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DirkSteele

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Everything posted by DirkSteele

  1. That whole TMB FAQ is an incredibly interesting read. His passing away at only 50 really was a loss to the astronomical community. As for the 130mm f/9, some of the comments certainly mean you and I are very fortunate to own such a remarkable scope. I just need my first light... “Thanks for the spot diagram. I see there are 4 perfect color crossings and color #5 is extremely close to this crossing, therefore is this lens design a ‘super apochromat’? Well, the official designation for a four color crossing, highly corrected lens, is a Super-Achromat. Five crossings is called a HyperAchromat. Now it might not sound so great to have achromat in the definition, instead of apochromat, but what matters is the performance, not the words that define it. The only other lens that I know that reached Super-Achromatic performance was the APOMAX, but the fourth crossing was well into the near infrared (passed 1000nm), so it didn't really have any visual impact on the performance.” …. “I want to add that the TMB 130mm f/9 nearly meets the Baker SuperApochromat criteria. It is better that 1/10 P-V wavefront from 450nm to 706nm, very close to achieving what is considered the Gold standard or ultimate lens design. I believe this will be the highest corrected lens of it aperture ever put into production.” Speaking of being a lucky chap, I know you have already shared many pics on other threads, but how about a nice photo of your 130mm for this thread?
  2. Haha. Not if I want to stay married! And wowzer, that is a big one.
  3. Yep, it is a bit tichy. I have since upgraded to an 80mm finder which also helps shift the balance point so the scope sits higher in its cradle and gets me off my knees at the zenith.
  4. checked the email account attached to my website. Been approached by another Astro mag asking if I will write reviews for them.

  5. And sometimes it is fun to duel-wield LZOS scopes as I did at Astrocamp in 2012. The 115 on the left, and 105 on the right.
  6. The APM TMB 105 f/6.2. Purchased in 2012 (but made in 2006, Marcos at APM had it sitting in inventory for a long time so offered me a small discount) so I could start taking scopes abroad (in the aircraft cabin). Lens cell 407. Thanks to a sliding drawtube, the scope shrinks down to only about 19” long so it is very transportable, if a bit heavy at just over 6kg. This one is from the desert in Oman.
  7. The TMB LZOS 115 f/7. I bought this one back in 2004. Lens cell 142. It was my first super high-quality scope and made me realise what quality optics looked like at the eyepiece.
  8. Next, is my latest acquisition, the APM LZOS 130mm f/9. Lens cell is 122. I have not had first light with it yet, real life plus the weather (in case anyone wondered why the heat wave ended….Its my fault!). ?
  9. I am not a member of CloudyNights (perhaps I should consider it, as there are a lot of knowledgeable members, though it can get a bit emotional sometimes…) but I do find that threads sometimes appear in Google searches I run. I recently came across a thread which I am going to borrow as I thought it was a great idea, “Show us your LZOS scope.” For those who do not know, LZOS (Lytkarino Zavod Optychisovo Sticklo – translates as Lytkarino Optical Glass Works is based in Lytkarino in Russia), was founded in the Soviet-era to manufacture high end optics for military and research use, and also operated as a Zeiss subcontractor. In the late 90’s / early 2000s, a tie-up between TMB in the US and APM in Germany allowed the skill of their opticians to be experienced by the amateur astronomy community. Unlike virtually all other telescope companies, LZOS manufacture the optical glass used in their telescope lenses as well as fabricating the lens cells. LZOS produce their own extra-low dispersion glass, OK-4, which has very similar optical properties as the well-known O’Hara produced FPL-53, though they are able to produce blanks in far larger sizes which allows LZOS to offer triplet refractors of up to 20” diameter. I would love to have a go with one of those! The late Thomas M Back (sadly passing away aged only 50 in 2007) had a lifelong passion for amateur astronomy and a particular interest in optics which saw him become a prolific designer of telescope optics and eyepieces. He started the TMB Optical business selling high-end refractors of his design, sourcing lenses made to his design and specification by LZOS in Russia, optical tubes from APM in Germany and focusers from Starlight Instruments in the US. APM have been in business since 1990 offering a range of reflecting and refracting scopes including large research grade instruments to a variety of observatories around the world. They became the exclusive world-wide agent for LZOS made TMB designed lenses in 1998. After Thomas Back suddenly passed away, APM retained the rights to his designs and continued to offer them in APM branded scopes. APM and TMB scopes are not the only brands to have featured LZOS made lenses over the years. I know that some have appeared in Stellarvue, Officina Stellare, William Optics and possibly more besides. I have also been left wondering about the serial numbers, and the fact there may be more of certain models out in the wild under the stars than the serial numbers might suggest. When the lenses first rolled out of Russia, the lens cell would often state “Made for T.M.B” or “TMB Design” or similar but I have also seen in older scopes (if I recall correctly), Fluorstar, and more recently, “LZOS Made” “LZOS for APM” and perhaps some other variations as well. Given some serial numbers I have seen compared to those on my own scopes and comparing year of manufacture, had led to believe that some serial numbers may have “reset” when the inscription on the lens cell changed. In particular, I am sure I have seen an 180mm LZOS lens with a higher serial number than mine, but produced many years earlier. So, if you are lucky enough to have one (or have had one and still have photos), why not share them here. Just like the Cloudynights thread, include your interferometry certificate if you have it. We could probably start a whole active thread about the usefulness of those certificates, with some suggesting they tell you little and are a bit of marketing. I take a slightly more pragmatic approach. While it is true that a mono-chromatic strehl measurement tells you only a little about an optic (an achromat could have a high mono-strehl), my view is that if the strehl is high in the measured wavelength (532nm for LZOS), it means the optical figure is smooth and given the skill and reputation of the LZOS opticians, a decent degree of confidence can be taken that the optic has been manufactured close to its design parameters which means its poly-strehl should be good (within the confines of the original design limitation of course). For example, the 130mm f/9 triplet Apo, has a design poly-strehl of 0.984, which means that a perfectly executed example, when focused on a central wavelength, would measure a strehl ratio of at least that value across the visible spectrum. Enough with the history lesson. So, to get the ball rolling, here is my APM LZOS 180mm f/7 triplet Apo. Lens cell number 22. It has featured in an episode of The Sky at Night. I am 180cm (5’ 11”) tall for reference. Certificate below:
  10. I could not resist the offer that came via an Astrograph email back in February. A new APM LZOS 130mm f/9.24 triplet apo, a scope I have wanted for years. I placed my order in March and paid the deposit to secure the lens of my choice. At the same time I also ordered a Lozmandy style clamp for my Tele Optic Ercole Alt Az mount. Rupert kept me updated on the progress of the manufacturing of the optical tube. In early July, everything was ready so I paid the balance of the purchase price. A week later, on a day of my choosing, Rupert personally delivered the scope to my door, having checked over everything including the collimation of the lens, not that I think it would have budged based on the the quality of the flight case and packaging. He also delivered the clamp at the same time. A very good service, and given some of the reported shipping knocks we have seen recently, rather pleased to have it delivered by someone who cares about what is inside the box.
  11. A new telescope was delivered a couple of weeks ago, and combination of real life and weather, has prevented a first light! I am starting to dream about using the scope now...

  12. My new APM LZOS 130 f/9 has arrived!  Looks great.  It has arrived one day before the forecast thunderstorms so no blaming me! ?

    1. GavStar

      GavStar

      Nice! What mount are you going to use with it Matthew?

    2. DirkSteele

      DirkSteele

      At the moment, my Tele Optic Ercole.  I might also see what happens with my iOptron Az Pro, but it might be a bit long for that.

  13. Expect to take delivery of my new APM LZOS 130 f/9 scope this week.  Rather excited and not just because it has a very high quality lens (even for LZOS). Wanted this telescope for years. So if this remarkable streak of clear skies suddenly ends, I apologise!

  14. A thoroughly enjoyable read! Thanks for sharing that with us all.
  15. Thanks! Did not know it was going to be on the cover so was quite a surprise when it arrived on my doormat.
  16. It is a great scope. Mine has traveled south of equator and provided some memorable DSO views under dark skies. And so easy to transport as well.
  17. A stunning array of Takahashi scopes on display in showrooms. But I wonder, have any of them seen starlight? No Tak should be denied what is was designed to do.., Just like this one.
  18. My next equipment review for Astronomy Now is in the June issue which I believe hits newsstands at the end of the week. Means my mother will be buying another issue! :icon_biggrin:...And I am not joking. She will buy it. 

    1. jabeoo1

      jabeoo1

      Well done again !

    2. DirkSteele

      DirkSteele

      My review actually made the cover. Certainly a nice surprise.

  19. That is a beautiful scope. I always enjoyed looking at Richard's creations at Astrofest. Shame he has not attended the last couple.
  20. Here you go: http://alpha-lyrae.co.uk/2014/10/25/vixen-sg-2-1x42-binoculars-review/ I love them.
  21. @FLO, any thoughts how one might either mount this on a small dovetail for use on a small telescope mount or directly on to a photo-tripod thread?
  22. I might treat myself to this as a tiny travel scope when even the Tak FS-60 is too much...And there was me thinking I was done purchasing equipment
  23. There is one on display on the Skywatcher stand at Astrofest. Had a quick look and seemed to have a very solid build quality.
  24. That looks fun! I like small scopes (guess it is the traveler in me that appreciates being able to take them to dark places). Will it come to focus with a diagonal in place or is is straight through only?
  25. I love that photo of the EM-3500 mount with the person next to it. It provides context to how large that mount is which suddenly gives insight into how large some of those scopes are! Especially the FCT200 and 250.
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