#1  
Old 23-04-2013, 01:22 AM
LewisM
Novichok test rabbit

LewisM is offline
 
Join Date: Aug 2012
Location: Somewhere in the cosmos...
Posts: 9,326
Odd SX issue

When I was imaging on Saturday, about 3/4 the way through my entire set for the night, my SXVR-M25C did something odd - it seemed to lose light intensity.

I was debayering in MaxIM between shots (set to Autosave). Was getting GOOD colour and brightness, then suddenly the brightness and colour rendition muted for the next shot, and stayed that way. No cloud, no frost over camera face or focal reducer, no dew.

Noticed it again tonight, but from the start. Still producing a good image, but seemingly it is now LESS sensitive. Almot like I now need to do a 10 minute exposure to get what previously only took me 5.

This has me concerned. When the camera "dimmed", it was running at -4.4C. I had a small program glitch in between (MaxIM stopped responding momentarily), and the cooling reset than came on again. Could this have thermally shocked the sensor, damaging it?

Got me really worried. Photos are still good, just seem less intense.
Reply With Quote
  #2  
Old 23-04-2013, 06:39 AM
PeterM's Avatar
PeterM
towards 2000 posts-slowly

PeterM is offline
 
Join Date: Jun 2006
Location: SE Qld
Posts: 1,602
Hi Lewis,
I have noticed what you describe with my SXVRH9.
It sometimes loses the light intensity now and then in 30second images. A good example for me was a test shot of NGC5189 the planetary in Musca, one 30 second image was fine showing tremendous detail, the next you could barely see the pn
My other camera the older SXVH9 has never done this in 6 years. But the newer camera is cooled and I wonder if there is something in what you note about the cooling.
Overall in several thousand images taken with the SXVHR9 I might see the effect you describe perhaps in a few images per night. Has had me wondering, maybe time to pose the question directly to Starlight Xpress or on the Yahoo site.
Anyone else noticed this?
Reply With Quote
  #3  
Old 23-04-2013, 07:21 AM
LewisM
Novichok test rabbit

LewisM is offline
 
Join Date: Aug 2012
Location: Somewhere in the cosmos...
Posts: 9,326
Peter, I have shot off this link to Terry at SX, so hopefully he has some feedback when the UK wakes up.

I am going to try it on a bright target like Eta Carinae again tonight, and see what happens. I did my first ever lunar imaging with it last night, and had to set the exposure to 0.002 sec, so it is still sensitive enough, just what the chip spits out is maybe not so.
Reply With Quote
  #4  
Old 23-04-2013, 08:25 AM
cfranks (Charles)
Registered User

cfranks is offline
 
Join Date: Feb 2008
Location: Tungkillo, South Australia
Posts: 599
Do you save the images in Fit format? The Fit's header will show some information about the camera including the electronic gain. A comparison between 'bright' and 'dimmer' images might show a difference in something.

Charles
Reply With Quote
  #5  
Old 23-04-2013, 05:12 PM
LewisM
Novichok test rabbit

LewisM is offline
 
Join Date: Aug 2012
Location: Somewhere in the cosmos...
Posts: 9,326
Terry got back to me promptly (Peter, could you email him please too to tplatt@starlight.win-uk.net about yours). He emailed me a copy of the new gain script, as the older one was unstable.

Great service as usual!
Reply With Quote
  #6  
Old 23-04-2013, 06:29 PM
Shiraz's Avatar
Shiraz (Ray)
Registered User

Shiraz is offline
 
Join Date: Apr 2010
Location: ardrossan south australia
Posts: 4,787
good that it's sorted Lewis, what exactly is a gain script?
Reply With Quote
  #7  
Old 23-04-2013, 08:55 PM
PeterM's Avatar
PeterM
towards 2000 posts-slowly

PeterM is offline
 
Join Date: Jun 2006
Location: SE Qld
Posts: 1,602
Thanks Lewis,
Just emailed Terry. I guess the gain script is a firmware upload is that right?
Muchly appreciated. never got round to chasing up myself as the original camera is the one that does most of the work.
This is what makes this forum so very useful as well as friendly...people sharing issues and resolutions.
Thanks again
Reply With Quote
  #8  
Old 24-04-2013, 07:33 AM
LewisM
Novichok test rabbit

LewisM is offline
 
Join Date: Aug 2012
Location: Somewhere in the cosmos...
Posts: 9,326
No problem Peter. Hope it works. I flashed mine last night, and yes, the camera worked afterwards, so fingers crossed

Lewis
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 12:11 AM.

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