Comments on: Fractal sharpening a new digital processing tool from Noel Carboni http://www.newforestobservatory.com/2009/06/30/fractal-sharpening-a-new-digital-processing-tool-from-noel-carboni/ Adventures in Imaging Deep-Sky Objects Mon, 06 Feb 2012 08:36:47 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Greg Parker http://www.newforestobservatory.com/2009/06/30/fractal-sharpening-a-new-digital-processing-tool-from-noel-carboni/comment-page-1/#comment-558 Greg Parker Fri, 03 Jul 2009 19:59:43 +0000 http://www.newforestobservatory.com/?p=820#comment-558 Hi Graham, Greg here - the one that does the imaging, Noel does the image processing. I had problems with narrowband filters and the Hyperstar due to the reasons you give - but that's because the Hyperstar is f#2 which means a considerable cone angle to the rays passing through the filter. I had no trouble using the same filters on a Sky 90 at f#4.5 so I am not expecting any problems on my Canon 40D at f#4 or above. I'll let you know if I run into problems. Best, Greg Hi Graham,

Greg here – the one that does the imaging, Noel does the image processing. I had problems with narrowband filters and the Hyperstar due to the reasons you give – but that’s because the Hyperstar is f#2 which means a considerable cone angle to the rays passing through the filter. I had no trouble using the same filters on a Sky 90 at f#4.5 so I am not expecting any problems on my Canon 40D at f#4 or above. I’ll let you know if I run into problems.

Best,
Greg

]]> By: Graham Malcolm http://www.newforestobservatory.com/2009/06/30/fractal-sharpening-a-new-digital-processing-tool-from-noel-carboni/comment-page-1/#comment-555 Graham Malcolm Fri, 03 Jul 2009 12:28:30 +0000 http://www.newforestobservatory.com/?p=820#comment-555 Hi Noel, Just wondering about your choice of 77mm IDAS filter with a wide angle DSLR setup. I think you'll find it disappointing due to the gradient across the frame. This is due to the angle of incidence at the edges giving a greater thickness of the filter towards the outside. I found my 67mm IDAs filter was just usable with my P67 kit and 165mm lens and even then it had a gradient. I'd be interested to hear how you get on with it. Best Regards, Graham. Hi Noel,

Just wondering about your choice of 77mm IDAS filter with a wide angle DSLR setup. I think you’ll find it disappointing due to the gradient across the frame. This is due to the angle of incidence at the edges giving a greater thickness of the filter towards the outside. I found my 67mm IDAs filter was just usable with my P67 kit and 165mm lens and even then it had a gradient. I’d be interested to hear how you get on with it.

Best Regards,
Graham.

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