APM LZOS 130 f/9

[JeremyS]

9 hours ago, Marki said:

Thanks John.

You're not kidding. Just been reading up some of the very long, convoluted, tortuous and even heated threads about the evolution of the 130 f/9 (ish) design, cool-down times and actual focal lengths over on CN..... . Informative, but exhausting in equal measure ;). After all that, at this point all I want is a clear night to try mine out... ;).

Heated threads on CN? Surely not! 🤣

I hope you get clear skies soon to test this beauty out 👍🏻

[Marki]

So, the clouds have parted and the scope has been out an hour. I'll post a proper first light report later, but for now all I'll say is, I get it. I now get it. I really finally get it. I get why a premium 'frac justifies its title. I also have a better appreciation of just how good a telescope a third the price can actually be as well.

A quick star test on Arcturus shows no false colour, absolutely none, inside or outside of focus (or actually at focus more importantly ;)) @240x. Near perfect and identical diffractions rings either side too and so far as I can tell given the conditions, no sign of coma or astgmatism etc.

So far so good.... 

 

[Space Hopper]

Excellent.

Take a look at M37 in Auriga.

Its a magical view through a big refractor......

[Captain Scarlet]

4 minutes ago, Space Hopper said:

Excellent.

Take a look at M37 in Auriga.

Its a magical view through a big refractor......

Look for the prominent red star in the middle, one of my highlights...

[Marki]

A few observations on my LZOS. I find the dew shield cover a bit of a pain; its one of those screw-in  types (how do you call them?) and is surprisingly noisey at 2am when packing up.... :). The scope is really quite heavy; I've just weighed it at 11.5 kg with rings, plate and handle and dewshield cap. Thats fully 2kg more than my SW Evostar 150 ED.

The tube is finished in that slightly textured powdered paint. The dewshield cap is metal.

I nearly dropped the scope whilst trying to get it on my mount. I'd forgotten to open up the saddle grip enough for the losmandy plate (only ever had skywatcher/vixen dovetail plates before). I started to rapidly unscrew the grip even more whilst trying to support the scope, and went too far and the grip piece fell out of the saddle entirely! I'd have been in serious trouble but for the handle!

Once safely attached and balanced, the AZEQ 6GT handled the scope with no problem at all, with little vibration. I wouldn't like to use anything in a lighter class though. Although heavier, the scope seemed happier on the mount than the 150 - maybe because the overall configuration is shorter and the mass more centrally balanced? I felt there was less vibration in the whole setup anyway.

Despite some episodes of cloud-dodging I was able to get a couple of hours in last night. The seeing and transparency were variable - seemed to be a fair bit of moisture in the air, but things generally got better after c. 1am. My initial impressions were effectively confirmed with regard to the optical qualities of the lens - simply better than anything else I have looked through (I admit my experience is somewhat limited though). I can only put that down to the way light is just put in the right place, so that the contrast is maximised.

I tried it out on a number of targets. A few gighlights from my notes: M3 and (especially) M13 were wonderful  - subtly scintillating with myriads pinpricks of light as the edges of the clusters just began to resolve. M57 a clear ghostly smoke ring. M81 and 82 clear and obvious. I tried many of my usual doubles in and around Bootis, with very pleasing results. Izar was a walk in the park. I even had some luck with Zeta herc, a target that has repeatedly frustrated me in the past. Although not clear, I could distinctly see the secondary, waving in and out of vision on the edge of the first diffraction ring as moments of clear seeing came and went. 240x  - went to 360x but wasn't really any better (I think seeing wasn't really up to that high mag). I don't know whether this is simply because I'd got my eye in better or the seeing had improved or this is really a tribute to the opitcal quality of this scope, but I've never got that close with any of my other scopes before.  Can't wait to try this out on the moon and the planets!

A couple of final thoughts. M13 in particular does look better in my 150ED. Not withstanding the better quality of the LZOS's lens, up against a decent quality ED in tonights seeing, the extra 20mm of aperture edged it on this sort of target. Actually, the SW150ED holds up pretty well, especially when you consider its effectively more than three-times less expensive.

Nevertheless, I am very happy with last night's first night for the LZOS and consider myself very fortunate to be able to have both this and the SW150ED in my current stable.

 

 

 

[John]

Very interesting report Mark.

Aperture does tend to "win" with globular clusters.

When the seeing is steady you should get a nice split of Zeta Herculis with the 130 LZOS I think. The ED150 should do this as well of course.

It does take a bit of practice to get used to mounting these scopes using the Losmandy fitting, I agree.

Hope you get lots of great observing with your refractors over the coming months

 

 

 

[Stu]

Sounds like you’ve got a winner there @Marki, looking forward to further reports. Zeta Herc is a tricky one. I’ve since done it in smaller scopes, but it took a Tak Mewlon 210 to first show it to me. With good seeing conditions it should be very doable in your 130 (and 150 as John says). As you say, there is a certain quality to the views through these top end refractors which is what makes them so attractive; the contrast and star shapes being the most obvious merits.

Out of interest, have you tried the AZEQ6 in Az mode? It’s certainly much more convenient for visual than EQ, because the eyepiece stays in the same orientation regardless of target, it just moves up and down as it were. Well worth a try.

[Marki]

Thanks John. I use the AZEQ in mainly EQ mode at the moment - this is mainly as it gets the tube a little higher fromthe ground. I did have short prier extension but it wasn't really "tight" with shifted as the scope slewed - not ideal. I've been looking into different models of pier extension/mounting recently but I don't have the option of a permanent set-up regretfully. For now bend or kneel. And my back doesn't tahnk me for it... .;)

[John]

1 hour ago, Marki said:

...I don't have the option of a permanent set-up regretfully....

Me neither.

All my setups have to be reasonably portable and quick to setup / tear down.

With hindsight the Istar 150mm F/12 on the EQ6 / Meade Giant Field tripod was not my smartest decision

[Deadlake]

2 hours ago, John said:

Me neither.

All my setups have to be reasonably portable and quick to setup / tear down.

With hindsight the Istar 150mm F/12 on the EQ6 / Meade Giant Field tripod was not my smartest decision

My neither, I went for an SXP2 because it’s lighter then the competition. I can be in and packed up in 10 minutes at the end of the night. That means the scope, mount and tripod are disassembled and stored.

[John]

40 minutes ago, Deadlake said:

My neither, I went for an SXP2 because it’s lighter then the competition. I can be in and packed up in 10 minutes at the end of the night. That means the scope, mount and tripod are disassembled and stored.

My solution for the 130 f/9.2 is alt-azimuth with no power / alignment requirements.

 

 

[cfrommen]

Very nice scope, Mark and welcome to the club 🙂

I recently bought an LZOS 130 f/9 (0.974 Strehl) from a colleague in Germany and am very happy with it. Instead of opting for the heavy APM tube with 3.7" focuser (an additional 2000 EUR at APM) he had mounted the cell inside a Bresser Messier 127L OTA and had kept the 2.5" HEXAFOC with 10:1 reduction.

To be honest, I am really happy that I went with this lightweight solution. The OTA is nicely flocked inside and has a sufficient number of baffles (4). I never noticed any stray light or glare entering the tube. It also cools down quickly, and I can start observing already after 30 minutes or so. The 2.5" HEXAFOC  is good enough for visual use and to avoid vibrations during focus change, I have ordered a Rigelsys nFOCUS which runs on batteries.

The only downside that I see with the Bresser OTA is that it has a fixed dewshield and the scope is quite long. From dew shield to the end of the focuser the scope measures about 135 cm, so the momentum arm is quite long. It's challenging for my TTS Panther 160 Alt-Az mount but the Rigelsys Focusmotor helps to eliminate vibrations when changing focus or touching the scope.

I had problems initially to get any of my eyepieces into focus with my 2" WO Diagonal. There were about 5 mm of inward focus travel missing, so I replaced the diagonal with a Baader Zeiss Prism with T2 connections and now I can reach focus.

So far, I find myself just looking at the moon (an object that I neglected for many years) and enjoy those high contrast views and this enormous perception of depth in the craters, mountain ranges and the change between light and dark regions.

I have not used the scope photographically besides for some lunar imaging with a CCD. Once I get a suitable flattener and reducer I might give that a try though. But so far, I am just happy to use the scope visually instead of spending time setting up the mount for imaging, dealing with guiding etc. and then post processing the data.

 

CS

Christoph

 

 

Edited April 30, 2021 by cfrommen

[DesertSky]

I have read controversial posts about the quality of LZOS glass. Some say they are overrated because they are technically equivalent to FPL51 but not FPL53 or FCD100. Any comments about that?    

[John]

19 minutes ago, DesertSky said:

I have read controversial posts about the quality of LZOS glass. Some say they are overrated because they are technically equivalent to FPL51 but not FPL53 or FCD100. Any comments about that?    

Welcome to the forum

 

[Deadlake]

15 hours ago, DesertSky said:

I have read controversial posts about the quality of LZOS glass. Some say they are overrated because they are technically equivalent to FPL51 but not FPL53 or FCD100. Any comments about that?    

OK-1 and OK-4 are more akin to Takahashi Fluorite lens then FPL series of glass. I think Daniel Mounsey did a shoot out of all 4" APO's in a rolling review on CN, and in the end it came down to the TSA-102 and the LZOS. Unless you have all the scopes (Daniels review stretched into 30-40+ scopes, some the same model) you can to review an objective rating is hard to make. 

Edited May 15, 2021 by Deadlake

[dweller25]

15 hours ago, DesertSky said:

I have read controversial posts about the quality of LZOS glass. Some say they are overrated because they are technically equivalent to FPL51 but not FPL53 or FCD100. Any comments about that?    

Where did you read that ?

[JAC51]

They are indeed excellent telescopes. I have aTMB 130/1200LW version from 2005, lens number 005. It has a draw tube and 2" Feather light focusser which I think is to make it bino friendly.

The contrast as already said is superb , the tube dews up but the lens at the business end never has so far in 10 years of ownership and it seem to have very little in the way of tube currents when cooling. The f9+ focal length is very forgiving of any eyepieces used and the cool time down is no where near as bad as I feared (45min?+) perhaps due to thinner glass  in the more gently curved lenses compared to shorter focal lengths.

Below is things that I have read online and perhaps half remembered , if I'm wrong I apologise and please contact me..

OK4 glass by accounts  I have read is very close to FPL53.

Now I wish I had the link to this but here goes..

Years go I remember reading, I think on APM website that their 6" ED F8 doublet using FPL51 glass was equivalent to an achromat of F30.

They also produced for a short while a 6" LZOS F8 doublet using OK-4 which was equivalent to a F45 achromat.

I think my memory is accurate in which case the above would suggest that OK-4 is optically  superior to FPL51, though of course the mating elements matter a great deal as well.

Now for complete speculation from me. It is possible that FPL51 and OK4 might be equivalent in how easy they are to work . FPL53 is I believe said to quite  soft and difficult to work with, something  I have not heard about OK-4. 

This by the way is my first post after saying hello, please forgive any typos.

John

 

 

[Space Hopper]

Afaic, where optics are concerned, the Russians know what they are doing.

Tried and tested, and world class. Enough said.

[Stu]

1 hour ago, JAC51 said:

This by the way is my first post after saying hello, please forgive any typos.

Thanks for the info John, and welcome to the forum! 👍

[Stu]

18 minutes ago, Space Hopper said:

Afaic, where optics are concerned, the Russians know what they are doing.

Tried and tested, and world class. Enough said.

Yes, I would back an LZOS lens made out of the bottom of a bottle (well, almost 🤪) vs a cheap mass produced scope which happens to use fpl-53.

[John]

1 hour ago, JAC51 said:

They are indeed excellent telescopes. I have aTMB 130/1200LW version from 2005, lens number 005. It has a draw tube and 2" Feather light focusser which I think is to make it bino friendly....

 

 

 

Welcome to the forum John

I have the same scope. Mine is #20 from 2006. Very fine scope optically and very nicely put together as well. Top drawer in my opinion.

I understand that the LZOS OK4 glass is somewhere between Ohara FPL-53 and FPL-52 in properties. A bit ahead of FPL-51. The key thing with LZOS is that they make both the OK4 glass and the bespoke mating element glass so the match and colour correction are excellent. Their figuring and polishing is done to very high standards as well so the resulting objective lenses are up there with the best.

This is what Professor Ian Morrison has to say:

http://www.ianmorison.com/everything-about-refractors-part-1-their-objective-lenses/

 

[JAC51]

15 minutes ago, John said:

 

This is what Professor Ian Morrison has to say:

http://www.ianmorison.com/everything-about-refractors-part-1-their-objective-lenses/

 

Thank you for the link John, very interesting link.

I looked up the Abbe numbers  (google) of FPL-51 ( 82 ), FPL-52 (90,)  OK-4 ( 92 ) and FPL-53 ( 95 )   (rounded to whole numbers)

Though of course as you say the mating elements are just as important.

Then the figuring and polishing.

Then the steel  lens cell.

John

[Deadlake]

Also some reviewer who went through lots and lots of scopes in the states rates them

https://www.cloudynights.com/topic/100005-4-apochromatic-hyper-shootout/?p=2381946

Edited May 16, 2021 by Deadlake

[DesertSky]

On 15/05/2021 at 16:16, Deadlake said:

OK-1 and OK-4 are more akin to Takahashi Fluorite lens then FPL series of glass. I think Daniel Mounsey did a shoot out of all 4" APO's in a rolling review on CN, and in the end it came down to the TSA-102 and the LZOS. Unless you have all the scopes (Daniels review stretched into 30-40+ scopes, some the same model) you can to review an objective rating is hard to make. 

This data table below shows the facts. LZOS glass is inferior than FPL53 and its producer Russians discontinue scope production long ago. A German vendor is promoting it like a first class glass by overrating it. I think it is not bad but certainly it is a second class glass. 

 

Common Optical Glass Types (from RefractiveIndex.info, LZOS):

 

Glass        Type                        Manufacturer   Abbe No. (Vd)   Refractive Index (n)   Extinct Coef (k)

H-FK61     Flour Crown            CDGM              81.59                 1.497                           9.3613E-09
D-LAK5     Lanthanum Crown   CDGM              54.9                   1.6779                        1.4009E-08
K4A          Crown                      CDGM             61.06                 1.508                          2.3438E-08
F1             Flint                         CDGM             38.01                 1.6034                        4.6783E-09
E-C3         Crown                      Hoya               58.96                 1.5182                        2.0923E-08
BSC7       Borosilicate Crown     Hoya               64.2                   1.5168                        4.6783E-09
E-F1         Flint                         Hoya               35.74                 1.6259                        1.4049E-08
FCD100   Dense Flour Crown    Hoya                95.1                   1.437                          4.6783E-09
FCD1       Dense Flour Crown    Hoya               81.61                  1.497                          4.6783E-09
FC5          Flour Crown               Hoya               70.44                  1.4875                        4.6783E-09
LAC7        Lanthanum Crown     Hoya               54.8                    1.6516                        4.6783E-09
OK-4        Special Crown           LZOS              92.04                  1.4473                        --
K8            Crown                       LZOS              64.07                  1.5164                        --
F8            Flint                           LZOS              35.57                  1.6249                        --
KF7          Crown Flint               LZOS              51.15                  1.5176                        --
FPL-51    Flourophosphate        Ohara              81.61                  1.497                         0.0000E+00
FPL-53    Flourophosphate        Ohara              94.96                  1.4387                       0.0000E+00
BSL1       Borosilicate               Ohara              63.63                  1.5101                       1.7652E-08
LAL7        Lanthanum               Ohara              58.52                  1.6516                       0.0000E+00
LAFN7     Lanthanum Flint        Schott             34.95                  1.7495                       9.3754E-09
N-KF9     Crown Flint                Schott              51.54                  1.5235                      8.2503E-09
F2           Flint                           Schott             36.37                  1.62                           3.7445E-09
K2           Crown                       Schott             60.41                  1.5111                       1.0879E-08
BK           Borosilicate Crown    Schott             63.58                  1.5197                       3.7786E-08
BK7         Crown                        Schott             64.17                  1.5168                       9.7525E-09
Soda-Lime Clear                       NA                  63.97                   1.5234                      3.8974E-07
Fused Silica - Quartz                 NA                   67.82                  1.4585                       --

[John]

16 minutes ago, DesertSky said:

This data table below shows the facts. LZOS glass is inferior than FPL53 and its producer Russians discontinue scope production long ago. A German vendor is promoting it like a first class glass by overrating it. I think it is not bad but certainly it is a second class glass. 

 

Common Optical Glass Types (from RefractiveIndex.info, LZOS):

 

Glass        Type                        Manufacturer   Abbe No. (Vd)   Refractive Index (n)   Extinct Coef (k)

H-FK61     Flour Crown            CDGM              81.59                 1.497                           9.3613E-09
D-LAK5     Lanthanum Crown   CDGM              54.9                   1.6779                        1.4009E-08
K4A          Crown                      CDGM             61.06                 1.508                          2.3438E-08
F1             Flint                         CDGM             38.01                 1.6034                        4.6783E-09
E-C3         Crown                      Hoya               58.96                 1.5182                        2.0923E-08
BSC7       Borosilicate Crown     Hoya               64.2                   1.5168                        4.6783E-09
E-F1         Flint                         Hoya               35.74                 1.6259                        1.4049E-08
FCD100   Dense Flour Crown    Hoya                95.1                   1.437                          4.6783E-09
FCD1       Dense Flour Crown    Hoya               81.61                  1.497                          4.6783E-09
FC5          Flour Crown               Hoya               70.44                  1.4875                        4.6783E-09
LAC7        Lanthanum Crown     Hoya               54.8                    1.6516                        4.6783E-09
OK-4        Special Crown           LZOS              92.04                  1.4473                        --
K8            Crown                       LZOS              64.07                  1.5164                        --
F8            Flint                           LZOS              35.57                  1.6249                        --
KF7          Crown Flint               LZOS              51.15                  1.5176                        --
FPL-51    Flourophosphate        Ohara              81.61                  1.497                         0.0000E+00
FPL-53    Flourophosphate        Ohara              94.96                  1.4387                       0.0000E+00
BSL1       Borosilicate               Ohara              63.63                  1.5101                       1.7652E-08
LAL7        Lanthanum               Ohara              58.52                  1.6516                       0.0000E+00
LAFN7     Lanthanum Flint        Schott             34.95                  1.7495                       9.3754E-09
N-KF9     Crown Flint                Schott              51.54                  1.5235                      8.2503E-09
F2           Flint                           Schott             36.37                  1.62                           3.7445E-09
K2           Crown                       Schott             60.41                  1.5111                       1.0879E-08
BK           Borosilicate Crown    Schott             63.58                  1.5197                       3.7786E-08
BK7         Crown                        Schott             64.17                  1.5168                       9.7525E-09
Soda-Lime Clear                       NA                  63.97                   1.5234                      3.8974E-07
Fused Silica - Quartz                 NA                   67.82                  1.4585                       --

You have been banging this drum on the CN forum as well:

https://www.cloudynights.com/topic/770738-who-services-lzos-lenses-in-the-us/?p=11103126

Have you personally actually used a scope with a LZOS objective in it ?

If you don't rate the glass they use, feel free not to purchase and use one. You might at least respect the fact that others do really enjoy using their LZOS lensed scopes though.

Roger Vine for example:

http://www.scopeviews.co.uk/WO123.htm

http://www.scopeviews.co.uk/TMB175.htm

http://www.scopeviews.co.uk/TMB_C8.htm

And our own Matthew Hodgson:

http://alpha-lyrae.co.uk/2018/06/03/apm-lzos-115-triplet-apo-refractor-review/

http://alpha-lyrae.co.uk/2014/01/01/the-apm-tmb-105-f6-2-triplet-apochromatic-refractor/

So why not get a LZOS lensed scope yourself, compare it with some worthy rivals, and post your report ?

 

 

 

Edited May 22, 2021 by John