#1  
Old 10-11-2018, 08:33 AM
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graham.hobart (Graham stevens)
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ZWO ASI 1600pro advice

Hey brains trust, just got on the CMOS train and looking for experienced heads advice.
I want to know what people have found is a good exposure length and gain/ etc for this camera as I am moving from a KAF 8300 chip.
Using maxim DL and bortle 6 skies sometimes.
Also are people saving in mono 8 or 16 ?- that is the choice in sharpcap, is there a choice in maxim or is it default?
any other tips gratefully hoovered up!
thanks
Graham
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  #2  
Old 10-11-2018, 09:47 AM
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Atmos (Colin)
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Gain 76 will get you the full 12 bits and I found at F/5 180s worked RGB and 120s L.
At Gain 139 you hit unity which I’ve used 400s with 3nm narrowband.
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Old 10-11-2018, 09:58 AM
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Unity is a good balance just work with that to start with and similar to Colin I use 300s for NB and and around 60s for LRGB just depends on how dark your site is mine is in suburbia.
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Old 10-11-2018, 10:13 AM
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You definitely want to capture in 16 bit, not 8 bit.

The camera itself is 12bit, so you truncate 4 bits if you capture 8 bit.

The file it outputs is 16 bit with the 4 least significant bits padded with 0's.

The only reason to shoot 8 bit would be to increase frame rates for planetary.

At least, that's how I understand it. Others may correct me.

Markus
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Old 10-11-2018, 10:15 AM
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Also, as I discovered recently, don't route cameras through a hub - go direct to the computer or you will get choppy bandwidth as the other equipment is polled.

Markus
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Old 10-11-2018, 10:22 AM
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Quote:
Originally Posted by Stonius View Post
Also, as I discovered recently, don't route cameras through a hub - go direct to the computer or you will get choppy bandwidth as the other equipment is polled.

Markus
Ive been running thru a hub for 18mth never had an issue in fact I have about 5 other devises plugged into it with one cable to pc and never had an issue . I would be blaming your hub .
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Old 10-11-2018, 10:45 AM
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I have two MBeat hubs that are commonly used apparently. Both had the same issue. So if it's the hub, it's not hardware failure, but rather a design issue or a configuration issue, which is possible, I guess. But short of getting a 'google-PHD' in USB3 issues, plugging direct just worked for me, and with the onboard hub in the 1600-pro itself, it seems to have solved the issue.

USB can be finnicky and weird. Thats why people recommend always plugging into the same ports. I'm glad yours works for you. I'm just happy I now have a solution that enables me to continue. Maybe I'll get around to getting to the bottom of it again one day, but for now, I'm happy. :-)
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Old 10-11-2018, 11:00 AM
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Originally Posted by Stonius View Post
I have two MBeat hubs that are commonly used apparently. Both had the same issue. So if it's the hub, it's not hardware failure, but rather a design issue or a configuration issue, which is possible, I guess. But short of getting a 'google-PHD' in USB3 issues, plugging direct just worked for me, and with the onboard hub in the 1600-pro itself, it seems to have solved the issue.

USB can be finnicky and weird. Thats why people recommend always plugging into the same ports. I'm glad yours works for you. I'm just happy I now have a solution that enables me to continue. Maybe I'll get around to getting to the bottom of it again one day, but for now, I'm happy. :-)
Well as long as you found a way to get it to work it must be in the hardware design I guess , mine was expensive but lucky has no issues and in dc powered
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Old 10-11-2018, 11:04 AM
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I think you need 1 bit for every stop of dynamic range and it looks like even at the highest gain on the ASI 1600 you have 9 stops, so you'd be throwing away data to use 8 bits.

Optimal exposure length will vary wildly depending on your conditions (light pollution, moon phase) and various other factors (mount tracks / guides poorly? shorter is probably better). That said, I think Colin's recommendations would be a good starting point.
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Old 10-11-2018, 11:08 AM
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Well as long as you found a way to get it to work it must be in the hardware design I guess , mine was expensive but lucky has no issues and in dc powered
Sorry, don't mean to hijack the thread - what hub are you using, if you don't mind me asking? :-)
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Old 10-11-2018, 11:19 AM
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Sorry, don't mean to hijack the thread - what hub are you using, if you don't mind me asking? :-)
No worries
https://www.startech.com/Cards-Adapt...s/~ST7300USBME
DC 7 to 48v and individually isolated
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Old 16-11-2018, 10:13 AM
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Just ensure you take sky limited subs and lots of them

Also, don't be put off by how a single sub looks...they pop with integration!
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Old 16-11-2018, 11:02 AM
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I have been testing with gain 200 and getting good results with 30 second subs even in narrowband, but I'm working at f/3.6 or faster and taking a *lot* of subs. I haven't done the sums yet to figure out if I'm sky limited but the core of M42 is burned out in a 30 second Ha sub...

Cheers,
Rick.
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Old 17-11-2018, 06:20 PM
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I have been testing with gain 200 and getting good results with 30 second subs even in narrowband, but I'm working at f/3.6 or faster and taking a *lot* of subs. I haven't done the sums yet to figure out if I'm sky limited but the core of M42 is burned out in a 30 second Ha sub...
My guess is it got burned out a lot sooner than 30 seconds
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Old 18-11-2018, 02:02 PM
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My guess is it got burned out a lot sooner than 30 seconds
The 2 seconds subs hit a max of about 18000 ADU in the core so anything over 7 or 8 seconds would be blown out, Dunk
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Old 18-11-2018, 09:18 PM
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