H-Alpha filter and the moon

[evil_yoda]

Hi All,

After recently moving from DSLR to an ASI1600MM-C with LRGB filters, I've told myself (but mostly the girlfriend) that I wouldn't spend any more money. She doesn't know about the focal reducer I just bought

Not had much chance to get out and image for the past week or so due to the weather, but looking at the clearoutside forecast for the coming week there might be a few clear nights coming up. The full moon must scare away the clouds.
I never bothered trying to image much around a full moon with the DSLR, but I've heard that NB imaging reduces the pollution from the moon somewhat. 

I was looking at the 7nm Baader Ha filter. Will this allow me to get some usable subs around the time of the full moon? Assuming I'm not trying to image something right next to the moon of course!

Matt

[Marky1973]

Yep, should be fine - I use the same filter for NB work and have never had trouble getting an image with the moon around....but, as you say, obviously not right next to it! ?

[david_taurus83]

I have a 12nm Astronomik clip filter for my Canon and was thinking the same thing for next week. Waiting for moonless nights for RGB on M31 but was thinking about Ha next week. I noticed last time out on the Veil, that there is a definite contrast improvement with no moon. Full moon and the background sky looks brighter in the subs. You might have better luck with your 7nm but your camera is also more sensitive! I'd say give it a go if the moon is behind where you are aiming.

[tooth_dr]

I agree with David. You can still shoot ha but it’s not going to be as quite as good as without the Moon.  I’ve tried 7nn and 12nm, both seem ok. A clear night is a clear night ?

3nm filter users seem to have more success.  

[evil_yoda]

Thanks for the comments,

Sounds like just the excuse I need to pick up a filter then! It'll have to be 7nm as the 3nm ones seem a little on the pricey side.

[wimvb]

Sound advice about the filters.

Here's one bit more:

Not spending any more money and astrophotography are mutually exclusive. You might want to explain that to your girlfriend, before she sees your Christmas wishlist. ?

[gorann]

Just to show that Ha imaging is very possible under a full moon, and even with a colour camera, here is about 4 hours of data I collected last night with my cooled colour CMOS camera (an ASI 071 MC pro) with a 7nm Baader Ha filter and the Esprit 150. 46 x 5 min (gain 200, offset 30, -10°C). So far just stretched in PS with no noise reduction applied. I am now adding old RGB data to it and may do a separate post about it under Deep Sky Imaging.

[ollypenrice]

The tighter the bandpass the better. The 3nm Astrodon roundly beats the 7nm Baader in strong moonlight, for instance, but at a hideous price! Goran's image is really smooth. I tend not to do quite so well in the moonlight when shooting in Ha. I don't do it often though. Moon time is rest time!

Olly

[gorann]

16 minutes ago, ollypenrice said:

The tighter the bandpass the better. The 3nm Astrodon roundly beats the 7nm Baader in strong moonlight, for instance, but at a hideous price! Goran's image is really smooth. I tend not to do quite so well in the moonlight when shooting in Ha. I don't do it often though. Moon time is rest time!

Olly

Olly, I also regarded moon time as rest time but no more. An Astrodon would be nice but paying that much for such a small package in the mail just does not seem right to me. I am sure it costs more than its weight in gold, but is it worth more?

[evil_yoda]

8 hours ago, wimvb said:

Sound advice about the filters.

Here's one bit more:

Not spending any more money and astrophotography are mutually exclusive. You might want to explain that to your girlfriend, before she sees your Christmas wishlist. ?

It's more that I was going to space the purchases out a bit to make it appear better to the girlfiend, but that doesn't seem to have happened.
I was going to ask for a Ha filter in my Christmas stocking, but maybe it'll be a SII or OIII now. That's unless I end up getting them for myself before Christmas  

[evil_yoda]

3 hours ago, gorann said:

Just to show that Ha imaging is very possible under a full moon, and even with a colour camera, here is about 4 hours of data I collected last night with my cooled colour CMOS camera (an ASI 071 MC pro) with a 7nm Baader Ha filter and the Esprit 150. 46 x 5 min (gain 200, offset 30, -10°C). So far just stretched in PS with no noise reduction applied. I am now adding old RGB data to it and may do a separate post about it under Deep Sky Imaging.

That's a great image. I'm looking forward to getting my 7nm Baadar now, hopefully it'll arrive in time for the clear skies this week!

[wimvb]

1 hour ago, ollypenrice said:

The 3nm Astrodon roundly beats the 7nm Baader in strong moonlight, for instance, but at a hideous price!

I believe a wise man once said: "it's not what filters let through, but what they block that's important." I wonder who that was? ?

[ollypenrice]

8 minutes ago, wimvb said:

I believe a wise man once said: "it's not what filters let through, but what they block that's important." I wonder who that was? ?

No great wisdom needed to understand this!

Olly

[tooth_dr]

Taken during an 81% moon with 7nm Ha filter. The noise is more apparent but I’m still ok with it. Roughly similar exposure to @gorann around 4.5 hours in 300s subs. 

 

[gorann]

14 minutes ago, tooth_dr said:

Taken during an 81% moon with 7nm Ha filter. The noise is more apparent but I’m still ok with it. Roughly similar exposure to @gorann around 4.5 hours in 300s subs. 

 

Nice! What camera and scope?

[evil_yoda]

15 minutes ago, tooth_dr said:

Taken during an 81% moon with 7nm Ha filter. The noise is more apparent but I’m still ok with it. Roughly similar exposure to @gorann around 4.5 hours in 300s subs. 

 

Very nice.
I assume integrating subs taken at full moon with those taken at new moon is still beneficial? It still adds to the overall "depth" of data.

[tooth_dr]

3 minutes ago, gorann said:

Nice! What camera and scope?

Thanks. Atik 383L+ and ED80

[tooth_dr]

1 minute ago, evil_yoda said:

Very nice.
I assume integrating subs taken at full moon with those taken at new moon is still beneficial? It still adds to the overall "depth" of data.

I’m not totally clued up but I’d favour no moon and discard full moon subs accordingly. 

[evil_yoda]

Hi all,

I finally got the 7nm Baader Ha filter and managed to get some subs at and around the full moon.
This is my first go at narrowband imaging, but I was really impressed at the level of detail at full res, especially given the washed out state of the sky. Can't wait to try this at a new moon.

This ended up being around 5 hrs of Ha, processed in pixinsight.

Some of the subs were taken with a focal reducer and some without but seemed to stack ok without too many problems.

 

[tooth_dr]

45 minutes ago, evil_yoda said:

Hi all,

I finally got the 7nm Baader Ha filter and managed to get some subs at and around the full moon.
This is my first go at narrowband imaging, but I was really impressed at the level of detail at full res, especially given the washed out state of the sky. Can't wait to try this at a new moon.

This ended up being around 5 hrs of Ha, processed in pixinsight.

Some of the subs were taken with a focal reducer and some without but seemed to stack ok without too many problems.

 

Wow that’s totally fab. Well worth buying the filter for sure 

[evil_yoda]

Thanks. I think getting more data could end up being quite addictive. Nice to see the details come out and the noise start to lessen as more subs are added.
Some colour subs next I think.

[ollypenrice]

3 minutes ago, evil_yoda said:

Thanks. I think getting more data could end up being quite addictive..

Your warning is right on the money. I am in rehab after spending 400 hours on one image (under the influence of a certain Mr O'Donoghue.)

lly

[evil_yoda]

1 minute ago, ollypenrice said:

Your warning is right on the money. I am in rehab after spending 400 hours on one image (under the influence of a certain Mr O'Donoghue.)

Wow, 400 hours! I doubt I'd see 400 hours worth of clear skies in 10 years around these parts
 

[gorann]

4 minutes ago, ollypenrice said:

Your warning is right on the money. I am in rehab after spending 400 hours on one image (under the influence of a certain Mr O'Donoghue.)

lly

 

1 minute ago, evil_yoda said:

Wow, 400 hours! I doubt I'd see 400 hours worth of clear skies in 10 years around these parts
 

I hope Olly is talking about a mosaic or otherwise he and his friend have lost it....

[ollypenrice]

1 minute ago, gorann said:

 

I hope Olly is talking about a mosaic or otherwise he and his friend have lost it....

We are talking about a mosaic but that doesn't mean we haven't lost it!

lly