Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

EAA with a manual Dobson... it´s working!

EAA
  • Please log in to reply
108 replies to this topic

#26 Ubuntu

Ubuntu

    Explorer 1

  • -----
  • topic starter
  • Posts: 91
  • Joined: 27 Oct 2018

Posted 17 December 2018 - 09:18 AM

Thank you Adun! I measured now with the measure stick and got down to a reduction of 0,58x which leads to F/D of 3.4. So a little bit better. On the ST80 i can reduce further with some spacers if I do not use the diagonal. However that is not an option on the dob. I'll try how it goes with 3.4. Doesn't sound too bad actually. There is always the option to stack multiple drifts.I assume Ubuntus stacked single drifts.

Hi Sondob... you're right I mostly stack single drifts... but repositioning the scope allows you to stack as many drifts as you want...

 

F/D 3.4 starts to be good but don´t forget that the objective is to go under 2 (exposition time will be divided by 2.5).

 

My advice would be to put a spacer to reach this F/D :)

 

But I'm already curious to see results with F/D 3.4 :)



#27 SonDob

SonDob

    Sputnik

  • -----
  • Posts: 36
  • Joined: 15 Aug 2018

Posted 20 December 2018 - 05:52 AM

Hi Ubuntu,

 

I grinded down my camera box case to a more circular shape. The case looks really scary now but I am able to dive deep into the focusser without any adapters. This way I achieve a reduction factor of 0.33x with brings me down to a F/D of 1.93. I could test on the moon through some cloud hole and it fits completely into view so FOV is around 0.5 degree. Already impressive how slow everything drifts compared to before. I am able to integrate in-camera for close to 5 seconds before seeing star trails. Next test will be with sharpcap when clouds and moon are gone. Planning to go for that Horsehead Nebula on my bucket list.


  • Adun and cmooney91 like this

#28 Ubuntu

Ubuntu

    Explorer 1

  • -----
  • topic starter
  • Posts: 91
  • Joined: 27 Oct 2018

Posted 20 December 2018 - 06:48 AM

Hi Ubuntu,

 

I grinded down my camera box case to a more circular shape. The case looks really scary now but I am able to dive deep into the focusser without any adapters. This way I achieve a reduction factor of 0.33x with brings me down to a F/D of 1.93. I could test on the moon through some cloud hole and it fits completely into view so FOV is around 0.5 degree. Already impressive how slow everything drifts compared to before. I am able to integrate in-camera for close to 5 seconds before seeing star trails. Next test will be with sharpcap when clouds and moon are gone. Planning to go for that Horsehead Nebula on my bucket list.

Niceeee :)

Could you tell us the telescope that you use ?

1.93, now we are speaking... can't wait to see the pictures when your sky is better :)

 

Have you already used sharpcap ?



#29 SonDob

SonDob

    Sputnik

  • -----
  • Posts: 36
  • Joined: 15 Aug 2018

Posted 20 December 2018 - 07:16 AM

It's a skywatcher 205/1200 but I have access to a 305/1500 as well. So in the future I may try both. No experience with sharpcap so far except for the dry run to explore the live histogram stretching and capture settings.


  • Adun likes this

#30 Ubuntu

Ubuntu

    Explorer 1

  • -----
  • topic starter
  • Posts: 91
  • Joined: 27 Oct 2018

Posted 20 December 2018 - 02:41 PM

It's a skywatcher 205/1200 but I have access to a 305/1500 as well. So in the future I may try both. No experience with sharpcap so far except for the dry run to explore the live histogram stretching and capture settings.

 

Yeah it's important to play with the histogram... sharcap pro has also an autostrech function that does it automatically laugh.gif

 

Is your skywatcher motorized ?


Edited by Ubuntu, 20 December 2018 - 02:42 PM.


#31 SonDob

SonDob

    Sputnik

  • -----
  • Posts: 36
  • Joined: 15 Aug 2018

Posted 21 December 2018 - 04:16 AM

No it is all manual. No EQ platform either.



#32 Ubuntu

Ubuntu

    Explorer 1

  • -----
  • topic starter
  • Posts: 91
  • Joined: 27 Oct 2018

Posted 06 January 2019 - 06:01 AM

I did a little video to show what I'm seeing before stacking... :D

 

https://www.youtube....h?v=XxYw9eSeCm4


  • Ptarmigan, Asbytec, Adun and 1 other like this

#33 DSO_Viewer

DSO_Viewer

    Viking 1

  • -----
  • Posts: 826
  • Joined: 03 Jan 2016

Posted 06 January 2019 - 01:53 PM

I did a little video to show what I'm seeing before stacking... laugh.gif

 

https://www.youtube....h?v=XxYw9eSeCm4

Nice but if you can I would put a tracking system on that Dob in order to maintain round stars which is making your image or viewing blurry.

 

Steve



#34 Ubuntu

Ubuntu

    Explorer 1

  • -----
  • topic starter
  • Posts: 91
  • Joined: 27 Oct 2018

Posted 06 January 2019 - 02:55 PM

Nice but if you can I would put a tracking system on that Dob in order to maintain round stars which is making your image or viewing blurry.

 

Steve

 

Hi... i can't afford a mount but I did this video to show what we could see... before stacking...

I'm usually stacking with a lower exposure to keep the stars round...


  • DSO_Viewer and SonDob like this

#35 Ptarmigan

Ptarmigan

    Lagopus lagopus

  • *****
  • Posts: 4557
  • Joined: 23 Sep 2004
  • Loc: Arctic

Posted 06 January 2019 - 03:46 PM

I did a little video to show what I'm seeing before stacking... laugh.gif

 

https://www.youtube....h?v=XxYw9eSeCm4

Looks good. cool.gif waytogo.gif like-button.jpg

 

The image looks good for 2 seconds and highest gain for IMX385 for Orion Nebula.

 

Andromeda and M81 and M82 are clearly visible under 1 second at highest gain.

 

How was the sky condition like?



#36 Ubuntu

Ubuntu

    Explorer 1

  • -----
  • topic starter
  • Posts: 91
  • Joined: 27 Oct 2018

Posted 06 January 2019 - 06:21 PM

Looks good. cool.gif waytogo.gif like-button.jpg

 

The image looks good for 2 seconds and highest gain for IMX385 for Orion Nebula.

 

Andromeda and M81 and M82 are clearly visible under 1 second at highest gain.

 

How was the sky condition like?

The sky condition where I live is quite good...


  • Ptarmigan likes this

#37 Lukes1040

Lukes1040

    Vostok 1

  • *****
  • Posts: 186
  • Joined: 26 Dec 2016
  • Loc: Ohio, USA

Posted 06 January 2019 - 08:00 PM

Fantastic results! I may have to give this a try. I have done planetary imagining in my manual dob, but have not given dso’s a go. Thanks for the inspiration 


  • Ubuntu likes this

#38 Ubuntu

Ubuntu

    Explorer 1

  • -----
  • topic starter
  • Posts: 91
  • Joined: 27 Oct 2018

Posted 07 January 2019 - 03:27 AM

Hi Ubuntu,

 

I grinded down my camera box case to a more circular shape. The case looks really scary now but I am able to dive deep into the focusser without any adapters. This way I achieve a reduction factor of 0.33x with brings me down to a F/D of 1.93. I could test on the moon through some cloud hole and it fits completely into view so FOV is around 0.5 degree. Already impressive how slow everything drifts compared to before. I am able to integrate in-camera for close to 5 seconds before seeing star trails. Next test will be with sharpcap when clouds and moon are gone. Planning to go for that Horsehead Nebula on my bucket list.

Hi SonDob... any results ? :D



#39 Ubuntu

Ubuntu

    Explorer 1

  • -----
  • topic starter
  • Posts: 91
  • Joined: 27 Oct 2018

Posted 08 January 2019 - 09:27 AM

M81 & M82: 37 frames, total 37s

 

Stack_37frames_37s_WithDisplayStretch V2.jpg

 

Sharpcap M82.jpg


  • saguaro and Lukes1040 like this

#40 SonDob

SonDob

    Sputnik

  • -----
  • Posts: 36
  • Joined: 15 Aug 2018

Posted 08 January 2019 - 09:37 AM

Hi SonDob... any results ? laugh.gif

yes and no smile.gif So far I got one clear night only with the 8" under Bortle 5 skies but a lot of moonlight. I first played around without sharpcap with the hardware monitor only. As you remember I wanted to capture the horse head nebula. No luck. IC434 was not visible at all. However the nearby flame nebula was visible. I would say a liitle bit less clear and smaller then in your video. However, with much more noise - but that's ok and expected from using an analog camera.Having no luck with IC 434 and no stacking I wanted to use the notebook, but the capture driver crashed and I couldn't make it work outside. Bad luck. The rest of the night I stayed visual only in Orion to get that dark hole (nowadays assumed to not be a globule but a real hole) in NGC1999 of my bucket list.

Meanwhile the software problem is fixed and I am waiting for clear skies again.

 

Btw I tried the flame nebula with the 80mm Achromat without tracking and it is visible, too. Of course it appears much smaller and I could use a  longer exposure of 5s or so.

 

 

Thanks for the video. The shown looks very familiar smile.gif

 

More to come



#41 SonDob

SonDob

    Sputnik

  • -----
  • Posts: 36
  • Joined: 15 Aug 2018

Posted 08 January 2019 - 10:12 AM

Hi Ubuntu,

 

could you do me a favor please and try if you can see IC 434 without stacking or stretching? Under what bortle skies are you imaging?

 

Thank you!



#42 Lukes1040

Lukes1040

    Vostok 1

  • *****
  • Posts: 186
  • Joined: 26 Dec 2016
  • Loc: Ohio, USA

Posted 08 January 2019 - 10:17 AM

Hi Ubuntu,

 

could you do me a favor please and try if you can see IC 434 without stacking or stretching? Under what bortle skies are you imaging?

 

Thank you!

IC 434 is very difficult to see without very dark skies or large aperture, filtered with an H-Beta filter. Stacking will most likely be required. 


Edited by Lukes1040, 08 January 2019 - 10:17 AM.


#43 Ubuntu

Ubuntu

    Explorer 1

  • -----
  • topic starter
  • Posts: 91
  • Joined: 27 Oct 2018

Posted 08 January 2019 - 11:25 AM

Hi Ubuntu,

 

could you do me a favor please and try if you can see IC 434 without stacking or stretching? Under what bortle skies are you imaging?

 

Thank you!

Hi Sondob... hope you'll have better sky soon smile.gif

 

Yes I did already IC434 and with the cam (no stacking) it is hardly visible... visible but very very faint...

I did a stacking and it gave that:

Stack_35frames_35s_WithDisplayStretch V3.jpg

 

For me this nebula is very difficult because very diffuse...


  • Ptarmigan, Starman27 and SonDob like this

#44 Ubuntu

Ubuntu

    Explorer 1

  • -----
  • topic starter
  • Posts: 91
  • Joined: 27 Oct 2018

Posted 09 January 2019 - 06:36 AM

Observations from yesterday night... with quite some wind... but thanks to the short exposure... was OK laugh.gif

 

IC434 horse head nebula: 29 frames, total 29s

 

Stack_46frames_46s_WithDisplayStretch V2.jpg

 

NGC2014: flame nebula: 76 frames, total 76s

 

Stack_76frames_38s_WithDisplayStretch V2.jpg

 

NGC7635 Bubble nebula: 61 frames, 61s

 

Stack_61frames_61s_WithDisplayStretch V2.jpg

 

NGC 7023, Iris nebula: 54 frames, 54s

 

Stack_54frames_54s_WithDisplayStretch V2.jpg


Edited by Ubuntu, 09 January 2019 - 06:36 AM.

  • Ptarmigan, Starman27, rob961 and 2 others like this

#45 SonDob

SonDob

    Sputnik

  • -----
  • Posts: 36
  • Joined: 15 Aug 2018

Posted 09 January 2019 - 10:17 AM

IC 434 is very difficult to see without very dark skies or large aperture, filtered with an H-Beta filter. Stacking will most likely be required. 

Incredible, thank you. So it should be in reach. I saw it visually with the 8" at the same place some month ago. Probably the sky was not good enough when I tried with camera. Will try again.



#46 Ubuntu

Ubuntu

    Explorer 1

  • -----
  • topic starter
  • Posts: 91
  • Joined: 27 Oct 2018

Posted 09 January 2019 - 11:22 AM

Here are some videos of the stacking to help you guys see what happens during the stack :D

 

https://www.youtube....h?v=qDcgzlA8dZc

 

https://www.youtube....h?v=2k-9DsMcMSU

 

https://www.youtube....h?v=ufHtXH4BNuU


  • Lukes1040 and SonDob like this

#47 Ubuntu

Ubuntu

    Explorer 1

  • -----
  • topic starter
  • Posts: 91
  • Joined: 27 Oct 2018

Posted 11 January 2019 - 06:16 AM

M33: 44 frames, total 44s

 

Stack_44frames_44s_WithDisplayStretch V2.jpg

 

Running man nebula: 35 frames, total 35s

 

Stack_35frames_18s_WithDisplayStretch V2.jpg

 

NGC 891: 161 frames, total 81s

 

Stack_161frames_81s_WithDisplayStretch V2.jpg


  • saguaro, Adun, Lukes1040 and 2 others like this

#48 SonDob

SonDob

    Sputnik

  • -----
  • Posts: 36
  • Joined: 15 Aug 2018

Posted 11 January 2019 - 08:11 AM

Here are some videos of the stacking to help you guys see what happens during the stack laugh.gif

 

https://www.youtube....h?v=qDcgzlA8dZc

 

https://www.youtube....h?v=2k-9DsMcMSU

 

https://www.youtube....h?v=ufHtXH4BNuU

Thank you, very enlightening. I also like the one with the 50mm lens. Did you try stacking with it as well?



#49 Ubuntu

Ubuntu

    Explorer 1

  • -----
  • topic starter
  • Posts: 91
  • Joined: 27 Oct 2018

Posted 11 January 2019 - 09:10 AM

Thank you, very enlightening. I also like the one with the 50mm lens. Did you try stacking with it as well?

 

I stacked with it but I did not do a video of the stacking :)

 

Yeah people tend to forget that having a huge FOV is also fun and there are couple of objects to stack :)



#50 mikenoname

mikenoname

    Ranger 4

  • *****
  • Posts: 342
  • Joined: 29 Jan 2015
  • Loc: Death Valley

Posted 11 January 2019 - 08:44 PM

 

So my choice was the Rising Tech IMX385, I got it at 285€ on offer and I took an X0.5 reducer from SVbony... I know the reducer is not of good quality (besides it was mounted upside down) but good as I didn't know where I was going and I preferred to ensure at the budget level smile.gif

 

 

 

Thank you for the hint with reversing the reducer. That made all the difference.

 

 

Confused. Are you actually reversing the direction of the focal reducer before installing it on the camera?




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics







Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics