First light - Herschel Wedge

[Stu]

Wow, in between watching Murray winning, I put the Stellarvue 80ED out with the APM Herschel Wedge. Popped in a 32mm TV Plossl as a finder and fairly easily got the sun in view. Even at that low magnification, the detail is stunning.

I played around with a few EPs before settling on an 8mm Delos which gave the best sharpness and detail for the conditions which are a little shimmery in the heat.

There is a very large active region nicely placed and the detail visible is amazing! I tried the Continuum filter with and in place of the Polarising filter but really didn't find it added anything. Maybe on another day when conditions are more stable it may help.

I shall have a lot of fun with this, and alongside the PST it will be a lovely way to go solar observing. Long term aim is for a stage 2 mod with a Vixen 80M but the PST will do nicely for the moment.

Enjoy the sun while its out :-)

Stu

[Steve Ward]

Nice report Stu ...

Nearly pulled the trigger on one earlier in the year , but when I realised I couldn't use it on the big Mak I decided against it .

Hope it gives you years of great views ...

[Stu]

Thanks Steve, I think it will!

Here's my little setup, works well.

I would say, if you are tempted then go for it, you can pick up a nice long focal length refractor to use it with for not much money and have some lovely views.

Cheers

Stu

[Steve Ward]

It would complicate my imaging routine though , and the prospect of better detail in the full disc shots without being able to replicate it in close-up with the Mak180Pro would really grate ...

[lukebl]

Please forgive my ignorance but what does a Herschel Wedge do, given that you're still just viewing in white light, that a £20 sheet of Baader Solar film won't do?

They seem to me to be a heck of a lot of money for little gain, but I guess I must be missing something.

[Stu]

It's definitely more expensive than Baader Solar Film but I didn't think €199 was too bad for the kit including filters.

The wedge itself passes only 5% of the light through towards the eyepiece, the rest goes into a heat sink. This is still too bright obviously, so you use an ND 3.0 filter which reduces the brightness by a factor of 1000. This is ok for imaging I believe but still too bright for observing so you use a polarising filter in the ep barrel to reduce it further. By rotating the eyepiece you can adjust the brightness to the optimum level.

I've not done too much with solar film (a bit with an ST80) so haven't too much to compare with, but by all accounts the level of resolution is far better with a Herschel Wedge. My first experience with it today tends to back this up, I'm very pleased, and am sure it will be even better with the 106mm apo :-)

Stu

[Merlin66]

A couple of comments:

The TS 102/ Lyra refractor will take both a Stage 2 PST mod and works very well with the Herschel wedge. Go for a "quick change-over" adaptor...

The Herschel wedge brings out that subtle detail that seems to get lost with other filters. Think of it as a significant "eyepiece" upgrade - like going from a GSO plossl to a Nagler/ Delos - same view, but different!!!

[Stu]

Thanks Ken. Will have a think! Trying to keep costs down at the moment, D-ERF gets that much more expensive at 102mm but am sure the view is fabulous

Stu

[Moonshane]

I looked through Mark's Herschel wedge and long achro at PSP 2012 and the difference in detail over film is significant. in fact the view was so crisp it almost made me want to get a frac (seriously). if you have a frac for me it's worth it. enjoy Stu!

[Stu]

Thanks Shane. It really was a nice view. Very clear definition between umbra and penumbra in the sunspots, and loads of other detail including lots of what I think are pores. Still learning the terminology!!

Couldn't see much in the way of granulation but perhaps the seeing wasn't up to it. From Steve's report, perhaps early morning is best?

Stu

[michael.h.f.wilkinson]

Glad you like the Herschel wedge. I find it is very sharp indeed with my 80mm APO, and gave stunning views of AR 1785, which is putting on a real show at the moment

[Stu]

Thanks Michael. Yes, am delighted, thought a Herschel Wedge was out of reach financially so very pleased to find out about this one ( through a thread on SGL of course :-) )

Is your 80mm a triplet? I was impressed with the level of detail and the contrast available in my 80mm ED doublet, and can't wait to try the 106mm

Stu

[michael.h.f.wilkinson]

Thanks Michael. Yes, am delighted, thought a Herschel Wedge was out of reach financially so very pleased to find out about this one ( through a thread on SGL of course :-) t

Is your 80mm a triplet? I was impressed with the level of detail and the contrast available in my 80mm ED doublet, and can't wait to try the 106mm

Stu

Mine is a triplet. I have not tried using the ST80 (why bother if you have the APM 80/480).

[Stu]

Sounds very nice. Yes indeed, why bother with ST80!!

[Mark at Beaufort]

Stu I knew you would like the Herschel Wedge. Now try viewing with binoviewers it will blow you away

[Stu]

Thanks Mark, I do indeed! :-)

I was tempted to try the binoviewers yesterday but didn't want to push my luck - family and children around for a BBQ so managed to sneak the scope out in a post lunch lull!

I did notice quite an annoying floater in my observing eye which hopefully would be alleviated by using BV's? I guess using the 106mm at similar mag (x70) would also push the exit pupil up a bit and improve things.

Let's hope this weather holds!

Stu

[Stu]

Sorted the Giro so I now have Ha with the PST side by side with the Herschel Wedge/80ED. Very nice! Slightly confusing because the image orientation is different between the two, but I'll cope.

Stu

[michael.h.f.wilkinson]

Nice set-up. I have used a side-by-side set-up with my Lunt and APM 80/Herschel wedge on the GP mount. Works nicely

[Stu]

Very nice Michael. Looks a bit fresh though!!

I'm still trying to work out which filter combination gives best results. I have tried polarising filter, continuum and both together. Polariser on its own is nice as you can vary the brightness. The Continuum seems to give slightly sharper results but I'm still only seeing glimpses of granulation. Perhaps because I have mainly been observing with the sun low down? Will try with the 106 and see if that helps.

Stu

[Mark at Beaufort]

Stu I don't see granulation across the whole surface every time but it certainly has been visible in my 4" Astro Tech APO frac. Because the weather has been good I have been solar observing every day either with the William Optics SD66 or the Astro Tech. I have decided that the most comfortable viewing is with both the continuum and polarising filter in place. Having some great sunspots over the past few days has made the observing very enjoyable either with binoviewers or my 8mm Ethos on the SD66.

Have you ventured to try the TV76? yet?

Mark

[Stu]

Thanks Mark

I do see it fleetingly with the SV 80ED, will try both filters together and also use the 106mm.

Yes, I tried the TV76. Worked well as standard but I couldn't get it to focus with the Binoviewers. I think I may need to find some different adaptors to shorten the optical path. I managed with the SV80ED but had to use the correctors to bring it to focus. Can always use the removable section of tube for this though so I know it will work. The TV76 seems to be more of a challenge!

Is there a 2" adaptor which connects directly to the thread on the Wedge? Any idea what size this thread is? I think this will help, and make for a more stable connection too.

Also, can you connect the BVs more directly to the Wedge whilst still being able to put the filters in the optical path?

My final problem with the BVs is that they don't seen to be collimated, need to have a play around with the various adjustments.

Too many variables at the moment, will work through them one by one.

Stu

[michael.h.f.wilkinson]

I can see granulation across the disc with my 80mm and just the Baader Solar Continuum filter. My 7mm XW is the EP I use most often (should get myself a 5 too)

[Mark at Beaufort]

Stu I need to use the 1.6x barlow to obtain focus with the binoviewers when I use the Herschel Wedge on the 4" frac. I screw both filters into the barlow and then mount the whole lot into the HW. The HW has a longer tube to accomodate the filters so the inward focus can become a bit tight. I have not be able to gain focus with the William Optics SD66/Binoviewers until the other day. I have been given the opportunity to try the Baader Q Turret barlow which lengthens the outward focus but the supplied optics don't have a filter screw thread which means in theory will be no good on the HW. However, I have the Baader Hyperion barlow which does work and has a filter screw thread.

I have inserted the Q Turret barlow with Hyperion barlow and screwed both filters into the base and then added the binoviewers. This brings out the focuser by about an inch and therefore I obtain sharp focus on the WO SD66. The downside is the weight at the back and the mag is increased by 2.25x although with the extra travel I think its nearer to 3x.

The view with binoviewers using 25mm plossls is excellent and the Sun fills the FOV.

Does that answer your query?

Mark

[scoobee]

Hi

I have tried to use my Herschel Wedge several times for imaging but fail to get the image in focus despite using a 50mm extension tube (focusing).

What makes me like the herschel Wedge is the sharp and crisp views you get when observing, well-worth the money.

[Mark at Beaufort]

Reading my thread again I think I needed to explain why I was using the whole Q Turret and not just the optical coorector/barlow. My binoviewers have the wrong thread size to screw in a corrector or filters so I needed an adapter. Stu I would guess that using something like the Baader Hyperion zoom barlow which can be screwed direct into your binoviewers will allow you to gain focus with the TV76. This is the product that I am referring to - http://www.firstlightoptics.com/baader-planetarium/baader-hyperion-zoom-barlow.html

However, you may feel that £90 is not worth the expense when you can have a great view of the Sun with a single EP.