Urban M81/M82 combo; in 30 mins

[PortableAstronomer]

Hello,

finally I had a break of the clouds last night, so setup the scope and see what I could do in 40 mins.

Schedule:

06-Mar-2010

19:00 carry scope outside, setup mount/scope/bits

20:00 calibrate/align/focus cameras

21:00 start imaging Rosette nebula

21:10 Rosette nebula aborted after one frame, due to obstruction

21:00 start imaging 6x5 min subs of M81 / M82

21:30 stop imaging

22:00 pack up / dismantle, go home

This is 6x5min subs of M81 / M82, processed using PixInsight.

The two pictures here show before and after using 'Dynamic Background Extraction' to remove the light pollution here in the Netherlands. This tool 'Dynamic Background Extraction' never ceases to amaze me.

Lessons learned : You can see some star trailing in this image; the stars are not round, I believe this is due to differential flexure between the guidescope and the main scope.

Equipment:

Skywatcher 190MN / QHY8 CCD (imaging)

Equinix 80 / QHY5 camera (guiding)

EQ6 + EQMOD / ADM dual mounting bars

The processing was done using the steps shown in the videos at Harry's AstroShed.

Clear skies

Regards

Chris

[Psychobilly]

Welldone Chris.. thats a cracking image for 6x5mins the QHY8 and SW MN190 are a nice combo...

and well done Harry...

Nice demo of the power of Pixinsight

Peter...

[PortableAstronomer]

Here is the result from a *single frame* of 5 mins from the QHY8 on the Rosette Nebula, just before my guide star sank below the house rooftop.

Obviously very grainy from being just one frame, and being gamma stretched to reveal the faint details.

This was also with 9-volt supply to the QHY8 cooling, to save battery power and reduce risk of mist forming on the camera's front plate.

The first image is just a stretched image from the camera.

The second image is after performing 'Dynamic Background Extraction' (DBE) in PixInsight. The middle of the picture should not actually be black ; it appears very dark because I was over-agressive in the DBE process, to remove the light pollution.

But interesting to see what can be done in just 5 minutes of imaging, from an urban patch of grass.

Regards, Chris

[PortableAstronomer]

... actually I was surprised the Rosette Nebula almost fit into the frame, at prime focus of the 190MN scope. And when I re-scaled the image to 1/4 of the size, it blew my socks off because it looks almost like some of those images that were made from several hours of exposure. But once you enlarge the image you'll see the grainyness and it will become immediately obvious it was a single frame !

The 190MN has half the FOV as the Equinox 80mm ; but the massive sensor size of the QHY8 really made up for that.

I'd love to add some H-Alpha data and some more colour frames ; hopefully I can get a chance next weekend before the winter sky sinks down into the Western horizon.

Cheers, Chris

[ollypenrice]

Darned impressive given that you are battling through all those highly illuminated tomato tunnels that my Dutch guests all hate! Very well done indeed.

Olly

[PortableAstronomer]

Yes, this is a typical street at night, here in the Netherlands.

A mix of low-pressure sodium lights and industrial greenhouse lights in various fields just outisde town.

This photo was taken on a cloudy evening, which does exaggerate the problem.

But a lot can be done by choosing transparent sky conditions, and shielding yourself from nearby lights.

As for imaging, narrowband filters do well on nebulae, obviously this is bad for galaxies!

Chris

[harry page]

Hi

Sorry missed this

Glad you are getting some nice results now with pixinsight , keep up the good work

Harry

[PortableAstronomer]

Thanks Harry, now all I need are some clear skies.. and being above sea level would help. I'll see what I can do..

[astoc]

blumming hell. Whats the exposure time on that light pollution pic?

Absolutely awesome astrophotos. I'm amazed you've managed to get these in such conditions. I live in the city myself and this is very encouraging! lol

John

[derrickf]

This an excellent result for such a short integration and is made even more impressive considering the adverse conditions you have to contend with. The camera obviously has excellent sensitivity to H-alpha and PixInsight has helped you make the most of the data.

Derrick

[adamsp123]

Very impressive Chris, do you use any form of LP filter? Doesn't look like it from the first image. Amazing this PI software.

I am wondering if I would be better imaging without a filter and using PI to fix the result, I have somewhat polluted skies but not bad as yours.

[PortableAstronomer]

Well many thanks for all those responses.

I used an IDAS filter for these pics, obviously the street image was (a) cloudy and ( unfiltered. I'm not finding my benefit of the IDAS filter for galaxies; but certainly good for nebulae (as expected).

Shame the nearest hills to me are in the Ardennes in Southern Belgium. Need to buy a helicopter I think...