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Re: sticky exposure length or sticky gain/offset for sky-limited exposures?

Posted: Sat Sep 15, 2018 2:14 am
by mAnKiNd
Thin clouds here aswell... shooting darks as well...

Re: sticky exposure length or sticky gain/offset for sky-limited exposures?

Posted: Sat Sep 15, 2018 3:59 pm
by mAnKiNd
Managed to get 6x15m calibrated stacks constructed from 30x30s G230 O100 exposures with the HO filter. I had started at f/4 but didn't like the star shapes, so after about 40 minutes, I stopped the lens down to f/5.17 (with filter rings) and started again. Was much happier with the star shapes, but maybe could have stepped it down a bit more to f/5.77 with one more ring. That would have given even better starshapes but at the cost of more speed.

Brightness Filter was working very well to reject frames containing thin clouds.

Forecast looking good for tonight as well so I'll try to collect more data to integrate with last night before I start playing around with processing.

Brian, hope you got on well too in upstate NY!

Cheers
Minos

Re: sticky exposure length or sticky gain/offset for sky-limited exposures?

Posted: Sat Sep 15, 2018 4:21 pm
by oopfan
Ooooo nice, Minos!

I just captured darks last night from 9pm to 6am. I'll post results under another topic.

BTW, north is to the right in your stack.

Have the neighbors called the police on you yet? :lol:

Brian

Re: sticky exposure length or sticky gain/offset for sky-limited exposures?

Posted: Sun Sep 16, 2018 1:15 am
by mAnKiNd
Nope, no one has called the cops on me yet...at it again tonight, waiting for clouds to get out of the way and Robin's cloud blasting script to be written.

How's it looking up there?

Cheers

Re: sticky exposure length or sticky gain/offset for sky-limited exposures?

Posted: Sun Sep 16, 2018 1:51 am
by oopfan
Minos,

I am collecting darks again tonight. I'm waiting for the hurricane to pass and the subsequent clear, cool nights to come.

Do the neighborhood kids show any interest? If it was me I'd ask: "Whaddya doin' mister?"

Brian

Re: sticky exposure length or sticky gain/offset for sky-limited exposures?

Posted: Sun Sep 16, 2018 3:22 am
by mAnKiNd
Yes! Kids around here sometimes come up and have a look and they're all wow and curious, but it's past bedtime for most of them.. during later times I get visits from cats, bugs and the occasional raccoon.

Re: sticky exposure length or sticky gain/offset for sky-limited exposures?

Posted: Sun Sep 16, 2018 3:39 am
by oopfan
What, no coyotes? Got plenty of them here. They scare the bejeezus out of me. One night there was a pack of them up the hill. I turned on my flashlight and saw a dozen glowing yellow eyes fixated on me.

Brian

Re: sticky exposure length or sticky gain/offset for sky-limited exposures?

Posted: Sun Sep 16, 2018 4:01 am
by mAnKiNd
That's scary! I once had a snail climb up all the way on my back, until I noticed something slimy on my ear and picked the mister off me with a grin. I was so fixated and immobile when observing and fine-tuning a long livestack, this guy had all the time in the world to climb me. This experience has now led me to be stuck with frequent habitual checking behaviours of my clothing when seated outside by the rig.

Re: sticky exposure length or sticky gain/offset for sky-limited exposures?

Posted: Sun Sep 16, 2018 10:52 am
by oopfan
Creepy Crawlers are one big reason to go fully-robotic. That's what I am shooting for.

Was the Snail Incident on Long Island? It's been 25 years ago since I lived there. The Island has a huge snail problem. I remember leaving the house in the morning and seeing slime trails all over. Every so often I hear about teenagers daring each other to swallow a snail. Invariably they end up dead 24 hours later.

I just completed another 10 hours of capturing darks. I'm adding it to my collection now.

Brian

Re: sticky exposure length or sticky gain/offset for sky-limited exposures?

Posted: Sun Sep 16, 2018 4:33 pm
by mAnKiNd
Yes, Long Island snails indeed!

I saw your other post about your darks project. Some very good stuff going on there.

To bring back this topic to relevance, I chose to stack 15 minutes constructed from 30 frames made from 30 second exposures with a gain of 230 and offset of 100 with my HO filter. Though choosing to auto-save the stack every 15 has this peculiar addition of a 31st frame..

I managed to collect 16 stacks so far, for a total of 4hrs 8 mins. That is a total of 496 subframes.

I'll start a new topic for this, but here's the link to the project so far.

https://www.astrobin.com/367007/C/?nc=user

Cheers
Minos