Herschel Wedges

[bomberbaz]

I have been looking at the Altair version and it makes many claims which can be found here at the webpage link. https://www.altairastro.com/altair-imaging-ready-2-solar-herschel-wedge-445-p.asp

Has anybody got one and how have they actually found it for visual. FYI I have a 80MM F7.5 Frac that I am considering using it with if it's as good as they reckon. 

I realise it states imaging ready btw, just thinking of visual too.

The in built polarising filter sounds very innovative and the sun finder at it's rear also sounds a good idea. 

But I have used a front mounted white light filter before and although it was fun to use, I never got much granulation which is something this wedge claims to excel at. Also this is also a 100 quid more expensive than the lunt alternative.

The other thing I am not sure about is the effectiveness of a continuum filter, perhaps someone could also shed some light (pardon the pun) on this for me.  Is it more a imaging aid rather than visual. Done a little reading but sometimes you find yourself going around in circles.

TIA

Steve

[Chaz2b]

1 hour ago, bomberbaz said:

Also this is also a 100 quid more expensive than the lunt alternative.

it’s also over A kilo heavier, so you’re  getting your monies worth ...lol, but bear the weight in mind...2.5kg!

chaz

1 hour ago, bomberbaz said:

 

 

[Louis D]

1 hour ago, bomberbaz said:

Also this is also a 100 quid more expensive than the lunt alternative.

It appears to be the same price or less as the 2" Lunt when cross shipping back to the US from the UK (no VAT, duties, or sales tax but large shipping cost).  The 2" Lunt is $299+tax and the 1.25" Lunt is $229+tax (and backordered) in the US while they are £339.00 and £149.90, respectively, in the UK.  The Altair is only £238.33 shipped to the US, which works out to $294 at today's exchange rate.  If it didn't weigh 5.5 pounds, I might be tempted to get one.

[bomberbaz]

37 minutes ago, Louis D said:

It appears to be the same price or less as the 2" Lunt when cross shipping back to the US from the UK (no VAT, duties, or sales tax but large shipping cost).  The 2" Lunt is $299+tax and the 1.25" Lunt is $229+tax (and backordered) in the US while they are £339.00 and £149.90, respectively, in the UK.  The Altair is only £238.33 shipped to the US, which works out to $294 at today's exchange rate.  If it didn't weigh 5.5 pounds, I might be tempted to get one.

Yes you are right, I was looking at the Lunt 1.25 version at £150

 

[Merlin66]

Using the Continuum filter improves contrast for both visual and imaging.

IMHO for bang per buck the Lunt 1.25" would do the job.

Don't expect to see much granulation - you really need a larger scope.

(I use the Baader Cool Herschel wedge)

[Louis D]

Would the view through a Herschel wedge and 90mm APO be superior to an 8" Dob with Baader Solarfilm?  I have the latter setup, but recently acquired a 90mm APO and am now considering getting a Herschel wedge for it.  I'll have to try six vintage new old stock notch interference color filters from Optica b/c I bought several years ago to see if they improve solar observing:

[Merlin66]

Louis,

You need aperture to really see the granulation, and good seeing, the cells are only around one arc sec.

I’d say the 8” with the Baader Solar film would give you the best chance.

[Stu]

I see plenty when the seeing is good in my 4”, although excellent conditions seem quite rare to really be able to open up the individual cells. I do have a 6” f10 scope which needs sorting but could be fun to try. It is intended as a PST Mod but could be good for white light too. I’m not sure how often the seeing would support an 8” scope for solar in the U.K. though?

[Merlin66]

IMHO the "sweet spot" seems to be around 100 - 125mm aperture.

Under good/ very good seeing you should get some worthwhile white light results.

 

[Stu]

12 minutes ago, Merlin66 said:

IMHO the "sweet spot" seems to be around 100 - 125mm aperture.

Under good/ very good seeing you should get some worthwhile white light results.

 

Yes, I completely agree with that 😄😄

[Bobby1970]

I bought the APM 1.25 wedge fairly recently. I have only used it twice so far on my 72mm scope. 

I would say the granulation was more noticeable than a solar film filter. Definitely more texture visible even with my small scope. 

Need to hook my ZWO 178 up to it to check how much better the images may well be. 

 

[bomberbaz]

Thanks for the replies people, I will think about it for now.

Maybe go 2nd hand rather than buy new. I have no intention of upping my aperture, I am very happy with the 80mm and buying another on top in the current situation is not something I am prepared to do. 

[PeterW]

2” wedges need greater back focus and might be an issue with some scopes, I have a 1.25”‘and have no trouble. I’d be very careful about suitable filtration of the image between eyepiece and camera use! Check twice before putting your eye down the eyepiece! A continuum filter is very useful. Some nice small scale subtle surface texture visible at the weekend. 
Compared to solar foil filters a wedge is way better... night vs day.

 

Peter 

[RT65CB-SWL]

I have the 1.25" Lunt wedge and use it with a TeleVue Ranger and extremely pleased with it. The reason I purchased the Lunt was the ND3.0 filter is built-in.

When used with the Baader Solar Continuum filter, (I also use a polarising filter with it), you see the Sun as a green disc, (it takes a bit of getting used to; after using a Thousand Oaks type 2+ glass filter for many years, which gives an orange/yellow disc). 

Edited April 8, 2020 by Philip R

[PeterW]

For imaging sometimes you want the option of less dense filtration to keep exposure times short - always check the filters before use. The green disk detail is a bit like the surface detail in hydrogen alpha, your eyes need to tune into it and get used to the colour.

Peter

[Chaz2b]

I just spent a good hour under the sun...phew! Using a Lunt 1.25” HW and ALL my eyepieces to get some comparisons, I found the TV 20mm pls gave my best view, plus I found the TV 32mm not to be parfocal and actually pulled it slightly up the tube to get focus, needs an extension!

The scope is a Celestron C80ED-R, I could just about make out some granulation, that’s with using a Baader continuum filter and then with a Baader polarising filter added.

I couldn’t see much green that everyone is mentioning, more yellowy, with slight greening to the edges.

Its a bit cloudy/hazy, and with humping it all downstairs then back up, I balked at getting the TS-130 out!

My advice? Get the best you can afford, go for the 2” HW, 2” filters too.

chaz

[bomberbaz]

thanks for all the responses guys, took delivery of a lunt wedge along with baader continuum filter today, good conditions to try it out. 

I enjoyed a good hour with it under a hot but very quiet sun.  I didn't check out the H-A scope for activity but no sign of any spots in white light.

I see what you mean about tuning your eyes to the view in order to pick out granulation, I was managing to get a little towards the end after trying different ep's and magnifications but it was difficult to get detail.  I think with further viewing and training the eye I can improve on it but probably the issue effecting it the most is a lack of aperture. I think I will see how I get on before I rush out and change/upgrade OTA's though.

Cheers, Steve