Blue camera issue

[RomanAkhmetshyn]

Bias images on Blue appear to be different than on other telescopes. The images have less median flux and almost all of them have a bright dot on the upper right side, some have a bright line across the upper side as well. I compared two Bias frames of Green and Blue taken on the same day and hour, and there is a clear difference between them. Biases that were taken manually in Maxim DL do not show this behavior. Sometimes data sky fields collected has the same images as described above. More details in Telescope Log: Log I will post the Log in Slack channel as well Here are two Biases: right is from Green, left is from Blue click-here

[RomanAkhmetshyn]

I think it would be useful to run some scheduled Bias image collection every day. The Blue haven't got any data since 06.28

[mjmazur]

The median bias levels are determined by, I believe, the settings for 'black sun' and 'black level' in addition to the merge settings. Black sun and black levels are, by default, the same for the 3 cameras. The merge settings are not the same and the median bias levels are not expected to be the same, just close to one another.

The bright dot I haven't seen before. It is visible in the Maxim images as well as the colibrigrab and FLIPilot images when scaled correctly. In Maxim, the auto-dark correction needs to be turned off. I think that it's normally on by default in Maxim. It affects several pixels in 2x2 binned images. With FLIPilot, it looks like a single pixel that is brighter than the average. About 50% greater.

What's odd is that the background levels in a bias with Maxim are much higher than they are with FLIPilot and ColibriGrab. Also, the bright spot is inconsistent. The location is always the same, but sometimes it is reduced to a few pixels, most of the time it is much brighter.

My guess is that it is bad pixels and that there's not much we can do about it. We just have to treat it as 'not a star'.

And the reason that there was a night of blue images with no data is likely because the shutter was set to manual and closed in FLIPilot. I've unchecked the manual control box.

Maxim - bright spot at ca. 1492,50 in 2x2 binning [cid:06c8584c-3fc8-4f05-a61d-62a37bc0663b]

FLIPilot - bright spot at 1492,50 in 2x2 binning [cid:67600c64-913d-4499-b4b6-46dd8e43b1cc] FLIPilot - 1x1 binning [cid:21a062ca-bbc9-422f-a0f5-97952fb5d932] And another, showing that it's not always consistent [cid:161e180e-0827-4694-a027-005b8c83135e]

FLIPilot - 2x2 but streamed to disk [cid:573696c0-b00b-457c-8b8a-8dbb891c8c2a]

ColibriGrab.exe - 2x2 binning [cid:bdf52ae6-2f07-4628-ab97-1a9619f33b1a]

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From: RomanAkhmetshyn @.> Sent: July 4, 2022 1:39 PM To: ColibriKBO/ColibriObservatory @.> Cc: Subscribed @.***> Subject: [ColibriKBO/ColibriObservatory] Blue camera issue (Issue #7)

Bias images on Blue appear to be different than on other telescopes. The images have less median flux and almost all of them have a bright dot on the upper right side, some have a bright line across the upper side as well. I compared two Bias frames of Green and Blue taken on the same day and hour, and there is a clear difference between them. Biases that were taken manually in Maxim DL do not show this behavior. Sometimes data sky fields collected has the same images as described above. More details in Telescope Log: Loghttps://uwoca-my.sharepoint.com/personal/rbrow232_uwo_ca/_layouts/15/Doc.aspx?sourcedoc=%7B51ceb4ac-f4cb-46d2-be4e-5bfb79005f72%7D&action=edit&wd=target%28Blue.one%7C39a0160f-6a5b-4650-aa67-bb2ebda45f5f%2F2022-06-28%7C6c03da72-1ff9-44d3-923f-4d7888537e00%2F%29&wdorigin=NavigationUrl I will post the Log in Slack channel as well Here are two Biases: right is from Green, left is from Blue click-herehttps://drive.google.com/file/d/1y-YMGjMteVYE39n0fc4BS-wQaTW_86PW/view?usp=sharing

— Reply to this email directly, view it on GitHubhttps://github.com/ColibriKBO/ColibriObservatory/issues/7, or unsubscribehttps://github.com/notifications/unsubscribe-auth/ABPGQYJ66V2JFW2I6UGOA7DVSMOWXANCNFSM52T2WDGA. You are receiving this because you are subscribed to this thread.Message ID: @.***>

[mjmazur]

That's odd, they should have just been inline images. I can forward the message separately.

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From: RomanAkhmetshyn @.> Sent: July 4, 2022 3:41 PM To: ColibriKBO/ColibriObservatory @.> Cc: Michael Mazur @.>; Comment @.> Subject: Re: [ColibriKBO/ColibriObservatory] Blue camera issue (Issue #7)

I'm having trouble reading cid images you have attached

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