Hi guys,

I just uploaded 3 images to the Flickr site www.flickr.com/photos/tags/irishastronomy/
It will probably take a while before they are listed but when you get a chance take a look and pass on your comments. Images are of M31, M42 & Running Man Nebula and Rosette Nebula.

Images taken with SXVH16, Skywatcher 80ED and Celestron CG5GT mount.

Kieran Rooney

Hi Kieran.
I'm lookimng for your shots but they may as yet not be up...

You can post the images directly into the thread by using the code buttons
(located just above where you type a new message)

Simply click the button that says: Img
Copy and past the URL for the image.
Then click the Img button again

(when it is hosted on Flikr an easy way to get the link
is to click the 'all sizes' icon above the photo,
click the size you want, then left click and select 'view image'
the address in the address bar can then be copied and pasted into
the thread)


Apologies if you already know this.

Regards,

OK Frank here goes and I hope this works

Kieran





[albertw: fixed images]

fabulous images kieran

Holy smokes Kieran!
:shock:
They are really impressive!!

That is one serious piece of kit you got there!
Please keep us posted with any further shots.

Thanks for the coments guys.

M31 Binned 20min 2x2
M42 Binned 1x1 17min RGB 7min each
Rosette 32 min 2x2I

I was absolutely amazed at the images I was getting with this camera. I was using an SXVM7C in a very light polluted area and this will now become my guide camera. I am currently setting up an observatory and I am just about ready to pour concrete for a pier to hold an 10" LX200GPS. Hopefully within the next few weeks/months I will have everything set up. Currently the CG5GT does not track well enough to allow long exposures so by the time I get to imaging in RGB I have to clip the images. I still have not tried autoguiding with the CG5GT as yet. The main problem is that I use the Star 2000 system and my lap top has no RS232 port and I am waiting on an an interface cable. My next target will either be the veil nebula or the horse head.

PS Many Thanks Frank

Incredible images! :shock: :shock:

One question, I notice that some of the bright stars have a trail in one direction. Is this something from the optical system, the camera or the processing?
BTW, those images are a great advert for the camera!

Regards,

Hi Micheal,

The spikes show up on bright stars in some images. I think this may be due to flexture in the imaging train. The SXVH16 has a front panel which can be altered to make the chip perpendicular to the optical path but as yet I have not tried to alter it. Each time I mount the camera I would have to make this alteration but I am still having too much fun with this to worry about it now. It takes long enough to get set up and clear sky time is just too precious.

Kieran

cool. thanks for the explanation.
regards,

WOW! superb images. I am getting into this game with the aim to eventually take photos( when i can afford a good camera!) but if i could get anywhwere near this standard i would be thrilled. fantastic shots dude! did you do much processing after actually taking the shots?

For example the M42 shot was 100 times 10 second 1x1 luminance images and 40 times 10 second 2x2 images each for red, green and blue. Images stacked, dark field extraction (to get rid of hot pixels) and coregistered in astroart. Red, green and blue images then processed in Photshop with histogram stretches and curves and then resized to match the luminance image. Luminance image then processed with histogram stretch and curves with a slight sharpen. All images combined in photoshop to give final image and colours balanced. There was some trial and error with the curves but total processing probably took about an hour.
The more frustrating part is knowing how much exposure to go for. I tend to stack the images in astroart as I aquire them to get an idea of what the final product will be. A lot of concentration at 2.30am!

Kieran

Thats some excellent imaging there Kieran,
Do you have dark skies or do you use filters ??

Thanks Dave,

I have relatively good sky and the nearest town is six miles away to the east which causes some problems on low down targets. The local village primary school got funding for an all weather pitch which they have put floodlights on. Its in use a lot at night up till 10pm. So far I have not needed to use any filter but its in the toolbox if required.
Spent all day today looking at clear skies and thought I would have a go at comet swan. As soon as I had finished setting up the god of clouds did his thing and all the gear came back in. Any cloud filters out there?

Kieran

As soon as I had finished setting up the god of clouds did his thing and all the gear came back in. Any cloud filters out there?

Kieran

Bin there, done that. As for cloud filters, maybe you could go hire a helicopter, although I'm not sure what effects the blades would do to your seeing :wink:

Or you could contact the Beijing Olympic bureau...
ask them for a loan of thier cloud buster....

www.edie.net/news/news_story.asp?id=11568

Whoa! :shock:

OK Guys,

Just when you think that imaging is easy things go up the left. The image below was suposed to end up as a beautiful image of the Pelican Nebula. What went wrong? The moon was up so the sky glow showed up the vignetting in the system. I was imaging with my back to the house and did not know that three bedroom lights were on( with no curtains) so light leaked through the filter wheel AND I under exposed all images. I have over processed this image to show the defects. For all those aspiring to take images PLEASE NOTE you will get more than enough of your share of nights like this.



Kieran

One question, I notice that some of the bright stars have a trail in one direction. Is this something from the optical system, the camera or the processing?

Those are fabulous images Kieran. The SXVH9 is really doing the biz for you.

I'd say the streaks on the bright stars is caused by blooming. That is a residue left when the image is read off the CCD chip. Software such as Maxim DL has filters to help remove this.

That's what I was thinking too initally, but it's only in one direction. Usually it would act in two directions, would it not?

That's what I was thinking too initally, but it's only in one direction. Usually it would act in two directions, would it not?

No blooming only shows in one direction. The reason for it is that some ccds read off the data by shunting each line towards the read buffer as each line falls off the edge it goes into the read buffer and is then read off. However as highly saturated pixels are shifted they wells don't fully recover before the next line is shunted. The result is a remnant of the bright star being left over and beuing added to the next line, resulting in a little streak like the one that shows in Kierans images. Progressive scan ccd's commonly used in DSLRs dont suffer from this due the frame being broken into odd and even lines which are read off independently of each other.

At least thats how I understand it!

[later edit] another type of blooming can occur because of highly saturaded pixels bleeding into the ones adjacent. That type of blooming doesn't occur much in modern ccds. That would show in two directions.

ah, understand now. thanks for the explanation.

cheers,

The H16 has an interline ABG chip which is the same one as used in the SBIG STL-4020M which is just over a grand more expensive. Must of the images were stacked 10 second or 30 second exposures so I am surprised that the stars have bloomed. I could use the deblooming routine in astroart or I may stick some cross hairs over the front lens and go for diffraction spikes (not very realistic but looks very nice). Ian King had this camera on trial from Starlight Express. He took some images of the Gamma Cygni region with longer exposures and no obvious blooming. I might contact a guy on the Yahoo Starlight Express group who has the camera and ask what his images are like.

additional: Spoke to Charlie Warren who has had no blooming with his H16. So its either an internal reflection problem or a potentiometer needs adjusting to control the pixel bleed. My next clear night I will test the system for relection with a different camera.


Kieran

Quick update,

Apparently after speaking with Terry Platt at Starlight Express the camera needs to have a higher rated capacitor put in so its going back to them next week. I suppose that I will have clear skies and perfect seeing over Co. Down the moment its on its way.

Kieran

Hi Kieran,
Sorry to hear that your having problems with your new camera, however Starlight Xpress offer excellent customer service, and you'll get your camera back very quickly. I had a HX516 camera a couple of years ago which developed a fault, even though it was out of guarantee, Michael Hattey had it fixed in a couple of days, FOC!!
I bought a secondhand SXVH9C 1.5 years ago, and its worked perfectly for me, even though it has a couple of dead pixels!
I'd love a larger chip like the new SXVH16 for the larger objects, but can't afford the admission fee!! I please keep posting your results for us all to enjoy.

PS Where are you located in Co. Down?

David (Belfast)