And in living colour - NGC6559

[pmrid (Peter)]

Complete with column defect - NGC6559 in NB mapped HOS for a change.
Peter

[Bolts_Tweed (Mark)]

Nice Peter

This is one of my favourites - I have had it as my desktop for about 2 years and thats a record.

You have done it credit mate.

MB

[renormalised (Carl)]

Column defect...nah....that's where you tried to cut off the right side of your piccie with a stanley knife because it wasn't up to scratch

Seriously though, nice shot there

[ozstronomer (Geoff)]

Pete

Great shot, you are really getting into this Narrow banding. Nice piece of sky, might give it a go at Duckadang

[jase (Jason)]

Really like the image scale and composition Peter. It frames nicely. Not certain of the technical aspects of the image but some constructive feedback if I may.

On the hot pixels and column defects, if you aren't dithering between subs (you ultimately should be), build a bad pixel map using MaximDL or similar. This will at least clean the subs for you. Dithering however is far more effective.

You may wish to take shorter subs to manage the stellar profiles so that they don't appear white clipped. You are looking to obtain a bell curve in profile so that colours will come through. Given this is a narrowband image, its probably a mute discussion as stars get in the way. Alas, stars are what make an aesthetic image. May wish to checkout this post.

[pmrid (Peter)]

Thanks folks.
Jase, in the moments before I spotted your post, I was thinking " .. I do believe I may finally be getting the hang of MaxIm. I never thought I would." And now I have to go and learn about dithering between subs -- sob - will it never end!!!!! AAAAgh!!

Peter

Originally Posted by jase

On the hot pixels and column defects, if you aren't dithering between subs (you ultimately should be), build a bad pixel map using MaximDL or similar. This will at least clean the subs for you. Dithering however is far more effective.

[jase (Jason)]

Originally Posted by pmrid

Thanks folks.
Jase, in the moments before I spotted your post, I was thinking " .. I do believe I may finally be getting the hang of MaxIm. I never thought I would." And now I have to go and learn about dithering between subs -- sob - will it never end!!!!! AAAAgh!!

Peter

Don't fret though Peter. Seriously dithering in Maxim is a set and forget feature. The only thing you need to keep in mind that the dithering value in pixels is that of the guider, not the main imaging camera. You only need to dither a few pixels depending on your arcsec/pixel combination.

With dithering enabled, photons will fall on different parts of the sensor between subs so that when it comes time to register/align the subs the defects aren't in the same place on every sub. Due to this they will be seen as outlier pixels and be rejected producing a clean master. Simple solution to a complex problem.

[atalas]

Nice work Peter.

[DavidTrap (David)]

Dithering and pixel mapping are quite easy in Maxim Peter - I can show you how to setup a batch process to essentially automate the pixel mapping too.

You are certainly flying with this new camera - you'll be unstoppable when the PMX arrives!

DT

[pmrid (Peter)]

Originally Posted by DavidTrap

Dithering and pixel mapping are quite easy in Maxim Peter - I can show you how to setup a batch process to essentially automate the pixel mapping too.

You are certainly flying with this new camera - you'll be unstoppable when the PMX arrives!

DT

Thanks David. I'll certainly take up that offer. I did have a run at this tonight. I had been guiding with PHD and imaging with Maxim until now. The reason is a combination of 2 things: very long FL (3900) and using OAG. Effectively guiding at that FL means that images tend to bounce around a bit even with relatively good seeing and no breezes. I didn't think Maxim could handle the guiding. So when I bit the bullet tonight, I found that when Maxim tried to dither, it came up against PHD wanting to keep the scope steady and so we had contention between the two.
When I switched the guiding over to Maxim so it could dither and guide, it couldn't keep the star in the guide box. What I didn't immediately see (I have now) is that the size of that box is configurable. So I'll go back tonight and try the same thing at 64x64 or some such and see what happens.
By the way, how many pixels of dither should be used - given the FL I'm working at? Any idea?
Peter.

[jase (Jason)]

Originally Posted by pmrid

When I switched the guiding over to Maxim so it could dither and guide, it couldn't keep the star in the guide box.

Did you calibrate before starting to guide Peter? MaximDL needs to know which direction to tell the mount to move when the star's centroid drifts from center. Calibration configures this. Good calibration is when you have a red L shape on the calibrated star. You'll see this in the guider exposures.

Originally Posted by pmrid

By the way, how many pixels of dither should be used - given the FL I'm working at? Any idea?
Peter.

If you're guiding at the same focal length, I would suggest 4 pixels to start with. Too high, and you'll loose the guide star or it will take a while for Maxim to recenter and settle.

[Ross G]

Nice closeup photo Peter.

I like the colours.


Ross.