M31 and friend.

[Mac]

At the moment i've very little time to spare what with work being so busy,
but i was't working this Saturday and as the skies were clear i decided to go out and do some imaging, (hurah, a night off and the skies were clear.)

Every thing was set up and then the usual gremlins happened, cameras would not connect, guiding didn't work, ect ect
so i decided to set the D3 up on top of the  scope and have a go at M31.

Nikon D3 70-300mm f5.6
49 @ 30s
iso 3200 F7
200mm
Darks and bias.

No filters

Quick stack in registaxs and adjustment in photoshop, only the Jpg's
will have a go on the raws when i get a moment.

Why 49 you ask,
Simple, $*&(ing battery.

Mac.



http://farm7.static.flickr.com/6015/5998771609_6266d28183_o.jpg

[JohnP]

and then the usual gremlins happened, cameras would not connect, guiding didn't work, ect ect

Blimey Mac there is not a lot of hope for us if a computer pro like yourself has problems with software not working etc...

Nice start anyway especially for such short subs...

John

[Fay]

Well done Mac, the RAWS will be even better.
Oh the fun of imaging!!!

[Carole]

Very nice for 30sec subs Mac.

What are all those red and blue streaks (seen more in the larger version)?

Simple, $*&(ing battery.

I just bought myself an "electric battery" from Astronomiser.  Hopefully this will stop above problems.

Carole  

[Mike]

Electric Battery?

So have the ones i've been using all these years got clockwork stuff inside them?

[Mac]

Blimey Mac there is not a lot of hope for us if a computer pro like yourself has problems with software not working etc

It was just one of those nights, where i wasnt in the mood to try and work out how, what and where it was going wrong, so i just turned on the Scope and plonked the D3 on the top. (ps, the drift after 49 images was about 3 pixels. )

I noticed the red and blue artifacts after i had stacked them, I havent looked at the raws yet.

As for the battery it was less then 25% charged, but hey ho, im happy with the result.

One other thing i've noticed on the Jpg's is the background looks like its raining.
If you look at the red and blue streaks, its pretty obvious not too sure at this stage what is causing that,
might be just the artifacts from the jpeg compression. I'll see if its on the raws.

Mac.

[RobertM]

Great start Mac, it's good to see you getting the time to be outside and imaging again.

Hopefully you can get some more subs.  It'll be interesting to see how your camera performs for astro work.

[MarkS]

Mac,

Shame about the battery!

The streaks are the usual DSLR artifact caused by hot and "warm" pixels.  The hot pixel streaks are very obvious but it is the slightly "warm" pixels creating that general background of smeary "rain".

It's all caused by thermal noise - calibrated dark frames would eliminate almost all of it.

Mark

[Carole]

Electric Battery?
So have the ones i've been using all these years got clockwork stuff inside them?

Well what I mean is a dummy battery with a cable that plugs into a 12V socket.
Sorry, don't know the proper terminology for these things. 

Carole

[mickw]

Great result using jpegs and short subs

Looking forward to the results from the raws

[Mac]

It's all caused by thermal noise - calibrated dark frames would eliminate almost all of it.

They were, that why im puzzled with the streaks,

8 darks, 12 bias, 49 light 0 flats.

The only images i never took were flats,
Darks, Lights and Bias, were taken, DSS was used to do the stacking, i might look at re running it and see what happens,
might have missed a setting
i'll also have a go with maxim and see if the results are any different.

Mac.

[MarkS]

Assuming you processed correctly, the effect you are seeing indicates that the darks were taken when the CCD was cooler than it was during the imaging.

Mark

[Mac]

Assuming you processed correctly, the effect you are seeing indicates that the darks were taken when the CCD was cooler than it was during the imaging.

The darks were taken midway through the imaging, so the frames should have been at the same temperature as the images.
I also had image review off so the camera was not being heated up by displaying the images.

Puzzleing.

Mac.