Visual filters

[ONIKKINEN]

This thread has piqued my interest. Most often i am stargazing from a B6 zone, would you folks say it makes a big difference to get a UHC filter on applicable targets? Mostly i just avoid fuzzies because its a bit disappointing from the skyglow perspective.

[John]

6 minutes ago, ONIKKINEN said:

This thread has piqued my interest. Most often i am stargazing from a B6 zone, would you folks say it makes a big difference to get a UHC filter on applicable targets? Mostly i just avoid fuzzies because its a bit disappointing from the skyglow perspective.

A UHC or O-III filter might actually let you see something of some nebulae that you can't see anything of currently. They work better still under dark skies of course.

 

[bosun21]

1 hour ago, John said:

UHC followed as rapidly as possible by an O-III

Astronomik is a good brand to aim for.

 

Just bought the UHC and the OIII . The others have to wait. Thanks folks 👍

[PeterC65]

2 minutes ago, bosun21 said:

Just bought the UHC and the OIII . The others have to wait. Thanks folks 👍

I'd be interested to hear how you compare these two when they arrive, as I decided to go for UHC rather than OIII.

[bosun21]

2 minutes ago, PeterC65 said:

I'd be interested to hear how you compare these two when they arrive, as I decided to go for UHC rather than OIII.

I’ll let you know Peter once they arrive and the clouds clear 

[Voyager 3]

Stu nailed it . The reason why folks say the OIII is not suited to smaller apertures is because , the larger exit pupil required for the OIII to strut it's stuff , will be  pretty low magnifications . Hence the nebulae will be smaller . This , is obviously a personal preference . Some folks swear that OIII below 6mm exit pupil will be a black view , while others use it upto 2mm or even lower for planetary nebulae . 

UHC, being larger in bandwidth , can generally take lower exit pupils(higher magnifications) compared to OIII/H-Beta which are line filters . 

PS : UHC is a combination of OIII and H-Beta lines . 

Edited November 24, 2021 by Voyager 3
Typo

[John]

10 minutes ago, bosun21 said:

Just bought the UHC and the OIII . The others have to wait. Thanks folks 👍

If the Veil nebula is still placed OK for you, the difference between these filters on that target will make an interesting comparison. If the Veil is not in a good place, the Owl Nebula (M 97) ) in Ursa Major is also another interesting "test" target for these narrowband and line filters.

[bosun21]

27 minutes ago, John said:

If the Veil nebula is still placed OK for you, the difference between these filters on that target will make an interesting comparison. If the Veil is not in a good place, the Owl Nebula (M 97) ) in Ursa Major is also another interesting "test" target for these narrowband and line filters.

Is the lumicon OIII any good or should I pull the trigger on the Astronomik. The UHC is already bought 

[bosun21]

The Astronomik OIII was out of stock but I found someone selling a Lumicon OIII. Please tell me that they are okay 

[Jiggy 67]

43 minutes ago, John said:

If the Veil nebula is still placed OK for you, the difference between these filters on that target will make an interesting comparison. If the Veil is not in a good place, the Owl Nebula (M 97) ) in Ursa Major is also another interesting "test" target for these narrowband and line filters.

An excellent idea John, below are my notes on the Owl sometime ago
 

 

Very faint, very small Planetary Nebula with a possible hint of blue. Used the Baader 8mm (x 125 mag), initially with the O111 filter but found this filter to obscure and darken the image too much so switched to the UHC filter which was much better and created a decent image, especially with averted vision. Also made an attempt with the Vixen 6mm (x 166 mag) plus UHC filter but very difficult with high mag and sky quality. Note: High wispy cloud crossing at times affecting view

[jetstream]

1 hour ago, ONIKKINEN said:

This thread has piqued my interest. Most often i am stargazing from a B6 zone, would you folks say it makes a big difference to get a UHC filter on applicable targets? Mostly i just avoid fuzzies because its a bit disappointing from the skyglow perspective.

Filters work well for nebula and an OIII will provide more contrast IMHO. Exit pupil selection is critical.

Btw, OIII,UHC and Hb work well in my scopes from 90mm to 609mm, with exit pupil being the critical factor. Filters dont work for galaxies, IMHO.

Get the OIII...

Edited November 24, 2021 by jetstream

[Stu]

14 minutes ago, bosun21 said:

The Astronomik OIII was out of stock but I found someone selling a Lumicon OIII. Please tell me that they are okay 

Hopefully it should be good. Lumicon used to be excellent, went through a dodgy patch but are now good again I believe. Have you got a picture of it? I have three original Lumicons all with very high transmission stats, and they are excellent.

[Stu]

59 minutes ago, Voyager 3 said:

This , is obviously a personal preference . Some folks swear that OIII below 6mm exit pupil will be a black view , while others use it upto 2mm or even lower for planetary nebulae . 

My 4” Genesis is f5, so with a 31mm Nagler I get x16 and a 6.2mm exit pupil, ideal for those big nebula.

Even with a little 72mm f5.9 the 31mm gives 5.25mm which is still fine with an OIII. At higher powers on PNs the UHC likely makes more sense to give a bit more throughput. Some of the Baader OIIIs can be very tight bandpass and so less suitable for smaller scopes I think.

[bosun21]

9 minutes ago, Stu said:

Hopefully it should be good. Lumicon used to be excellent, went through a dodgy patch but are now good again I believe. Have you got a picture of it? I have three original Lumicons all with very high transmission stats, and they are excellent.

There you go 

[John]

40 minutes ago, Jiggy 67 said:

An excellent idea John, below are my notes on the Owl sometime ago
 

 

Very faint, very small Planetary Nebula with a possible hint of blue. Used the Baader 8mm (x 125 mag), initially with the O111 filter but found this filter to obscure and darken the image too much so switched to the UHC filter which was much better and created a decent image, especially with averted vision. Also made an attempt with the Vixen 6mm (x 166 mag) plus UHC filter but very difficult with high mag and sky quality. Note: High wispy cloud crossing at times affecting view

That's interesting. For me, the O-III usually does a noticeably better job of enhancing the contrast of the Owl than a UHC does.

 

Edited November 24, 2021 by John

[Stu]

40 minutes ago, bosun21 said:

There you go 

Do you have the plastic case? They normally have transmission specs on the back.

[Stu]

1 hour ago, Jiggy 67 said:

An excellent idea John, below are my notes on the Owl sometime ago
 

 

Very faint, very small Planetary Nebula with a possible hint of blue. Used the Baader 8mm (x 125 mag), initially with the O111 filter but found this filter to obscure and darken the image too much so switched to the UHC filter which was much better and created a decent image, especially with averted vision. Also made an attempt with the Vixen 6mm (x 166 mag) plus UHC filter but very difficult with high mag and sky quality. Note: High wispy cloud crossing at times affecting view

Those are small exit pupils to be using so I’m not surprised the views were dim.

That’s where aperture does come into it, allowing you to maintain a larger exit pupil at higher powers. Some may be using 12” scopes and the same mag in an f5.3 12” would be achieved with a 13mm eyepiece, giving a 2.45mm exit pupil vs 1.6mm in an 8” f5 making the image brighter and an OIII more useable.

[bosun21]

14 minutes ago, Stu said:

Do you have the plastic case? They normally have transmission specs on the back.

I only bought it tonight so obviously not arrived yet. I saw that it was the older type that’s why I bought it. Here’s a very similar one 

Edited November 24, 2021 by bosun21
Photo

[Stu]

1 minute ago, bosun21 said:

I only bought it tonight so obviously not arrived yet. I saw that it was the older type that’s why I bought it. Here’s a very similar one 

Specs look good so fingers crossed you should be pleased with it 👍

[bosun21]

Just now, Stu said:

Specs look good so fingers crossed you should be pleased with it 👍

If not then I’ll just get the Astronomik OIII as they should be back in stock by then 

[bosun21]

I just noticed that one of the posts was talking about a night in the past viewing the Owl Nebula. The poster was referring to his journal. I am now going to keep a detailed journal of my nights under the stars. I am just wondering how many of you keep a proper journal?  I Maybe start a thread 

[jetstream]

10 minutes ago, Stu said:

That’s where aperture does come into it, allowing you to maintain a larger exit pupil at higher powers

Excellent reply Stu, this ^^ is the critical concept to understand. Upping the mag too much and reducing needed eye illumination will kill a filtered view in any scope.

Hopefully more members will use the concept of exit pupil vs mag... and then good filters will work in any scope.

[Kon]

12 minutes ago, bosun21 said:

I just noticed that one of the posts was talking about a night in the past viewing the Owl Nebula. The poster was referring to his journal. I am now going to keep a detailed journal of my nights under the stars. I am just wondering how many of you keep a proper journal?  I Maybe start a thread 

Already discussed here. I do not keep a journal but tend to post in SGL, this is my 'journal'.

 

[Stu]

I got lucky with mine which is why I will never sell them. I’ve yet to use the Hbeta but will hopefully give it a go on the Horsey this winter in the 16”.

[Stu]

12 minutes ago, Kon said:

Already discussed here. I do not keep a journal but tend to post in SGL, this is my 'journal'.

 

I’m the same, I still go back and reference reports I wrote years ago one here!