M33 From Headcorn

[Whitters]

48 minutes (48 x 60 sec)
800mm f5.6 and MX916 CCD
Astronomik IR Block Filter
Headcorn DSC III

[JohnP]

Great image Paul - some of the stars look like they have got dark rings around them - Is that some kind of artifact from post processing? Any how it's a brill image - I like your star cluster in Cassiopia as well.

How's your leg?

Cheers,  John

[Whitters]

Hi John,
The dark rings are an artifact from the deconvolution filter I applied to try to bring out the dust lanes.
The leg is fine now thanks.
All set for the next DSC in October.

[Rocket Pooch]

Nice on Paul.  I've noticed that burnout on the stars as well, I get it when I've over stretched the histogram.  Someone told me on the SAC groups that it was caused by a limitation in the MAG levels of CCD's.  Did you do the deconvolution before the stretch?

Also could I have a copy of the FITS (by e-mail) pre-processed, I'd love to have a play.

[Whitters]

Deconvolution was done before the Histogram stretch, you get similar artifacts when using unsharp masking if you go too far.
I'll send them thru this evening.

[Rocket Pooch]

Ta

[Whitters]

They are on the way

[Greg]

Paul,

Excellent image. Please - pretty please - could I also have a copy of the original image to play with.

[Whitters]

Do you want all the raw images or the un-processed stacked image?

[Whitters]

M33 image no deconvolution

[JohnP]

Nice one Paul - I prefer it to your original post - The blacks look blacker & you haven't got those strange artifacts around the stars also, on my laptop the dust lanes seem more pronounced. A great image. Have you ever considered imaging in colour using filters?

John.

[Whitters]

Hi Jon,
There was not enough time to take a decent amount of RGB images at DSC od M33 due to the cloud, but it is on my list. I' trying to identify the globular clusters of M33 in the image at the moment.

[Rocket Pooch]

[Mike]

Is it my imagination or are there 2 of everything?

[Rocket Pooch]

probably.

[Whitters]

Chris, The A set and the B set need to be processed seperately, then combine the results of each. Then the image has to be flipped as 0,0 is in a different corner on the imaging software to that on your processing software.

[Rocket Pooch]

Hi Paul,

Did it right this time.  I used an application I've been dying to use for some time to do the following.

Firstly these images were a stack of ten from the (a) set using Stella Magic.  

Then I put them into PixInsight for a Histogram and SGBNR Gaussian filter (astronomy specific, see http://pleiades-astrophoto.com ) and ended up with the following: -

without SNGBR filter



with SNGBR filter



I must admit the original FITS we're an educaiton because the histogram of each image was very thin but it seemed to contain quite a lot of dynamic range.

I tried not to burn out the stars.  Hope you like them.

Bye

[ This Message was edited by: csuddell on 2004-08-21 00:26 ]

[Mike]

Top image looks better to me.

[Whitters]

That's more like it. I prefer the top image too the star images are smaller and it is sharper. If you want I can send you the callibration files, but there are rather a lot of them >150 files. But they will remove the verticle bias and a lot of the grainy noise.

[Whitters]

Greg has had a go too, here is his image, again Greg did not have the callibration files.

[Rocket Pooch]

Na that's ok, I'll collect some more of my own soon, hopefully.  Nice pics though, I'm positive with a little more processing these FITS will give an excellent result.

Something for you to do on cloudy nights eh!  Oh thats now....

[Rocket Pooch]

Hi Paul,

I finished off a second attempt with your M33, details as follows.  

Stacked in API4WIN, unsharp mask, levels applied in PS7, gausian blur in PixInsight.

You really should show your M33 at the next meeting.




P.S. If you ever feel like giving away the camera, I'll have it.


[ This Message was edited by: csuddell on 2004-09-11 11:26 ]