Author Topic: BPP with no bias?  (Read 1820 times)

Offline sdelisle

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BPP with no bias?
« on: 2018 April 01 23:09:51 »
I am a very new PI user and astrophotographer so forgive me for my ignorance . I recently purchased a centralds canon5d mark111. its an interesting camera - extensively modified and cooled to -30 degrees. The modification means you can only use BULB mode - so exposures are limited to 1 second minimum. This makes taking Bias frames impossible - so i contacted centralds who informed me that "Canon DSLRs are having a image processing algorithm that 0sec exposure data subtraction from each pixel per each shots. This is canon’s patent technology and you need not to take bias frame."
So - no bias frames.
BUT - if i want to calibrate in PI using the batch preprocessing script - i need bias frames! It wont work unless i have lights, darks, flats and bias.
I am currently using deepskystacker. Is there some kind of work around for this in PI? Maybe take 1 second bias frames?
cheers
Steve

Offline RickS

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Re: BPP with no bias?
« Reply #1 on: 2018 April 02 00:00:09 »
I'm pretty sure that you get a warning message if you're missing some of the calibration files but you can continue anyway?  I haven't done exactly what you're trying to do but I have done similar things, e.g. omitted darks and lights when building master flats.

Offline aworonow

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Re: BPP with no bias?
« Reply #2 on: 2018 April 02 04:10:04 »
You could always use the Image entry on the tool bar, select New and make a black image and just call it a master bias for bpp purposes.