TEC140 vs. Ceravolo HD145
Posted 28 August 2011 - 05:37 PM
For pictures go to Tamiji Homma's site here http://www.pbase.com...oakpark20110827
Let me know of any tech errors as I am exhausted from last night. It's time to share the comparison of the TEC140 vs. Ceravolo HD145 in a VERY constructive way and guess what! We were shooting it out till 3am in the morning last night non-stop! We had some hidden "low key" guest stars, all who participated as follows and what an incredible turnout it was with at least a 100 guests. This shootout was conducted by over a half a dozen observers all trying to be very careful not to stand too near the telescopes while comparing images. I am SUPER critical with people standing around the telescopes. Ask them. I found myself asking everybody to please move behind the scopes. Trust me when I tell you this. Humans give off lots of heat currents which can degrade images and that is a fact! Most of the beginners finally left around 11pm so, we were just about all to ourselves to battle it out to the death for the next 4 hours. I specially wish to thank John Fisanotti for being kind enough to let us scutinize his TEC140 serial #125 to the near max.
For those of you who have never participated in a shootout of this caliber, let me describe the atmosphere. It's intense and intoxicating. It's like watching the greatest boxing match in history. You never know what's going to happen till they meet face to face and the tensions are palpable. You hear things but you never know till they are faced together. It brought me back to the greatest shootouts during the Charlton Flats era with the best telescopes you could possibly look through. The average observer only sees a very small percentage of what is possible with a world class instrument under the best conditions like Charlton.
The guests were as follows and all their opinions are what made up this comparison. This is not a shootout by just me. These are the combined opinions of the most critical eyes and I will share my thoughts as well. Ridwan Angkasa paid me a surprise visit but had top leave early. Ridwan was instrumental in the 4" hypershootout.
THE GUEST OBSERVERS:
He was hiding in the back ground. Evan has an amazing collection of the finest optics in the world, but he is very low key on CN. Don't be fooled hehe! Evan had to leave earlier than the rest but had a few peeks in the 140.
Thank you for providing the incredible array of eyepieces. The all new Takahashi wide fields. The Nikon hypwerwide fields. in 12.5mm and 17mm you loaned me last month. Tamiji has an incredible eye for quality and is incredibly unreserved. I like that. Tammy just calls it like it is without hesitation.
Through thick and thin June has been the quiet eyes behind the scenes. He has conducted nearly every shoout I have ever posted and without his thoughts, we would not have made an important discovery last night which I will share. June pulled me aside to enlighten me.
In reality Joe is a movie director, but is hooked on astronomy and mans this fine Ceravolo HD145 for our comparison.
Luigi is bright and new but boy does he ever have an incredible addiction and utter appreciation of fine optics!
This guy is very critical and loves Dick Suiters star testing book. He has a lot of great experience at the eyepiece.
Owner of the TEC140. A pleasant guy to observe with. John was critical but in a very mellow way. He just seemed pleased to look through both of these fine scopes.
Dennis has the longest, most difficult last name no one can even remember. I had to ask him to repeat it several times but it was broken English and he had some difficulty making magnification calculations on the spot because he was pressing 8 for 3 and 2 for 7 and so on. Dennis is a brand new observer seeing his first shootout ever, but my gosh!!!! Talk about enthusiastic and super critical!! This guy was hooked and no one even knew him, myself included. Great observer and a really nice guy. Joe and I were amazed.
What compells me is to see light focused to a single point.
Oak Canyon Park California.
THE SEEING CONDITIONS:
7 out of 10
TEC140: F-7 980mm
CERAVOLO HD145: F-6 870mm
University Optics 7mm
Televue Dilos 6mm
Nikon 102 deg. 12.5mm
Nikon 102 deg. 17mm
Televue Ethos 13mm
Televue Ethos 17mm
Televue Nagler 16mm T5
Takahashi UW 5.7mm
Televue Nagler 5mm T6
Televue Nagler 3.5mm T6
Pentax XW 5mm
Pentax XW 7mm
a) T-Lyra, an incredible red carbon star to determine color saturation and contrast in each telescope.
b) Epsilon Lyra, better known as the double double in Lyra to determine the cleanest and most beautiful split.
c) Jupiter to determine detail, color contrast, color saturation etc.
d) The Double Cluster in Perseus to determine overall "wide field" pinpoint clarity and sharpness edge to edge.
LETS GET DOWN TO BUSINESS SHALL WE:
We fired both scopes at T Lyra first. The TEC140 was positioned about 12ft away to the north west of the Ceravolo. We used a 6mm Ortho in the TEC140 at 163x while the Ceravolo was using a 5mm Pentax at 174x. Take in mind that it's hard to match the magnifications exactly. This would give an exit pupils almost exactly the same of .83 for the Ceravolo .85 for the TEC140. That's close enough for me. The eyepieces could alter things slightly but it comes with the turf. As everybody went back and forth between the two scopes, it was near to next to impossible to tell which was which. Tammy thought that the reddish color of T Lyra was slightly deeper red in the TEC140. Most of the crowd were undecided and not sure. Some of the observers thought the image in the HD145 may have been a bit cleaner. You could start to see the airy disc of the star in the Ceravolo.
Then after 45 minutes of comparing this object, the images started to look unstable in the TEC140. We were all baffled and perplexed! How could a darn refractor be more unstable looking than a reflector? The HD145 was noticibly nicer and we all agreed. Take in mind that the HD145 was on a Losmandy Gemini mount with smooth servo motors while the G11 an TEC140 used stepper motors. Could it be the steppers we all thought? This actually happened once at Charlton Flats. In this case John asked me to look in the eyepiece of the TEC while he switch the tracking on and off. I could not detect any differences with certainty and said it must be something else.
While all this was going on, Tammy said that there was a colder air blowing right in front of the TEC140 causing eddies with the warmer air, so everybody took turns at standing right where Tammy said the air was blowing. Everyone agreed 100% overwhelming majority vote it was the cause. Incredible just 12ft away from the Ceravolo!!!!! Every time we took turns standing next to the Ceravolo we all agreed it was noticibly warmer air. The second you stepped over to the TEC, it was easily cooler. We believe that the position of a set of big trees to be the root cause while a car also appeared to block colder air from flowing right in front of the Ceravolo's optics. Everyone agreed, so four of us literally lifted the entire G11 mount and TEC140 next to the Ceravolo to stay in the warmer air but not too close to cause harm from our body currents. We re-polar aligned and the problem was immediately solved and we could get back to testing after nearly 30 minutes of torture to the TEC140. This gives you an idea of how important the environment is.
Still pounding away at T Lyra, people were still preplexed myself included. We decided to use the all new Takahashi 5.7mm UW at 172x in the TEC to match the Ceravolo. So hard to decide and some felt that the Ceravolo had an edge. After this, June pulled me aside in private. He said Daniel, I think there's something up with the diagonal in the TEC. Look at what diagonal is in the TEC. I will not say the brand name in this forum. I said, how could I forget that DANG, I forgot! I would never expect a TEC owner to use one of these mass produced 2" 99% diagonals but sure enough that's what it was, no hard feelings. I went back and said let's fix this right now. June handed me a 2" mirror diagonal we knew was good. Incredibly we could all descern the difference and everybody was teasing John to get a new diagonal. I said that's like putting regular unleaded into a Mclaren F1 and everyone agreed.
After the change, no one appeared to be able to make a clear conclusion, myself included. It was just too dang hard! As everybody took turns going back and forth, someone would say I like the TEC! then a minute later I like the Ceravolo! I found myself leaning a bit towards the Ceravolo because the airy disc just and the ill-defined faint diffraction ring seemed a tad cleaner. The brightness was identical and the guys kept commenting that the background may have "appeared" to be a bit darker in the Ceravolo. Could it be two decimal points of the exit pupil? the eyepiece? who knows? but both scopes scored even to the group unless any of the guys have something to share I may have overlooked. I'd never seen so many dang confused observers in my life, myself included. It appeared that no one could really decide for sure. Both images were awesome!!!!!
Now this gets interesting. We decided on the 6 Delos in the Ceravolo and the 7 Pentax in the TEC. This would give the Ceravolo 145x with an exit pupil of 1.00 and the TEC140 at 140x with an exit pupil of 1.00 as well. It was a pretty split race. Once again it was hard to say which scope was nicer. Luigi commented that he saw very faint but extremely subtle hint of color while the Ceravolo was completely apochromatic. Dennis said he was favoring the TEC a bit while on T Lyra he was favoring the Ceravolo a bit but still remained unsure during both observaions of T Lyra and Epsilon Lyra. I was favoring the Ceravolo a bit. Then John Hawk was favoring the Ceravolo a bit as well as Tammy. Some of us thought the slight fluctuations may have been what caused us to enjoy one scope over the other for that brief moment we were comparing them. Once again we found ourselves all having a really difficult time comparing which scope looked nicer, but I still liked the Ceravolo a tad more because I know when pushing doubles as hard as I have in the past, it's an incredible scope hands down and just doesn't quit impressing me. To me, it just appeared a hair bit tighter on these doubles. Regardless, most thought it was pretty even. I'm not a fanatic about seeing color but I admit that when you really wonna push stars to their absolute limits, a fully apochromatic scope does have the potential to produce a slightly cleaner image around airy discs, but this was by no means what we saw on Epsilon with the TEC at these particular magnifications.
We then decided to fire both scope at Jupiter. This was really quite an astonishing comparison. There were a couple of moments for whatever the reason where June and I saw scattering in the Ceravolo or bending of light around Jupiter, probably atmospheric. We both attributed it to the seeing or refraction of the light. When we all looked through the TEC, Joe, captain of the Ceravolo thought Jupiter may have had a bit more clarity in surface detail in the TEC. I took a look as well and my conclusion was that it looked a hair bit nicer in the TEC at that particular moment, then I quickly ran over the the HD145 and waited. Sure enough there were moments where it looked equally as beautiful, crisp and contrasty. We made a point to rotate the focuser of the Ceravolo so we were viewing downwind. Luigi said he could not even tell a difference and it was driving him mad. John Hawk thought Jupiter may have looked a bit nicer in the Ceravolo but still seemd unsure as was I. Tammy thought maybe the TEC had an edge. Honestly, I believe most of the differences were attributed to slight fluctuations in seeing because Jupiter was quite low compared to the other targets so far. It was hard to really be sure. I've done many shootouts. I can assure you that when you spend a good amount of time looking through telescopes of this caliber, sooner or later you are going to get some amazing moments! That's the key to success. The more you study and the more you stare, the more susceptible you make yourself to capturing astonishing detail on Jupiter!
THE DOUBLE CLUSTER IN PERSEUS:
It was now time for wide field. In the TEC140 we used the Nagler 16 type 5. This would give 61x with an exit pupil of 2.25. The image in the TEC was absolutely beautiful however on some of the brighter stars it seemed just a wee bit not so flat in the TEC but the faintest stars looks like pin points out to the very edge. All of us were really impressed. At times we used the other eyepieces above but pretty much settle on these eyepieces. We decided to go with the 12.5mm Nikon 102 deg eyepiece in the Ceravolo at 69x with an exit pupil of 2.10. This eyepiece is incredible and is corrected for angular magnification distorsion. This easily gobbled up both clusters in the HD145. It was like a freaking Mural from an Isaac Asimov science fiction tale! Pin pricks right into the field stop regardless of their brightness. At these lower magnifications, the seeing almost seemed non existant and even if we used a Nagler it the Cerevolo, it's pinpoint right to the field stop. I think Tammy liked the Ceravolo here or at least had an easier time deciding. The wide field test seemed pretty easy to conclude unlike the other tests. I think everyone agreed. John the owner of the TEC seemed pleased with both scopes on all targets.
Just toss a coin. I think if anyone was in our shoes this night, they would have had the hardest time making a solid and conclusive choice. The TEC140 has almost become the standard of its class, but it just comes to show how awesome the Ceravolo HD145 truly is when properly executed with a cooling fan before observations and what an incredibly versitile, light weight telescope it truly is. We wished we could have had more time to star test each scope on Altair but it took a lot of looking with just these few objects. My prediction is that the TEC140 at really high magnification would not have been completely apochromatic, while the Ceravolo would have been. Does this matter during most observations? Of course not but for me, regardless of price, the Ceravolo HD145 is my favorite telescope in its size class ever! I love that it's different, I love that it's rare, I love that they are so hard to find, yet it is still so sad they are no longer made because there really are observers out there who do appreciate the difference and that to me, is something special. It's just not normal to see a reflector compete with top quality refractor in the same size class, but the Ceravolo will do just that and then some. It doesn't surprise me one bit that Ceravolo does commercial aerospace optics. The man is simply a master. I'm sure some of my friends may pop into the forum and offer more insight with various opinions and maybe we can better discuss it further. In the meantime, Joe, I want my other Ceravolo back, you already have two!
Posted 28 August 2011 - 08:09 PM
Posted 28 August 2011 - 08:43 PM
This review I think serves to re-enforce what many experts have said over the decades, which is that an obstruction of 20% or less does not do enough damage to the contrast that it would be detectable when compared to an unobstructed aperture.
Of course the HD had some extra aperture, to this doesn't provide absolute confirmation, but I think it is rather close enough. A few percentage of differnce in contrast loss is almost impossible to see except under lab conditions.
I have owned two Intes Micro MNs and while the quality is not QUITE as perfect as the Ceravolo, I would say that they were among the best I have ever owned. And the first time I looked though a 6" MN, it floored me.
I didn't realize it at the time, but I was looking at a view that was VERY similar to that of a 6" APO.
I know that now.
Congratulations on you Ceravolo. I totally agree that the HD145 is very rare and desirable.
And a heck of a fine telescope, I am totally sure.
Posted 28 August 2011 - 09:05 PM
Posted 28 August 2011 - 10:21 PM
Thank you for a lot of write-up. I enjoyed the shootout very much. I was surprised that everyone stayed focused for the long duration. Adrenaline rush kept us going, I guess.
The micro airflow effect around the scopes was interesting. I think that it resulted in disadvantage for TEC 140 until we figured that out. As you mentioned, two scopes were only 12 feet apart. They showed different images, one steady on HD 145, the other scintillating on TEC 140. It was quite puzzling until we knew why.
I think that the target selection you made for shootout was excellent not only showing beautiful image but also forcing us to think what to look for to see difference between excellent scopes.
One thing, it was very warm day. When I arrived around 18:40, it was 92 degree. When I left around 2:40am, it was 78 degree.
Double Cluster was breathtaking. It was nice way to end observation.
Be safe in driving to OSP next week and enjoy.
Posted 28 August 2011 - 10:21 PM
It also illustrates how critical external conditions are when doing these types of evaluations.
Thanks for posting.
Posted 28 August 2011 - 10:32 PM
I'd love to see a follow-up using some doubles closer to the resolution limit of each scope. Perhaps some >4 mag unequal pairs, and some pairs in the 1.x arc second separation range. Some head-to-head in the 80-90x per inch range, too, would be interesting.
Any chance of that happening at some point?
You also said: "My prediction is that the TEC140 at really high magnification would not have been completely apochromatic, while the Ceravolo would have been."
You would be 100% correct. It's not too difficult to tease a little false color out of the TEC 140 at higher magnifications on brighter targets; particularly blue and white first magnitude stars.
Thanks again for matching up these two scopes!
Posted 28 August 2011 - 11:16 PM
It was really almost impossible to be one sided one way or the other - these are two telescopes that set up right are hard to beat. I packed up the Ceravolo at 3am wanting more and we discussed trying to schedule another shootout under darker skies and with the emphasis on matching eyepieces to bring magnifications closer to each other and utilizing equal quality eyepieces, exit pupils etc. I can honestly tell you one thing that blew me away was the experience of looking through the new Nikon eyepieces. Thanks for bringing them Tammy. Having a wonderful scope like the Ceravolo obviously pinpoint stars edge to edge is something I live to see every time I look through the scope. With the Nikons, not only are they pinpoint but there seems to be plenty more of them across a very flat field -Amazing views - Bravo Nikon! Thanks everyone for a most memorables and enjoyable evening, I hope we do it again soon.
Posted 28 August 2011 - 11:21 PM
Well done sir. As always very complete and an interesting read. Most interesting is the fact that regardless of the type (reflector/refractor), all the good stuff is hard to come by.
Posted 28 August 2011 - 11:41 PM
If I had to choose between the two, Id pick the refractor due to confortable eyepiece position only.
Posted 28 August 2011 - 11:42 PM
Posted 29 August 2011 - 01:03 AM
Very enjoyable read, thank you.
If I had to choose between the two, Id pick the refractor due to confortable eyepiece position only.
you're welcome guys. Yes, I can understand this. On the other hand, Joe determined that a Televue Air Chair is a perfect arrangement for the Ceravolo. Also, Joe's little home made cooler works perfect. It simply sucks warm air and any dust out of the tube. By sundown, the scope appears to cooperate so far.
Posted 29 August 2011 - 01:16 AM
As Jim mensioned, it would also have been interesting to see the difrence, "if any" when both scopes were pushed to the extreme in excellent seeing, maybe then tiny difrences in optics would start to show its self
Anyways thanks for a great report
Posted 29 August 2011 - 01:51 AM
Posted 29 August 2011 - 02:47 AM
Posted 29 August 2011 - 06:55 AM
For pictures go to Tamiji Homma's site
Although I know most everyone by name wish I could identify the major players in those excellent photos by Tamiji.
Also did you folks use binoviewers or it was all mono view?
Posted 29 August 2011 - 07:34 AM
Posted 29 August 2011 - 10:52 AM
Posted 29 August 2011 - 12:57 PM
You're welcome to join the party
I uploaded my eyepiece basket photo that we used for shootout. We tried to match magnification on TEC 140 (focal length 980mm) and HD 145 (870mm) so that some of them didn't get any airtime last Saturday.
I thought TEC 140/XW 7 (140x) was tiny bit better than HD 145/Delos 6 (145x) but it would have been slight seeing changes between switching scopes (5 seconds or so). They were incredibly close, they both were showing what the aperture could show under the condition.
When near perfect scopes are side by side, both would show almost identical image, wouldn't it?
Thank you Joe and John for bringing such excellent scopes to the party. Star party is the only way for us to have such opportunity.
Posted 29 August 2011 - 01:33 PM
Posted 29 August 2011 - 03:23 PM
Posted 29 August 2011 - 05:56 PM
Posted 29 August 2011 - 06:02 PM
I can bring up a TEC160FL if you have a 7" MakNewt that you want to compare it to.
Posted 29 August 2011 - 06:49 PM
Great party! I'm sorry I missed it. It looks like you guys really had some fun.
I'm extremely curious about the homemade "cooler" which "Joe" made as is depicted in the photograph you posted.
Perhaps, Joe could chime in about how he did it.
Posted 29 August 2011 - 10:22 PM
The Ceravolo must be something to match a similar apertured quality APO!