Atik Cameras

Author Topic: BIAS Frame length  (Read 3368 times)

Matt_H

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BIAS Frame length
« on: January 30, 2018, 10:30:06 am »
Hi,

Just wondering how long the bias frames should be? Should they be 0.001 secs and at the same gain etc as the lights (and darks?)
 First light with this camera tomorrow ;D
 Thanks
Matt

dpaul

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Re: BIAS Frame length
« Reply #1 on: January 30, 2018, 02:30:17 pm »
Hi Matt,

I'm a relative newcomer myself but I have no problem with 0.001 secs and ''not'' doing a new set of bias frames per observing session. I do change if 2x2 or 4x4 binning for example but otherwise use a generic bias. I typically save about 40 frames, integrate in Pixinsight then modify this ''master bias'' to ''superbias'' in Pixinsight. 

All seems to work well.

Regards

David
(Atik Horizon mono user)

Matt_H

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Re: BIAS Frame length
« Reply #2 on: February 06, 2018, 07:30:22 am »
Hi David,

I received this reply. I also had a glow AMP on a long exposure.

Hello Matthew,

You are correct on all counts! The amp glow is normal for a CMOS camera taking long exposures, calibration will remove it.

Best regards
Vince

Atik Support

dpaul

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Re: BIAS Frame length
« Reply #3 on: February 06, 2018, 06:56:34 pm »
Hi Matt,

Yes don't worry about the amp glow -

Just for interest, what length exposures are you using?

David

Matt_H

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Re: BIAS Frame length
« Reply #4 on: February 07, 2018, 02:08:23 am »
G'day David,
Thanks for that.

I'm still experimenting. I am typically doing 600sec exposures. The AMP glow is on the right of the image in the darks. Hard to see in the light images as depends on the target etc. For those subs I use the high pre-set.
I've never used a CMOS sensor before so trying to work it all out. I use SGP pro and having a few issues working out Gain etc. The subs come up fine but frame and focus, and auto-focus the subs come out white and hard to see the stars. I think its the auto histogram in SGP Pro.  I'm using narrowband filters at the moment however will be heading to some dark sites next week when the moon goes. RGB then.
regards
Matt

dpaul

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Re: BIAS Frame length
« Reply #5 on: February 08, 2018, 07:39:25 pm »
Hi Matt,

What scope do you have, what binning are you doing (1x1, 2x2 .......?).  Also just for interest, what general location?

Thanks

David

Matt_H

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Re: BIAS Frame length
« Reply #6 on: May 14, 2018, 11:29:10 pm »
Hi David,

Sorry for not replying. I just switched off for a few months as I had to send back my Horizon camera due to a thread fault attaching the camera to the EFW2 and then Vince found that the circuit board was faulty and had to replace that. Tonight will be first light for the horizon!!

I have a TAK 106 EDX IV. I never Bin. I have the reducer and the extender. I'm located in Melbourne Australia.

I'm going to post a question about Dark Frames...

regards
Matt

bwa

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Re: BIAS Frame length
« Reply #7 on: May 21, 2018, 02:54:38 am »
G'day David,
Thanks for that.

I'm still experimenting. I am typically doing 600sec exposures. The AMP glow is on the right of the image in the darks. Hard to see in the light images as depends on the target etc. For those subs I use the high pre-set.
I've never used a CMOS sensor before so trying to work it all out. I use SGP pro and having a few issues working out Gain etc. The subs come up fine but frame and focus, and auto-focus the subs come out white and hard to see the stars. I think its the auto histogram in SGP Pro.  I'm using narrowband filters at the moment however will be heading to some dark sites next week when the moon goes. RGB then.
regards
Matt
I normally shoot 30-60sec. subs with Gain: 1, Offset: 15.  Even with my slowest scope and narrowband images 600sec. subs would be totally blown out!  With the High pre-set I'd get nothing but bright white!!

bwa