ICEINSPACE
Most Read Articles
Moon Phase
CURRENT MOON Waxing Crescent
6.6%
The Sun Now
Time Zones
Sydney*
3:39 pm
Perth
12:39 pm
Auckland*
5:39 pm
New York
11:39 pm
Paris
5:39 am
GMT
4:39 am




Go Back   IceInSpace > Beginners Start Here > Beginners Astrophotography

Reply
 
Thread Tools Rate Thread
  #21  
Old 14-09-2017, 08:53 AM
The_bluester's Avatar
The_bluester (Paul)
Registered User

The_bluester is offline
 
Join Date: Feb 2011
Location: Kilmore, Australia
Posts: 1,299
Virtualdub seems to do much the same thing but from a GUI. The Timlapse Tool software I tried first seems to be better in some ways but not in others, I am not all that keen to pay $130 to confirm my suspicions about it's limitations though.

I am still hunting around for options to batch apply dark frames, I have not worked out how to do it in Pixinsight, there is a script to do it in GIMP, but it does not seem to respect any processing order by way of file names (While spitting out files it has applied the dark to with new, sequential file names) so the dark applied frames end up out of order and useless to create a lapse with. I have to look more closely at that one and make sure I am not missing a setting that will resolve it.

Anyway, nothing to do for a bit now, I am away this weekend so I won't have any new files to play with for another week and a bit.
Reply With Quote
  #22  
Old 14-09-2017, 09:25 AM
Mickoid (Michael)
Registered User

Mickoid is offline
 
Join Date: Feb 2016
Location: Melbourne, Australia
Posts: 262
Why not just use the built in noise reduction function that most digital cameras have as an option to turn on or off. The noise reduction function is basically a dark frame applied automatically to each frame, you just have to make sure your interval time allows the camera to process the dark frame which is essentially your frame exposure time. So if your frame exposure is 20 seconds, then your interval time with noise reduction on will have to be at least 40 seconds.
Reply With Quote
  #23  
Old 14-09-2017, 09:47 AM
The_bluester's Avatar
The_bluester (Paul)
Registered User

The_bluester is offline
 
Join Date: Feb 2011
Location: Kilmore, Australia
Posts: 1,299
In this case I have two issues. First up the camera I am currently using is too old to take and automatically apply a dark frame (Unless I have missed it in the menus) but as much as anything else, I am wanting as many frames as I can get to make the lapse smooth where using internally generated dark frames will more or less halve my frame rate (I have been inserting a pause between frames to help control sensor temperature)

It may yet be feasible though with shorter exposures, I just worked out that the camera keeps defaulting to F7.1 on startup and sometimes even changes if the lens is zoomed in and back out again, so I should be able to capture more detail at the same or shorter exposure time now that I have worked out that niggle. I just have to remember to check every time I touch the thing that it has remained at F3.5, it is not obvious unless you check out the image exif data afterwards as you have to check it specifically, the default display if you look through the finder is exposure time.
Reply With Quote
  #24  
Old 14-09-2017, 12:09 PM
Mickoid (Michael)
Registered User

Mickoid is offline
 
Join Date: Feb 2016
Location: Melbourne, Australia
Posts: 262
Googled info on noise reduction for your camera and found a photo forum with this about the topic: "go to menu 2nd utility menu (orange color tab with wrench and hammer in it) custom functions number 2 allows you to turn on or off noise reduction I also hear that it doesnt really make any noticable difference, but I DO know that when you use it, and say for example you take a 30sec exposure, it will take a additinal 30 seconds for the camera to process it. hope this helps!"
Reply With Quote
  #25  
Old 14-09-2017, 01:17 PM
The_bluester's Avatar
The_bluester (Paul)
Registered User

The_bluester is offline
 
Join Date: Feb 2011
Location: Kilmore, Australia
Posts: 1,299
I will have to look at it, and make sure it has the latest (Final) firmware on it. A lot of the time Canon seem to give their own names to common functions so I must have missed it.

I have to have another go anyway given that I just worked out that the camera was by default stopping itself down to F7.1 instead of F3.5. I can stay with a 20 second exposure with NR turned on assuming the firmware on it supports it, if not, I will update to the final one) and get a lot more data with a frame rate still around once every 45 seconds. I might even be able to cut it to 15 seconds exposure with 15 seconds dark frame time, a few seconds processing internally and download and get 40 seconds per exposure overall or a bit less.

Next weekend, unless I get home and the forecast for the night looks worth having a go at.
Reply With Quote
  #26  
Old 14-09-2017, 04:48 PM
The_bluester's Avatar
The_bluester (Paul)
Registered User

The_bluester is offline
 
Join Date: Feb 2011
Location: Kilmore, Australia
Posts: 1,299
Well the long exposure noise reduction does work fairly effectively, you need to drill well down into the menus to find it though. People saying it does not make a noticeable difference I would have to suspect are not aware of what they are looking for.

I will have to have another go at the next opportunity now I have worked out that it is available and fairly effective (there still seems to be some random hot pixels on some frames, where normal light frames were quite noisy before) and that it had changed back to F7.1.

F3.5 at 15 seconds in a 40 second cycle (I timed a couple of cycles with NR on) should get me a lot more detail in the sky than I was getting out of 30 seconds at F7.1
Reply With Quote
  #27  
Old 14-09-2017, 05:38 PM
Mickoid (Michael)
Registered User

Mickoid is offline
 
Join Date: Feb 2016
Location: Melbourne, Australia
Posts: 262
Yes, as long as you shoot at around ISO 3200 then 15secs@f3.5 should give you good detail on a moonless night. So as an example, if you shoot for 12 hours, say 7.00pm until 7.00am, with a 40 second interval, you will capture 1080 frames: 12hrs X 60 X 60 = 43200 seconds. 43200/40 = 1080. Now @ 24fps your time-lapse will run for 45 seconds. If you choose 15fps , the time-lapse duration will be 72 seconds, not as smooth but still very watchable. It really depends on whether you want quantity or quality.

Personally, I'd use 24fps because 45 seconds is quite long enough to maintain the viewers interest and the result will look smoother. Do you shoot in AV priority so the camera can compensate for the fluctuating light conditions? That way, your sunset and sunrise transitions will be exposed correctly.
Reply With Quote
  #28  
Old 14-09-2017, 05:44 PM
The_bluester's Avatar
The_bluester (Paul)
Registered User

The_bluester is offline
 
Join Date: Feb 2011
Location: Kilmore, Australia
Posts: 1,299
The camera maxes at iso1600 so that is what I use. I am aiming for the best quality I can manage so I will have to play with the frame rate to see what looks best. I can't use AV as it seems to top out at about half a second exposure. I have to look into that more as it would be nice to get good transitions, even a full 24 hour lapse.

The camera is a bit of a pain, I am not at work tomorrow so I have it doing another test run tonight to see how the in camera noise reduction goes. IN the time powered down between the house and shed it defaulted back to off.
Reply With Quote
  #29  
Old 15-09-2017, 10:55 AM
The_bluester's Avatar
The_bluester (Paul)
Registered User

The_bluester is offline
 
Join Date: Feb 2011
Location: Kilmore, Australia
Posts: 1,299
OK, last go before I get a combination of no moon to speak of, the IR/UV cut filter to make processing colour easier and a better weather forecast (I know, I want everything!)

Anyway, long exposure noise reduction turned on in camera (Which seems to have to be done every time the battery pack is removed) and mostly 20 second exposures on as high a rotation as I could get without upsetting the software. Brought down to 800 X 533 in size and a bit of a colour tweak in Virtualdub to reduce the cast form the lack of an IR filter. Output at 15 frames per second.

https://youtu.be/S6TW_xd_6So
Reply With Quote
  #30  
Old 17-09-2017, 07:37 PM
The_bluester's Avatar
The_bluester (Paul)
Registered User

The_bluester is offline
 
Join Date: Feb 2011
Location: Kilmore, Australia
Posts: 1,299
The sky was clear so I decided to have another play tonight. As I suspected, AV mode is not usable for the purpose. I thought from testing in the house it would top out at about 1/3 of a second exposure which was not right, it went longer than that but pegged at 2.5 seconds.

I will have to have a try with my wife's D3 and see how it behaves, though I am not allowed to leave that out all night before I find a weatherproof enclosure for it. At least I could let it run in the dusk and see if it keeps on going to a decent exposure time.
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 02:39 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Advertisement
Lunatico Astronomical
Advertisement
SkyWatcher Star Discovery
Advertisement
Meade Instruments
Advertisement
Tasco Australia
Advertisement
Bintel
Advertisement
FLI Cameras and Imaging Accessories
Advertisement
Atik 16200
Advertisement
NexDome Observatories
Advertisement
OzScopes Authorised Dealer
Advertisement
Astronomy and Electronics Centre
Advertisement