Altair 2nm G Band filter

[Highburymark]

Not sure it’s been discussed much here, but the Altair G-band 2nm filter is getting some great comments from white light observers and imagers elsewhere. Significantly improved faculae and granulation, from the images on Solarchat.

[Mandy D]

@Highburymark Looks impressive, but a bit ouchy on the price (1.25" £179.50), but 2 nm bandwidth is always going to cost. If I ever get any Sun, I might consider buying one.

[Highburymark]

31 minutes ago, Mandy D said:

@Highburymark Looks impressive, but a bit ouchy on the price (1.25" £179.50), but 2 nm bandwidth is always going to cost. If I ever get any Sun, I might consider buying one.

That’s the catch - but it does seem to be a game changer, whereas the narrower (7nm) Continuum filter from Baader is of borderline benefit, according to the imagers on other forums. 

[Mandy D]

@Highburymark I've currently got the 10 nm continuum filter, but so far have had no opportunity to try it out. Once I've got my wedge up and running successfully, I think I'll have to look into this.

[PeterW]

Similarly I am waiting for some more reviews, seems to do best with larger optics than I have available?!

Peter

[kmaslin]

Has anyone tried a 1nm filter? Aware they are not cheap >£500 with a supplier in US but wonder if significant improvement?

[Paz]

I have the 10nm and 7.5nm baader solar continuum filters and whilst the 10nm allows enough brightness to be dialled if for any set up or magnification that I might use, the 7.5nm sometimes means I run out of brightness and have to take the polarising filter out of the line to get as much light as I can.

I think a 2nm filter at Blue wavelengths is going to be quite dim for visual and so small exit pupils would be a challenge.

I'm sure I've tried deep sky filters on the sun before, a Hb filter would be not far off but I guess this Altair filter is very specifically designed and something slightly different is not going to show the same results.

[kmaslin]

should have stated that was only looking at this for astrophotography so image can be quite dim (and using a Herschel wedge to cut out majority of sunlight

If someone has used a 1nm filter would be interested to know if they see any structure (apart from sunspots) 

[Nigella Bryant]

The Altair G-Band filter is really great for white light. This image was taken using one.

[PeterW]

What size scope do you need to benefit from it?

Peter

[Nigella Bryant]

1 hour ago, PeterW said:

What size scope do you need to benefit from it?

Peter

Hi Peter, to get high resolution of granulation, etc it depends on a number of factors including seeing. However the G-Band will enhance these with any size scope. I do use a 127mm achromatic scope at the mo stopped down to 100mm. The images I took above were taken with this along with a 3x barlow. You don't need an expensive refractor because you're only in one bandwidth. So a cheap refractor will suffice. My 127mm was just £250.

[Highburymark]

On 02/02/2024 at 21:00, Nigella Bryant said:

Hi Peter, to get high resolution of granulation, etc it depends on a number of factors including seeing. However the G-Band will enhance these with any size scope. I do use a 127mm achromatic scope at the mo stopped down to 100mm. The images I took above were taken with this along with a 3x barlow. You don't need an expensive refractor because you're only in one bandwidth. So a cheap refractor will suffice. My 127mm was just £250.

Fantastic image Nigella. Incredible detail.