Does Raw to Tiff conversion stay linear?

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Kristov48
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Joined: Tue Nov 12, 2013 11:56 am

Does Raw to Tiff conversion stay linear?

Post by Kristov48 »

To avoid too much loss of colour when loading raw files to Deep Sky Stacker, I've been converting the files to Tiff format first. It seems to have done the trick with regards to colour but I'm wondering whether I've created other problems in doing this.
I use Digital Photo Professional for conversions.

If you do convert the raw file conversions to Tiff format for stacking, remember to convert darks, flats and bias also.
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Re: Does Raw to Tiff conversion stay linear?

Post by admin »

Kristov48 wrote:To avoid too much loss of colour when loading raw files to Deep Sky Stacker, I've been converting the files to Tiff format first. It seems to have done the trick with regards to colour but I'm wondering whether I've created other problems in doing this.
I use Digital Photo Professional for conversions.

If you do convert the raw file conversions to Tiff format for stacking, remember to convert darks, flats and bias also.
It does sound like a bad idea unfortunately. Don't worry about color until after you're in StarTools. What you want is to have minimal modifications to the data as it came from the imaging chip in your camera. No color balance, nothing!
Even DSS actually doesn't convert things properly, so for absolute best results, use dcraw from the command-line.

See here;
http://www.startools.org/forum/viewtopi ... craw#p1012

Performing color balancing before getting into StarTools will introduce more noise, while the debayering algorithms in some software introduces even more (they are not suitable for low-light applications). Some software even applies noise reduction without asking, which completely destroys any hopes of recovering faint detail. In other words, avoid, avoid, avoid! :evil:
Ivo Jager
StarTools creator and astronomy enthusiast
Kristov48
Posts: 18
Joined: Tue Nov 12, 2013 11:56 am

Re: Does Raw to Tiff conversion stay linear?

Post by Kristov48 »

Thanks Ivo.
Understood, couldn't be clearer.
Takes me back 30 years to MS DOS and all. Had to try it. :thumbsup:
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CHRIS

SW100ED APO & SW200PDS
HEQ5
SPC900NC & QCPRO
EOS T3 REBEL
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