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Allinthehead

Tak Epsilon 130 Quick First Light

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Hi everyone. My new scope arrived on Tuesday, and Wednesday night the clouds vanished for 2 hours which gave me the opportunity to test. In my haste and surprise at the clear sky i calculated the spacing wrong for my Asi 1600. I think i was out by 2 mm. First impressions are good and the first subs put a big grin on my face. Given that conditions were poor and i was imaging close to the moon i'm very happy with the result for such short imaging time.

15 * 5 minute subs 1 hr 15 mins

No calibration files yet

Takahashi Epsilon 130 with Asi 1600mm at 0 gain -10, Astrodon 5nm Ha

AzEq6, captured with Sgpro. Stacked in APP, Processed in APP and PI.

Thanks for looking

Richard.

rosette_unstret.thumb.png.460737dde0577f0ff9549c098b44d196.png

 

Jpg

rosette_unstret.thumb.jpg.8bc910973872da6cebc66e42e62375d6.jpg

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Amazing result, Richard. Well done!

Any chance of some pics of your new set-up?

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Just now, JeremyS said:

Amazing result, Richard. Well done!

Any chance of some pics of your new set-up?

Thanks Jeremy. Sure thing.

20180327_200246.thumb.jpg.c912425cb836b75d0566efbc83f14ad4.jpg20180327_205753.thumb.jpg.7dc551757184de142ed481bb3aade604.jpg

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That's a lovely result supercrisp, especially for a rush job!

I'm amazed you managed to get that with gain at 0. I've just been doing the Rosette in NB with ASI1600, also at -10, also with 5 mins subs - but gain set at 300 I think.

The wonders of F2.8!!

I used my Tamron 300mm camera lens at F4 - it will go to F2.8 - but a very different result to your Tak F2.8 I think!

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3 hours ago, Tommohawk said:

That's a lovely result supercrisp, especially for a rush job!

I'm amazed you managed to get that with gain at 0. I've just been doing the Rosette in NB with ASI1600, also at -10, also with 5 mins subs - but gain set at 300 I think.

The wonders of F2.8!!

I used my Tamron 300mm camera lens at F4 - it will go to F2.8 - but a very different result to your Tak F2.8 I think!

Thanks. The 130 is f3.3. I use 0 gain on bright objects like Rosette, Horsehead, Orion etc but for feinter stuff unity is better or 10 minute subs. I prefer to use 5 min subs to stack more as compensation for 12 bit Asi 1600.

3 hours ago, Ronclarke said:

Love the Bichon and the set up!!

Thanks Ron. He's actually a Coton de Tulear. Elmo

DSC_0225.thumb.JPG.d00c6771e55fc17f13c17fb3224cdde1.JPG

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That's a new one for me!! We have a 4 year old Bichon Frise, always out with me when I'm stargazing!!

 

Ron

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6 minutes ago, Ronclarke said:

That's a new one for me!! We have a 4 year old Bichon Frise, always out with me when I'm stargazing!!

 

Ron

Nice one. Always good to have some company when out.

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The Ha extension coming from the bottom of the nebula suggests that you've already gone very deep with this. Looks more than promising.

Olly

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Hi Richard,

congrats! The tube rings are very common to me :-)
You will have a lot of fun with the Epsi!

Jens

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3 hours ago, ollypenrice said:

The Ha extension coming from the bottom of the nebula suggests that you've already gone very deep with this. Looks more than promising.

Olly

 

3 hours ago, Barry-Wilson said:

Well done Richard :thumbsup: great first light - congratulations!

Thank you Olly and Barry.

 

2 hours ago, Jedi2014 said:

Hi Richard,

congrats! The tube rings are very common to me :-)
You will have a lot of fun with the Epsi!

Jens

Thanks Jens. I've no idea what you're talking about. These are custom one off rings.? Thanks again for the info.

Edited by Allinthehead

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Very Nice Richard.  What is the difference between 0 and unity gain?  Also--where is your filter wheel?  

Rodd

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Thanks Rodd. There's is a huge difference between 0 and unity gain. Unity is 139 gain. I find a large increase in dynamic range at 0 gain and no clipping of stars. I use 5 to 10 minute subs at 0 gain and 5 at unity for the feinter objects. 

The image above of the setup is with my Asi 071. Osc.

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On 3/31/2018 at 13:35, Allinthehead said:

Thanks Rodd. There's is a huge difference between 0 and unity gain. Unity is 139 gain. I find a large increase in dynamic range at 0 gain and no clipping of stars. I use 5 to 10 minute subs at 0 gain and 5 at unity for the feinter objects. 

The image above of the setup is with my Asi 071. Osc.

Following on from my earlier comment I'm amazed you get such good results in NB with 0 gain. I'm not questioning your method - far from it -the result speaks for itself.

Having recently switched to the ASI1600 myself (from DSLR), I started with LRGB 60s exposures using unity gain just because it seemed a good place to start. But have had such limited clear sky I really haven't had the chance to properly experiment with different gain levels. I then went to NB, and went to high gain with 300s exposures. Results generally OK, but with 60s L I get very bloaty stars and similar with OIII and SII at 300s.

You're working at F3.3, where I'm at F4, so not a direct comparison, but now I'm wondering if I should be using lower gain settings. Thing is, even with my existing gain, there isn't much to see on the unstretched subs.

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41 minutes ago, Tommohawk said:

You're working at F3.3, where I'm at F4, so not a direct comparison, but now I'm wondering if I should be using lower gain settings. Thing is, even with my existing gain, there isn't much to see on the unstretched subs.

Well i was at f4.9 this is the first at f3.3. Here is an unstretched image 0 gain 300 seconds at f3.3

5ac20e751990a_Target1_300sec_1x1__frame8.thumb.jpg.5219a6175b4eee1fb7ff905d88dd2f7d.jpg

This is 5 hrs or so at f4.9 600 second subs gain 0

5ac20ede0a556_OrionFinalblend.thumb.png.130a2efd729525e347d0193d546677a1.png

And single unstretched. Core totally blown out but easily fixed with short subs.

5ac210f52fbf6_orionha71-58.thumb.jpg.ebc6bfddc6f4d1669e8899f3389fefc1.jpg

 

0 gain i find at 300 is fine for bright targets but i need to up it to 600 for feint stuff or change to unity. Changing to unity is probably the better approach as you need to recover bit depth by stacking lots of subs. If i was using the L filter i don't think i'd go above 0 gain as the stars clip too easily. When i was unguided i used gain 300-399 60 seconds with my 5nm Ha filter. I've only been guiding since just before Christmas so i'm still experimenting with gain and time.

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hi.

interesting topic,i have just bought the zwo183 mono cooled and i don't have a clue about the gain settings,lol.

so with a bit of help from friends i took this photo of m82,settings where.

manual gain 122. 14x2min subs,camera cooled to -15, no filters,taken through an Altair Astro 115 triplet apo f7.

still a long way to go.

bodes-jpeg.jpg

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1 hour ago, Allinthehead said:

Well i was at f4.9 this is the first at f3.3. Here is an unstretched image 0 gain 300 seconds at f3.3

 

OK well that confirms what i thought - not much too see when unstretched, but obviously its all there! Wish there was more clear sky to allow experimentation with all this!

Thanks for taking the time to post those images - very helpful.

42 minutes ago, jarraman said:

hi.

interesting topic,i have just bought the zwo183 mono cooled and i don't have a clue about the gain settings,lol.

so with a bit of help from friends i took this photo of m82,settings where.

manual gain 122. 14x2min subs,camera cooled to -15, no filters,taken through an Altair Astro 115 triplet apo f7.

still a long way to go.

 

Well you're off to a good start! Not at all sure about settings for that camera - try and follow the recommended settings though.

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2 hours ago, jarraman said:

still a long way to go.

Looks like a good start.

1 hour ago, Tommohawk said:

Wish there was more clear sky to allow experimentation with all this!

Ha yes. I've had this camera for about 18 months and i'm still experimenting.

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