DirkSteele

Congrats. Always a best view and that first one will stay with you. The great thing about Jupiter and it’s moons is over short periods of time you can easily see changes in the orbits and cloud features. It’s one of the few things we can watch that change quickly l.

21 hours ago, JAC51 said:

https://www.astrotreff.de/forum/index.php?thread/95328-vier-apos-von-apm-lzos-vor-dem-interferometer/
The above link is to a 2009 article on a German site where a APM LZOS 130 F9 and a 115 F7 where tested over 9 different wavelengths, with repeats to show their polychromatic strehl

I used the translate option on my browser to read it.

Really interesting, thanks for sharing. Certainly shows how special the 130 f/9.2 is. Considering how many amateurs are hard core optical perfectionists, it is a real shame that more did not realise how good this scope is and purchase one.

It has redefined my definition of what optical perfection is.

So those of you who paid attention to what did the postman bring v2 yesterday would have seen I have taken delivery of a new Tak FC-100DC. There was a brief spell of semi clear skies this evening. Looking a the forecast that might be it for quite some time. I wanted to try out the scope and thought I will have a quick peak at Saturn and the Moon. Here is the thing, neither of them can be seen from ground level at my house currently so I popped the scope out on the roof, about 40ft up (I travel for most of my Astronomy sadly).

Even with an uncooled scope, heat rising off the house and a turbulent atmosphere, I was quite impressed by the quick glance. Saturn held up quite well even at 185x. Look forward to seeing what this scope can do when I have a proper session with it.

Yep that is the chimney. Saturn was just under the dish.

4 minutes ago, Deadlake said:

Well the original price Matthew quoted would in todays money be considerably more.

The 130mm/F6 I have is the same price and in 2021 money around £6500.

Talking to Rupert the cost new would be almost double. The lens cells are bought on a fixed 10 year contract and due to cost increases that was the end of LZOS as APM would have too buy a fixed amount per year. Not even going near the current situation.

The only comparable European scopes I can find are Zeiss APQ here 

https://apq.de/en/products/uni_polychromats.htm

Which are at *new* LZOS prices.

A bit like houses everyone priced out…

Wow, look how far those correction graphs showing theoretical strehl to wavelength go into the UV and near IR! “Price on application.” If you have to ask….

3 hours ago, Deadlake said:

Good write up Matthew, would be ingested to see how the F9.25 compare with the F6 model at some point. 

I always think the F6 model is long enough, but yes the 130 mm / f9.25 is one of a kind and maybe only the TOA 130mm and Zeiss APQ's are the only real match available at a huge price.

How wobbly is it on the Gitzo tripod?

It is pushing the limit of that tripod. It’s ok but once the magnification starts to get pushed something more robust is really needed. I just tend to favour the Gitzo when out and about with the scope as it keeps the weight down of what I have to carry (2.8kg in this case).

Been thinking about a light weight 4” refractor for a while and one that could be airline portable with some disassembly as my LZOS 105 is a bit heavy and needs a beefier mount. Found my finger hovering over the buy button of the FC-100DC all weekend before finally pulling the trigger at 23:30 on Sunday evening. Also added a dovetail and some tube rings.

Received an email early Monday afternoon stating order was complete and then communications from DPD the courier who provided a 1 hour slot on Tuesday to deliver the packages. I like DPD as you can track the driver so I headed home when the courier was 4 deliveries away and he showed up less than 10 mins after I did.

The box for the scope had taken a knock which had punctured the outside box and dented the inner second box, but Takahashi triple box with polystyrene inserts and chips so all seems fine. Hopefully that clear skies guarantee* holds true so I can actually use it some point this year!

Box1 and Box 2

Box 2 and Box 3

*eventually

45 minutes ago, John said:

I really enjoyed reading your review Matthew. Thank you so much for compiling it and posting the link 👍

Yours is undoubtedly the most comprehensive review of this instrument that I have read to date. 

Yours and my 130mm F/9.2 objectives come from different ends of the manufacturing life of the optic. Mine is from 2006 and yours 2017 from the optical test certificates. Mine is a mid-range .965 strehl whereas yours is in the top tier for the objectives. LZOS measure in green light. As you so rightly say though, these figures are only a small part of the story. In the field (where it matters !) my scope delivers the best pure optical performance that I have experienced from any telescope I've owned / used. 

It would be interesting to know how many of these there are in the UK. I know of one other SGL member who has one (apart from yourself). There are probably a few more out there I guess but they are not a commonly encountered instrument.

Thanks again for the excellent and comprehensive review. I will probably print off a copy to hold with the other documentation I have on these scopes 🙂

Thanks, glad you liked it and spotted the quote from yourself near the end.

I know of one other owner, actually a fellow committee member of the Baker Street Irregular Astronomers though he keeps his in Tenerife where he goes several times a year as his wife is from there. I imagine there may be a couple more but that means mid single digit owners of this scope in the UK. Shame there are not more.

Clouds. Mostly clouds! Little unfair, as we did see Jupiter as it was rising in the east but was a mushy mess as it was so low and a few stars early in the session but alas the clear skies during the afternoon did not hold into the evening so about 50 attendees to the Baker Street Irregular Astronomers star party in Regent’s Park were not rewarded for their effort to travel.

I did attempt to find Saturn hoping it might cut through the high cloud in a scope even though it was not visible naked eye, using a compass and digital spirit level to point my manual Alt Az in the right direction (having checked that both were accurate by using the same method to find Jupiter without looking at it), but sadly the cloud was too thick.

I note the two inch visual back is optional. Wonder if it vignettes using the full 2” field stop?

if it is usable that gives just shy of a max 1-degree field which isn’t terrible though not sure what the off axis performance would be like.

Oh and I hope this guarantee holds as the next named storm hit the UK very shortly after the courier dropped it off!

A few weeks ago I created a post to celebrate 10 years of my little astro website, Alpha-Lyrae which caused a few people to mention that my reviews had cost them money.

Well some of you have returned the favour. As much as I love my APM LZOS 105 triplet which is airline portable, it’s a big lad, which requires a more robust mounting solution and I wanted a four inch scope which was a little more svelte so it could go on a smaller mount and tripod.

So what is in the box above? It’s the FC-100DC. I am not naming names but @Stu, @JeremyS, @mikeDnight and @John all of whom have variations on this scope may have a question or two to answer! 😉

To quote Ed Ting. “It’s a good day….new telescope.”

Dragged the APM LZOS 130/1200 across London for the Baker Street Irregular Astronomers star party the other night in Regent’s Park.

BT (Nebula) Tower in the background.

It has been a while since I have written a review (about 2 and half years in fact) but after more than 5-years of ownership (always like to own things for a long time so the view can be very considered, unlike the time pressure of magazine reviews), I have put fingers to keyboard and written a review of what I think is a rather special telescope, the APM (TMB) LZOS 130-1200 f/9.2 triplet apo.

Contents:

·         Preamble (about fate and other such nonsense)

·         Who are LZOS and the APM/TMB Relationship?

·         The history of the TMB LZOS 130 f/9.2 (and some controversy)

·         The OTA 

·         The focuser

·         Details on flatteners and focal reducers

·         The lens

·         What is the Focal length?

·         What is the big deal about this specific model?

·         Under the stars

·         Current Availability

·         Conclusion

Quite a long one but aren’t they always when I write them? Review is on the link below (I know talk of controversy has got you all curious so click away!).

http://alpha-lyrae.co.uk/2023/10/15/apm-tmb-lzos-130-f9-2-triplet-refractor-review/

Hope you enjoy and feedback always appreciated.

Clear skies (which I think we could all really use some of at the moment),

Matthew

I use the triple click on my iPhone to avoid white light when shutting the app or unlocking the phone but agree with @John, if you are pushing the limits of visibility, no amount of light of any colour (no matter how dim) is doing you any favours.  Red is just less damaging, rather than not damaging.

I did make a sleeve for my iPad years ago in Blue Peter style.  I managed to get superglue on my finger tips.  This was quite a problem as I use a finger print scanner at work to use my financial terminal and it made my finger print unreadible (so the crime movies are right!).  I had to call the supplier from the centre of the trading floor and explain why I needed an unlock code for the day.  As you might imagine, there was an eruption of laughter across the floor when I explained I had glue on my fingers! 😄

Not personally, but several attendees to AstroCamp in Wales which is in a dark sky park do rent motor homes for the event and it seems to work quite well.

A Mak wouldn't have diffraction spikes as it does not have spider vanes.  A little more information to help us diagnose the problem would be helpful.  Are the four "spikes" all orientated in the same direction?  Or are they perpendiuclar / random orientations?  Do the spikes run out into space off the planets surface / rings, and do they extend equally in both directions?

Couple of experiments for you to try to potentially eliminate culprits.  Do the spikes appear if using another eyepiece?  If they do, it may well indicate the issue is with the telescope.  If they do not, it may be the eyepiece.  Second, trying spinning the eyepiece in the eyepiece holder of the scope.  Do the spikes change orientation?  If yes, then the eyepiece may be at fault.  If not, the problem may be with the scope.  I note from your signature, you have a second scope.  The 14mm will be lower power in the ZS73 but do you see anything similar when looking at Saturn?

Saturn is quite a bright object which may well make the spikes easier to see.  Also try Jupiter.  Please also try to observe Vega. Do you see the spikes?  Assuming you keep Saturn roughly in the centre of the field, slowiy move Vega up and down the field in the centre to see if the spikes appear.  As Saturn has an apparent diameter, it may be that surface scraches in one of the optical elments are showing up. Vega won't have that diameter so you will need to move it to see if you pass over a scratch. 

While I won't advocate a full star test at this stage, if the seeing is good, use a high power eyepiece and defocus a star like Vega and expand the fresnel diffraction pattern so you expand 5-6 rings.  Does the outer ring look "hairy" especially outside of focus?  By hairy, I mean it looks like lots of little strands stand up off the outer ring.  I have seen this in a Mak before and is indication of surface roughness.

On the one or two occasions I have suffered the same feeling over the 30+ years I have been stargazing, I have found a break away from it really invigorates me to get back in to it. That might be as short as month, but there was one instance where it was nearly 6 months.

10 hours ago, Bugdozer said:

I had the Collins Gem Guide to the Night Sky, which was a tiny little book but did have one constellation per page, and it was really useful. The maps were excellent. I don't know if it's still available but it was my constant companion in my early days of observing. 

That was my first star chart book as well. Bought mine back in 1986 I think when I first started to look at the sky as a 6-7 year old. Wil Tirion was the stellar cartographer so the charts are good if a little small. Even took this to Namibia back in 2011 when luggage allowance was very restricted.

I have done similar on Wimbledon Common and Primrose Hill in the past which don’t close over night (the latter Monday to Thursday). Sadly your location is an 1 hour drive away from me in central London but seems like a great idea. Hopefully some more local SGL members will be in touch.

I am less familiar with EQ mounts as I almost exclusively use Alt-Az but I would imagine you would see the benefit of the upgrade.  I have always thought of the EQ5 as the bare minimum really in the EQ space and the EQ3 and lower just come as a starter kit to get the new telescope owner going.  If you are serious about pursuing astrophotography further, you may even be better served with the HEQ5 but others with more experience of these mounts will be able to provide better commentary on this matter.

Speaking as a refractor man, the short answer is no.  A well collimated 130 Newtonian will likely out perform the ST 120.  While the refractor may have slightly better contrast (though not quite the match of the top tier Apos), it will probably do no more than match the extra light gathering ability of the 130 and quite possibly fall short of it.  If you want better views of DSOs, you would be better served with something like an 8" Dobsonian.  You could always keep your 130 on the EQ mount so you can continue to dabble in planetary photgraphy with the benefits of polar alignment.

Awesome piece of work.

5 hours ago, badhex said:

Ah damn. Just tried it on some houses across road and I ran out of focuser travel before it got to focus. Oh well, that's the end of that very short saga! 

What started me on this was wondering whether a focal extender is available for the ZS73, since it performs surprisingly well on planets when you bump the magnification up. Sadly it seems not, however such an accessory would turn this scope from a widefield wonder to a solar system slayer.

I guess shall just have to stick to the tried and tested BCO + barlow/PM method for now! 

Don’t forget that you need more out focus to bring nearby objects to focus so you should still try it at infinity with the stars just in case it works.

When I was teenager stargazing in my parent’s garden, the neighbour’s cat would often come and sit under the tripod and go to sleep. He was never happy when I packed down his little house and called it a night.