Lunt 2" Herschel Wedge

[RichieP]

Just a quick review of my Christmas present! I wanted one because I wanted to improve on the white light views provided with solar film, but I can't afford to get into Ha just yet.

I plumped for the 2" version of the wedge as it is rated for refractors up to 6", whereas the 1.25" is only rated for refractors up to 4". Although I only intended to use a 4" refractor, I wanted the flexibility, plus I always like the sturdiness of 2" diagonals.

The wedge comes nicely packed in its own aluminium carry case, with space to fit in some extra filters. The wedge on it own (with its integral ND filter) will reduce light by 99%, but this may be still too bright for some, so an optional polarising filter is recommended. As the ND filter is itself polarised, rotating a second polarised filter would allow one to adjust the brightness. I haven't gone down this route, and wanted to use a Baader Solar Continuum filter instead.

I have managed to get out with it a couple of times, using a 4" Helios Evostar refractor (that hasn't been used in years) on a EZTouch mount. The sun duly obliged with a good crop of sunspots. Used without the continuum filter, it was too bright, but with the filter it was the perfect level of filtering. Despite the sun being a bit too low in the sky, in those moments when the atmosphere steadied, I was astounded with how clear and contrasty the image was. It is a real step up from the Skymax 127 with solar film that I was using before.

In short, this has done exactly what I wanted it to do and I can't wait for the spring and summer months to really get to use it. Next thing will be to get a binocular viewer as I feel that this may make things even better.

Richard

[Luke]

Very nice write-up, Richard. The clarity in white light with a Herschel wedge and 100mm frac and reasonable seeing really is something!

[Moonshane]

I agree the step from film to a lunt wedge is worth the cost although I went for the 1.25" option. It works fine with my 120mm f5 sw cheapie frac. I also find the pol filter of benefit even with the bsc.

[Mark at Beaufort]

A great purchase Richard. I use my 4" Astro Tech APO plus the HW and Continuum filter and some binoviewers. The views are 3D and brilliant. I have been viewing the Sun since the mid 1960s and this new setup is such a great step up.

[PeterW]

2" wedge needs more In focus than a 1.25". There is no reason for needing a 2" as 96% of light travels straight through and out the back so it ought to work on any size scope. Another thing to be aware of is that the ND3 is fixed in, which means you have a very safe device, but if you want to take pictures with barlows you will end up with quite a long exposure, being able to choose the attenuation can be helpful.

Wedges are definitely the way to go for white light views, add in a green or continuum filter to help bring our granulation. Let's hope we get so,e good sun spots in 2015!

Cheers

PeterW

[Pig]

Great report Richard, the wedge aids higher magnification in my opinion compared to the film and some great close ups of sunspots and their surrounding detail can be achieved. Congratulations on the purchase

[bingevader]

Nice write up.

How do you find the heat trap and it's heat dissipation?

[spaceboy]

I'd be interested to see how the heat sinks coped in a side by side comparison of the 1.25" and 2" versions in various scopes. I have briefly tried my 1.25" in a 6" scope and it faired quite well but I did feel the need to constantly check the sink to make sure it didn't get too hot.

I managed 30-40 mins yesterday tracking the sun with my 4" and found that this got up to a similar temperature as in 6" after only 10 mins. Given how cold it was outside yesterday I think the Lunt HW has a duty cycle no matter what the recommended aperture to use it in. As with any solar observing you should always use the upmost of caution and treat a solar scope in a similar way as you would a loaded gun. Never leave one unattended, always supervise those who don't know how to use them and never underestimate the possibility of something going wrong .

[RichieP]

Nice write up.

How do you find the heat trap and it's heat dissipation?

It was only slightly warm. So no problems there.

[michael.h.f.wilkinson]

Nice write-up. BTW, the reflected light from the wedge itself is polarised, the ND3 filter generally isn't (though it could well be, in theory)