#1  
Old 19-07-2014, 08:49 PM
astronobob's Avatar
astronobob (Bob)
Casual Cosmos Capturer

astronobob is offline
 
Join Date: Jun 2010
Location: Gold Coast SE QLD
Posts: 3,708
Are these Dark Frames Normal?

HiYall,

Ive taken my 1st set (20 subs) of Darks with the QHY 10 OSC (One Shot Color) 400 seconds @ -35deg. I did them between 2am & 4am after an image session on the triffid.
Strange thing to me is that they have come up brighter than the Light frames of the Triffid ?
I had the Newts 10" front Lid on and had a black towel wrapped about it, and also had another black towel around the rear Mirror cell end as its Not closed - so just thinking on the safe side
I was also catching some shut eye at the time in the Obs, so, no lamps on
All Dark sub are very identical, smooth even lighting over the entire chip !
But they have turned out a rather medium to light grey shade ??

Here is a couple of Screen Snips of a Dark Frame.
1st is (Full Frame) with a Linear streach & 2nd is same Linear Steach Dark @ 100% view,
3rd is (Full Frame with ArcSinH(x) Streach & 4th at 100% View with ArcSin(x) Streach ?

Also A Lightframe at Linear & ArcSin(x) Streaches !

Interesting seeing the Light Frames in the same streached manor and they are quite a bit Darker than the Darks
Normal or Not ?
Thanx ,,,,,
Attached Thumbnails
Click for full-size image (400Drk.JPG)
119.8 KB38 views
Click for full-size image (400Drkb.JPG)
125.8 KB25 views
Click for full-size image (400Drkc.JPG)
119.6 KB21 views
Click for full-size image (400Drkd.JPG)
121.6 KB20 views
Click for full-size image (400Drke.JPG)
105.9 KB22 views
Click for full-size image (400Drkf.JPG)
120.4 KB24 views
Reply With Quote
  #2  
Old 19-07-2014, 11:36 PM
Eden's Avatar
Eden (Brett)
Registered Rambler

Eden is offline
 
Join Date: Jan 2014
Location: Melbourne, Australia
Posts: 399
Hi Bob,

This is normal, mate. I've attached one of my own darks, captured with the QHY12 (which is also one shot color, like QHY10) at -18.

I have set the white and black levels in the screen stretch window to similar values you have in your screenshot to demonstrate. I captured mine with the lens cap on the camera but the way you did it with the scope lid on is just as effective.
Attached Thumbnails
Click for full-size image (dark.jpg)
152.7 KB13 views
Reply With Quote
  #3  
Old 20-07-2014, 12:54 AM
astronobob's Avatar
astronobob (Bob)
Casual Cosmos Capturer

astronobob is offline
 
Join Date: Jun 2010
Location: Gold Coast SE QLD
Posts: 3,708
Hey Thanx very much for That Eden
I was using the rig for 5 nights straight in the Obs, so had no reason to take the qhy off, and wanted to grab them then & there while air temps were near zero and the sky turned to cr*p ! Looking forward to processing them into the mix
Reply With Quote
Reply

Bookmarks

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 08:11 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Advertisement
SkyWatcher Australia
Advertisement
Lunatico Astronomical
Advertisement
NexDome Observatories
Advertisement
Meade Australia
Advertisement
Celestron Australia
Advertisement
Bintel
Advertisement
OzScopes Authorised Dealer
Advertisement
Astronomy and Electronics Centre
Advertisement