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24.4" truss dob first & second light report

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#1 vasilas432

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Posted 13 July 2016 - 10:18 AM

On 9th July Saturday was the second light. Same company (Vassilios Katzourakis, Dimitris Manousos and Manos Tsikalas) gathered in a dark location (sqm 21.55) 45 minutes away and in more than 1000 meters high. There were some guests this time too. Transparency was good but seeing was limited.
The moon was up until 00:00 so after assembling the scope quite easily, only me needed, I started playing with the moon. 230x with the 10mm Ethos was a great view so started experimenting and upped magnification to 377 using a cheap orthoscopic eyepiece. View was better than before and a specific crater I was looking was more detailed. I put a barlow and magnification became 754x. First time I was using so high magnification and I must confess image of the crater on this magnification was crystal clear and reminded me and the other guys, some 60s old movies of the moon! We passed by Jupiter but above 140x using my 17mm Nagler wasn't good due to bad seeing.

At about 00:20 the scope pointed something serious, Arp 32. It has 2 galaxies a+b. a is UGC 10770 and was the visible in direct vision. b was easily spotted using indirekt vision 100% of the time and was seen by all of us. It is a 17 mag galaxy!

Later we had the scope pointing near M13. Ethos 10mm was used and here is the picture: It was a small bright part of M13 on the right looking magificent, NGC 6207 looking rich on the left of field of view and the tiny IC 4617 on the center! That was spectacular view even though IC 4617 was indirect! Next was Stephan's Quintet which was screaming out of the eyepiece in fully direct vision and showing some detail too!

Another highlight was Cresend Nebula using OIII or UHC with Ethos 21! Like the photo! Nothing less. I also tried the 31mm Nagler in that one with great results even though exit pupil is 8.5. A useful eyepiece with my scope.  Trifid nebula and the Veil were great and impressive. Swan nebula was even more impressive with a lot of detail not seen in colorful photos. Black and white can have advantages sometimes in detail over the red and other colors. I can say the same for Trifid nebula too.
Other impressive objects seen were M14 globular. Last but not least during the first light on 04th of June among others, we observed M101 galaxy which btw through my 24,4 mirror is looking like a photo too! Very impressive!

I would like to say some words for the scope and the mirror. f/3.2 is great, all people observed through the scope just needed a step of 10cm only near the zenith while we had our feet on the ground for 95% of the time. Assembling the scope is very easy too, it takes me 10 minutes without any help and I can do it in the dark too. Paracorr usage is not an issue anymore because you just move Paracorr's tunable top by just watching through the eyepiece and every eyepiece becomes parfocal with the others (Don's advise from cloudynights and it works like a charm). You only have to adjust the focuser some millimeters for a sharp focus. You don't need to read the instructions of the Paracorr when changing eyepieces.

Credit for the scope design  and making from scratch goes to the scope manufacturer Manousos Dimitris. He designed and brought to life every piece, base, mirror box, mirror shell, upper cage, secondary spider, truss holders. Everything is really strong and accurate. Telescope is stiff and can hold in some wind too. During the second observation we made some small fixes and while the scope is f/3.2 it does hold collimation inside the tuBlug centre at all heights and during the whole observation. As I said above it is very easy to assemble for only one person and during the dark. Luckily me we are friends and we enjoy observation sessions together. I only need two more people to load and unload the scope in and out of the car. BTW the scope can be loaded in my Toyota Yaris!!

John Nicol's mirror is great giving me very sharp images with a lot of contrast. I can get sharp focus pretty easy too. The mirror is λ/8 and images through the eypiece can prove that anytime. All in all I am very happy with the mirror and talking with John was a great experience. I am very happy to have bought a premium mirror from him. Constraction of the mirror was fast and shipping packing was strong like a tank! I definitely recommend John Nichol to everyone looking after a great quality large aperture mirror.

Here is the first light report described by my friend and scope manufacturer Manousos Dimitris:

On Saturday 4th of June we had the opportunity to have the first light and make a first assessment of what can be seen through such a telescope. We arrived at the field at the 8:30pm. We were all anxious. We faced an issue in unloading from the car because of the size of the scope. Eventually we start setting the trusses with the auxiliary ring and then the upper cage. In general the setup of the scope was easy and we did not encounter problems in the dark. We started with the alignment of the optics using the Howee Glatter's, tuBlug. The process did not take more than two minutes to complete. Both secondary and primary mirrors were aligned easily. We started with the first object M51. The UMa was in a good spot. We putted the Paracorr with an Ethos (do not remember focal length) and adjust the position of Paracorr. The Paracorr needs to be regulated in the correct position which slightly delayed the process every time we change the eyepiece. I place my eye over the eyepiece and focus. Spend a few milliseconds until my brain to understand what's happening. The galaxy M51 was visible with direct vision with the spirals and the bridge of the companion. The galaxy was not only visible with direct vision but you had a three-dimensional texture in its structure. For comparison we had a 16" f/4,5 truss Dobsonian side by side. The difference was evident and greater than we expected. We change to M3. The cluster had a feeling of depth. Then we switched to NGC4565. The galaxy seemed 2x in size compared to 16" while the dark  lane were obvious. We then switched to M101, M27, M57 and other Messier objects. All very impressive and much brighter than ever. The biggest difference we saw in these two telescopes were on a tight galaxy cluster Hickson 79 or else "Seyftert's Sextet". This cluster is sparsely with only 6 members. The three brightest members a, b, c (16,5 v-mag I find) immediately appeared without difficulty while on the 16" had to make an effort to separate them. By averted vision appeared the fourth member.

The test showed that generally the Paracorr in deep sky observation did not seem to be a necessity when using Ethos and Nagler eyepieces (Ethos 21, 17, 10 and Nagler 31 T5 and T6). Although the telescope is extremely fast (f/3.2) the coma was not annoying. The biggest difference using the Paracorr were visible at a very dense point in Cygnus over the galaxy with full of stars in the field. In the middle of the observing session we checked the collimation. The missalighnment was in the limits of the central mark on the primary.

Clear Skies to everyone
Vassilios Katzourakis

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Edited by vasilas432, 13 July 2016 - 04:11 PM.

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#2 Achernar

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Posted 13 July 2016 - 08:30 PM

Thank you for sharing your first light with us, it's a special accomplishment to build a large telescope then take it out under the night sky for the first time. I built my 15-inch truss-tube F/4.5 Dob back in 2011 and I savored every moment of first light with that telescope. Savor yours and enjoy views of the Universe that few humans will ever see. The workmanship on your telescope is first rate, and beautiful to behold. Well done! I enjoyed reading your report.

 

Taras


Edited by Achernar, 13 July 2016 - 08:31 PM.

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#3 Tim M

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Posted 13 July 2016 - 09:06 PM

Congratulations!  Very nice looking scope!  What is the light (silver?) material around the bottom of the rocker box?  Is the rocker sitting in a "tray" that forms the ground board?

 

clear skies,

Tim


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#4 vasilas432

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Posted 14 July 2016 - 02:39 AM

Thank you for sharing your first light with us, it's a special accomplishment to build a large telescope then take it out under the night sky for the first time. I built my 15-inch truss-tube F/4.5 Dob back in 2011 and I savored every moment of first light with that telescope. Savor yours and enjoy views of the Universe that few humans will ever see. The workmanship on your telescope is first rate, and beautiful to behold. Well done! I enjoyed reading your report.

 

Taras

Thank you

 

Congratulations!  Very nice looking scope!  What is the light (silver?) material around the bottom of the rocker box?  Is the rocker sitting in a "tray" that forms the ground board?

 

clear skies,

Tim

Thanks

The rocker box is normal and it isn't sitting on a tray. The light silver you see are metal protectors.  That was my idea.  You can put things like ladder,  chair or table up there squeezing them in the car without worrying about scratches on the fine quality wood and cherry paint. Except that when the rocker box goes in and out of the base multiple times by 2 people there would be hits on the base's corners.  Now everything is protected for heavy usage and no scratches. It ended up to look better for me combined with cherry :) 


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#5 Manousos

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Posted 14 July 2016 - 02:53 AM

Hello,

 

It is really a pleasure to see such a scope working. From my side I would like to thank Vasilis for being so patient with me. The total time for building the scope took about 10 months (as a part time work) due to the challenges that we faced on the design and implementation but also to the limited free time. A lot of things were need to be re-designed and implemented for first time (truss system, spider, secondary holder etc.). All parts were made by hand except the upper cage accesories (focuser, finder and telrad of course).


Edited by Manousos, 14 July 2016 - 02:57 AM.


#6 vasilas432

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Posted 15 July 2016 - 01:52 AM

Hello,

 

It is really a pleasure to see such a scope working. From my side I would like to thank Vasilis for being so patient with me. The total time for building the scope took about 10 months (as a part time work) due to the challenges that we faced on the design and implementation but also to the limited free time. A lot of things were need to be re-designed and implemented for first time (truss system, spider, secondary holder etc.). All parts were made by hand except the upper cage accesories (focuser, finder and telrad of course).

I am a tough customer and love perfection. You did great with the scope. I can't imagine something better than this. 


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#7 Achernar

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Posted 17 July 2016 - 10:01 AM

 

Hello,

 

It is really a pleasure to see such a scope working. From my side I would like to thank Vasilis for being so patient with me. The total time for building the scope took about 10 months (as a part time work) due to the challenges that we faced on the design and implementation but also to the limited free time. A lot of things were need to be re-designed and implemented for first time (truss system, spider, secondary holder etc.). All parts were made by hand except the upper cage accesories (focuser, finder and telrad of course).

I am a tough customer and love perfection. You did great with the scope. I can't imagine something better than this. 

 

I know this question is not related to this thread, but how are the skies where you are? I get the impression from a couple of photos you posted they are dark enough for you to use that 24-inch to good advantage on faint and very faint fuzzies. Where I am, a 24-inch probably would not show much more than my 15-inch would due to severe light pollution and chronically milky skies. From a dark site, I have looked through 24 and 25-inch Dobs and was amazed what appeared in the eyepiece. Another question is what do you use to collimate it? I use Tectron collimation tools, namely the sight tube and Cheshire eyepiece to keep my 15 and 10-inch F/4.5 Dobs accurately collimated.

 

Taras



#8 vasilas432

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Posted 19 July 2016 - 06:11 AM

Observation took place on a 21,55 dark site. I couldn't push the scope to its limit due to mediocre seeing though. I haven't tried the scope at my 5,2mag backyard yet.  My collimation tools are Howie Glatter's 2" tuBlug with 2" 635 nm laser.  2 minutes to collimate with great precision. 


Edited by vasilas432, 19 July 2016 - 06:13 AM.


#9 MoosBros

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Posted 19 July 2016 - 10:42 PM

:bow:  :waytogo: wow... just wow....my next scope MUST in in the ballpark of 24" aperture.   

 

Nice report on the first light....



#10 Shmals

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Posted 22 July 2016 - 09:34 PM

Sweet, congrats!  :waytogo: Nice 'action' shots in the field! 




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