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Re: High speed Tesla spark photographs

Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>

Hi Terry,
As Dan has suggested, I think you want to upload the RAW files into the computer and I think you said you can do that. In this way the computer now has all the original info and nothing is lost. Still use the dark frame to remove the hot pixels. Once you have the contrast and brightness set, running the picture thru a noise filter to remove any random noise will certainly help. You may also want to use a sharpening filter to restore the edge sharpness loss from the first filtering (dont know if this will reconstitute the noise but its worth a try). Given the scene content, you may not need to gamma correct and I dont know what your SW does when converting to JPEG. Important thing is to keep RAW so you can always go back to the original and start processing over again. I would be nice to stack multiple images but as Dan says, the arc wont stay still for this. 

Gerry R.


Original poster: Vardan <vardan01@xxxxxxxxxxxxxxxxxxxxxxx>

Hi Dan,

At 07:46 AM 9/16/2006, you wrote:



Terry,

A "dark" frame will only remove non-random noise such as hot pixels.
That is a big problem in my case. The old CCD sensor has significant hot pixels and the "fixed" noise floor has risen over time. This camera does not have a built in function to remove that. The software fix really cleans up super dark photos well. 


To
remove random noise generated by the sensor itself, you basically would need
to take multiple exposures of an identical object (such as stars for
example) and then average those frames to remove random noise.
The software just does a 2nd order low pass function which is surprisingly good at this type of noise. It has a lot of various filters but this one does fine. It does chew up the good image just a little but not bad. 


Of course,
our arc is not a constant image, so you cannot do that.

Dan


It should be good enough right now.  I will just have to see what happens.

Cheers,

        Terry