When you take the photos using the 3 filter types do you take them right after each other? 2 hrs filter 1 then 2 hrs filter 2 and then 2 hrs filter 3. The stars will be in different locations in the sky for the 3 filter types. Are you concerned about the quality difference depending on how much atmosphere the 3 set of photos are taken though. Would it be better to take 40min filter 1 then 40 min filter 2 then 40 min filter 3 and then repeat that 3 times? I'm thinking about switching to a mono camera.
Hi there! This is a great point and there are a couple things to consider here. You are correct in that photographing something low on horizon with the OIII filter and then photographing that same object 4hrs later as its at zenith will produce different results. If you want to discard those lower quality frames from your final stack you definitely can. You can also choose to start imaging when the object is above 30 degrees which is what a lot of astrophotographers do to mitigate these issues. If you are using a widefield refractor with a short focal length, this really becomes a non issue as you are undersampled and poor atmospheric conditions wont affect your image quality... too much.. When using a Newtonian or an SCT with much longer focal lengths, you do need to be a bit more "picky" when it comes to image quality. I personally image Ha for a few nights until I get about 15hrs of data, then I do the same for Sii and Oiii. From there, I only stack the best frames reducing my project from 45hrs to about 35hrs. Again, what you choose to discard is personal preference and comes with experience. That being said, If you were to shoot a target using three narrowband filters in a single night as you explained above, you should be okay if you start imaging when the target reaches 30 degrees above the horizon! Switching a filter every 40 minutes and going through that cycle a few times is also a great way to approach this. But remember.. there is no substitute for exposure time. Adding more exposure time helps average everything out a bit and the additional signal will only improve your images. A monochrome camera is a great choice and the resulting photo quality is unmatched compared to a one shot color.
I already have a H-Alpha filter for my 294MM Pro camera, should I get an Oxygen filter next or Sulphur? I am wondering which one should get priority. Thanks.
We highly recommend an OIII filter first! This will allow you to capture and edit using the HOO palette which is very versatile and common! Adding a sulfur filter later on will completely transform your images and make them very dynamic.
Good question. You can do LRGB alone, but just keep in mind that you need significantly more integration time (some astrophotographers go for 20-30 hours of data) to compensate for severe light pollution. Another possible way to go is to take RGB data at a dark sky site and then combine it with Ha/SII/OIII data at your location, but this is more for emission nebula.
Awesome, i wish i had this video from the beginning, really helps a lot, thank you!
Awesome, we're glad you enjoyed the video!
Just spotted the deliberate mistake. The Helix Nebula in the table towards the end, is NGC 7293 not 7294 :)
When you take the photos using the 3 filter types do you take them right after each other? 2 hrs filter 1 then 2 hrs filter 2 and then 2 hrs filter 3. The stars will be in different locations in the sky for the 3 filter types. Are you concerned about the quality difference depending on how much atmosphere the 3 set of photos are taken though. Would it be better to take 40min filter 1 then 40 min filter 2 then 40 min filter 3 and then repeat that 3 times? I'm thinking about switching to a mono camera.
Hi there! This is a great point and there are a couple things to consider here. You are correct in that photographing something low on horizon with the OIII filter and then photographing that same object 4hrs later as its at zenith will produce different results.
If you want to discard those lower quality frames from your final stack you definitely can. You can also choose to start imaging when the object is above 30 degrees which is what a lot of astrophotographers do to mitigate these issues.
If you are using a widefield refractor with a short focal length, this really becomes a non issue as you are undersampled and poor atmospheric conditions wont affect your image quality... too much.. When using a Newtonian or an SCT with much longer focal lengths, you do need to be a bit more "picky" when it comes to image quality.
I personally image Ha for a few nights until I get about 15hrs of data, then I do the same for Sii and Oiii. From there, I only stack the best frames reducing my project from 45hrs to about 35hrs. Again, what you choose to discard is personal preference and comes with experience. That being said, If you were to shoot a target using three narrowband filters in a single night as you explained above, you should be okay if you start imaging when the target reaches 30 degrees above the horizon! Switching a filter every 40 minutes and going through that cycle a few times is also a great way to approach this. But remember.. there is no substitute for exposure time. Adding more exposure time helps average everything out a bit and the additional signal will only improve your images.
A monochrome camera is a great choice and the resulting photo quality is unmatched compared to a one shot color.
I already have a H-Alpha filter for my 294MM Pro camera, should I get an Oxygen filter next or Sulphur? I am wondering which one should get priority. Thanks.
We highly recommend an OIII filter first! This will allow you to capture and edit using the HOO palette which is very versatile and common! Adding a sulfur filter later on will completely transform your images and make them very dynamic.
If you're using a monochrome camera in a fairly light polluted area, should you combine LRGB filters with a CLS filter or just use the LRGB alone?
Good question. You can do LRGB alone, but just keep in mind that you need significantly more integration time (some astrophotographers go for 20-30 hours of data) to compensate for severe light pollution. Another possible way to go is to take RGB data at a dark sky site and then combine it with Ha/SII/OIII data at your location, but this is more for emission nebula.
CLS? - always name TLAs when you 1st use them!