help_outline Skip to main content

Shopping Cart
cancel
Add Me To Your Mailing List

Astrophotography

January Image Challenge
Author Last Post
Mark,

Your data looks great on both images, I am not sure which one I like the most, "the skull" pops out a little more in your latest version.


Thanks for sharing,


-Lou

Hello friends! I'm embarrassed to admit I made a rookie mistake in calibrating the Rosette nebula image I shared. Here is the updated image with the correct calibration. I still like the original because it is visually very interesting but the colors are completely wrong. This time I just used an HOO pallette. (Red=H, Green=O, Blue=O)

Mark

As January draws to a close, I decided another attempt at the Rosette.
Imaged over 2 nights @ ISO 800 at 10 seconds and 7 seconds with a 200mm lens
Imaging dates: 1/19 and 1/30)
Polar alignment was not great as it was freezing
But I determined that ISO 1600 is the ideal ISO for my camera. I also managed to get the histogram to the mid-point this time.
Total imaging time: 40 min
Stacked as 2 groups in DSS & processed in Photoshop
I know it would look even better if I wait until the new moon, so I plan to combine this with more subs taken from the near clear sky night we have.
Thank you sir! Please be sure to share the links if you see your image out there!

Facebook.com/dvaastronomers
Instagram.com/delvalamateurastronomers
Hi Bill,
Happy to say yes!
Best,
Mark
Mark, might I be able to share your rosette image for either our facebook or instagram pages, or both? If not, that's ok too.

Sure! Here is a photo of my rig. Everything runs off the ASIAir (Raspberry Pie computer - red enclosure below the guide scope). It has a limited Wi-Fi range so I added a WiFi range extender (white box on near side of mount). The camera is a cooled color CMOS from ASI (ASI294 MC Pro)

Fantastic image Mark!


This is a beautiful example of the Rosette Nebula, thank you for your entry to the January image challenge.

Welcome to the forum,

-Lou
That's breathtaking! Excellent job Mark! Do you have a picture of your rig?

Hi everybody. Here is the result of my first attempt to create a color image from my L-Enhance filter. I used PixelMath in Pixinsight to combine the Hydrogen alpha and Oxygen III monochrome images Red (100% Ha) Green (20% Ha 80% O III) Blue (10% Ha 90% O III). Orion ED80 Refractor with 0.8x flattener and Orion Sirius EQ-G mount and ASIAir Pro. 30x300sec images stacked and the two channels (Ha OIII) extracted using AstroPixelProcessor. Post-processed in PixInsight. Images of Rosette Nebula collected Jan 23 in the NJ Pine Barrens

Thanks for clarifying Lou. This is very helpful

Hari,

Try and remember this, it will save you from unneeded aggravation.

There is no reason to waste time trying to level your tripod when using your MSM to track the sky, leveling is irrelevant in this situation. Your only goal is to align the RA axis (the part on your MSM that rotates the ball mount and your camera) so that center axis of rotation is aligned exactly to the pole in the sky.


I know I mentioned this to you before and I will mention it one more time

It doesn't matter how level the tripod is or even what position your camera is pointed, as long as the tripod can solidily lock your MSM to keep the central axis of rotation (RA axis) oriented to the pole.

I remember when I first started learning to polar align my star tracker it took me a while to become familiar with the nuance required to manipulate the RA axis to point North.

Move any part of your mount you need to to achieve that goal and forget about leveling anything.

Keep practicing, this is something that you will eventually be able to do in your sleep.


CS,


-Lou


.
Thanks Lou- this makes sense.. I will try this out. What is still not clear to me is why I was getting star trails after 10 sec on a135mm lens when I was able to easily get up to 45 sec in the past. The only variables can think of is that I messed up my old tripod’s legs and ended up buying a new one off Amazon. My MSM rotator sits on top of a wedge (which pans alt-azh) which in turn sits on top of the tripod.

I could have tried leveling my tripod tonight, but decided to use the evening to image the moon instead with my celestron nexstar 8” scope which was a very good decision in hindsight :)

pictures to come soon


From: mailer@mail2.clubexpress.com <mailer@mail2.clubexpress.com> on behalf of Astrophotography <astrophotography@dvaa.org>
Sent: Thursday, January 21, 2021 8:35:05 PM
To: Doraisamy, Hari <hari.doraisamy@sap.com>
Subject: re: [Astrophotography] January Image Challenge
 
<<-------------------------------------------------------------------------------------->>
Posted by: Elias Varvarezis on 1/21/2021 at 7:33 PM
View/reply online: https://www.dvaa.org/content.aspx?page_id=2155&club_id=951143&item_id=1089950&message_id=2754512
Reply to forum at astrophotography@dvaa.org (be sure to copy the message subject exactly so your reply is attached to the correct thread)
Reply directly to Elias Varvarezis at evarvarezis@verizon.net
If this message contains inappropriate content, you can report the message online: https://www.dvaa.org/content.aspx?page_id=2163&club_id=951143&item_id=2754512&thread_id=1089950&forum_id=23526&show_message=y
<<-------------------------------------------------------------------------------------->>


Hari,
I am assuming you are using a ball head along with the MSM in which case don't go too crazy trying to get your tripod level, it doesn't matter what the tripod is doing (even if it's leaning sideways) as long as your axis of rotation is polar aligned. The ball head should pointing 40° above the horizon and be lined up exactly to the North.
The good news is you will be able to apply the same skills to polar align a GEM if you decide to go in that direction and it will be easier.

My best advice to you is to try this from a dark location on a night with good transparency with absolutely no Moon in the sky. In other words you will need to wait 2 or 3 weeks until the Moon goes away. When it's dark again I want you to try taking 25 subs each of the same subject at ISO 800, 1600, 3200 and 6400. This should only take a couple of hours and you should be able to easily complete this task on a DARK (that means no Moon) clear night. Then calibrate and stack your data to compare .

Remember, all of the noise lives on the left side of your histogram, if you want to reduce it then you need to either increase your exposure time or your ISO. The key to collecting good data is to histogram off of the left edge. If you are unable to extend your exposure time because of polar alignment error then (aside by being limited by your aperture) the only other thing left to do is to amplify the signal before it’s converted to a digital value, yes you do this by increasing the ISO. Otherwise the ADC will not be able to distinguish the signal (your image data) from the noise its burried in from the left edge of the histogram.

CS,

-Lou













Sent from my Galaxy

<<-------------------------------------------------------------------------------------->>
Posted by: Hari Doraisamy on 1/21/2021 at 4:54 PM
View/reply online: https://www.dvaa.org/content.aspx?page_id=2155&club_id=951143&item_id=1089950&message_id=2754386
Reply to forum at astrophotography@dvaa.org (be sure to copy the message subject exactly so your reply is attached to the correct thread)
Reply directly to Hari Doraisamy at hari.doraisamy@sap.com
If this message contains inappropriate content, you can report the message online: https://www.dvaa.org/content.aspx?page_id=2163&club_id=951143&item_id=2754386&thread_id=1089950&forum_id=23526&show_message=y
<<-------------------------------------------------------------------------------------->>


 Thanks Lou! This was taken with:
 ISO 1600 F 5.6 10 sec subs
 Increasing to 15 sec+ gave me severe star trails

From: mailer@mail2.clubexpress.com <mailer@mail2.clubexpress.com> on behalf of Astrophotography <astrophotography@dvaa.org>
 Sent: Thursday, January 21, 2021 5:46:27 PM
 To: Doraisamy, Hari <hari.doraisamy@sap.com>
 Subject: re: [Astrophotography] January Image Challenge <<-------------------------------------------------------------------------------------->>
 Posted by: Elias Varvarezis on 1/21/2021 at 4:45 PM
 View/reply online: https://www.dvaa.org/content.aspx?page_id=2155&club_id=951143&item_id=1089950&message_id=2754378
 Reply to forum at astrophotography@dvaa.org (be sure to copy the message subject exactly so your reply is attached to the correct thread)
 Reply directly to Elias Varvarezis at evarvarezis@verizon.net
 If this message contains inappropriate content, you can report the message online: https://www.dvaa.org/content.aspx?page_id=2163&club_id=951143&item_id=2754378&thread_id=1089950&forum_id=23526&show_message=y
 <<-------------------------------------------------------------------------------------->>
 
 
 Hari,
 
 
 I am in a constant battle with the trees, I feel your pain.
 
 
 Your polar alignment looks pretty good but it looks like the data was pushed a little too far in post-processing.

Can you post your exposure information? (shutter speed, aperture and ISO).
 
 CS,
 
 -Lou
 
 
 >>--------------------------------------------------------------------------------------<<
 View the full Forum Policy: https://www.dvaa.org/content.aspx?page_id=2355&club_id=951143
 
 You have received this message as a member of: Delaware Valley Amateur Astronomers
 Change preferences (including opt-out): https://www.dvaa.org/content.aspx?page_id=13&club_id=951143. Click on 'Forum Memberships' to change your settings for this forum, or 'Forum General Preferences' for all forums.
 
 
 


>>--------------------------------------------------------------------------------------<<
View the full Forum Policy: https://www.dvaa.org/content.aspx?page_id=2355&club_id=951143

You have received this message as a member of: Delaware Valley Amateur Astronomers
Change preferences (including opt-out): https://www.dvaa.org/content.aspx?page_id=13&club_id=951143. Click on 'Forum Memberships' to change your settings for this forum, or 'Forum General Preferences' for all forums.





>>--------------------------------------------------------------------------------------<<
View the full Forum Policy: https://www.dvaa.org/content.aspx?page_id=2355&club_id=951143

You have received this message as a member of: Delaware Valley Amateur Astronomers
Change preferences (including opt-out): https://www.dvaa.org/content.aspx?page_id=13&club_id=951143. Click on 'Forum Memberships' to change your settings for this forum, or 'Forum General Preferences' for all forums.


Hari, 

I am assuming you are using a ball head along with the MSM in which case don't go too crazy trying to get your tripod level, it doesn't matter what the tripod is doing (even if it's leaning sideways) as long as your axis of rotation is polar aligned.    The ball head should pointing 40° above the horizon and be lined up exactly to the North. 

The good news is you will be able to apply the same skills to polar align a GEM if you decide to go in that direction and it will be easier. 


My best advice to you is to try this from a dark location on a night with good transparency with absolutely no Moon in the sky.   In other words you will need to wait 2 or 3 weeks until the Moon goes away.    When it's dark again I want you to try taking 25 subs each of the same subject at ISO 800, 1600, 3200 and 6400.  This should only take a couple of hours and you should be able to easily complete this task on a DARK (that means no Moon) clear night.   Then calibrate and stack your data to compare . 


Remember, all of the noise lives on the left side of your histogram, if you want to reduce it then you need to either increase your exposure time or your ISO.  The key to collecting good data is to histogram off of the left edge.   If you are unable to extend your exposure time because of polar alignment error then  (aside by being limited by your aperture) the only other thing left to do is to amplify the signal before it’s converted to a digital value, yes you do this by increasing the ISO.  Otherwise the ADC will not be able to distinguish the signal (your image data) from the noise its burried in from the left edge of the histogram.   


CS,


-Lou














Sent from my Galaxy


<<-------------------------------------------------------------------------------------->>
Posted by: Hari Doraisamy on 1/21/2021 at 4:54 PM
View/reply online: https://www.dvaa.org/content.aspx?page_id=2155&club_id=951143&item_id=1089950&message_id=2754386
Reply to forum at astrophotography@dvaa.org (be sure to copy the message subject exactly so your reply is attached to the correct thread)
Reply directly to Hari Doraisamy at hari.doraisamy@sap.com
If this message contains inappropriate content, you can report the message online: https://www.dvaa.org/content.aspx?page_id=2163&club_id=951143&item_id=2754386&thread_id=1089950&forum_id=23526&show_message=y
<<-------------------------------------------------------------------------------------->>


  Thanks Lou! This was taken with:
  ISO 1600 F 5.6 10 sec subs
  Increasing to 15 sec+ gave me severe star trails

From: mailer@mail2.clubexpress.com <mailer@mail2.clubexpress.com> on behalf of Astrophotography <astrophotography@dvaa.org>
Sent: Thursday, January 21, 2021 5:46:27 PM
To: Doraisamy, Hari <hari.doraisamy@sap.com>
Subject: re: [Astrophotography] January Image Challenge     <<-------------------------------------------------------------------------------------->>
Posted by: Elias Varvarezis on 1/21/2021 at 4:45 PM
View/reply online: https://www.dvaa.org/content.aspx?page_id=2155&club_id=951143&item_id=1089950&message_id=2754378
Reply to forum at astrophotography@dvaa.org (be sure to copy the message subject exactly so your reply is attached to the correct thread)
Reply directly to Elias Varvarezis at evarvarezis@verizon.net
If this message contains inappropriate content, you can report the message online: https://www.dvaa.org/content.aspx?page_id=2163&club_id=951143&item_id=2754378&thread_id=1089950&forum_id=23526&show_message=y
<<-------------------------------------------------------------------------------------->>


Hari,


I am in a constant battle with the trees, I feel your pain.


Your polar alignment looks pretty good but it looks like the data was pushed a little too far in post-processing.

Can you post your exposure information? (shutter speed, aperture and ISO).

CS,

-Lou


>>--------------------------------------------------------------------------------------<<
View the full Forum Policy: https://www.dvaa.org/content.aspx?page_id=2355&club_id=951143

You have received this message as a member of: Delaware Valley Amateur Astronomers
Change preferences (including opt-out): https://www.dvaa.org/content.aspx?page_id=13&club_id=951143. Click on 'Forum Memberships' to change your settings for this forum, or 'Forum General Preferences' for all forums.


  


>>--------------------------------------------------------------------------------------<<
View the full Forum Policy: https://www.dvaa.org/content.aspx?page_id=2355&club_id=951143

You have received this message as a member of: Delaware Valley Amateur Astronomers
Change preferences (including opt-out): https://www.dvaa.org/content.aspx?page_id=13&club_id=951143. Click on 'Forum Memberships' to change your settings for this forum, or 'Forum General Preferences' for all forums.


Thanks Lou!
This was taken with:

ISO 1600
F 5.6
10 sec subs

Increasing to 15 sec+ gave me severe star trails



From: mailer@mail2.clubexpress.com <mailer@mail2.clubexpress.com> on behalf of Astrophotography <astrophotography@dvaa.org>
Sent: Thursday, January 21, 2021 5:46:27 PM
To: Doraisamy, Hari <hari.doraisamy@sap.com>
Subject: re: [Astrophotography] January Image Challenge
 
<<-------------------------------------------------------------------------------------->>
Posted by: Elias Varvarezis on 1/21/2021 at 4:45 PM
View/reply online: https://www.dvaa.org/content.aspx?page_id=2155&club_id=951143&item_id=1089950&message_id=2754378
Reply to forum at astrophotography@dvaa.org (be sure to copy the message subject exactly so your reply is attached to the correct thread)
Reply directly to Elias Varvarezis at evarvarezis@verizon.net
If this message contains inappropriate content, you can report the message online: https://www.dvaa.org/content.aspx?page_id=2163&club_id=951143&item_id=2754378&thread_id=1089950&forum_id=23526&show_message=y
<<-------------------------------------------------------------------------------------->>


Hari,


I am in a constant battle with the trees, I feel your pain.


Your polar alignment looks pretty good but it looks like the data was pushed a little too far in post-processing. 

Can you post your exposure information?  (shutter speed, aperture and ISO).

CS,

-Lou


>>--------------------------------------------------------------------------------------<<
View the full Forum Policy: https://www.dvaa.org/content.aspx?page_id=2355&club_id=951143

You have received this message as a member of: Delaware Valley Amateur Astronomers
Change preferences (including opt-out): https://www.dvaa.org/content.aspx?page_id=13&club_id=951143. Click on 'Forum Memberships' to change your settings for this forum, or 'Forum General Preferences' for all forums.


Hari,


I am in a constant battle with the trees, I feel your pain.


Your polar alignment looks pretty good but it looks like the data was pushed a little too far in post-processing.

Can you post your exposure information? (shutter speed, aperture and ISO).

CS,

-Lou
My second attempt at the Rosette Nebula from last night after using focusing techniques (10x zoom and FWHM in BYE). Interesting enough, I saw a shooting star in live view while focusing - pretty neat!

Polar alignment was a bit off since i have a new tripod and suspect it was not level.
Not too happy with the framing, but there's a tree in the way and I had to either wait until very late in the evening or just proceed

Date: 1/20
Willistown Twp - Bortle 5 with partial moon out
Canon EOS Rebel T6 (modded) with Pentax 135mm prime lens and a MSM tracker

Nice! Glad to see you had some time under the stars. It has been kinda cold for me – and pretty cloudy.

 

Don

 

Hari,

Your polar alignment is spot on, Great work! However, it seems like you're still having a bit of trouble with focus. This could be due to the modification done to your camera but don't worry if that is the case, it can be easily fixed. You need to find out exactly how your camera was modified, what filter was used to replace the stock ir-cut filter and the frequencies it's designed to cut off.

Clear skies buddy,


-Lou
Here's my first attempt at imaging the Rosette nebula!

Details below:

H-alpha modified Canon EOS Rebel T6
Move Shoot Move Star Tracker

152 subs at 10 seconds with 20 darks taken on 1/7
96 subs at 20 seconds with 20 darks taken on 1/10
6 subs at 30 seconds taken on 1/10

Used Backyard EOS
Stacked as a group in Deep Sky Stacker and processed with Photoshop with Noel Carboni's Astronomy Tools and Gradient XTerminator.

Clear Skies!
Hari
Return to Forum