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Relpet

TS-Optics 1,25" Solar Prism with Polarizing and Narrowband Filter

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I missed the last Transit of Mercury in 2016 and as I shall be 93 when the next one comes around I thought I'd make an investment  for this year's.  Never having done any solar observing a fair amount of research was needed and it was quite clear I could spend either no more than two week's state pension or a couple of years' worth.  As I was going to be in England for the transit and being very familiar with the normal ghastly weather in an English November the more modest amount seemed appropriate.  After looking at various Herschel wedges the TS-Optics seemed the best value for what might be a one-off experience.  It seemed similar in design to the Lunt but came with polarising and narrowband filters, extra costs with the Lunt.  On the other hand the Lunt came with a ND3 filter pre-installed.  Looking further into this it seemed the ND3 filter in the Lunt could only be removed by voiding the warranty and breaking some kind of seal.

So, I bought the TS-Optics job to see how I got on with it just using the supplied filters.  There was a bit of sunshine around the day after it arrived so taking all the necessary precautions that I had read about (and taken to heart) I lined up my TS-Optics 80mm Photoline refractor using a variety of eyepieces and both filters.  Seeing a green sun was a bit unnerving but I was getting sharp focus down to 5mm and the polarising filter did the job of adjusting the brightness level by simple rotation of the eyepiece.

However, further reading suggested that the ND3 filter would improve the observing experience so I bought the Baader filter from FLO.  The eyepiece holder is removable from the TS wedge so I was able to screw the filter into the interior of the eyepiece holder effectively between the prism and the eyepiece itself.  So, it can either be a permanent fixture in the wedge or removable if I want to use it elsewhere.

Today the sun shone again, albeit through some thin haze, so I was able to try  the new combination.  Now I know what they mean by white light.  It was a revelation.  I'm not experienced enough to know what perfect conditions are like for solar observing but I have high hopes now when conditions are better.  Focusing down to 3.5mm using a SW7mm with a 2xBarlow suggested that when there is something to see like sunspots I stand a good chance.  Sadly in south-east England the chances of seeing the Transit of Mercury next Monday seem ever more remote.  Thanks for reading.

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The TS wedge comes with an ND3 filter preinstalled. It’s double stacked with the continuum filter in a single filter cell. You can remove this double stacked filter and just use a plain ND3 filter if ypu don’t like the green image.

Edited by johninderby

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That's great. I was set on getting one myself until a second hand Lunt wedge came up here. I'm happy with the Lunt but wondered if I was missing out not having the extra filter. I tend to view at 50x magnification but not recently because of clouds and lack of sunspots. Fingers crossed for Monday.

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There’s nothing wrong with the Lunt but if buying new the TS wins on value.

Just checked the forecast for the 11th. Wish I hadn’t now. 😢

613E9B68-CF8E-426B-A570-F7C8A319007D.jpeg

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2 hours ago, johninderby said:

The TS wedge comes with an ND3 filter preinstalled. It’s double stacked with the continuum filter in a single filter cell. You can remove this double stacked filter and just use a plain ND3 filter if ypu don’t like the green image.

This is the description by TS:  There's no mention of the ND3

The advantages of the TS-Optics 1.25" Solar wedge:

  • Particularly high-quality surfaces for very high contrast
  • Enclosed housing with integrated light trap - no escaping stray light
  • Cooling fins for quick removal of the heat
  • 1.25" polarising dilter for screwing into the eyepiece or into the filter for continous adjustment of the brightness without without additional colouring.
  • 1.25" narrow band interference filter dor significantly enhancing the contrast of the solar surface. Especially faculae regions are shown better. The filter has a bandwidth of approximately 40 nm and a peak at 540 nm. Now sun observation is possible with fast Fraunhofer refractors, as the chromatic aberration is removed.
  • Especially faculae regions are shown better. The filter has a bandwidth of approximately 40 nm and a peak at 540 nm. Now sun observation is possible with fast Fraunhofer refractors, as the chromatic aberration is removed.

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There certainly is an ND3 filter. Take apart the double stacked filter if you don’t beleive me.

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If we meet up on Monday Peter, we can take a look and fully understand what is there in terms of filters. My understanding is that an ND3.0 is absolutely required, along with either a polarising or continuum filter, just as John suggests.

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Just emphasising what @Stuhas already said. The Herschel Wedge is only suitable for fracs and the ND 3.0 filter is imperatively necessary - it is not a choice. A polarising filter to varying the remaining light output is optional, so too a Continuum filter. But NOT the ND 3.

I am aware of Herschel wedges which include the filter and likewise of wedges which do not. About a decade ago I purchased Lunt's 1.25" Herschel Wedge and even though I was assured it did have the filter included by the retailer, I still sent an email to Lunt and asked them to confirm this.

When it comes to viewing the Sun, I feel it's just not necessary to take any pointless risks. Make sure you're 100% confident in your set up before putting your eye to the eyepiece.

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Well said @Rob Sellent, can never emphasise that enough. I was too scared to try a Herschel Wedge for a long time, they just seemed inherently dangerous to me! The reality is that if you educate yourself properly, and always have a methodical approach when setting up, they are perfectly safe. In some ways safer than a front filter as if anything happens to the wedge, worst case you get a hot leg, or the view degrades.

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My old A&E wedge put a lot of heat out the bottom and you could burn your hand if you put it right under the wedge not to mention any children or pets looking up into the bottom of the wedge would get the full unfiltered sun. Definately not a safetry wedge and if you come across one bin it.

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9 hours ago, johninderby said:

There certainly is an ND3 filter. Take apart the double stacked filter if you don’t beleive me.

I don't want to quarrel over this but attached is a picture. of the narrowband filter.  Short of taking a bacon slicer to it there's no way I can see that there are two separate elements.

Narrowband filter.jpg

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9 hours ago, Rob Sellent said:

Just emphasising what @Stuhas already said. The Herschel Wedge is only suitable for fracs and the ND 3.0 filter is imperatively necessary - it is not a choice. A polarising filter to varying the remaining light output is optional, so too a Continuum filter. But NOT the ND 3.

 

That's why I bought the Baader ND3, Rob,  after reading extensively and taking previous advice from Stu and others.  As it is it looks like another significant investment to meet the needs of a special event will fail to pay a dividend.  I sent an email to Teleskop-Express asking them to confirm that an ND3 filter was not incorporated in their package - which they did.

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Unscrew the inner ring on one side of the filter and you will find two filter elements stacked together inside..Note there are a couple of tiny slots on the inner ring that you can use to unsrew it using a tiny screwdriver. There is a pic of this in the thread I linked to but here it is again. Please also note the OP of the thread I linked to asked TS about it and they confirmed there was an ND filter. Did you ask if there was a seperate ND filter which there isn’t as it is a combined filter.

514713B2-6088-4879-884B-CAA42C3671BD.jpeg

Edited by johninderby

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45 minutes ago, Relpet said:

That's why I bought the Baader ND3, Rob,  after reading extensively and taking previous advice from Stu and others.  As it is it looks like another significant investment to meet the needs of a special event will fail to pay a dividend.  I sent an email to Teleskop-Express asking them to confirm that an ND3 filter was not incorporated in their package - which they did.

FLO will take the ND3.0 as a return if not needed Peter. It does appear the TS is already fitted with one, otherwise to be frank it would be dangerous to use.

Did you say the view improved when you fitted the Baader?

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As John said, there is an ND3 filter stacked on top of the narrowband filter. I spoke to TS optics who confirmed the dark element is an ND3. I also have a separate Baader ND3 filter which I sometimes use instead of the ND3/Narrowband filter. Just gives me the option of a white Sun instead of a green Sun.
 

Nice review of a very good value for money wedge :) 

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Useful post, I bought one of the TS solar wedges a couple of months back and never realised there is an ND3 in effect built in with the continium, so just bought a separate ND3 to use under the clouds Monday.

Don't need the second ND3 now, bit unimpressed as everything indicated no ND3.

Just separated the TS filter and yes there is an ND3, will say I did wonder why the continium appeared rather dark, now I know.

Have to remove the ND3 I bought from the internals of the wedge as I would expect ND6 to be a little on the dim side. That was money I didn't need to spend.

Also need to clean the TS filter now.

Suppose like Neil I can have white or green.

Edited by PEMS

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TS just say all necessary filters included which as an ND3 is necessary infers that one is included but they should state clearly that one is included to prevent any misunderstanding..

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22 hours ago, johninderby said:

Unscrew the inner ring on one side of the filter and you will find two filter elements stacked together inside..Note there are a couple of tiny slots on the inner ring that you can use to unsrew it using a tiny screwdriver. There is a pic of this in the thread I linked to but here it is again. Please also note the OP of the thread I linked to asked TS about it and they confirmed there was an ND filter. Did you ask if there was a seperate ND filter which there isn’t as it is a combined filter.

514713B2-6088-4879-884B-CAA42C3671BD.jpeg

Thanks for putting me right about that, John.  I managed to unscrew it with a toothpick.  This was the question I asked TS.

"I believe that the TS-Optics solar prism, unlike some other brands, does not incorporate an ND3 filter within the unit.  A friend has recommended I buy one so I have ordered a Baader filter from a UK supplier. Where in the sequence should I fit an ND3 filter please?"

Their reply was:

"yes you are right is not incorporated. a polarizer is provided, but you can use also a ND one, as you prefer. the sequence is the same."

So, it seems to me TS are missing a trick as it seems their wedge is even better value than I thought.

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10 hours ago, johninderby said:

TS just say all necessary filters included which as an ND3 is necessary infers that one is included but they should state clearly that one is included to prevent any misunderstanding..

Especially when they told me in writing that it ain't included!  Thanks to all.

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22 hours ago, Stu said:

FLO will take the ND3.0 as a return if not needed Peter. It does appear the TS is already fitted with one, otherwise to be frank it would be dangerous to use.

Did you say the view improved when you fitted the Baader?

I like the Baader, Stu, and it's now a permanent fixture in the wedge so I'll never forget.  The improvement was the difference between white and green and may have been only apparent as the tests were some days apart.  I haven't used it under a perfectly clear sky yet and being completely new to solar can't guess how good it is or if it should be better.  I look forward to comparisons if Monday works out.

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On 08/11/2019 at 00:54, johninderby said:

Unscrew the inner ring on one side of the filter and you will find two filter elements stacked together inside..Note there are a couple of tiny slots on the inner ring that you can use to unsrew it using a tiny screwdriver. 

Thanks again, John.  I just realised that by removing the ND3 element from the TS filter it would leave me with the green element to use by itself.  So with the Baader ND3 permanently installed in the wedge I can then apply the green filter to the EP if that gives me a clearer view, take it away again if not.  The polarising filter still comes into play in any case.  Thanks again for your patience.

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Another nice feature is the T2 thread on the eyepiece holder. I use my Baader clicklock eyepiece holder on top of this. I also use this with my Baader diagonal. Makes for easy eyepiece changes and if you want to rotate the eyepiece to adjust brightness with the polarising filter. 

ED484489-8F78-42ED-A940-6E27607A0511.thumb.jpeg.ebaa7e5d474ef3331fca1389a212ca3b.jpeg

F4F4EEC8-D7A3-4781-855B-4539A0D8701B.thumb.jpeg.564f535851476b352af71b9db987d0bd.jpeg

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On 07/11/2019 at 14:22, Stu said:

...an ND3.0 is absolutely required, along with either a polarising or continuum filter...

I use either or both at the same time with my Lunt wedge. The ND3.0 is built in to it, (any attempt to remove or modify it, voids the 'lifetime' guarentee/warranty).

Edited by Philip R
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