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Hole lot of Rosette

Chris

By Chris
in Imaging - Deep Sky

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Gina

Gina

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Yes Chris, the Rosette is what I'd like to capture next. Not quite sure how big it is so not sure which gear I would use. I had a link to a web site where you could put your scope and camera details in and it would show you how big the object would be in the frame for hundreds of DSOs but I've lost it and Google doesn't help this time. As I read it you used your 150p and 350D for this image so I would imagine my ED80 and 314L+ would be a suitable combination. What's the focal length of your 150p and did you crop the image?

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Gina

Gina

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Hi Gina:) My 150p has a focal length of 750mm and I only cropped the sides in a touch (5-10mm each side).

is this the one:)

http://www.12dstring.me.uk/fov.htm

hth

Chris

Yes, that's the one :) Many thanks :)

The Rosette, C49, is a bit too big for the 314L+ without FR/FF so I'll use the 1100D. Later I want to see if I can set up the Atik kit to fit onto the SW FR/FF. Not for the field flattener but to reduce the FL by 0.85x. Though even then the Rosette won't quite fit in the frame :( So to use the Atik with objects this big I shall need the wide field set-up with telephoto prime lens.

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ollypenrice

ollypenrice

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Hey, nice one!

To clean up those primary coloured hotties don't use the clone stamp or healing brush. Here's the easy way; Use Select-Colour Select and zoom in to pixel scale. Click on a few hot pixels (I'd do one colour at once or you can make mistakes) and set a fuzziness which looks as if it has got all the hotties but nothing real in the image. Then just go to Filter-Noise-Median. Use the lowest value on the slider that will make them vanish. Median just sets a selected pixel to the average value of its neighbours. This really works quickly and well. (Original source, Adam Block.)

Olly

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Chris

Chris

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Yes, that's the one :) Many thanks :)

The Rosette, C49, is a bit too big for the 314L+ without FR/FF so I'll use the 1100D. Later I want to see if I can set up the Atik kit to fit onto the SW FR/FF. Not for the field flattener but to reduce the FL by 0.85x. Though even then the Rosette won't quite fit in the frame :( So to use the Atik with objects this big I shall need the wide field set-up with telephoto prime lens.

I've found it quite addictive playing around with different scopes, cameras and objects in 12dstring:D I notice with your 314L you would need something like what I've got (WO66 Apo FL388mm plus 0.8 reducer). I've been quite surprised when plugging in the figures what objects actually fit in the FOV with my WO66 and say even a QHY6 which is only 300 pounds, hhmmm tempting:D The QHY8 seems to have a crazy big FOV for the money! Obviously at this stage Atik have the QC more sorted though.

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michael.h.f.wilkinson

michael.h.f.wilkinson

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Hey, nice one!

To clean up those primary coloured hotties don't use the clone stamp or healing brush. Here's the easy way; Use Select-Colour Select and zoom in to pixel scale. Click on a few hot pixels (I'd do one colour at once or you can make mistakes) and set a fuzziness which looks as if it has got all the hotties but nothing real in the image. Then just go to Filter-Noise-Median. Use the lowest value on the slider that will make them vanish. Median just sets a selected pixel to the average value of its neighbours. This really works quickly and well. (Original source, Adam Block.)

Olly

I could easily adapt our "area-opening" code to deal with them fully automatically (or better yet, get a student to do it for me). This is a fast operator to remove isolated bright regions below a certain surface area. It could be adapted to see the difference between a hot pixel and a star (the latter shows the PSF of the optics to some extent, the former is just an isolated spike. I will give it some thought after the Xmas break.

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Chris

Chris

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Hey, nice one!

To clean up those primary coloured hotties don't use the clone stamp or healing brush. Here's the easy way; Use Select-Colour Select and zoom in to pixel scale. Click on a few hot pixels (I'd do one colour at once or you can make mistakes) and set a fuzziness which looks as if it has got all the hotties but nothing real in the image. Then just go to Filter-Noise-Median. Use the lowest value on the slider that will make them vanish. Median just sets a selected pixel to the average value of its neighbours. This really works quickly and well. (Original source, Adam Block.)

Olly

Thanks Olly:) sounds good I'll certianly need this tip until I can get round to buying and modding another camera or take the next next step into CCD territory, I'll copy and paste this tip and others into a word doc so I don't forget:)

Many thanks,

Chris

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Chris

Chris

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I could easily adapt our "area-opening" code to deal with them fully automatically (or better yet, get a student to do it for me). This is a fast operator to remove isolated bright regions below a certain surface area. It could be adapted to see the difference between a hot pixel and a star (the latter shows the PSF of the optics to some extent, the former is just an isolated spike. I will give it some thought after the Xmas break.

Clever stuff! I think this would be a very popular tool if you can make it work:)

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Andyfx

Andyfx

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Funny thing was Chris, that i had a blimin bin liner over the scope! I thought it was secure but the pesky wind managed to blow it off then the rain started lol. Stupid English weather, id love to be back in the maldives with all my kit, never seen such a dark site :-)

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