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Messier 36 report, PVS-7

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#1 DMala

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Posted 20 March 2019 - 11:31 PM

Yesterday (March 19) I managed to take out my TV Pronto, the PVS-7 and some new equipment I just got to try some NV photography. Main objectives were to test the combination of the inexpensive, used 2" Orion 50mm Plossl eyepiece that I bought on the CN Classifieds, connected with a Novagrade afocal adapter to the original Envis objective of my PVS-7. 

 

For details on the adapter, see cnoct's page (I will also post soon some details)  https://www.cloudyni...r-nv-astronomy/

 

A few disclaimers: I never tried before the above equipment, and only very marginally used the Pro mode of my Galaxy S9. In addition, the cell phone adapter that I have does not line up properly the camera with the PVS-7 ocular, nor does it keep the phone perpendicular. A better one on its way from ModArmory.

 

The tree canopy in my yard leaves few open spaces but I found the Pinwheel Cluster Messier 36 (discovered however by Giovanni Battista Hodierna) to be in sight.  Strong moonlight from the SE, no breeze. Visually with my Nagler 20mm I could faintly see a fuzz.

 

See below single-exposure pics of the PVS-7 screen, which are quite close to real time views. 

 

General impressions: the Novagrade adapter is easy to use and it provides a reasonably strong attachment of the PVS-7 to the eyepiece. I like a lot the idea to try afocal pics with a variety of EPs of my choice. I connected the PVS-7 to a 1.25" 40mm EP by changing the Novagrade compression ring size, and it was fast and easy.

 

The ENVIS lens seems sharp in the center but it has a lot of distortion elsewhere. I plan to see if I can modify the rig to use my Pentax camera lenses instead.

 

The middle-level tube of my PVS-7 seems still more than enough for where I am now along the learning curve.

 

And now the required technical data:  19 March 2019, Verona, NJ, 23:15h Televue Pronto 70x480mm, SkyWatcher AZ-EQ5 Pro (altaz mode), 2” TV diagonal, 2” Orion 50mm PL, Novagrade T-mount adapter, PVS-7 with MX-10130D tube contract W9124Q-05-D-0821 (OMNI VII), Samsung Galaxy S9 Camera in Pro Mode, f2.4, ISO-50, 1 sec. single exposure. Green images cropped but not processed. 

Attached Thumbnails

  • 20190319_231405a.jpg
  • 20190319_230155a.jpg
  • 20190319_232352d.jpg
  • 20190319_232352b1.jpg


#2 DMala

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Posted 21 March 2019 - 09:44 PM

I just found for comparison the views from jdb_astro's TSA-120, see 0' 44" 

 

https://www.youtube....h?v=068Xz0-oAsE



#3 Vondragonnoggin

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Posted 21 March 2019 - 09:49 PM

Very nice capture.

 

No filters used, right? It might pop more with a longpass filter, but cluster is clearly recognizable in your pic.

 

of course the same effect could be done with a few tweaks on the photo itself, but I like the raw unprocessed images like these.


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#4 DMala

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Posted 21 March 2019 - 11:53 PM

No filters indeed.

#5 Jeff Morgan

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Posted 22 March 2019 - 01:44 AM

Nice job on the equipment shake-down.

 

On to M35!


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#6 DMala

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Posted 22 March 2019 - 01:01 PM

Hello, am I calculating correctly the effective speed of my rig above:

 

Televue Pronto f 6.8

50 mm 2" EP

PVS-7 with Envis 27mm lens in afocal mode

 

 

EP exit pupil = 50/6.8 = 7.3

 

Effective f value = 27/7.3 = 3.7

 

Thx



#7 The Ardent

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Posted 22 March 2019 - 01:36 PM

Since the Pronto has short focal length, I advise prime focus or maybe even a Barlow since the cluster is small. And some strong filtering for the moonlight. That is if you want to specifically capture the cluster.

If you were to center the FOV on say, 18 Auriage or Phi Aur, 50mm is a good choice since there are many clusters in the vicinity.

Good job!
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#8 DMala

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Posted 29 March 2019 - 12:06 PM

On March 27 I went back to the Pinwheel cluster, taking a different approach. Use of a Lumicon Night Sky filter, prime focus instead of afocal, and Sony NEX 5N camera+Novagrade adapter instead of cellphone adapter+Galaxy S9.  

 

Below are the results. 

 

Technical data: 27 March 2019, Verona, NJ, 22:30h Televue Pronto 70x480mm, SkyWatcher AZ-EQ5 Pro (altaz mode), 2” TV diagonal, Lumicon NightSky 1.25" filter on a PVS-7 with MX-10130D tube contract W9124Q-05-D-0821 (OMNI VII), Novagrade T-Mount adapter, Sony NEX 5N camera in manual mode, f4, ISO-400, 2 sec. single exposure. First image as is from camera (size reduced), second image cropped but not processed.

 

In the future I plan to try different combinations of ISO speed/exposure parameters. From past experience I understood that the ISO range 400-1600 is very good for this camera. Last night I took pics with ISO 1600 and 400 values and exposure duration ranges 1/5 to 3.2 secs, from what I can see based on my modest experience, the tracking of the mount was adequate, so that's encouraging.  A few years ago I also got a LCD screen to connect to my camera, so if I want I can also try a NV-EAA poor man's mix grin.gif !

 

I easily processed the cluster image below by removing the green and turning it into a b/w pic, but from what I understand it can not be posted here. Anyone interested can find it on the "what did you observe today" thread of the Classics forum....

 

Any comments are welcome.

 

Attached Thumbnails

  • Messier 36 Nightsky Filter_DSC3197a.jpg
  • Messier 36 Nightsky Filter_DSC3197b.jpg



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