Simeis 147 in Ha

[Gina]

Simeis 147 in Ha slightly cropped and custom stretched.  45x3m + 21x7.5m = 292.5m which is just under 5 hours.  Binned 3x3, gain 300.  Processed in PixInsight.

135mm f2.5 Asahi Super Takumar lens, 3nm Astrodon filters in ZWO EFW, ASI 1600MM-Cool camera.   FoV 10° x 7.5°.  EQ8 mount, no guiding.

 

[Adreneline]

This is one of my favourite objects. Very nice Gina.

Your 135mm certainly does the business.

Adrian

[Mr Spock]

Really nice image of such a delicate object.

[simmo39]

I'm being drawn to one of these lenses. You must stop posting such good images.

[Mr Spock]

Yes, the image quality makes you forget how old this lens is. 

[Jkulin]

Lovely image Gina, how are you managing such tight stars with no guiding?

That lens is a cracker.

[JeremyS]

This is a stunning image, Gina!!!

[Benjam]

Impressive image Gina, well done. 

With my vivid imagination... I see a jellyfish swimming amongst plankton in your image, minus the colour. 
 

 

[Gina]

Found a few more Simeis147 light subs, calibrated, aligned and added to the stack then re-processed.  This is the result.

 

[MartinB]

Well done Gina, it's a faint devil isn't it.  More nice work with the 135mm lens

[ollypenrice]

Hey, that's really great. The object itself is unreasonably huge and yet, even so, you've casually pulled in another Ha object to the right! Wow.

Olly

[ApophisAstros]

Wonderful details, Gina  , cant wait to get my astrodons..

Roger

[Gina]

Thank you Olly, I really appreciate your comment.

The 3nm Astrodons are quite something, Roger.  Thanks for your comment.

Edited January 26, 2020 by Gina

[ollypenrice]

1 hour ago, Gina said:

 

The 3nm Astrodons are quite something, Roger.  Thanks for your comment.

But not easy to focus. How did you do it here?

Olly

[Gina]

I have a DIY remote controlled stepper motor focuser to drive the focus sleeve on the lens.  The stepper is run off the controlling and capturing Raspberry Pi with the Astroberry Focuser INDI driver (the author of this is a member here).  On my main indoors desktop KStars/Ekos controls focus either manually or with an auto-focus routine.  This takes images, selects a square with the best stars and measures the focus HFR then adjusts the focus, producing a V curve from which it finds the best focus.  I get a focus HFR of around 1.2 to 1.3 pixels.

[wimvb]

Great image, Gina. It seems your building projects are a success.

1 hour ago, Gina said:

On my main indoors desktop KStars/Ekos controls focus either manually or with an auto-focus routine.  This takes images, selects a square with the best stars and measures the focus HFR then adjusts the focus, producing a V curve from which it finds the best focus.  I get a focus HFR of around 1.2 to 1.3 pixels.

I can never get this to work. I always have to go over to the rig and put a B-mask on my scope to get focus. What settings do you use in the focus module?

[Gina]

I haven't used a B mask for years!

Here 's a screenshot.

Sometimes the auto-focus doesn't work right and then I use manual focussing,  using ROI in the imaging section and exposures of a few seconds, moving large amounts at first and going smaller as I approach focus.  I use the Absolute Position and enter the focus count in the control box and click on Set to change focus.

[Gina]

Had some thoughts.  There's more to this than the Astroberry Focuser and KStars/Ekos settings.  I use a 28BYJ-48 5V Stepper Motor modified to work with an A4988 driver module which is driven from the RPi GPIO.  The stepper drives the the focus sleeve with a quadrant gear and pinion on the motor.  These are an earlier rig but the latest is similar with a different lens and dew shield.  Different filter wheel too, as it happens.

On 29/08/2016 at 17:37, Gina said: