Using my Celestron 120mm Omni XL T

[wookie1965]

Used my Celestron 120mm Omni XL with a aperture mask with a 18mm BST, herschel wedge, variable polarising filter and S21

[Highburymark]

I wonder if you might get slightly sharper images with a green filter, or (more expensively) a Continuum filter, which Baader fits into its wedges. Obviously it turns the Sun into an unnatural colour, but you quickly get used to it, and with achromats it also reduces CA and boosts sharpness. Just a thought if you might have a green filter somewhere.

[wookie1965]

On 26/06/2024 at 17:04, Highburymark said:

I wonder if you might get slightly sharper images with a green filter, or (more expensively) a Continuum filter, which Baader fits into its wedges. Obviously it turns the Sun into an unnatural colour, but you quickly get used to it, and with achromats it also reduces CA and boosts sharpness. Just a thought if you might have a green filter somewhere.

Normally I do get sharper pictures but I was dodging clouds just wanted to see if it worked. I would love a continuum filter but like you said mega bucks. I use a magnifying glass to get the focus better but like I said I was just trying it. I do have a green filter also a UHC and a oiii filter I could try those. 

Thank you for the information appreciate the input.

[Stu]

Why using an aperture mask Paul @wookie1965? seems a shame to cut the aperture down? How was it visually?

[Mr Spock]

I have the Helios 120mm. It is completely transformed by a Continuum. At the moment you are only operating at about 10%!

This is a single shot. It doesn't capture anything like the actual detail.

 

[wookie1965]

10 hours ago, Stu said:

Why using an aperture mask Paul @wookie1965? seems a shame to cut the aperture down? How was it visually?

I only have a 1.25" Herschel wedge as far as I know they are only good up to 4" not supposed to use them on more aperture. I would need a 2" one and I haven't got the money for one of them. 

[wookie1965]

9 hours ago, Mr Spock said:

I have the Helios 120mm. It is completely transformed by a Continuum. At the moment you are only operating at about 10%!

This is a single shot. It doesn't capture anything like the actual detail.

 

Wow I will have to get saving then cracking shot. Saying that I can only use anything above 18mm eyepieces in my vixen it has not enough inward travel with the wedge, I have been told to cut a half inch off the tube but I am not so sure about that.

[Mr Spock]

What about the Astro Essentials green or dark green filters? At £9 there's little to lose by trying one. They won't have the narrow bandwidth of the Continuum but will cut out completely red and blue.

I also used my 120mm with a 1.25" Lunt without issue. It got a little hot on the back plate (that red thing that says 'Caution HOT' ) but not excessively so. It got to a similar temperature with a 100mm. I don't think a 120mm + 1.25" wedge is a problem in our climate.

[Stu]

5 hours ago, wookie1965 said:

I only have a 1.25" Herschel wedge as far as I know they are only good up to 4" not supposed to use them on more aperture. I would need a 2" one and I haven't got the money for one of them. 

I think that’s a myth Paul, particularly in our climate there is little risk of over heating; the back plate is designed to get hot and also designed to cope with a 4” scope in hot climates with the sun over head, so our conditions will be much cooler. Could always fit a UV/IR filter to the front just to be doubly sure.

[wookie1965]

7 hours ago, Mr Spock said:

What about the Astro Essentials green or dark green filters? At £9 there's little to lose by trying one. They won't have the narrow bandwidth of the Continuum but will cut out completely red and blue.

I also used my 120mm with a 1.25" Lunt without issue. It got a little hot on the back plate (that red thing that says 'Caution HOT' ) but not excessively so. It got to a similar temperature with a 100mm. I don't think a 120mm + 1.25" wedge is a problem in our climate.

Do you think this will work. 

[Mr Spock]

19 minutes ago, wookie1965 said:

Do you think this will work. 

Try it and see. 56 is the one listed as Green by FLO with 58a as Dark Green.