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Retoucher
LEBOE
Posts: 50
Berlin, Berlin, Germany


Hello guys, I retouch on a big night new york panorama for an client. The image was taken with the PhaseOn and the IQ 180 back. It is a stitching out of 8 images.
The resolution is amazing (37700x9600 pixel) but I got several HOT PIXEL.

Is there any good technique or tool to fix those pixels? I could reduce the pixel a bit with the dust and sketch filter, but i want it perfect.

http://pixelcreate.de/MM/panorama_new-york_night_2000.jpg

http://pixelcreate.de/MM/hot_pixel.jpg
Jan 11 13 08:28 am  Link  Quote 
Photographer
Michael Broughton
Posts: 2,211
Winnipeg, Manitoba, Canada


if it were me, dust & scratches filter in cs6 with a threshold around 30, then noise reduction in lightroom 4.
Jan 11 13 10:29 am  Link  Quote 
Photographer
WMcK
Posts: 5,262
Glasgow, Scotland, United Kingdom


You could try re-processing your Raws in ACR, which detects and conceals hot pixels.
If that doesn't you could try the Median filter at Radius 1. It's good for fixing hot pixels, but deteriorates the image slightly. There are "hot pixel" filters, some of them free like this one http://www.redpawmedia.com/hotpixel.html which may be worth trying.
(edited to say that this filter only seems to work with the 32 bit version.)
Jan 11 13 11:32 am  Link  Quote 
Photographer
Raoul Isidro Images
Posts: 6,080
Sydney, New South Wales, Australia


Long exposures are the breeding ground of hot pixels and no sensor from any manufacturer is ever immune to these imperfections.

Create a hot pixel map for the whole frame of the sensor (you could use this map over and over again for future shots) and try to fix the hot pixels before the merge.

Try to rescue from RAW by manipulating the Luminance slider to smoothen the sky.

.
Jan 11 13 03:49 pm  Link  Quote 
Photographer
WMcK
Posts: 5,262
Glasgow, Scotland, United Kingdom


Here are two processed versions of the example you posted. The first is treated with the Median Filter, the second to the hot pixel filter I linked to above.

https://dl.dropbox.com/u/40782900/Median.jpg

https://dl.dropbox.com/u/40782900/PixelFilter.jpg
Jan 11 13 04:13 pm  Link  Quote 
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Photographer
Robb Mann
Posts: 10,150
Baltimore, Maryland, US


Im not sure those are hot pixels. Looks more like read noise. CCDs used with an electronic shutter can do all kinds of crazy things.

Actually, that sucker is smearing all the highlights to hell. Hate to say it, but a CCD camera was the wrong choice for a long-exposure night image.
Jan 12 13 04:51 am  Link  Quote 
Retoucher
LEBOE
Posts: 50
Berlin, Berlin, Germany


Thanks everybody for the advices! I could correct the problem with HotPixels Eliminator. http://www.mediachance.com/digicam/hotpixels.htm

And also i will turn the highlights a bit back, it is to harsh.
Jan 12 13 12:35 pm  Link  Quote 
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