jetstream

Buy one IMHO. Used one for years and are considered the best out there. Your 100mm Triplet will give extremely good views. I've found that going up to 120mm makes observing much more seeing sensitive. My 90mm is much more flexible in regards to this. That being said, when conditions allow, the extra aperture really makes a difference. You might be shocked at the views with your scope and a Baader Cool Wedge.

You ever explore Gemini or Auriga?

Great haul Stu! M108, great catch. This one can be a frustrating object and is a good test of skies. Spent lots of time here and the near area.

I find M33 and M101 similar in nature, both offer very nice detail when conditions allow and the equipment is well matched. I really like the "skewed S" arms in M33 and M101 offers a very delicate mass of spiral arms, spectacular in nature. On a dark site trip another object that will give up its spirals is M81- I see 2 short staccato spikes for spirals, buried in the glow. The objects mentioned highlight the fact that matching the EP to the object (and conditions) is truly important.IMHO.

What I find interesting is the whole Blackwell, Clark data and the OMVA deal. Basically it says to enlarge an object enough to see it- and at some point the reduction in eye illumination (exit pupil) will outweigh the positive effect of the increasing mag. More interesting to me are large objects and the effect of decreasing mag ( thereby upping eye illumination). Because many objects are already "too large", decreasing their size to the OMVA using low mag high illumination can reap nice rewards. In the extreme were talking "detection" - not great views, but detection. To the OP, from your location, dropping the mag might work and you will be looking for a roundish "shade difference" to the sky. You will have to play with the mags, to find the optimum but I do believe you will see M33. https://clarkvision.com/visastro/omva1/

I presume you used the 31mm EP? M33 is a very big, low surface brightness object and to just "see" it responds to lower mag than you think. In the H130 a 24mm ES 68 presents a "bright puffball" (from dark skies). Up the mag and details spread out and then disappear. In addition to dark skies, very low mag can help pull M33 out. I use a 42mm EP in my f7-f7.5 fracs on it.

Take a flashlight and shine it on the mirror from the back in the dark and see if any light is visible through the mirror as seen from the front ( coated side).

Great report, aperture really does make a difference. Is there a center bolt that you can tighten a bit to reduce the AZ bearing clearance?

Kinda makes me wonder why others (than China) use Ohara and Schott but charge so much more... China, using this name brand glass sure adds marketability IMHO, even if they can make the equivalent, IMHO.

Clear dark skies and excellent seeing will bring out the differences in optics including eyepieces. IMHO.

I have the 20mm APM 100 and it is the mainstay in my 15" f4.8 with and without the PCII. The 30mm ES 82mm here is not used much at all these days- I find the Ethos like contrast of the 20mm APM overshadows the 30mm ES. The 20mm is also the mainstay in my 24" f4.1, with and without the PCII.

Depends on whether the mass produced optic is a " good one" - scatter (roughness) can be an issue in some. Many mass produced dobs benefit from stray light control -actually many high end structures do too. Controlling stray light in a dob is very high on my priority list. But then, we pull out the Heritage 130 and observe so many DSO with this scope.... M33 a bright puff ball, M101, M51 The Flaming Star neb, California neb, Lagoon, Rossette, Barnards Loop and on and on. I think this kind of points out the fact that dark skies are more important than the scope for DSO.IMHO.

Im curious what your targets were and how dark are the skies?

Excellent report Magnus- great observing!

I have no doubt you saw some nebulosity around the stars and I also have no doubt you can see the Pleiades "Bubble" with this telescope from very dark skies. It sounds like this scope might be "the one" for it actually.

Excellent observing Stu! Congrats for a fine session with an excellent telescope.This scope sounds like it will excel on DSO- Meissa nebula?

The purity of view is astounding in these scopes, thats what keeps grabbing my attention. No scatter, superb colour rendition and the ability to take super high mag- cant beat it.The TSA120 is not fussy on diagonals either- even if a prism "de values" the optics a bit, the specs are so high to begin with its not noticed. The TOA 130, from what Ive heard is the technically "perfect" refractor. What is really remarkable though is that other, more reasonably priced refractors are performing so well, which I believe their graphs etc would indicate.IMHO.

Because its as perfect as a scope can be 😀

👎

Yes thats the thing- take a true "1/4" wave (including secondary) newt with 8" + of aperture and it will show more, seeing considered.

Its hard to fathom how Tak engineered perfection into this telescope.

This scope might be the most technically perfect scope out there IMHO. I better quit thinking about it or ...

Check out the TOA130... https://www.takahashijapan.com/products.html

Yes its the TSA120 from Tak Japan web site

Hows does this one compare?