Herschel Wedge - does size matter?

[Dave Smith]

I am considering getting a Herschel wedge but am not sure if the size matters. 2" or 1.25" There is quite a big difference in the price so presumably people are buying the 2" for some advantage. I'm thinking of using it on my 90mm Megrez refractor for both imaging and visual observing. Is the Baader any better than the Altair Astro version? Thank you for any views.

Dave

[Pig]

I had the Lunt 1.25” and it worked superbly...... do you have many 2” eyepieces to use with the 2” wedge? if not I would go for the 1.25”.  I am not sure if the visual and imaging wedges are the same so it may be worth checking out before you purchase ?

 By the way I like the hat ?

[Dave Smith]

3 minutes ago, Pig said:

I had the 1.25” and it worked superbly...... do you have many 2” eyepieces to use with the 2” wedge, if not I would go for the 1.25”.  I am not sure if the visual and imaging wedges are the same so it may be worth checking out before you purchase ?

 By the way I like the hat ?

Thank you. I mostly use 1.25" eyepieces, I do have a 2" 30mm.

The hat is Kangeroo 

Dave

[Stu]

I have no idea if the size makes any difference, but I certainly saw a difference in performance between the Lunt 1.25” and the Baader CoolWedge. To me the differences become clear when the seeing is good and you push up to high powers. When used with a good scope the results can really be quite staggering.

[Red Dwarfer]

1.25 is suitable for refractors up to 100mm - 2" model is for up to 150mm 

So , in short , it`s different sizes for different size refractors 

[Doc]

I used to have the Baader Herschal wedge in 2" format and it was excellent. As Stu mentions it could handle high magnifications very well indeed. I have never used the Lunt so cannot comment on that but if you can stretch to the Baader it's worth it.

[AdeKing]

The choice between the 1.25" and 2" Herschel wedge will depend on your preferred eyepiece size (1.25" or 2") and the diameter of the Frac you'll be using.

When I was researching my purchase of a wedge, I found that the Lunt website recommended a 2" wedge was used for refractors up to a 6" diameter and the 1.25" for refractors up to 4" diameter but I've read reports that it's good for larger diameters.

https://luntsolarsystems.com/product/white-light-solar-wedges/

I opted for a 2" Lacerta Herschel wedge with the view that I might upgrade to a larger Frac, but I picked up a used 1.25" Lunt Wedge for a good price and it only gets slightly warm with a ST102.  The 2" wedge doesn't even get slightly warm when attached to the ST102 and is absolutely massive in comparison (see attached).

https://www.365astronomy.com/Lacerta-Brewster-angle-Herschel-Wedge-with-48mm-Prism-ND3.0-2-Nosepiece-and-2-Rotator-Eyepiece-Holder.html

The 1.25" Lunt is what gets used 99% of the time, but the 2" one is there waiting for the day I get my 6" Frac.

Unless you're using 2" eyepieces or a larger Frac I'd go for the 1.25" wedge.

[Dave Smith]

Thank you all for the very helpful comments. I have plenty to ponder on there.

Dave

[At dusk]

I’ ve owned a baader 2” herschell prism for over 5 years. I really enjoy It. The picture of the sun spot in my avatar was taken with It. However I would  recommend the 1.25” wedge unless most of your eyepieces are 2” . Many 1.25 eyepieces won’t reach  focus and you will have to buy a shorter t2 adapter to use them

(I can’t reach focus with any 1.25” eyepiece with my fc100dc and only with some in my tsa 120 feathertouch version)

if you need different ND filters for visual or photographic  applications, they are most expensive...

there’s only an advantage in case of using It with a really big refractor.

 

[Moonshane]

I chose the Baader 2" for a different reason, that of T2 connectivity. This helps particularly with my binoviewers which also connect through T2. This allows the binoviewers on my unmodfed 120mm Equinox. That said I happily used the 1.25" Lunt with my old 120mm ED with no issues.

[Piero]

I have the 1.25" Lunt HW and 2" Baader HW, and I agree with what Stu said previously. Nowadays, my 1.25" Lunt is only used with my TV60 which comes with a 1.25" focuser.

The Lunt is very good but to me the 2" Baader offers the following advantages: 

1. even crisper view, particularly at higher mags (in line with Stu's comment);

2. much better heat dissipation with my 100mm refractor (the Baader only reaches mild temperatures);

3. the Baader comes with the 2" solar continuum filter which to me is a great tool;

4. the 2" solar continuum filter is placed before the ND3.0 filter, resulting in less reflections compared to the Lunt. In the Lunt, that filter can only be placed at the end of the filter stack;

5. last point, my most used eyepieces are in 2" format, so the Baader is handy. I only use medium-high power only for WL solar obs. 

 

 

Edit after reading Moonshane's post. 

If you intend to observe with binos at some point, the Baader can be user friendly as you can replace the clicklock with the binoviewer gaining some light path. 

[Space Hopper]

like this.....

 

     

[Stu]

41 minutes ago, At dusk said:

Many 1.25 eyepieces won’t reach  focus and you will have to buy a shorter t2 adapter to use them

(I can’t reach focus with any 1.25” eyepiece with my fc100dc and only with some in my tsa 120 feathertouch version)

That is interesting. I don’t have any problem reaching focus with 1.25” eyepieces in my DC but it does have a FeatherTouch fitted. I use binoviewers most of the time now but with the Barlow elements used inwards focus is no problem. I tend to use anything up to x200 when seeing is good enough.

I believe there is a removeable section in the Tak focuser that can give you a lot more infocus if needed.

[John]

I have the Lunt 1.25" Hershel Wedge. I've used it very successfully with my ED doublet refractors which are 70mm, 100mm, 102mm and 120mm aperture. The heat sink at the rear of the wedge gets no more than warm even with the larger aperture mentioned. The eyepiece end filter I use is a single polariser which seems to do a good job and, by turning the eyepiece in the holder, allows the brightness of the solar image to be adjusted quite finely.

I'm not a solar aficionado though, more of an occasional observer. I've been impressed by the the Lunt Wedge though and it's been very popular at outreach events too.

[LukeSkywatcher]

All of my Eps are 1.25 so I bought a 1.25 wedge. I use it with a 70mm refractor. 

[25585]

This is a good thread topic!

Newbie question, what is the whole sun's FOV in degrees? To look at the whole orb in an ep with sufficient TFOV and eye relief would be the determining factor for me on size to buy. 

Also H alpha for prominences and surface detail generally. 

Cooling obviously is important, so glad to read of recommendations on that. 

Solar scopes are small fracs so presumably they come with 1.25 wedges. For (say) a Lunt 60mm double stack kit, would there be any point in choosing a 2 inch wedge?

[Pig]

The sun is half a degree the same as the moon, hence the eclipse ? The focal length of the eyepiece used determines how much of the disc you see, a full disc is very achieveable, in my 80mm Esprit a 6mm SLV delivered a full disc. The wedge does not work with a dedicated solar scope.

[Stu]

11 minutes ago, 25585 said:

Solar scopes are small fracs so presumably they come with 1.25 wedges. For (say) a Lunt 60mm double stack kit, would there be any point in choosing a 2 inch wedge?

Be careful, you are mixing Ha and white light. A wedge is only for white light with a standard refractor, not to be used with Lunt or Coronado Ha scopes.

[Stu]

14 minutes ago, 25585 said:

To look at the whole orb in an ep with sufficient TFOV and eye relief would be the determining factor for me on size to buy. 

Full disk is nice, and quite achievable even at relatively high powers. If seeing is good enough though I prefer high power detail views.

[25585]

Would a solar continuum filter increase detail used with a HW?

[Pig]

Yes... granulation is increased but only very slightly in my opinion. It also gives a green colour like a green filter.

[Stu]

3 minutes ago, 25585 said:

Would a solar continuum filter increase detail used with a HW?

I find that it helps particularly with faculae and to a lesser extent granulation. Another one of those marginal improvements that all help though.

[At dusk]

8 hours ago, Stu said:

That is interesting. I don’t have any problem reaching focus with 1.25” eyepieces in my DC but it does have a FeatherTouch fitted. I use binoviewers most of the time now but with the Barlow elements used inwards focus is no problem. I tend to use anything up to x200 when seeing is good enough.

I believe there is a removeable section in the Tak focuser that can give you a lot more infocus if needed.

I purchased the Fc100 because its low weight to use it as a grab`n`go telescope on my SW wifi gt. I`m thinking of buying a feathertouch focuser from flo when it's back in stock although it will add some weight, because the back focus is a real pain

In order to reach focus I must remove the section you mention and add a 2" extender.  

It's good to know that the ft will help

[Pig]

I can achieve focus with all my eyepieces with both 1.25 and 2 “ diagonals in my DF.... the Nagler 12mm was a bit of a problem with back focus but a 1.25” adapter placed in the 2” diagonal corrected it ?

[Stu]

24 minutes ago, At dusk said:

I purchased the Fc100 because its low weight to use it as a grab`n`go telescope on my SW wifi gt. I`m thinking of buying a feathertouch focuser from flo when it's back in stock although it will add some weight, because the back focus is a real pain

In order to reach focus I must remove the section you mention and add a 2" extender.  

It's good to know that the ft will help

Good choice, same as me  

There is a thread around which discusses the various focuser options, I’ll dig it out.