Testing increasing integration times (OSC, Bortle 8)

[CloudMagnet]

Ill be honest, I cant comment on PixInsight. I just stick to good old DSS. The settings dont look like they would cause any problems at first glance. Could try in DSS and if you get the same we can rule out pre-processing as the cause.

[Lee_P]

1 hour ago, CloudMagnet said:

Ill be honest, I cant comment on PixInsight. I just stick to good old DSS. The settings dont look like they would cause any problems at first glance. Could try in DSS and if you get the same we can rule out pre-processing as the cause.

I've tried using DSS but can't get a decent image out of it, so obviously I'm doing something wrong. Why is nothing ever easy?! 😅

[CloudMagnet]

haha, well if you got the perfect picture first time with no learning and improving, it wouldn't be as fun.

I think ill try the same experiment with some of my data this week, and see if I get a similar effect.

[Lee_P]

FYI I've conducted a few more tests and have started a new thread about this: 

 

[ollypenrice]

I've no experience of imaging in light pollution* but I remember a Craig Stark video in which he demonstrated that LP can be overcome by sufficiently long integration. This runs totally counter to the argument that LP imposes a certain limit beyond which it isn't worth exposing for longer. According to Craig Stark, the opposite is true.

When deciding on exposure times I like to know why I'm going to make a particular choice and this comes down to what I'm going to do with the data. If the idea is to prize some terribly faint signal out from just above the background sky then a huge integration time will certainly pay dividends.  If I'm not trying to do such prizing then four times less data will probably be fine.

Conversely, if I'm shooting Ha on a bright target with little faint signal, then I know I'm going to be adding it to the red channel in Blend Mode Lighten. In this case only the brighter parts of the Ha will influence the red channel and I don't need to build faint Ha signal.

Olly

* Conversely I have lots of experience of realizing that I've forgotten some small thing like the salt and now have forty-five minutes of driving to go and get it!