John

I don't have the facility to film it I'm afraid. You turn the laser collimator slowly around 360 degrees, stopping every 90 degrees and marking the position of the laser dot on a piece of paper taped up around 30 feet from the laser unit. The V-block and laser unit must stay completely still in one place of course during this rotation. That shows you how far out the unit currently is. Then you pick a grub screw, hold the laser collimator in place in the V block (and the V-block exactly where it was as well) and make an adjustment to the screw noting which way the laser dot moves - hopefully towards a spot at or near the centre of your 4 90 degree marks. The repeat the rotation, mark accordingly and adjust again as necessary. It is a bit trial and error I'm afraid.

It needs to be at least that I feel. The further the laser dot is projected, the easier it is to see where it varies as you rotate the laser around it's axis and the more accurate the collimation is, when you achieve it. I try and get around 30 feet and when adjusting, try and get the laser dot to stay within a 10mm circle, or better if possible.

I use the "V-block" method as described here (my laser collimator is the same design as shown here): http://www.stark-labs.com/craig/llcc/llcc.html The laser unit is held in the machined housing with a rubber "O" ring type thing at one end and three grub screws that go through the housing press against the laser unit at the other end of it. On some models you need to remove a label to reveal the grub screws I believe. You might need to loosen one grub screw a little to allow adjustment to another. You need to remove the screw on battery cover section and spring from the end of the collimator to allow the last unit inside to be free to move as well. It is a fiddly operation I agree and it can be more "miss than hit" at times.

I'm getting fonder and fonder of my TV Ranger. I've used it for white light (as per your setup) and it's done very nicely. At night it seems to do more than I've any right to expect from such a small, lightwweight scope. It's the 1st sub-100mm scope that I've felt that I actually want to hang onto. Plus I've got Al's signature on the manual !

I think Prinz were a brand name used by Dixons, the highstreet photo and electronics retailer. Dixons would source their stock from different manufacturers during the lifetime of the model. The one you have more recently acquired is an older one (1960's perhaps ?) wheras the one you already have is a later one, possibly from the 1970's or 1980's. Dixons sought the lowest manufacturing cost to maximise profitability and, over time, unfortunately the quality suffered. Dixons ceased trading in 2014 after 77 years of business. It will be interesting to see how the optical performance of these two scope compares. The result might not mirror the apparent external quality of manufacture ?

As this thread is about Chris's ED150, it's best to use another thread, or start a new one, to discuss other scope options for you

FLO are applying practical experience and feedback from this forum to their figure. They are the same mount. One of the most portable scopes with reasonable light grasp and resolution would be an 8 inch schmidt-cassegrain I think. They have some other compromises but, for the aperture, they are very compact and relatively easy to mount up as well.

Is that for imaging or visual ? I don't image but I found the Giro Ercole and Skytee II alt-azimuth mounts held the ED150 well enough for visual use. I was also using a very good hardwood tripod (Berlebach Uni 28). For imaging something equatorial and a lot more robust would be needed. A 6 inch refractor is never going to be a readily portable scope in my view. "Moveable" might be a more realistic prospect !

Neptune and Uranus are around. You should be able to get Triton at Neptune with the ED150 and maybe even a couple of Uranian moons. Lunar views will be superb I'm sure

Third time lucky ! They are wonderful scopes. I have the Tak FC-100DL

Excellent eyepiece sets and welcome to the forum McNewt I have similar sets with similar overlaps. I tend to use the 100's in my 12" dob whereas the 1.25" set get used with the refractors.

Lovely Matthew Interesting to see how the design of the 130 F/9.2 has changed from 2006 when mine (snipped photo below) was made until yours in 2018. I believe the objective cell design is just the same from other photos you have posted but the externals have changed more. My scope is the LW version with the Kruppax tube and 2" FT focuser. I can see that you have the 3" (APM ?) focuser and is it an aluminum tube ?. Production volumes have been low with, according to Markus, 114 being the total run of completed scopes over the life of the model. A few more of the objectives and cells have been made which I guess is why your serial number is in the 120's ? I believe that many more of the 130mm F/6's were made but they appeal to the imagers more I reckon. Hope you get first light with it ASAP

Can you tell us what the review scope is Matthew - or is it confidential ?

Nice further installment Chris I've got Lambda Cygni with my 130mm triplet and, when the seeing is very good, I have done it with my ED120. When it's not quite split the effect is rather like a tiny snowman with the dimmer secdondary star appearing like a dimmer, smaller, spot stuck on the side of the primary. It will be high on the list when I get my next example of the SW ED150. I agree with you re: the non-rotating focuser being an annoyance, especially when the scope is equatorially mounted.

I've not done this comparison although I have compared the Myriad 20mm 100 with the Ethos 21mm in my F/5.3 dobsonian. What I still don't know is whether the Lunt 20 is the same optically as the Myriad 20 ?. Here is my review of the Myriads anyway: https://stargazerslounge.com/topic/236613-skywatcher-myriad-100-110-degree-apparent-field-eyepieces/ Also another member here has compared the Lunt with the Ethos I believe: https://stargazerslounge.com/topic/295440-lunt-20mm-hdc/ Will you be using a coma corrector with the F/4 newtonian ? I feel you will certainly need one using 100 degree eyepieces with it !

Happy to oblige Matthew

Some interesting reading if you have not already seen them: APM's contract spec with LZOS for objective lenses (it's in the public domain on APM's website so not confidential): APMApo-Linsen-Spezifikationen.pdf Also some notes of thoughts from Thomas Back on his LZOS projects with quite a bit on the 130mm F/9 triplet: tmbFAQ-2.pdf

Next step a 254mm TMB designed LZOS triplet Matthew ?

I was using the Aero ED 40mm (or a clone of it at least). It works really well in my refractors and seems to have quite a flat field. Much lighter than my Ethos 21 or Nagler 31 too.

Good stuff Chris The O-III works wonders on the Veil - I was observing it last night with my ED120 and a 40mm SWA eyepiece - 3 degree true field and some superb views of the E & W Veil and Pickerings Wisp. Big refractors are really good DSO scopes.

I found it laying around the web somewhere I've no imaging abilities at all I'm afraid

Here is what I said about the Nirvana's eye cup in my review: "The Nirvana 28 is also heavy and feels even bulkier than the Nagler but is reassuringly solidly built and has 2 rubber grip rings. The eye relief feels the same as the Nagler but I found that the wide, slightly dished profile of the top of the eyepiece, even with the large, thick and rather inflexible eyecup (it’s almost a “face cup” at 75mm in diameter!) twisted down, needed a different technique to get my eye close enough to the eye lens to take in the whole FoV. To begin with my nose (a little larger than average I suppose!) seemed to be getting in the way and affecting where I could place my eye - though this is hardly the eyepiece’s fault! Turning my head a little to one side had the desired affect and this soon becomes second nature." I can appreciate that this design is not the best feature of the eyepiece and may cause folks to seek alternative designs. There is more choice available today then there was when I wrote the review

It looks fresh off the printer Neil

Good stuff Chris Did you notice the central star of M27 ? - I can get that, just, with the ED120 on a really good night. I think that star close to M57 is mag 13:

I tried binoviewing with my TMB/LZOS 130 triplet yesterday evening. First time that I've managed to get properly merged image with binoviewers and managed to reach focus withouth a barloe element in place. Whether I'll get bitten by the BV bug I don't know but it was fun