Go Back   IceInSpace > Beginners Start Here > Beginners Talk

Reply
 
Thread Tools Rate Thread
  #1  
Old 15-04-2022, 12:00 AM
Drac0 (Mark)
Registered User

Drac0 is offline
 
Join Date: Feb 2020
Location: Nowra, NSW
Posts: 275
First time imaging Ha - tips/suggestions?

Well I got myself a 7nm Ha filter & with MAYBE the chance of a few hours of clear sky & the full moon over the weekend I was thinking of giving it a go. But never tried it before so any tips & suggestions would be welcome.


My intended target is M20 - the Trifid Nebula. I do have a few of questions to get started.



1. Where to position the filter, close to the sensor (I have a ZWO adapter to put it right up close) or further out on the scope side of the flattener/reducer?
2. Going to also be capturing it with an OSC and combining them in post. What sort of integration time ratio should I be looking for? Say I do 4 hours OSC, how much time would be suitable for just Ha?
3. In regards to exposure time, do I keep them the same for both OSC & Ha, or should I do longer/shorter Ha subs.


That will do foe a start.


TIA!
Mark
Reply With Quote
  #2  
Old 15-04-2022, 08:18 AM
Startrek (Martin)
Registered User

Startrek is offline
 
Join Date: Dec 2017
Location: Sydney and South Coast NSW
Posts: 4,946
Mark,
With my experience imaging the Trifid over the past 2 years with my 2600MC OSC I found that no filter and no moon around works best in darker skies to bring out all three types of emission in this object ( Ha ,Dark and Reflection nebulosity)
My 2600MC just has an internalUV/IR cut filter as itís protective window.
But thatís not to say donít use the Ha filter , it all depends on your cameras ability to pick up that wavelength. Even with the Bayer matrix on my 2600MC this camera picks up quite a decent amount of Ha for an OSC

This image was captured from my South Coast Obs using my 8Ē f5 newt and 2600MC OSC (no filter ) on a moonless night last Winter.

From memory I think I used the following technical card -
3 minute dithered guided subs
Total integration 3 hours
Gain 0 or highest dynamic range
Camera cooled to -10C
No calibration frames although I should have taken and used them
Stacked in DSS
Processed in Startools V1.7

PS: I also used my old DSLR prior to owning the 2600MC and again used no filters , just a dark moonless night and plenty of good data, the DSLR use to produce a fair image but noting like the 2600MC , chalk and cheese

IMO try capturing data with and without the Ha filter ( canít help you with spacing etc... ) that way you have more options in post processing

Good luck

Iím heading down the coast on Saturday for 2 weeks , hope to get some clear nights after a horrible 6 or 7 months

Cheers
Martin
Attached Thumbnails
Click for full-size image (BC7404D9-BB90-4B6E-A99F-CBC9AA1127F3.jpg)
216.1 KB41 views
Reply With Quote
  #3  
Old 15-04-2022, 09:27 AM
Startrek (Martin)
Registered User

Startrek is offline
 
Join Date: Dec 2017
Location: Sydney and South Coast NSW
Posts: 4,946
Mark,
I just checked the specs on your 224MC ( if thatís what your using ) and itís more of a dedicated planetary colour camera with only a AR protective window , so using no filter probability wonít work.
Personally Iíd gather data with both a luminance filter ( if you have one as itís similar to a UV/IR cut filter ) and the Ha filter too.

Any thoughts of upgrading in the future to a cooled OSC with larger sensor ??

Cheers
Martin
Reply With Quote
  #4  
Old 15-04-2022, 04:20 PM
Drac0 (Mark)
Registered User

Drac0 is offline
 
Join Date: Feb 2020
Location: Nowra, NSW
Posts: 275
Hi Martin.
Great capture. I am looking forward to imaging under dark skies but you may have noticed our clear nights seem to be syncing with the coming of the full moon for some time now. I have heard you can get good Ha data even with the moon out, so going to try if it's clear.

Yeah, the 224MC is mainly a planetary camera but I do find it useful for smaller DSO compared to a DSLR, adding either the UV/IR cut or L-Pro filter depending where I am & how dark it is. I actually haven't got around to imaging with just the cut filter from here in town yet - the moon is always there. I am saving for a 533MC Pro with a sensor size in between the 224MC & DSLR then maybe a larger sensor later, after a new mount!


Cheers,
Mark
Reply With Quote
  #5  
Old 15-04-2022, 04:54 PM
Startrek (Martin)
Registered User

Startrek is offline
 
Join Date: Dec 2017
Location: Sydney and South Coast NSW
Posts: 4,946
Quote:
Originally Posted by Drac0 View Post
Hi Martin.
Great capture. I am looking forward to imaging under dark skies but you may have noticed our clear nights seem to be syncing with the coming of the full moon for some time now. I have heard you can get good Ha data even with the moon out, so going to try if it's clear.

Yeah, the 224MC is mainly a planetary camera but I do find it useful for smaller DSO compared to a DSLR, adding either the UV/IR cut or L-Pro filter depending where I am & how dark it is. I actually haven't got around to imaging with just the cut filter from here in town yet - the moon is always there. I am saving for a 533MC Pro with a sensor size in between the 224MC & DSLR then maybe a larger sensor later, after a new mount!


Cheers,
Mark
Mark,
All sounds good to me
The 533MC is a great camera too
You just have to check your FOV and image scale with your scopes
If I can give you a strong recommendation for a mount upgrade ( up to 15kg AP payload ) you canít go past the EQ6-R pro ( Iíve owned 2 off them for nearly 3 years now ). IMO the best 20kg class mount in the world under $3K
Hope we all get some clear nights

Cheers
Martin
Reply With Quote
  #6  
Old 15-04-2022, 09:50 PM
Drac0 (Mark)
Registered User

Drac0 is offline
 
Join Date: Feb 2020
Location: Nowra, NSW
Posts: 275
Martin,
FoV & image scale seems good with both scopes with the 533MC. And the EQ6-R Pro is my hoped for mount, though the way my saving progress is going I might need to pick up a 2nd hand HEQ5 as an interim mount otherwise I might be stuck with the EQM35 for too long.

Clear skies,
Mark
Reply With Quote
  #7  
Old 17-04-2022, 01:21 AM
Drac0 (Mark)
Registered User

Drac0 is offline
 
Join Date: Feb 2020
Location: Nowra, NSW
Posts: 275
So much for that idea, mount died tonight. RA motor won't operate correctly, I think it's the controller as I swapped the motor (and cables) with a spare I had & both do the same - no way they could both crap themselves on the same night...oh well, a lot of early nights ahead...
Reply With Quote
  #8  
Old 17-04-2022, 08:17 AM
Startrek (Martin)
Registered User

Startrek is offline
 
Join Date: Dec 2017
Location: Sydney and South Coast NSW
Posts: 4,946
Sorry to hear the bad news , hope you sort things out soon
You didnít miss anything last night , Iím down south on the coast at my Dome, seeing was poor as there was a heavy dew early so guide Star was bouncing around. Couldnít get below 1 arc sec Ra and Dec saw toothing. At 1.00am guiding was 1.30 to 1.40 with some jumps, not good .........
Stars were round but fat
I think same scenario tonight
Reply With Quote
Reply

Bookmarks

Tags
h alpha, osc, trifid nebula m20

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 08:19 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2022, Jelsoft Enterprises Ltd.
Advertisement
Limpet Controller
Advertisement
ScopeDome Australia
Advertisement
Bintel
Advertisement
Testar
Advertisement
Astronomy and Electronics Centre
Advertisement