Saturday, June 22, 2019

Ceravolo HD 145 - observing as it was meant to be!

Very recently I stumbled upon the opportunity to acquire a Ceravolo HD 145 and as someone that appreciates fine optics, I was intrigued.  I knew little of these instruments other than having heard of Peter Ceravolo and his reputation for crafting fine optical systems.  I did a bit of “googlevestigating” about this Maksutov Newtonian and learned that not only were these rare telescopes, but that there was scant information to be found about these instruments and most of what exists are old threads on Cloudy Nights.  What I did not find was poor reports about the optics; in fact, what little information is out there agrees that these telescopes are among the finest performers in the 6” range.  I did find one very interesting comparison with a TEC 140 carried out by several CN members and documented by Daniel Mounsey.  I don’t know Daniel personally, only having corresponded with him by email, however, I respect his experience as an observer and his passion for sharing the hobby.  Last week I had the chance to spend 2 hours using the Ceravolo from light polluted northwest Tucson, and observing the moon, Jupiter, several double stars and a couple clusters, I decided on the spot to purchase the telescope.

Milky way from my favorite observing site :)
Back to Daniel’s write up - One reason Daniel’s review was of great interest to me, is that in 2009 I purchased a TEC 140 as a 40th birthday present to myself.  A decade later, and I wish I had aged as well as that telescope!  I have enjoyed the TEC 140 immensely and while I have bought and sold many other telescopes in the intervening decade (and the one prior), it is the one telescope that I have enjoyed above all others.  Having owned several SCT’s, refractors, and a Dobsonian over the years I am not one to wax poetic about the virtues of my telescopes.  The TEC 140 is not a perfect telescope, yet it is perfect for me.   Sitting down at the eyepiece, the telescope gets out of the way and just delivers every time.

From the first night testing the Ceravolo and considering purchasing it, it was clear to me that it was the equal of the TEC 140, and just maybe, slightly better.  Keep in mind I did not have them side by side and was making a judgment call based on my 10 years’ experience with the TEC 140 under all kinds of conditions- and that is what I mean when I say “maybe, slightly” better.  Something about how sharp Jupiter’s moons were, and the detail and contrast on the lunar terminator took me by surprise.   Using my own eyepieces, an 8mm Ethos and a 6mm Delos the views were as pleasing as any telescope I have used in this aperture range.

The deal was done and a few days later I got the scope home.  Below is my current eyepiece lineup – or at least the ones I use the most with my TEC 140 and my 12.5” Dobsonian.  It should be noted that the Ceravolo has a 2.5-inch helical focuser and mine did not come with a 2” eyepiece adapter.  I have one being machined, and it will be a couple weeks until it is ready.  Using the original 1.25” adapter I was not able to bring the 13mm Ethos to focus (needed just a little more inward travel) and the 2” adapter should solve that issue as I will be able to fully seat the eyepiece into the focuser. 

Given the lack of a 2” adapter, I was not able to try the 21mm or 31mm as they are 2” eyepieces. There are 2 issues lurking with using these low power eyepieces, however, as both will undoubtedly vignette in the Ceravolo, it is just a question of how much.  The second issue is that of exit pupil – you see above that the 31mm Nagler has an ~5mm exit pupil and the 21mm is a bit better at 3.5mm.  Once I receive the 2” adapter I will try them out.  In truth, the 17mm Delos performed very well for me in the testing I have done, and if I am not satisfied with the results of either the 21 Ethos or 31 Nagler in the scope, I will probably purchase a 24mm Panoptic which would get me nearly another .5 degree FOV over the 17 Delos, delivering 1.87 degrees at 36 power with a 4mm exit pupil.  Low power is important to me, especially at dark sky sites, as I enjoy both sweeping the milky was as well as observing large scale objects that are inaccessible at most observing locations due to artificial lighting of the sky (for example the nebula surrounding the Pleiades, the North American Nebula, galaxy groupings).

So you have read this far and are wondering if I will ever get to the observing report – I have decided to break the observing report into two sections – first, in my suburban yard as that is a typical condition under which an amateur will use a telescope like this, and what I will share below.  Then, a report from a semi-dark location at which I will use the telescope next week.  I have also observed several of the same targets that Daniel Mounsey and friends observed in his 2011 comparison review with the TEC 140, as they are targets that most amateurs are familiar with in their own experiences.  To add to that short list of objects from his write up, I added a bunch of Messier objects as again, I and most amateurs are quite familiar with them.  Initially I was going to do a “part 2” to Daniel’s write up but decided that since I was not personally placing these scopes in competition against one another, I did not want to approach the write up in that way.  They are both amazing telescopes, and I am incredibly fortunate to have them both.  There are some comparison comments scattered below, yet please keep in mind I did not set these up side-by-side and any comparative comments are anecdotal based on my decade of observing with the TEC 140.

Night one – backyard bliss.   

I set the Ceravolo up on my Discmount DM6/Baader tripod which makes for a very simple and enjoyable platform to begin to get to know the telescope.  I do have a German Equatorial Mount that I may use at times if I desire go-to and tracking.  Fortunately, this telescope came with Parallax rotating rings installed which are essential to allow the eyepiece to be easily located in an accessible viewing location when using an equatorial mount.  As this telescope is a Maksutov Newtonian, cooling must be attended to – in my case, not having active cooling, I had the scope indoors during the day to keep it from heating up (temperatures outside are 100+ in the shade) and only took it outdoors in the shade about 45 minutes prior to sunset.  This provided the telescope about 90 minutes to warm up toward the falling ambient temps before I began observing.  NELM at zenith from my yard is around magnitude 5.5 – 5.7.  Seeing conditions were very good (8-9/10) for most of my observing but as the night progressed the stability began to deteriorate, and by midnight was below average (4-5/10).  I did catch an occasional smell of smoke, which is a little surprising as the nearest wildfires are northeast of Phoenix well over 150 miles away.  I did not notice any obvious smoke in the atmosphere; however, it did seem that the sky was slightly brighter than usual perhaps as a result of particulates in the atmosphere diffusing light.  Looking up, I was still able to pick out magnitude 5.5 stars overhead.

Earlier I mentioned that when observing with the TEC 140 the telescope disappears and simply delivers an outstanding image.  In my first night with the Ceravolo, the experience was nearly the same.  Time slipped away from me (one reason I love visual observing) and the moon was rising before my first yawn.  Using the helical focuser of the Ceravolo is a new skill for me to master and in that way, I did spend a little more time fiddling with focus than I do with the traditional rack and pinion on the TEC 140.  This is a minor quibble and one that I will likely not address in the foreseeable future.

Jupiter – I began with Jupiter for two reasons, both as it is bright, and I was not yet dark adapted and as it is a somewhat unforgiving target for optics under good seeing.  Slight miscollimation, thermal currents or poor optics can quickly obscure the subtle details.  Jupiter was about 30 degrees above the horizon and seeing in that area of the sky was better than average, say a 7 out of 10. (Or to put it another way, quite good for an object at low altitude).  Using the 8mm Ethos Jupiter was strikingly sharp, and the 4 Galilean moons were little spheres floating in their orbits.  I say floating as sometimes when observing with the TEC I will qualitatively perceive that objects take on depth to them.  Most often I notice this with nebula against a dark background, but last night I noticed this with Jupiter and its moons.  Perhaps it is the subtle limb darkening on the planet that suggests this – and using the 6mm Delos I noticed a very subtle tonal differences in the color of the Jovian moons.  Io and Ganymede had a slight warmth to them while Callisto and Europa seemed a purer white.  I’d like to look for this again to confirm my perception.   In terms of detail, I was easily able to discern details within and on the edges of the equatorial belts, and there were several other belts visible.  Shading towards the polar regions also hinted at bands within.  All in all, a very pleasing image of Jupiter and as far as a planetary scope, the Ceravolo HD 145 is a home run.  In the moments of steady seeing, Jupiter was truly picturesque – giving up stunningly sharp detail and possibly the best I have seen in a small telescope…(I may have to set the TEC 140 up side by side one day!!)

M13 – always a favorite of the masses at our outreach programs, I went to this cluster next as I am very familiar with its appearance in scopes of varied aperture.  It appeared beautiful in the Ceravolo, with brighter members resolved across the fuzzy core.  From my yard, the northeast is the darkest area of the sky and this object was the first teaser for me looking towards a darker sky trip next week.  I always love looking at globulars and in this case the tiny pinprick stars throughout and around the cluster were stunning.  I realized I still had the 6mm Delos in the scope so pushed up to the 4.5 mm and the cluster held together without any degradation of the image.  I enjoy some context in the field of my targets so I dropped back to the 8mm Ethos and the cluster was framed beautifully against a dark background.  It is hard to describe contrast from one scope to the next, however, I had the feeling that in the contrast department, this scope excels…so I probably should look at a nebula!

M57 – Another crowd favorite and one that I am exceedingly familiar with.  Planetary nebula are fuzzy creatures and demand magnification – so I installed the 4.5 Delos only to immediately replace it with the 3mm Delite.  Wow.  The Ring nebula stood out proudly from the background, with a clear elliptical shape.  The bright outer ring varied in brightness (with the ends of the ellipse fainter), and there was even a hint of uneven brightness across the inner portions of the nebula.  No central star, of course, this is still a small telescope in a suburban location!

Epsilon Lyra – the double double because…why not?  I never wondered about splitting these pairs of stars in the Ceravolo, but it is a target that was observed in Daniel’s 2011 shootout and would also give me an indication of how cleanly the Ceravolo splits up double stars.  I was not disappointed, with a beautiful, clean split in the 8mm Ethos.  Pumping up the magnification with the 6 Delos and then the 3 Delite, the airy disc and surrounding area was nearly perfect.  I have not seen this level of perfection, to my recollection in any scope I have owned.  Push the TEC to 300 power and there is a hint of color; the Ceravolo appears slightly more “apochromatic” at high magnification.  It should be noted that the seeing was excellent at the moment, around a 9/10.

T-Lyra – again a target from the 2011 shootout, and one of the nicer carbon stars available.  Nothing to report other than it has a nice red color, and again, seeing was fantastic at that time.

M5 – Another favorite globular, in Serpens, with a nice bright 5th magnitude star (5 Serpentis) in the FOV of my 8mm Ethos.  Personally, I appreciate observing this globular as much if not more than M 13.  ‘Brighter’ stars were again resolved across the cluster, with some very nice yellow/orange stars noted just beyond the periphery of M5.  At that point, I said to myself that the 8mm Ethos is a fantastic match for the Ceravolo and I could spend the entire night with just this one eyepiece.  Writing up my notes now, it occurs to me that the 8mm Ethos is also a favorite in the TEC 140, so perhaps there is just something about that eyepiece, my eyes and observing habits that I prefer a nearly 1 degree field of view at about 110 – 120 power with a comfortable exit pupil.  What’s not to like?

M22 – Keeping it real – Another globular!  M22, despite being much lower in the sky than M13 or 
M5, is a beautiful sight in any telescope.  In the Ceravolo, like my TEC 140, it appears large and well resolved.  Not quite as condensed as M5, the often used “like diamonds on black velvet” really does describe the view.  Pinpoint stars across the FOV.

M8 – Being in Sagittarius it was time to look at a few milky way nebulae.  Using the 8mm Ethos the view of the lagoon was excellent.  The nebula was extensive, nearly filling the FOV.  The cluster stars were noticeably less steady than earlier and looking up from the scope it was clear the seeing conditions were dropping off a bit as the stars which had previously been very steady were now twinkling somewhat. As I was in the heart of the Milky Way, I dropped down to the 17.3mm Delos and the 1.4-degree field of view was beautiful.

M20 – the next stop on the Ceravolo nebula train after M8, still using the 17.3 Delos.  M20 is not as bright, yet the dust lanes which transect the nebula are readily apparent.  Back to the 8mm Ethos, looking at the edges of the dust lanes, they are not simply smooth edges, they have a contour to them.  To me, this is another sign that the contrast of the telescope is first rate.

M17 – The Swan nebula, final stop on the Ceravolo Nebula train and it is awesome.  Installing the 6mm Delos, the body and tail of the swan take on quite a bit of mottling throughout.  Indeed, there is a faint puff of nebulosity behind the swan that can be seen.  This nebula is impressive and after a few minutes observing I again note it appears to float in front of the background stars.

M 51 – The whirlpool.  I had not yet looked at a galaxy and thought that M51 would be a good target due to the detail that can be seen in a good telescope.  I was not disappointed as the Ceravolo not only revealed the spiral structure from my backyard, but I also noted 2 stars superimposed on the main galaxy.  Best view was with the 6mm Delos.

Jupiter – again!  As the night was winding down and the moon was now up, I wanted to again look at Jupiter and see if the great red spot was perhaps visible.  It was not, and I noticed that the seeing was much worse than earlier, down to about 5/10.  Oops, I yawned starting a chain reaction of yawns as I waited about 10 – 15 minutes to see if the seeing would steady again…no luck.

Saturn – pretty low, about 30 degrees or so in altitude, and with less than steady seeing it was time to call it a night.  The Cassini division was visible, as well as Titan, Dione, Tethys, and Rhea in the 8mm Ethos. 

Night one conclusion – I am quite satisfied that I jumped on this telescope, despite already having my dream telescope, the TEC 140.  The opportunity to own such a unique and finely crafted optical system that will provide years of enjoyment is one that should not be missed.  I do not take for granted that I am fortunate to have the financial means to obtain these telescopes – and that not everyone can.  Given its performance in the same echelon as my TEC 140, I am a little surprised that on the rare occasions these telescopes come up for sale that they are only about 60% the cost of a TEC 140….so if you have the chance to buy one, do it!

Final note – There is a joy that I derive from sitting out under the stars and using a telescope to peer beyond what we see naked eye and appreciating the connection that we share with the Universe.  Earlier in the day yesterday, before I made these observations, I learned that a lifelong family friend and mentor to me passed away.  As I sat outside and used the telescope for the first time and thought about my friend and mentor, it was not lost on me that he always reminded people to pay attention to what matters – our connections to people close to us, and to the greater world around us.  Astronomy is for me, a way to maintain those connections and I will now associate this telescope with my friend whenever I use it.