Observing with Smaller Apertures: 130mm and Below

[Ray of LIght]

47 minutes ago, Mak the Night said:

I'm not sure to be honest Ray. I can't see the neodymium being of much use viewing solar. At least with the Sun you don't have to worry about it being too dim to find the image.

Lol, yep! You are right and I can always park it back on there for night obseving. Back in a bit.

[Mak the Night]

Out of all the filters I've ever owned, I think the Baader Neodymium is the most useful and used. It certainly is the Swiss Army Knife of filters. When I don't use it I always feel kinda naked lol. It was certainly worth what I paid for it.

[Ray of LIght]

39 minutes ago, Mak the Night said:

Out of all the filters I've ever owned, I think the Baader Neodymium is the most useful and used. It certainly is the Swiss Army Knife of filters. When I don't use it I always feel kinda naked lol. It was certainly worth what I paid for it.

For sure it is going right back on the diagonal nosepiece when I'm not doing solar. I am very interested to see how that #15 works on the Sun. Hopefully will arrive Monday.

[Ray of LIght]

17 minutes ago, Ray of LIght said:

For sure it is going right back on the diagonal nosepiece when I'm not doing solar. I am very interested to see how that #15 works on the Sun. Hopefully will arrive Monday.

I was thinking that my Neodymium might not be useful for solar viewing, but would it do any harm to leave it there? I wish I knew more about it. I guess can just test it both ways and find out.

[Stu]

47 minutes ago, Ray of LIght said:

I was thinking that my Neodymium might not be useful for solar viewing, but would it do any harm to leave it there? I wish I knew more about it. I guess can just test it both ways and find out.

This is the response curve, on Astrosurf. Looks like mainly aimed at cutting out high pressure sodium light which is getting less common in the UK as we switch to full spectrum lights.

[Mak the Night]

37 minutes ago, Ray of LIght said:

I was thinking that my Neodymium might not be useful for solar viewing, but would it do any harm to leave it there? I wish I knew more about it. I guess can just test it both ways and find out.

As far as I know it’s a red, green, blue intensifier and selective bandpass filter combined that intensifies the H-alpha visual spectrum with a transmission within its selected wave bands exceeding 95%. So, I'm guessing it should be alright to leave there. I think.

 

H-alpha ~ Wikipedia

[Ray of LIght]

48 minutes ago, Mak the Night said:

As far as I know it’s a red, green, blue intensifier and selective bandpass filter combined that intensifies the H-alpha visual spectrum with a transmission within its selected wave bands exceeding 95%. So, I'm guessing it should be alright to leave there. I think.

 

H-alpha ~ Wikipedia

Thanks guys! That link was very interesting Mak, what I could understand of it! Bottom line appears to be that my filters stay put and my #15, UHC-S, #47 etc can be put eyepiece to eyepiece. Hopefully Sun is good on Monday as advertised!

[Mak the Night]

2 hours ago, Ray of LIght said:

Thanks guys! That link was very interesting Mak, what I could understand of it! Bottom line appears to be that my filters stay put and my #15, UHC-S, #47 etc can be put eyepiece to eyepiece. Hopefully Sun is good on Monday as advertised!

I'm pretty sure the Baader Neodymium is much more than a light pollution filter. Although I believe many LP filters work on some sort of dichroic principle. There's more here:

http://www.company7.com/baader/options/moonskyglow.html

Your scope's definitely looking cool Ray.

[Stu]

19 minutes ago, Mak the Night said:

I'm pretty sure the Baader Neodymium is much more than a light pollution filter. Although I believe many LP filters work on some sort of dichroic principle. There's more here:

http://www.company7.com/baader/options/moonskyglow.html

Your scope's definitely looking cool Ray.

The link seems to back up the response curve in that the neodymium glass is designed to cut of the frequencies of light associated with high pressure sodium lighting and other similar ones. It is basically an LP filter, albeit a very effective one which enhances the view very nicely.

Ray, I wouldn't bother with it whilst doing solar, just use a colour filter or the UHC-S

[Dave In Vermont]

Now look what this forum has made me do!

I might have ordered yet another filter - until I checked my near-complete Master-List - and found I already have a #11, #15, and a #21 too.....

< I think I'll take some aspirin and a cold-compress..>

Mine are older Japanese Hoya filters. So very high-quality.

Dave - ...(and his advanced case of Filterphilia) *

 

* - http://philiagroup.com/story/tag/filter/

 

[Ray of LIght]

32 minutes ago, Stu said:

The link seems to back up the response curve in that the neodymium glass is designed to cut of the frequencies of light associated with high pressure sodium lighting and other similar ones. It is basically an LP filter, albeit a very effective one which enhances the view very nicely.

Ray, I wouldn't bother with it whilst doing solar, just use a colour filter or the UHC-S

I didn't mean for it to replace or add to my solar viewing, I was more wondering if I could just leave it on my diagonal nosepiece to no ill effect. I will definitely try my color filters at the eyepiece to see how they improve my view, or not. The Neodymium is either a detriment or will be neutral. That was main concern. I apologize if I wasn't more clear; my ineexperience is showing!

[Mak the Night]

The Baader Neodymium is obviously more than an LP filter, and I doubt it would be completely detrimental to solar observing although I can't see it doing any harm. I use it primarily as a contrast filter and the fact that it appears to improve red and blue wavelengths. As I said, it's a bit of a Swiss Army Knife, and definitely improves certain targets such as Jupiter, Mars and DSO's like M42. I find it very useful for lunar viewing when the Moon is very bright or at twilight. As I live in the greenbelt I don't really need a light pollution filter anyway. It's very well made, not unlike the Baader ND filters and appears well coated. As I said earlier it’s a red, green, blue intensifier and also a selective bandpass filter combined that intensifies the H-alpha visual spectrum. It doesn't do a great deal for the yellow-green of Saturn though. I've not noticed my Baader filters suffer from dewing but my coloured Wratten filters (GSO) seem to a lot of late. I have been considering getting a more expensive #11 filter specifically for Saturn, if it was better made or coated it might not suffer this dewing problem I've noticed recently. It isn't extensive but happens around the periphery of the glass in the filter. I'll have to talk to Dave about filters, if anyone knows, he'll know lol.

[Ray of LIght]

1 hour ago, Mak the Night said:

The Baader Neodymium is obviously more than an LP filter, and I doubt it would be completely detrimental to solar observing although I can't see it doing any harm. I use it primarily as a contrast filter and the fact that it appears to improve red and blue wavelengths. As I said, it's a bit of a Swiss Army Knife, and definitely improves certain targets such as Jupiter, Mars and DSO's like M42. I find it very useful for lunar viewing when the Moon is very bright or at twilight. As I live in the greenbelt I don't really need a light pollution filter anyway. It's very well made, not unlike the Baader ND filters and appears well coated. As I said earlier it’s a red, green, blue intensifier and also a selective bandpass filter combined that intensifies the H-alpha visual spectrum. It doesn't do a great deal for the yellow-green of Saturn though. I've not noticed my Baader filters suffer from dewing but my coloured Wratten filters (GSO) seem to a lot of late. I have been considering getting a more expensive #11 filter specifically for Saturn, if it was better made or coated it might not suffer this dewing problem I've noticed recently. It isn't extensive but happens around the periphery of the glass in the filter. I'll have to talk to Dave about filters, if anyone knows, he'll know lol.

That's a good idea, he can comment on what we have already put forth. Let's send out a search party, lol!

[Mak the Night]

5 minutes ago, Ray of LIght said:

That's a good idea, he can comment on what we have already put forth. Let's send out a search party, lol!

I think Dave's even got a search party filter!

[Ray of LIght]

22 minutes ago, Mak the Night said:

I think Dave's even got a search party filter!

Lol ?!

[Stu]

Ray, just a note that filters cannot intensify light. All they can do is cut out unwanted frequencies. It is quite easy to quote from the marketing words put out by Baader, but to say it is an RGB intensifier is I think misleading.

The company seven page says...

'What Does This Filter Do For Me? 
The filter is made with a special Neodymium glass that effectively filters out selective wavelengths of low-pressure sodium and other manmade sources typically used in street lighting. Although it is not a nebula filter, it enhances the views of deep-sky objects by increasing the contrast of these objects against the background sky. While nebula filters transmit only a few select wavelengths corresponding to various atomic lines, this filter transmits a large portion of the continuous spectrum while blocking a few select lines of the more common manmade light. Neodymium provides a unique, selective, blocking feature in that this element greatly reduces glare without reducing important color and brightness variations.'

So, what it basically does (and you can see this from the response curve I posted) is remove light in the specific frequencies associated with high pressure sodium light and with other man man light sources. Even living in the green belt in the UK does not get you completely away from light pollution so it will be of benefit in many places. The 'RGB intensifier' and 'Ha intensifier' parts in the description just mean that it passes very high levels of these frequencies in a more braodband fashion so that it maintains a nice neutral tone compared with those such as UHC or even the UHC-S. It is possible it also counteracts airglow which is a natural phenomenon but I don't see any reference to this.

The key point though is that once HP sodium lights are replaced by broadband LED white lights, the Neodymium may well become less effective.

https://en.m.wikipedia.org/wiki/Skyglow

As for use for solar, it probably won't cause any degradation in the image, and although the transmission seems to be good at the 540nm line that the continuum filter passes, I would probably not use both at the same time when you get one.

 

[Dave In Vermont]

Stu is quite correct - they can't 'intensify' the emitted light. The amount of light you can see is determined by a number of factors such as atmospheric-conditions and what you're seeing up there. So while they can't increase the light that lands on them - they can give the illusion that the object is brighter by cutting off certains wavelengths, thus allowing dimmer ones to come to the forefront and shine.

Enjoy your filters!

Dave

 

 

[Ray of LIght]

4 hours ago, Stu said:

Ray, just a note that filters cannot intensify light. All they can do is cut out unwanted frequencies. It is quite easy to quote from the marketing words put out by Baader, but to say it is an RGB intensifier is I think misleading.

The company seven page says...

'What Does This Filter Do For Me? 
The filter is made with a special Neodymium glass that effectively filters out selective wavelengths of low-pressure sodium and other manmade sources typically used in street lighting. Although it is not a nebula filter, it enhances the views of deep-sky objects by increasing the contrast of these objects against the background sky. While nebula filters transmit only a few select wavelengths corresponding to various atomic lines, this filter transmits a large portion of the continuous spectrum while blocking a few select lines of the more common manmade light. Neodymium provides a unique, selective, blocking feature in that this element greatly reduces glare without reducing important color and brightness variations.'

So, what it basically does (and you can see this from the response curve I posted) is remove light in the specific frequencies associated with high pressure sodium light and with other man man light sources. Even living in the green belt in the UK does not get you completely away from light pollution so it will be of benefit in many places. The 'RGB intensifier' and 'Ha intensifier' parts in the description just mean that it passes very high levels of these frequencies in a more braodband fashion so that it maintains a nice neutral tone compared with those such as UHC or even the UHC-S. It is possible it also counteracts airglow which is a natural phenomenon but I don't see any reference to this.

The key point though is that once HP sodium lights are replaced by broadband LED white lights, the Neodymium may well become less effective.

https://en.m.wikipedia.org/wiki/Skyglow

As for use for solar, it probably won't cause any degradation in the image, and although the transmission seems to be good at the 540nm line that the continuum filter passes, I would probably not use both at the same time when you get one.

 

Thanks Stu! I will remove the Neodymium once I get the Solar Continuum filter. I wil keep it on with my FK until then. Of course it will go back on for night observing. The Company Seven verbage is slightly confusing. Thanks again.

[Mak the Night]

Well, the Baader Neodymium intensifies red, green and blue in a way as it's designed to filter to create that effect, ipso facto, even if you live in the greenbelt. A filter is designed to filter things, hence the transitive/non-transitive verb descended from filtre originally Medieval Latin filtrum which was a piece of felt used as a filter, ultimately of Germanic origin. Either way, the Baader Neodymium still isn't just a light pollution filter. Although I haven't the need for a light pollution filter anyway as I doubt their efficacy. I live in the greenbelt. When the seeing is good I can easily see the Milky Way and I've even seen moons of Jupiter with the naked eye. Probably because I live in the greenbelt at a high altitude above sea level.

[Ray of LIght]

3 hours ago, Dave In Vermont said:

Stu is quite correct - they can't 'intensify' the emitted light. The amount of light you can see is determined by a number of factors such as atmospheric-conditions and what you're seeing up there. So while they can't increase the light that lands on them - they can give the illusion that the object is brighter by cutting off certains wavelengths, thus allowing dimmer ones to come to the forefront and shine.

Enjoy your filters!

Dave

 

 

One of my other questions, Dave, Mak and Stu, is using planetary color filters for solar observing and which ones might work best (before and after I get the Baader Solar Continuum). I have been doing some research on this subject but I appreciate the feedback from more experienced observers. The #15 dark yellow, #8 yellow and #47 violet have been specifically mentioned. Possibly the #80A blue and #11 yellow-green. Do you think any/all of these might help for solar use? I ordered the #15 as I read good feedback on that one.

[Stu]

19 minutes ago, Mak the Night said:

Well, the Baader Neodymium intensifies red, green and blue in a way, even if you live in the greenbelt. It still isn't just a light pollution filter. Although I haven't the need for a light pollution filter anyway as I doubt their efficacy. I live in the greenbelt. When the seeing is good I can easily see the Milky Way and I've even seen moons of Jupiter with the naked eye. Probably because I live in the greenbelt at a high altitude above sea level.

Mak, whichever way you argue it, the Neodymium filter is designed to cut out sodium light pollution, and other man made light sources. If, by doing that it enhance RGB then fair enough, but either way it is a form of light pollution filter.

I would be very surprised if you had ever seen the Gallilean moons with the naked eye, it is perhaps a mistake easily made when a field star is close by, but any reports of it are pretty much unsubstantiated. 

[Mak the Night]

2 minutes ago, Stu said:

Mak, whichever way you argue it, the Neodymium filter is designed to cut out sodium light pollution, and other man made light sources. If, by doing that it enhance RGB then fair enough, but either way it is a form of light pollution filter.

I would be very surprised if you had ever seen the Gallilean moons with the naked eye, it is perhaps a mistake easily made when a field star is close by, but any reports of it are pretty much unsubstantiated. 

I've seen Galilean moons with the naked eye. Are you suggesting I'm lying? The Baader Neodymium is not just a light pollution filter. I shan't reply to this topic again.

[Stu]

Just now, Mak the Night said:

I've seen Galilean moons with the naked eye. Are you suggesting I'm lying?

Not lying, I'm suggesting you may have been mistaken.

[Mak the Night]

2 minutes ago, Stu said:

Not lying, I'm suggesting you may have been mistaken.

It's the same thing. I wasn't mistaken. I know what I saw.  I'm bored with this Stu. And the Baader Neodymium still isn't just an LP filter. I won't reply to this topic again.

[Stu]

http://www.denisdutton.com/jupiter_moons.htm