What's a good Moon (neutral density) filter?

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What's a good Moon (neutral density) filter?

#1

Post by stewe »


I looked at the waxing crescent Moon today using a TS Optics 2" variable polarisation filter that I bought recently. The filter was screwed into the thread at the telescope side of my 2" diagonal mirror.
I am very disappointed with this filter, the views were quite awful due to massive reflections.
I bought this thing to replace my old 1.25" filters which also suffered from quite a bit of reflection. But the 2" filter is way worse. I can't believe I wasted cash on this garbage.

Can anybody recommend a decent Moon filter with no reflections, no ghosting whatsoever? Also, what densities do you recommend for a C9.25? Is any variable polarisation filter out there that can do the job nicely? Or do you recommend single density filters instead?

I am looking forward to reading your answers.
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Re: What's a good Moon (neutral density) filter?

#2

Post by notFritzArgelander »


I use B+W Professional neutral density filters 2x, 4x, and 8x. Very high optical quality!
Scopes: Refs: Orion ST80, SV 80EDA f7, TS 102ED f11 Newts: AWB 130mm, f5, Z12 f5; Cats: VMC110L, Intes MK66,VMC200L f9.75 EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, Plossl 32-8mm. Mixed brand Masuyama/Astroplans Binoculars: Nikon Aculon 10x50, Celestron 15x70, Baader Maxbright. Mounts: Star Seeker IV, Vixen Porta II, Celestron CG5
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Re: What's a good Moon (neutral density) filter?

#3

Post by Ruud »


I use no filter at all: zero distortion and no reflections. The full Moon is unpleasantly bright that way, which becomes better with sunglasses on, but when full the Moon is quite boring anyway so I just ignore it.

Now my shades are far from perfect optically, but I haven't yet noticed any blur, waviness, reflections, scatter and what have you. I wonder, using a filter close to the eye may have it's benefits.

Using the filter on the far side of a diagonal it is putting it in a disadvantages position. The light cone from any feature on the moon is still quite wide there, and the chance that a wide portion of the filter is perfectly plan parallel is very slim. Using the filter closer to the focal plane would be better.
7x50 Helios Apollo 8x42 Bresser Everest 73mm f/5.9 WO APO 4" f/5 TeleVue Genesis 6" f/10 Celestron 6SE 0.63x reducer 1.8, 2, 2.5 and 3x Barlows eyepieces from 4.5 to 34mm
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Re: What's a good Moon (neutral density) filter?

#4

Post by notFritzArgelander »


Ruud wrote: Sat Mar 28, 2020 11:49 pm I use no filter at all: zero distortion and no reflections. The full Moon is unpleasantly bright that way, which becomes better with sunglasses on, but when full the Moon is quite boring anyway so I just ignore it.

Now my shades are far from perfect optically, but I haven't yet noticed any blur, waviness, reflections, scatter and what have you. I wonder, using a filter close to the eye may have it's benefits.

Using the filter on the far side of a diagonal it is putting it in a disadvantages position. The light cone from any feature on the moon is still quite wide there, and the chance that a wide portion of the filter is perfectly plan parallel is very slim. Using the filter closer to the focal plane would be better.
The B+W filters are quite flat and can be used wherever. For that flatness one pays a price, though. https://schneiderkreuznach.com/en/photo-optics
Scopes: Refs: Orion ST80, SV 80EDA f7, TS 102ED f11 Newts: AWB 130mm, f5, Z12 f5; Cats: VMC110L, Intes MK66,VMC200L f9.75 EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, Plossl 32-8mm. Mixed brand Masuyama/Astroplans Binoculars: Nikon Aculon 10x50, Celestron 15x70, Baader Maxbright. Mounts: Star Seeker IV, Vixen Porta II, Celestron CG5
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Re: What's a good Moon (neutral density) filter?

#5

Post by Lady Fraktor »


I use B+W and Hoya polarizers when I do use them, can you post a link to the filter you purchased?

Normally when doing lunar observing I just do not let my eyes become dark adapted and the view is not bright.
See Far Sticks: Antares Elita 103/1575, AOM FLT 105/1000, Bresser BV 127/1200, Nočný stopár 152/1200, Vyrobené doma 70/700, Stellarvue NHNG DX 80/552, TAL RS100/1000, Vixen SD115s/885
EQ: TAL MT-1, Vixen SXP, AXJ, AXD
Az/Alt: AYO Digi II/ Argo Navis, Stellarvue M2C/ Argo Navis
Tripods: Berlebach Planet (2), Uni 28 Astro, Report 372, TAL factory maple, Vixen ASG-CB90, Vixen AXD-TR102
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stewe
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Re: What's a good Moon (neutral density) filter?

#6

Post by stewe »


Ruud wrote: Sat Mar 28, 2020 11:49 pm I use no filter at all: zero distortion and no reflections. The full Moon is unpleasantly bright that way, which becomes better with sunglasses on, but when full the Moon is quite boring anyway so I just ignore it.
I agree that it's the best to avoid extra optical elements, but above a certain aperture (>4"-5"), glare becomes a problem, even with the crescent Moon.
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Re: What's a good Moon (neutral density) filter?

#7

Post by stewe »


Lady Fraktor wrote: Sun Mar 29, 2020 4:29 am I use B+W and Hoya polarizers when I do use them, can you post a link to the filter you purchased?

Normally when doing lunar observing I just do not let my eyes become dark adapted and the view is not bright.
Don't buy this:
https://www.teleskop-express.de/shop/pr ... neten.html
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Re: What's a good Moon (neutral density) filter?

#8

Post by stewe »


notFritzArgelander wrote: Sat Mar 28, 2020 11:15 pm I use B+W Professional neutral density filters 2x, 4x, and 8x. Very high optical quality!
I checked out their website but I did not find any info about whether they make filters for 1.25" eyepieces. Do you know if they do?
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Re: What's a good Moon (neutral density) filter?

#9

Post by pakarinen »


Might be apples to oranges, but I’m not impressed with my Orion 1.25 ND filter. I get better views with an orange or green filter. This is with fast refractors; haven’t had a chance to try with my 90mm Mak. FWIW.
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Re: What's a good Moon (neutral density) filter?

#10

Post by helicon »


I haven't used any filters yet but like Gabrielle said it can be best to look at the moon at either the beginning of a session, when the eyes are not yet dark adapted or at the end of a session, when it doesn't matter.
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Re: What's a good Moon (neutral density) filter?

#11

Post by notFritzArgelander »


stewe wrote: Sun Mar 29, 2020 9:50 am
notFritzArgelander wrote: Sat Mar 28, 2020 11:15 pm I use B+W Professional neutral density filters 2x, 4x, and 8x. Very high optical quality!
I checked out their website but I did not find any info about whether they make filters for 1.25" eyepieces. Do you know if they do?
I've never looked for the 1.25" diameter. All I have are the 2" and that's all I use.
Scopes: Refs: Orion ST80, SV 80EDA f7, TS 102ED f11 Newts: AWB 130mm, f5, Z12 f5; Cats: VMC110L, Intes MK66,VMC200L f9.75 EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, Plossl 32-8mm. Mixed brand Masuyama/Astroplans Binoculars: Nikon Aculon 10x50, Celestron 15x70, Baader Maxbright. Mounts: Star Seeker IV, Vixen Porta II, Celestron CG5
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Re: What's a good Moon (neutral density) filter?

#12

Post by notFritzArgelander »


pakarinen wrote: Sun Mar 29, 2020 9:52 am Might be apples to oranges, but I’m not impressed with my Orion 1.25 ND filter. I get better views with an orange or green filter. This is with fast refractors; haven’t had a chance to try with my 90mm Mak. FWIW.
The Orion ND filters are worthless. I am surprised that the color filters work for you. My experience was that they are as bad as the ND filters optically. They aren't optically flat for one thing. My color filters are all Baader. I ditched the Orion filters years ago and replaced them.
Scopes: Refs: Orion ST80, SV 80EDA f7, TS 102ED f11 Newts: AWB 130mm, f5, Z12 f5; Cats: VMC110L, Intes MK66,VMC200L f9.75 EPs: KK Fujiyama Orthoscopics, 2x Vixen NPLs (40-6mm) and BCOs, Baader Mark IV zooms, TV Panoptics, Delos, Plossl 32-8mm. Mixed brand Masuyama/Astroplans Binoculars: Nikon Aculon 10x50, Celestron 15x70, Baader Maxbright. Mounts: Star Seeker IV, Vixen Porta II, Celestron CG5
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Re: What's a good Moon (neutral density) filter?

#13

Post by Lady Fraktor »


stewe wrote: Sun Mar 29, 2020 9:42 am
Lady Fraktor wrote: Sun Mar 29, 2020 4:29 am I use B+W and Hoya polarizers when I do use them, can you post a link to the filter you purchased?

Normally when doing lunar observing I just do not let my eyes become dark adapted and the view is not bright.
Don't buy this:
https://www.teleskop-express.de/shop/pr ... neten.html
Were you using the two pieces together or seperated?
One piece on the diagonal nosepiece and one on the eyepiece?
See Far Sticks: Antares Elita 103/1575, AOM FLT 105/1000, Bresser BV 127/1200, Nočný stopár 152/1200, Vyrobené doma 70/700, Stellarvue NHNG DX 80/552, TAL RS100/1000, Vixen SD115s/885
EQ: TAL MT-1, Vixen SXP, AXJ, AXD
Az/Alt: AYO Digi II/ Argo Navis, Stellarvue M2C/ Argo Navis
Tripods: Berlebach Planet (2), Uni 28 Astro, Report 372, TAL factory maple, Vixen ASG-CB90, Vixen AXD-TR102
Diagonals: Astro-Physics, Baader Amici, Baader Herschel, iStar Blue, Stellarvue DX, Takahashi prism, TAL, Vixen flip mirror
Eyepieces: Antares to Zeiss
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stewe
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Re: What's a good Moon (neutral density) filter?

#14

Post by stewe »


Lady Fraktor wrote: Sun Mar 29, 2020 6:29 pm
stewe wrote: Sun Mar 29, 2020 9:42 am
Lady Fraktor wrote: Sun Mar 29, 2020 4:29 am I use B+W and Hoya polarizers when I do use them, can you post a link to the filter you purchased?

Normally when doing lunar observing I just do not let my eyes become dark adapted and the view is not bright.
Don't buy this:
https://www.teleskop-express.de/shop/pr ... neten.html
Were you using the two pieces together or seperated?
One piece on the diagonal nosepiece and one on the eyepiece?
No, I used them together on the diagonal nosepiece.
The vendor's description says: "The brightness adjustment is achieved by rotating the lower part of the filter".
I also wanted to try them together on the eyepiece, but by eye I judged that they would probably be too long for the latter, so I decided I'd rather not try it.

Do you think using them separately would give better results? If so, why?
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Re: What's a good Moon (neutral density) filter?

#15

Post by stewe »


notFritzArgelander wrote: Sun Mar 29, 2020 5:11 pm
pakarinen wrote: Sun Mar 29, 2020 9:52 am Might be apples to oranges, but I’m not impressed with my Orion 1.25 ND filter. I get better views with an orange or green filter. This is with fast refractors; haven’t had a chance to try with my 90mm Mak. FWIW.
The Orion ND filters are worthless. I am surprised that the color filters work for you. My experience was that they are as bad as the ND filters optically. They aren't optically flat for one thing. My color filters are all Baader. I ditched the Orion filters years ago and replaced them.
So what's your experience, are the Baader filters any good?
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Re: What's a good Moon (neutral density) filter?

#16

Post by Lady Fraktor »


try one part on the nosepiece and one part on the eyepiece.
When you want to vary the density, turn the eyepiece.
That should get rid of your reflection issue. This can also occur when stacking different filters so the seperation is rather common thing to do.

Baader does make good filters, like anything though someone else may make the best.
The majority of my filters are Baader though.
See Far Sticks: Antares Elita 103/1575, AOM FLT 105/1000, Bresser BV 127/1200, Nočný stopár 152/1200, Vyrobené doma 70/700, Stellarvue NHNG DX 80/552, TAL RS100/1000, Vixen SD115s/885
EQ: TAL MT-1, Vixen SXP, AXJ, AXD
Az/Alt: AYO Digi II/ Argo Navis, Stellarvue M2C/ Argo Navis
Tripods: Berlebach Planet (2), Uni 28 Astro, Report 372, TAL factory maple, Vixen ASG-CB90, Vixen AXD-TR102
Diagonals: Astro-Physics, Baader Amici, Baader Herschel, iStar Blue, Stellarvue DX, Takahashi prism, TAL, Vixen flip mirror
Eyepieces: Antares to Zeiss
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Re: What's a good Moon (neutral density) filter?

#17

Post by stewe »


notFritzArgelander wrote: Sun Mar 29, 2020 5:08 pm
stewe wrote: Sun Mar 29, 2020 9:50 am
notFritzArgelander wrote: Sat Mar 28, 2020 11:15 pm I use B+W Professional neutral density filters 2x, 4x, and 8x. Very high optical quality!
I checked out their website but I did not find any info about whether they make filters for 1.25" eyepieces. Do you know if they do?
I've never looked for the 1.25" diameter. All I have are the 2" and that's all I use.
I see. I have to admit, I also had trouble finding any B+W filters in the 2" size online, all I saw at European vendors' sites were various filters for camera lens sizes.
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Re: What's a good Moon (neutral density) filter?

#18

Post by Lady Fraktor »


stewe wrote: Sun Mar 29, 2020 8:14 pm
notFritzArgelander wrote: Sun Mar 29, 2020 5:08 pm
stewe wrote: Sun Mar 29, 2020 9:50 am

I checked out their website but I did not find any info about whether they make filters for 1.25" eyepieces. Do you know if they do?
I've never looked for the 1.25" diameter. All I have are the 2" and that's all I use.
I see. I have to admit, I also had trouble finding any B+W filters in the 2" size online, all I saw at European vendors' sites were various filters for camera lens sizes.
They do not make astro sizes, you can buy standard 48mm or 46mm filters with a 48-46mm step down ring.
See Far Sticks: Antares Elita 103/1575, AOM FLT 105/1000, Bresser BV 127/1200, Nočný stopár 152/1200, Vyrobené doma 70/700, Stellarvue NHNG DX 80/552, TAL RS100/1000, Vixen SD115s/885
EQ: TAL MT-1, Vixen SXP, AXJ, AXD
Az/Alt: AYO Digi II/ Argo Navis, Stellarvue M2C/ Argo Navis
Tripods: Berlebach Planet (2), Uni 28 Astro, Report 372, TAL factory maple, Vixen ASG-CB90, Vixen AXD-TR102
Diagonals: Astro-Physics, Baader Amici, Baader Herschel, iStar Blue, Stellarvue DX, Takahashi prism, TAL, Vixen flip mirror
Eyepieces: Antares to Zeiss
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stewe
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Re: What's a good Moon (neutral density) filter?

#19

Post by stewe »


Lady Fraktor wrote: Sun Mar 29, 2020 8:11 pm try one part on the nosepiece and one part on the eyepiece.
When you want to vary the density, turn the eyepiece.
That should get rid of your reflection issue. This can also occur when stacking different filters so the seperation is rather common thing to do.

Baader does make good filters, like anything though someone else may make the best.
The majority of my filters are Baader though.
I will give it a shot if I have a chance and let you know what I found. Yet I still can't think of any obvious reason why would it work better that way, and if it indeed does, why on Earth do the manufacturers suggest otherwise. For example, the Baader tuneable polfilter cannot even be taken apart, according to their website. Also, I thought that by using the two parts together on the diagonal would allow me to use it also for 1.25" eyepieces, which would then not be the case.. Schade!
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Re: What's a good Moon (neutral density) filter?

#20

Post by Lady Fraktor »


Are you using a mirror or prism diagonal?

Using the filter in two pieces give you the convenience of tuning from the eyepiece instead of having to remove the diagonal/ eyepiece to turn it and then check if it is enough.
I cannot comment on the Baader but it is likely sealed for a reason.

Coatings and glass shape can cause many different filters to reflect and separation usually will stop the issue.
See Far Sticks: Antares Elita 103/1575, AOM FLT 105/1000, Bresser BV 127/1200, Nočný stopár 152/1200, Vyrobené doma 70/700, Stellarvue NHNG DX 80/552, TAL RS100/1000, Vixen SD115s/885
EQ: TAL MT-1, Vixen SXP, AXJ, AXD
Az/Alt: AYO Digi II/ Argo Navis, Stellarvue M2C/ Argo Navis
Tripods: Berlebach Planet (2), Uni 28 Astro, Report 372, TAL factory maple, Vixen ASG-CB90, Vixen AXD-TR102
Diagonals: Astro-Physics, Baader Amici, Baader Herschel, iStar Blue, Stellarvue DX, Takahashi prism, TAL, Vixen flip mirror
Eyepieces: Antares to Zeiss
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