xelasnave
28-05-2022, 09:15 AM
So I was delighted to find a clear sky last night which matched my hopes during the Sunny day and although at first the dew was tolerable I took precautions that bit me badly.
I opened the observatory and placed the camera on the HEQ 5 and resolved to shoot at 200 ISO for 90 second subs however I had forgotten that I had kicked the tripod a while back and the mount needed to be realigned so I tested until I found 15 second subs would deliver something. I was under the gun so I took the course that had the camera working the earliest...and probably the correct call given how the dew became very bad a little later..It was like snow or fine ash showing up in the head lights of the mower when riding back at the end of the session.
The next issue came from not checking at a high ISO (which was my plan) as in the 15 second sub at 200 ISO I could see stars and they were sharp (the blue tack does a great job holding the focus ring even allows fitting the dew shield but of course you need to check)...what I would have noticed if I had done a high ISO test was that my dew shield, made for a longer lens, produced very bad vignetting requiring a huge crop of over 50%.
So my plans had to take major adjustment to produce the image herewith.
What did I learn?...short exposures and only a few even at low ISO dont produce a decent dynamic range...I already knew not to despair and work with the mess you are left with and use it for practice.
And to end a not so perfect night the battery that runs the two winches for the roof went flat (why is a concern that I will address this morning) so I had to man handle the roll off roof to get it closed ...only just doable but not pleasant at that end of the night.
I am not confident this image will look any good at all but I will post it so I can see it here...I am interested to hear any comments on any issues you notice and even negative data is very useful.
alex
I opened the observatory and placed the camera on the HEQ 5 and resolved to shoot at 200 ISO for 90 second subs however I had forgotten that I had kicked the tripod a while back and the mount needed to be realigned so I tested until I found 15 second subs would deliver something. I was under the gun so I took the course that had the camera working the earliest...and probably the correct call given how the dew became very bad a little later..It was like snow or fine ash showing up in the head lights of the mower when riding back at the end of the session.
The next issue came from not checking at a high ISO (which was my plan) as in the 15 second sub at 200 ISO I could see stars and they were sharp (the blue tack does a great job holding the focus ring even allows fitting the dew shield but of course you need to check)...what I would have noticed if I had done a high ISO test was that my dew shield, made for a longer lens, produced very bad vignetting requiring a huge crop of over 50%.
So my plans had to take major adjustment to produce the image herewith.
What did I learn?...short exposures and only a few even at low ISO dont produce a decent dynamic range...I already knew not to despair and work with the mess you are left with and use it for practice.
And to end a not so perfect night the battery that runs the two winches for the roof went flat (why is a concern that I will address this morning) so I had to man handle the roll off roof to get it closed ...only just doable but not pleasant at that end of the night.
I am not confident this image will look any good at all but I will post it so I can see it here...I am interested to hear any comments on any issues you notice and even negative data is very useful.
alex