How Much Moon is Possible for Astrophotography?

[Karl Perera]

Please answer these questions to help me with content and research for my website. Every reply is appreciated!

[vlaiv]

I usually image when the full moon is 180 degrees away from the target

[RolandKol]

You should include Narrow Band or One Shot cam used....
I do H imaging further away from the moon, but dont touch LRGB

[wesdon1]

I'm still a newbie, but for your information, I will shoot narrowband if Moon is out, no matter the illumination, maybe except for when it's a 10% waning crescent, in which case i'll go colour without narrowband, just CLS filter. Please bear in mind I am very new to imaging, so I am still learning!

Wes.

Edited December 21, 2022 by wesdon1
I forgot to include the details about using CLS filter

[Lee_P]

Personally, I don't worry about what the Moon is doing. If the skies are clear, I'll collect photons. Good processing helps enormously with combating the Moon (and other sources of light pollution). This image of M45 was taken over two weeks, with a bright Moon nearby for most of that time. No filters used. Would it be better had there been no Moon? Sure, but I'm happy with the end result.

[tooth_dr]

3 minutes ago, Lee_P said:

Personally, I don't worry about what the Moon is doing. If the skies are clear, I'll collect photons. Good processing helps enormously with combating the Moon (and other sources of light pollution). This image of M45 was taken over two weeks, with a bright Moon nearby for most of that time. No filters used. Would it be better had there been no Moon? Sure, but I'm happy with the end result.

That is a really fantastic result.  Does the moon add much to your Bortle 8 site light pollution?  I think imaging in the full moon is possible, but it needs a lot more data.

[Lee_P]

3 minutes ago, tooth_dr said:

That is a really fantastic result.  Does the moon add much to your Bortle 8 site light pollution?  I think imaging in the full moon is possible, but it needs a lot more data.

Thanks  Yes, the sky is appreciably brighter when the Moon is up, especially close to the target. But there's still signal to be collected despite all the noise! I treat city astrophotography as a marathon, not a sprint. Every imaging project is multi-week. And what with the weather here, I can't afford to squander any clear nights. What gets me is people in the countryside that say they don't image when the Moon is up. I think, "my skies with no Moon are still brighter than yours with a full Moon!" 😂

[vlaiv]

3 minutes ago, tooth_dr said:

That is a really fantastic result.  Does the moon add much to your Bortle 8 site light pollution?  I think imaging in the full moon is possible, but it needs a lot more data.

https://skyandtelescope.org/astronomy-resources/astronomy-questions-answers/how-does-the-moons-phase-affect-the-skyglow-of-any-given-location-and-how-many-days-before-or-after-a-new-moon-is-a-dark-site-not-compromised/

According to this - full moon overhead is SQM18 which is equivalent to Bortle 8 zone. Adding same amount of illumination in already bright sky will just double the amount of background photons and that won't change SQM by 1 (x2 increase is + ~0.75 magnitudes).

Some calculations suggest that it takes about x35-40 more exposure compared to pristine dark skies (SQM 22).

When I did some calculations, moving to 2 magnitudes darker skies (from 18.6 to 20.6) yielded something like x6 reduction in total exposure time needed to achieve target SNR for regular targets (like SQM26-28 faint galactic outer arms and SNR 5+).

 

[wesdon1]

27 minutes ago, Lee_P said:

Personally, I don't worry about what the Moon is doing. If the skies are clear, I'll collect photons. Good processing helps enormously with combating the Moon (and other sources of light pollution). This image of M45 was taken over two weeks, with a bright Moon nearby for most of that time. No filters used. Would it be better had there been no Moon? Sure, but I'm happy with the end result.

Your M45 image is one of the best I've ever seen. The nebulosity is substantial, and colours are beautiful. May I ask, how many minutes of total integration did you get to achieve this image? ( btw, I am using terms like "integration" because thats what the pros say! I am a newbie and am YEARS away from being even half as good as yourself and other pros! LOL ).

Wes.

[Lee_P]

2 minutes ago, wesdon1 said:

Your M45 image is one of the best I've ever seen. The nebulosity is substantial, and colours are beautiful. May I ask, how many minutes of total integration did you get to achieve this image? ( btw, I am using terms like "integration" because thats what the pros say! I am a newbie and am YEARS away from being even half as good as yourself and other pros! LOL ).

Wes.

Thanks, you're very kind. All the imaging details can be seen on the webpage here, but the direct answer to your question is that the image is 660 x 120-second subframes, totalling 22 hours of integration time.

Don't worry about being a newbie, learning astrophotography is a long journey and no-one has all the answers. (Except maybe vlaiv 😂) SGL is the best place to ask questions and learn. I pick up a new piece of useful info every time I log on!

[wesdon1]

1 minute ago, Lee_P said:

Thanks, you're very kind. All the imaging details can be seen on the webpage here, but the direct answer to your question is that the image is 660 x 120-second subframes, totalling 22 hours of integration time.

Don't worry about being a newbie, learning astrophotography is a long journey and no-one has all the answers. (Except maybe vlaiv 😂) SGL is the best place to ask questions and learn. I pick up a new piece of useful info every time I log on!

Aww thanks Lee! I am a very eager learner so hopefully in time i'll start getting good at this amazing hobby!

My goodness that is a lot of total exposure/integration time! Tbh Lee, when I had just started out learning about astrophotography, I used to think I could get great images of DSO's with only a few minutes of subs/exposure, but I'm quickly learning that it really does matter how much light you collect on a target, even a target as bright as M45!? may I ask, did you use any filters for the m45 imaging? I recently purchased a Optolong L-pro 1.25" Filter, to deal with bad LP outside my home, and I was/am amazed at how much of a difference it makes in combatting local LP!? Did you use any CLS or LP filters, or indeed a Narrowband filter? Really sorry for questions Lee, I am just trying so hard to absorb and learn as much as possible.

 

[Lee_P]

4 minutes ago, wesdon1 said:

Aww thanks Lee! I am a very eager learner so hopefully in time i'll start getting good at this amazing hobby!

My goodness that is a lot of total exposure/integration time! Tbh Lee, when I had just started out learning about astrophotography, I used to think I could get great images of DSO's with only a few minutes of subs/exposure, but I'm quickly learning that it really does matter how much light you collect on a target, even a target as bright as M45!? may I ask, did you use any filters for the m45 imaging? I recently purchased a Optolong L-pro 1.25" Filter, to deal with bad LP outside my home, and I was/am amazed at how much of a difference it makes in combatting local LP!? Did you use any CLS or LP filters, or indeed a Narrowband filter? Really sorry for questions Lee, I am just trying so hard to absorb and learn as much as possible.

 

No worries, questions are good -- assuming the OP doesn't mind their thread going temporarily off on a tangent! 

* No, I didn't use any filter for the M45 image. I don't use any filters for broadband targets after I tested some and found no benefits. Read more here. Note that my my camera, a ZWO2600MC-Pro has an in-built UV/IR filter. 
* For narrowband targets I used to use an Optolong L-eXtreme, but have now upgraded to an Optolong L-Ultimate. Read more here. I've also been using Askar D1 D2 filters. Review coming soon.
* Long integration times are key, especially from urban areas as vlaiv demonstrated with his calculations. I've written tips for getting long integration times here.

[ONIKKINEN]

I try to image a target that is the most efficient for a given night, so under a significant Moon that means imaging the Moon itself, or one of the bright planets that dont care about the Moon.

If the Moon is too low to image and planets are not available (or the seeing is bad) then i will bite the bullet and image something to the far north.

[wesdon1]

22 minutes ago, Lee_P said:

No worries, questions are good -- assuming the OP doesn't mind their thread going temporarily off on a tangent! 

* No, I didn't use any filter for the M45 image. I don't use any filters for broadband targets after I tested some and found no benefits. Read more here. Note that my my camera, a ZWO2600MC-Pro has an in-built UV/IR filter. 
* For narrowband targets I used to use an Optolong L-eXtreme, but have now upgraded to an Optolong L-Ultimate. Read more here. I've also been using Askar D1 D2 filters. Review coming soon.
* Long integration times are key, especially from urban areas as vlaiv demonstrated with his calculations. I've written tips for getting long integration times here.

Oh wow! Lots to consider there, thanks lee! I did actually read that shooting full colour/broadband can sometimes be hindered, rather than helped, by using aggressive LP filters, like my L-pro? basically I live in supposed Bortle 7, but I have awfully bright main road white light street lights, that are extremely difficult to deal with because they're obviously white light, so they're broad spectrum, so my L-Pro and other LP filters aren't much good to combat them? ( I may be wrong? ). 

What I will now do is have a good read through the links you kindly gave me, and carry on learning and working out the best ways to image broadband DSO's from my specific location/circumstances. 

Just finally, I had to comment on that Optolong L-Ultimate! My goodness I have heard a LOT of rave glowing reviews about that filter recently! it's expensive, but I might still buy one! It looks awesome from what I've read and seen!

many many Thanks Lee! 

Clear Skies!

Wes. ( Liverpool, Bortle 7 )

[tooth_dr]

44 minutes ago, Lee_P said:

Thanks  Yes, the sky is appreciably brighter when the Moon is up, especially close to the target. But there's still signal to be collected despite all the noise! I treat city astrophotography as a marathon, not a sprint. Every imaging project is multi-week. And what with the weather here, I can't afford to squander any clear nights. What gets me is people in the countryside that say they don't image when the Moon is up. I think, "my skies with no Moon are still brighter than yours with a full Moon!" 😂

I have decent skies where I live, at the lower end of Bortle 4 and I can see an appreciable different in the quality of broadband data under a full moon.  I would be one of those who thinks twice about imaging under a 100% moon.  I think when you are used to good conditions, it's hard to get motivated to collect data under significantly unfavourable conditions.  I would however use narrowband under the moon and keep away from it as so far is possible.

[tomato]

I’m with Lee on imaging on every clear night, I can always do something with the data but there are too many cloudy nights when I can’t collect anything to let a clear (but moonlit) night pass me by.

[Lee_P]

19 minutes ago, wesdon1 said:

I did actually read that shooting full colour/broadband can sometimes be hindered, rather than helped, by using aggressive LP filters, like my L-pro? basically I live in supposed Bortle 7, but I have awfully bright main road white light street lights, that are extremely difficult to deal with because they're obviously white light, so they're broad spectrum, so my L-Pro and other LP filters aren't much good to combat them? ( I may be wrong? ). 

The filter might help you, it might not -- I can't say, unfortunately. It depends on your levels and sources of light pollution, and the kit you're using. I recommend doing some experiments and comparisons to test. Be as scientific as possible

 

[Elp]

The survey does needs a distinction between OSC and narrowband. My last visit to a dark site I wanted to image in RGB but a fairly near full moon was in the same quadrant as the target so much so that the images captured the glare of it even though it wasn't in the fov. I switched to HA in the same area with a mono cam and there was no major issue.

As per the survey, yes I do image during a fairly full moon, just because more often than not the moon is present and large whenever it is clear.

[vlaiv]

Those poll results are very interesting

I made a joke at the beginning that I like to image 180 degrees away from the full moon - but if you think about it - that is "on the other side" of the earth and when the moon is full - sun is on the other side, so what I actually said is that I best like to image during daytime - hence the joke.

In any case - 11 people so far, chose either 90 or 180 degrees away from very bright moon, and I'd argue that that is highly inefficient use of imaging time.

We can stipulate that bright moon is past first quarter or before third quarter. In any case - to be 90 degrees or more away from it - you'll be either imaging - during dusk or dawn or daytime if it is closer to being full, or very low towards the horizon - like 20-30 degrees or below.

All very inefficient usage of imaging time. I wonder why people do it like that?

 

 

[ONIKKINEN]

4 minutes ago, vlaiv said:

Those poll results are very interesting

I made a joke at the beginning that I like to image 180 degrees away from the full moon - but if you think about it - that is "on the other side" of the earth and when the moon is full - sun is on the other side, so what I actually said is that I best like to image during daytime - hence the joke.

In any case - 11 people so far, chose either 90 or 180 degrees away from very bright moon, and I'd argue that that is highly inefficient use of imaging time.

We can stipulate that bright moon is past first quarter or before third quarter. In any case - to be 90 degrees or more away from it - you'll be either imaging - during dusk or dawn or daytime if it is closer to being full, or very low towards the horizon - like 20-30 degrees or below.

All very inefficient usage of imaging time. I wonder why people do it like that?

 

 

You forgot about latitude here a little bit. The Moon is often at 10-20 degrees of elevation here at 60N so you could image almost to the opposite side and with a reasonable elevation.

Had there been a choice i would have answered more like 120-150 degrees or better said just "as far away as possible without compromise in elevation".

[vlaiv]

7 minutes ago, ONIKKINEN said:

You forgot about latitude here a little bit. The Moon is often at 10-20 degrees of elevation here at 60N so you could image almost to the opposite side and with a reasonable elevation.

Had there been a choice i would have answered more like 120-150 degrees or better said just "as far away as possible without compromise in elevation".

Fair point - if moon is very low due south and one images due north - then it is viable option.

[ollypenrice]

Here we go again, as with your other thread.  Because you are out of your depth, you are asking the wrong questions. Through my job I know, host and work with dozens of excellent imagers and I do not believe that any of them works to a spreadsheet of lunar position, phase or target proximity. I have literally thousands of hours of deep sky exposure time under my belt, yet I have no idea how to fill in your questionnaire. It reminds me of the nonsense OFSTED wanted me to tick-box when I was a teacher. The real world simply does not work that way. Rule Number One: Tick no boxes.

The fact that you do not include, in your questionnaire, any distinction between broadband and narrowband, or any refinement of narrowband into bandpass width, clearly indicates that you should come back with more knowledge.  Leave the production of astrophotography tutorials to astrophotographers. Become one, by all means, and you'll get endless help on here, as I have done. Then, when you have something original to contribute (as you will if you persevere)  then contribute it and it will be well received.

Even before the internet was thriving, friends and I used to joke about 'The advice mountain,' rather like 'The wine lake' of the time.  There is far more advice at large in the world than the world has any need for. Don't add to it.

Olly

[Karl Perera]

I tried to keep it simple. I, in fact, do image with narrowband duoband filter and HA filter to avoid the Moon effect, so its not a lack of knowledge. Forgive me for my oversights.