Atik Cameras

Author Topic: 383L+ Bias Frames  (Read 6421 times)

Guy Walsh

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383L+ Bias Frames
« on: January 15, 2012, 01:13:01 pm »

I read somewhere on one of the other big forums that bias frames are un necessary if using darks on the 314L, is it common practice with the 383L+ ?  surely the more data fed in the better?

my stacking software:
Deep Sky Stacker, ive got pixinsight but its so long winded..

Cheers
Guy

Kaidan

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    • Astrophotographie à l'île de la Réunion
Re: 383L+ Bias Frames
« Reply #1 on: January 15, 2012, 06:04:51 pm »
Easy : you process with bias frames, and without bias frames ... and you measure the sigma on both. If it's equal, it's no use, if it's lower when using bias frames, you need to use them. If it's higher, then you have a problem somewhere.
Jeremy Skuza
Astrophotographie à l'île de la Réunion
TMB Optical 130 Signature Series + 3" corrector
Losmandy G11 "O&V" [NS + Spacer] Gemini II
DS : ATIK 383L+, Astronomik LRGB | AG / P : ATIK Titan

Konihlav

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Re: 383L+ Bias Frames
« Reply #2 on: January 16, 2012, 08:33:45 pm »
314L+ dark frames are unnecessary! you only have to use biases (master composed of say 100 frames) and either bad pixel mapping or dithering when taking images in order to get rid of hot pixels. Also flats needs to be calibrated with master bias.

383L+ AFAIK and IMHO you do better if you rather use darks instead of biases and hotpixel mapping only. Stack 30-40-50 dark frames for one master and you'll be OK.

the SONY (314L+) vs. KODAK (383L+) difference seen on what I wrote is valid for Super HAD small sensors. With big Sony OSC detector I do have to use darks in order to get rid of electro-luminiscence and other problems (hotpixels in OSC CCD are hard to face).

DSS is one of the worst SW programs ever. But it's very simple.

best regards
Pavel



Lex

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  • We do it at night...
Re: 383L+ Bias Frames
« Reply #3 on: January 16, 2012, 10:02:46 pm »
Hi,

I always like to keep it simple and stupid. So the only correction i do acquire is Autodarks, for every exposure length I do, the second correction i do is Flat frame correction with a Gerd Neumann Aurora EL panel.

I do believe that the 383 doesn't need any Bias's because its Noise is practically as low as possible.

Concerning PI it is true that this SW is kind of confusing in the beginning.. I am working with it for over a year now and i have well familiarized with it! It is the best SW for AI purposes!!

Best

Lex
CGEM, C11, TS Carbon Apo Triplet 90/600, TS Carbon UNC 254/1250, Atik 383l+, EFW2,
TSOAG, Lodestar....

Konihlav

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Re: 383L+ Bias Frames
« Reply #4 on: January 16, 2012, 10:22:11 pm »
obviously, if you use darks, then it is no question - no need for bias as dark contains the readout pattern present in bias :) your initial question wasn't clear on what you know and what you ask.

Guy Walsh

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Re: 383L+ Bias Frames
« Reply #5 on: January 18, 2012, 05:18:12 pm »
Ok thanks everyone, I'll stop using DSS and use PI , why not I paid a lot of money for it  :'(

I just wish it was simpler...  >:(