy, though not surprising given the planet's low 20 degree altitude.

SM125 / TV PM2.5 / UVIR-cut / ADC / ASI462MC

Best 75% of 6000 3ms subs

[Paz]

I spent this evening indoors checking out how the scope works on an EQ5 getting used to balancing it with different weights at the eyepiece from light 1.25" to heavy 2", getting it on/off the mount, and getting the hang of where the eyepiece goes as it is pointed around in various directions.

When testing the focuser movement pointing straight up I noticed that when I screwed in the tensioner for the rotation of the focuser the focuser moved/cocked slightly. I eventually worked out that 2 out of the 3 the brass flat-head screws that set the underlying focuser rotation tension were loose, one being completely loose. I tensioned them up evenly and the unwanted movement appears to have gone, and interestingly the focuser will now rotate through 360 degrees freely and the single speed focuser knob does not does not now get stuck on the rotation tensioner knob, albeit the clearance is super-close.

I set my tripod legs so that when the eyepiece is as low as it will go that I can still look straight into it horizontally using my observing chair. There is an area of the sky at the zenith where the eyepiece would hit the tripod legs but it is very small. I tried an extension pillar with the EQ5 but I didn't like how high that puts the scope.

It was easy and stress free to manoeuvre around due to the light weight and the handle on the tube rings is actually useful. I thought I would be taking the handle off but it might stay on.

Now it's a wait for clear skies.

[Mark at Beaufort]

I had my first observing night yesterday with the  StellarMira 125mm ED Doublet frac.

I used my 100 degree EPs - 20mm, 13mm, 9mm and 6mm and started with some of my favourite DSOs.

Started with M13 and then move over to M57. Then down to M11. I noticed that everything was pin sharp. I thought I would try a double to I picked Albireo. Perfect. I decided to swing North and picked up  M81 and M82 and again everything was pin sharp.

Finally as Saturn was nicely placed I used my 6mm Ethos and the 4mm Nirvana and the latter giving me a mag of 244x. Saturn although low it appeared very sharp with the Cassini division very clear.

Well this was only my first attempt of using the 5" frac. I will have to get used to the low position but it was a good start.

[Paz]

I have had a couple of goes out in the field, I can share some feedback from those.

Nightime Session SM125 and Altair Starwave 102EDR

I picked out the 102EDR to compare it with, the point being to see if the SM125 behaves like a good quality refractor, I was therefore looking for the benefits (and drawbacks) of more aperture but whilst maintaining the same good quality refractor like views. I was mostly comparing the SM125 at 216x (Baader T2 prism diagonal, 4.5mm Delos) with the 102EDR at 204x (Tak prism diagonal, 3.5mm Delos). It was difficult to match magnifications exactly, this was the closest I could get, but it allowed me to be able to observe and compare going back and forth from one eyepiece to the other with no delay.

Epsilon Lyra 1 - This target was 77 degrees up and very good seeing. My notes on the SM125 were "...looks good, super clean, first rings mostly intact, big clear split, the gap between the inner edges of the airy disks is about the same distance as the diameter of an airy disk, could be the best split I've seen...". That's what I said in my dictaphone but I think on reflection my 14" reflector will have done better, I just would not remember enough detail without checking old observing notes and that is a completely different scope anyway. The 102EDR showed a good view also and a clear / clean split, but the gap between the airy disks was smaller in proportion to the size of the airy disks, as would be expected. The first rings looked slightly more complete/intact in the 102EDR but I only noticed this because I was looking specifically for things like this.

M13 - I used the same sets ups as for Epsilon Lyra above and M13 was about 65 degrees up and quite good seeing. The SM125 was went deeper, resolved more, and presented more extension of the object, but maintaining the same refractor type of the view. There was a very thin veil of turbulence from quite nearby houses that was visible in both scopes if I concentrated on it, but it was easier to see in the SM125.

Zeta Hercules - I've read about this one but I don't think I've had a go at it myself before. It was about 56 degrees up, I didn't state the seeing but it must have been pretty good given the results. I used the same set ups as above again, and then tried the 3.5mm Delos in the SM125 taking that up to 279x. Starting with the 102EDR this time (at 204x) my notes were "...definitely no split, maybe slight thickening of the diffraction ring at 2 o'clock...". However it turns out that thickening was the secondary so I think it can be called a split - it was better than a peanut or a bar. In the SM125 at 216x my notes were "...tighter airy disk, almost a split, clear blob on 1st diffraction ring closer to 1.30 o'clock..."., i.e. an improvement on the 102EDR at similar magnification, then at 279x in the SM125 my notes were "...clear knobble at 1.30 o'clock on 1st diffraction ring...". So both scopes were a win, but the SM125 was better due to having more aperture. Checking Sky Safari later the secondary was at position angle 88 degrees and just eyeballing the screen from my perspective it was at 1.30 o'clock, Although it was tougher, I am sure I would have pinned the position angle down just as accurately in the 102EDR if I had observed in that scope for longer.

Albireo - I did not compare scopes on this one, I just had a look at 279x with the SM125, Albireo being about 65 degrees up and good seeing. My notes were "...huge split, clean airy disks, almost intact rings, bright orange, smaller blue...". I would not usually look at Albireo at that magnification hence the comment that the split looked huge, but it was a fine view.

I had left both scopes out to cool for a while and the temperature was not very low so there were not the right circumstances to test for differences in cool down. I can say though when taking it down the OTA felt warm to the touch kind of like plastic would, I think this will be a bonus in the winter compared to handling a freezing cold metal tube, I didn't have any problems with vibes, the SM125 works fine on an EQ5, although I might raise the legs a bit for a little more height, as I only had the legs a little over half extended. The focuser did fine, collimation looked straight at various altitudes and rotations, but it has not yet been tested in the field with a heavy 2" eyepiece or binoviewers loaded with heavy eyepieces. I think I might want to get a longer dovetail bar for a bit more balancing range to cover light to heavy loads at the focuser, but I will keep going and see if I can cover the bases as it is, it might be a close call. 

Solar Observing - SM125 Only

Solar - The SM125 has enough in focus for me to use the same set up that I use on my ED102R which is good and as I hoped/expected. With Binoviewers and a wedge in green light (30mm NPL's + 2.6x GPC so about 85x) I can tell that the SM125 shows more detail than the 102EDR, for example looking at the stippling all over the face and the faculae around AR3394. The SM125 also shows up the seeing conditions more, the seeing was not great and this was more evident. I did not test it back to back with the 102EDR but white light solar with the 102EDR is what I am most current/familiar with and so I am confident about the comparison. I think the SM125 presents a similar nature refractor view to the 102EDR but resolving more as one would expect from more aperture. The detail/resolving of the sun from the SM125 is I think closer to a C8, but how close would require back to back testing with the C8 which I am not so familiar with when it comes to white light observing, However I can say that when solar observing with the C8 that presents details more softly and it shows up any seeing issues more,

A bright planet the moon are the other things I would like to try to cover most of the bases, and testing it with something heavier in the focuser, but fundamentally it seems to be a good quality 5" refractor that's light enough for me to handle happily. I did some star testing on Deneb and Vega but interpreting and reporting on those is beyond what I feel able to remark on, but I am happy with my notes above being fair comment.

[ScouseSpaceCadet]

Tonight I enjoyed my first extended observing session with the Stellamira 125ED f7.8 doublet. Equipped with a quality red dot finder and a matching red Altair Lightwave 1.25" dielectric diagonal, the telescope balanced perfectly using the Celestron AVX 4.5kg counter weight. On this occasion I went with the 1.25" diagonal because during a recent brief session ended by cloud, a 2" diagonal clipped the tripod legs. I had a couple of close shaves tonight. For peace of mind I'd suggest mounting this telescope on a pier or mount capable of using a pillar extension. Unfortunately I believe Celestron do not market an extension pillar for AVX. 🙄

Otherwise, roughly polar aligned and using a 2 star align plus 1 calib star, the mount goto worked flawlessly, placing every target within my 7mm Nirvana ES eyepiece's field of view and tracking each object as expected.

Starting at 2320, the temperature was in the mid teens. No coat required, a track suit top kept the light breeze off and me comfortably warm. I noticed seeing was steady with little scintillation, however transparency was poor, the sky remaining a grey hue. Bortle 7/8 urban sky.

I started at Albireo, with my shortest focal length eyepiece, a 4mm Vixen SLV providing 243x showing off the blue and yellow colours with tight diffraction rings.

Onto the Double Double. A Vixen 6mm SLV for 162.5x really showing off these doubles.

M27 was very faint but I could just make out the shape using one of my favourite eyepieces, the 7mm Nirvana ES.

Gamma1 Delphini a double with a separation of 9" and curious colours. My colour deficient sight registered the primary as yellow with a greenish secondary.

Globular cluster M15 had a surprising bright core and even twinkled somewhat in the 7mm Nirvana.

M2 looked larger than M15 however with a less distinct core and overall a more diffuse appearance.

Midnight arrived and the jewel of the solar system Saturn accompanied by its largest moon, Titan graced the eyepiece. A wonderful sight despite the poor transparency. I had to back off the magnification for a really crisp view. Sticking with the 7mm Nirvana again at 139x. Still during steady moments I managed to pick out the Cassini division and the different hues of atmospheric bands.

Twenty minutes was spent on Saturn then back onto my west to east tour.

Zeta1 Aquarii, sparkling white jewels with a 1.7" separation. Perfect through a 5mm SLV at 195x.

Down to the pale blue/green dot, Neptune. I've had better views using scopes of similar aperture. The planet being rather low on this occasion plus the seeing conditions did not do the planet justice.

Onward to another easy double, 61 Cygni at 32" separation but nonetheless stunning orange companions.

Flogging a dead horse I tried M31 and did not have the best at home observation of our neighbouring galaxy.

The Double Cluster was terrible, again  the light pollution and the murky sky conditions did no favours. It is possible with this sized telescope to get a decent view on the city outskirts but not tonight.

Finally, at 0050 I felt like I was making too much noise on a Monday morning so finished with Eta Cassiopeia. To my eyes, a gold primary and orange secondary.

Overall a very enjoyable session. The longest I've had for many months.

I'm far from expert, however optically the SM125 doublet performed as expected, exhibiting very high contrast, with no obvious spherical or chromatic abberations.

Mechanically, the focuser although a bit stiff compared to my 102mm ED refractor, was precise and objects snapped into focus. The focuser's rotating and locking mechanism was also really nice in use. The dew shield is a bit stiff when sliding. Any tips to improve this would be appreciated.

At home deep sky observations are primarily doubles and the telescope left me feeling it is fit for purpose.

I'm very much looking forward to taking the SM125 to this Autumn's astronomy camps (and hoping for a clear night or two!).

 

Edited August 21, 2023 by ScouseSpaceCadet

[Marian M]

On 17/08/2023 at 01:13, Paz said:

I have had a couple of goes out in the field, I can share some feedback from those.

Nightime Session SM125 and Altair Starwave 102EDR

I picked out the 102EDR to compare it with, the point being to see if the SM125 behaves like a good quality refractor, I was therefore looking for the benefits (and drawbacks) of more aperture but whilst maintaining the same good quality refractor like views. I was mostly comparing the SM125 at 216x (Baader T2 prism diagonal, 4.5mm Delos) with the 102EDR at 204x (Tak prism diagonal, 3.5mm Delos). It was difficult to match magnifications exactly, this was the closest I could get, but it allowed me to be able to observe and compare going back and forth from one eyepiece to the other with no delay.

Epsilon Lyra 1 - This target was 77 degrees up and very good seeing. My notes on the SM125 were "...looks good, super clean, first rings mostly intact, big clear split, the gap between the inner edges of the airy disks is about the same distance as the diameter of an airy disk, could be the best split I've seen...". That's what I said in my dictaphone but I think on reflection my 14" reflector will have done better, I just would not remember enough detail without checking old observing notes and that is a completely different scope anyway. The 102EDR showed a good view also and a clear / clean split, but the gap between the airy disks was smaller in proportion to the size of the airy disks, as would be expected. The first rings looked slightly more complete/intact in the 102EDR but I only noticed this because I was looking specifically for things like this.

M13 - I used the same sets ups as for Epsilon Lyra above and M13 was about 65 degrees up and quite good seeing. The SM125 was went deeper, resolved more, and presented more extension of the object, but maintaining the same refractor type of the view. There was a very thin veil of turbulence from quite nearby houses that was visible in both scopes if I concentrated on it, but it was easier to see in the SM125.

Zeta Hercules - I've read about this one but I don't think I've had a go at it myself before. It was about 56 degrees up, I didn't state the seeing but it must have been pretty good given the results. I used the same set ups as above again, and then tried the 3.5mm Delos in the SM125 taking that up to 279x. Starting with the 102EDR this time (at 204x) my notes were "...definitely no split, maybe slight thickening of the diffraction ring at 2 o'clock...". However it turns out that thickening was the secondary so I think it can be called a split - it was better than a peanut or a bar. In the SM125 at 216x my notes were "...tighter airy disk, almost a split, clear blob on 1st diffraction ring closer to 1.30 o'clock..."., i.e. an improvement on the 102EDR at similar magnification, then at 279x in the SM125 my notes were "...clear knobble at 1.30 o'clock on 1st diffraction ring...". So both scopes were a win, but the SM125 was better due to having more aperture. Checking Sky Safari later the secondary was at position angle 88 degrees and just eyeballing the screen from my perspective it was at 1.30 o'clock, Although it was tougher, I am sure I would have pinned the position angle down just as accurately in the 102EDR if I had observed in that scope for longer.

Albireo - I did not compare scopes on this one, I just had a look at 279x with the SM125, Albireo being about 65 degrees up and good seeing. My notes were "...huge split, clean airy disks, almost intact rings, bright orange, smaller blue...". I would not usually look at Albireo at that magnification hence the comment that the split looked huge, but it was a fine view.

I had left both scopes out to cool for a while and the temperature was not very low so there were not the right circumstances to test for differences in cool down. I can say though when taking it down the OTA felt warm to the touch kind of like plastic would, I think this will be a bonus in the winter compared to handling a freezing cold metal tube, I didn't have any problems with vibes, the SM125 works fine on an EQ5, although I might raise the legs a bit for a little more height, as I only had the legs a little over half extended. The focuser did fine, collimation looked straight at various altitudes and rotations, but it has not yet been tested in the field with a heavy 2" eyepiece or binoviewers loaded with heavy eyepieces. I think I might want to get a longer dovetail bar for a bit more balancing range to cover light to heavy loads at the focuser, but I will keep going and see if I can cover the bases as it is, it might be a close call. 

Solar Observing - SM125 Only

Solar - The SM125 has enough in focus for me to use the same set up that I use on my ED102R which is good and as I hoped/expected. With Binoviewers and a wedge in green light (30mm NPL's + 2.6x GPC so about 85x) I can tell that the SM125 shows more detail than the 102EDR, for example looking at the stippling all over the face and the faculae around AR3394. The SM125 also shows up the seeing conditions more, the seeing was not great and this was more evident. I did not test it back to back with the 102EDR but white light solar with the 102EDR is what I am most current/familiar with and so I am confident about the comparison. I think the SM125 presents a similar nature refractor view to the 102EDR but resolving more as one would expect from more aperture. The detail/resolving of the sun from the SM125 is I think closer to a C8, but how close would require back to back testing with the C8 which I am not so familiar with when it comes to white light observing, However I can say that when solar observing with the C8 that presents details more softly and it shows up any seeing issues more,

A bright planet the moon are the other things I would like to try to cover most of the bases, and testing it with something heavier in the focuser, but fundamentally it seems to be a good quality 5" refractor that's light enough for me to handle happily. I did some star testing on Deneb and Vega but interpreting and reporting on those is beyond what I feel able to remark on, but I am happy with my notes above being fair comment.

Paz, very nice and detailed reading!

 

How would you rate the 125 apo vs 102 apo on DSO only, is the light gathering substantial, it handles magnification better, what about the real resolution? Does it worth?

I have the TS 102 FPL53 and 120/600 achro, bino-addicted. Being a refractor only person, I am planning to increase the aperture for DSO only, for magnification up to 100x. The 152 f5.9 achro (TS, Tecnosky) has been my first option but many people, including my star parties budy, are pushing towards 125 FPL53- being the max I can afford. Weight, mount, rest I know and I can handle..

DSO only, up to 100x, would 125 be a better option? Or 152 achro, if by chance, you have ever compared. Sorry to jeopardize the thread..

 

Thanks a lot!

[Paz]

14 hours ago, Marian M said:

Paz, very nice and detailed reading!

 

How would you rate the 125 apo vs 102 apo on DSO only, is the light gathering substantial, it handles magnification better, what about the real resolution? Does it worth?

I have the TS 102 FPL53 and 120/600 achro, bino-addicted. Being a refractor only person, I am planning to increase the aperture for DSO only, for magnification up to 100x. The 152 f5.9 achro (TS, Tecnosky) has been my first option but many people, including my star parties budy, are pushing towards 125 FPL53- being the max I can afford. Weight, mount, rest I know and I can handle..

DSO only, up to 100x, would 125 be a better option? Or 152 achro, if by chance, you have ever compared. Sorry to jeopardize the thread..

 

Thanks a lot!

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.