Starting white light solar

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SimonM
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Starting white light solar

Post by SimonM » Mon Dec 28, 2020 1:57 am

I know absolutely nothing about white light solar viewing/imaging. I know it is the end of cycle 24 and the start of 25. Still, something to be trying?

I would like to get an expert opinion on starting with the Baader 2" Herschel Safety Wedge Solar Prism.

I have an Esprit 100 refractor 550mm and f/5.5 and would be using either a 5mm or 8mm 1.25" EP.

My understanding, so far:

1. The Baader Solar Continuum filter that's included is required e.g. if I considered using a Lunt 1.25"/2" Wedge then I would also have to factor in the cost of the filter.

2. The filter passes the green light (so the APO isn't that important) and stops harmful UV/IR by reflecting it back and out of the OTA. In the Baader, it is the first filter AFTER the prism.

3. The 5% of the light that passes past the prism is still much too bright for visual use and the ND 3.0 filter cuts 99.9% so it is no longer harmful, but perhaps still uncomfortable.

4. The polarising filter then cuts the light percentage depending upon the angle compared to the polarised output from the prism.

5. The Baader Solar Continuum filter has no "surprises" and is a second version (since 2015) that doesn't have "hidden" transmission of UV/IR, unlike a previous, thicker "mount" version.

6. Baader uses a 2" nosepiece that does have an M48 thread but suggests that no filter can be used ahead of the prism. That seems to be at odds with other solar setups e.g. a Quark, where putting a UV/IR filter ahead of the prism is deemed the right thing to do and because it reflects, there is no buildup of heat.

I was tempted by the Lunt 1.25", but would be using a 1.25" adapter and a 2" filter in the adapter, in front of a 1.25" EP. Is there a disadvantage of using the Lunt e.g. more heat dissipated, or moving to the 2" Lunt, needing the filter. The USP of the Baader seems to be for careful imaging the ND 3.0 can be slightly reduced. I'm guessing this allows shorter (and sharper) subs. It's also suggested that it is better to have the Solar Continuum filter ahead of the ND 3.0 filter - that isn't possible with the Lunt. Is that because it "reflects" the UV/IR back out of the OTA?

There seems to be a focus on h-alpha and not white light. Is that because the incidence of sunspot activity has been at a minimum e.g. 2019 and 2020 and that the cycle is now picking up e.g. 2025 will be the next peak and cycle 25 isn't going to be without activity. Is it not considered worth going for the white light imaging?

I do already have a UV/IR filter ahead of my mono 178 camera. No need to pull this filter?

178 and Esprit, equals a small crop. I realise a colour camera isn't ideal, but FOV from my 294C or DSLR is far wider, still not to use them? Or a simple 0.5x Reducer to open things up is a better option?

Simon



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Re: Starting white light solar

Post by Montana » Mon Dec 28, 2020 4:25 pm

A very warm and sunny welcome Simon :hamster:

I can only give you a view of the Baader photographic Herschel wedge as that is what I own.

There is no need for anything in front of the Herschel wedge, it reduces the light down to 5% as you mentioned. It is afterwards that you add the filters. In the Baader photographic wedge it comes with an array of neutral density filters so that you can mix and match any combination of light output for either visual or photographic views. There is always a combination to suit so there is no need for polarising filters. The Continuum filter only fits in one configuration so you can't get it in the wrong place. Unless you have an amazing refractor you must use a UV/IR filter to image with as the out of focus UV/IR will make the image blurry but not necessary for visual technically as you can't see it but I would be cautious with the eyes so it is up to you (technically safe). However with my TEC140 I have no need to add one as it is well corrected naturally. The Continuum filter does pass UV/IR so must be used with a cut filter in most cases. Try with and without to satisfy yourself.

Most folks haven't been using WL as there hasn't been any spots to see, but I adore WL granulation and polar faculae so I have carried on regardless throughout minimum :) I adore WL.

Kind regards
Alexandra



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Re: Starting white light solar

Post by DeepSolar64 » Tue Dec 29, 2020 1:44 am

Simon,

I use an Altair solar wedge. I do have a 540nm green Baader Continuum filter and a Svbony UV/IR cut filter which can be screwed into the eyepiece behind the wedge. It also comes with an eyepiece mounted ND3 filter as well. The polarizing filter is built into the wedge and brightens/dims the image by turning the eyepiece barrel. It works very well giving high contrast sharp white light images. Mine is a 2" model. It came with an adapter for 1.25" eyepieces.

I use my wedge with Celestron 102 and Astro-Tech AT72EDII refractors.

When I set up for solar I usually set a pair of scopes up. An Ha scope, in my case a Coronado and a white light scope. Either with the wedge or my little 70mm Orion which has a permanently installed glass filter over the objective. I set up this way no matter what the activity is. A spotless sun is still an observation nevertheless and is still important. Both Ha and WL compliment each other for a more complete view. Other wavelengths like CaK, Sodium D line and Gband even help more expand the view.

Blessings

James


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Re: Starting white light solar

Post by SimonM » Tue Dec 29, 2020 7:45 pm

Alexandra

Thank you for the spinning (zenith aligned) hamster.

See the attached link (at 3:00 there is “solar” activity – LOL):

https://www.youtube.com/watch?app=desktop&v=kGOTIt2wJXs

I have now ordered the Baader Herschel Safety Wedge and also a polarising filter from FLO.

I was originally trying to choose between either the Baader, Lunt or Altair 2” wedges and (briefly) the 1.25” Lunt model. It is difficult to make choices about something you don’t have any first-hand knowledge about.

I know that the sun emits about 50% heat and 50% light and is quite a powerful source of energy is up to about 1 kW/m2, so for my Esprit 100 that’s about 8W of energy entering the OTA. I have to assume that the design of the Herschel wedge (from the 1830s) is able to divert 95% of both the heat and light (otherwise we have a problem) so that there is “only” 400mW of energy before any of the supplied filters and about 7½W of “wasted” energy to dissipate.

Although the ND 3.0 filter reduces the light by another factor of 1000, I’m not convinced that there is no additional heat “bouncing around” inside the wedge, with some coming in the direction of my eyeball, so yes, I will always be using a UV/IR cut filter. If nothing else, at least half the energy is in the form of heat and since we are more aware of light than heat, I will consider that good “eyeball” insurance.

Originally, I was uncomfortable with the idea of having filters that could be exchanged, so the visual version of the Baader was more appealing, but (with some maths out of the way) I’m more comfortable with the photographic version especially as I might use one of the “spare” ND filters in addition e.g. on the filter thread of my 1.25” adapter.

There were some unknowns, which I tried to quantify e.g. will I have sufficient back focus for my 1.25” EPs and my DSLR as well as my two imaging cameras. I read up on your equipment and see that you have been using a TEC 140 scope and I know that the back focus is about 170mm. My Esprit 100 has a BF of 185mm, so should be OK. One thing I like about Baader products (aside from their build quality) is the level of information they publish. The path length of their wedge is 114mm e.g. only about 2mm more than one of their regular prisms. Unless you are stopping down the scope, there is a 2x reduction in glass area – so overall, I think it will be safe and likely to “work” e.g. get focus. If all else fails, I can either remove the 1.25” EP adapter and use my EP with a parfocal ring or switch to a different ClickLock.

The three issues I had to overcome were:

1. As a child we are told not to look at the sun and certainly not with a scope;
2. Uncertainty about how filters might react to the additional heat;
3. Uncertainty that the scope objective could be heat affected;
4. Uncertainty that unseen energy might cause eye damage.

I’m getting “over” this as #1 additional protection is being used and my finder will be uncapped – but also “put away” in a box, #2 filters are required but are not being too taxed, #3 the scope has to cope with cooling, so why not (marginal) heating too, #4 unseen energy that might not be obvious can be filtered with a UV/IR filter.

Simon



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Re: Starting white light solar

Post by SimonM » Tue Dec 29, 2020 7:46 pm

James

Altair was my second choice - too much choice... :seesaw. I wasn’t tempted to get the less expensive wedges that have either a 1.25” unit (worried about too much heat in too small a unit) or one without a ceramic tile. The Altair ticks all the boxes but I also have had good results with Baader filters and Click locks and prisms to know their stuff is good quality. Ian at Altair is very knowledgeable, so I would be tempted to get some of their other gear as they do seem to have the edge for providing stuff that works.

“A spotless sun is still an observation” good advice, but I’m hopeful that the situation will improve over the next 5+ years!

Whilst I realize I can do without the polarising filter and use one of the ND as an additional filter, I don't quite know how I will get on, so the filter can provide some additional "comfort" and I may find other uses for it. Two 1.25" filters on the EP provide, perhaps a better solution than one 2" filter on 1.25" adapter because I might want to take the adapter away.

For WL solar, I perhaps need a few pointers on selecting the optimum FL or at least using a means to project a bigger image e.g. with a Barlow. I do have a 2x TeleVue Barlow (not used for 25+ years) to try out. The only danger I can foresee is adding/removing equipment without first aligning the scope away from the sun – you wouldn’t want to be looking into a Barlow. Can I assume that a Barlow is safe to add after the wedge?

So, I’m excited to be able to try this out. It isn’t a good time to be getting into white light solar astronomy as we are only now emerging from a minimum. The only way is up! I don’t have any other forms of solar equipment e.g. no H-alpha equipment (so far). The results of H-alpha do look interesting, but I am more interested in observing the sun how it “looks” e.g. what can be seen (safely) of the photosphere and not indirectly from the chromosphere above, so to see the structure and detail in and around sunspots.

Simon



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Re: Starting white light solar

Post by dhkaiser » Tue Dec 29, 2020 9:04 pm

I have the Lunt 1 1/4" Herschel Wedge. I use a continuum filter along with a uv/ir. Works well with my WO 73 for full disk and my Lunt 102mm for closeups. And yes your barlow is safe after the wedge. I have a 25 year old 2.5x Tele Vue and find it a nice addition.


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Re: Starting white light solar

Post by rsfoto » Tue Dec 29, 2020 10:04 pm

Hi Simon,
“A spotless sun is still an observation” good advice, but I’m hopeful that the situation will improve over the next 5+ years!
Do not worry. The Sun has been doing it for the last 4500 million years and it will do it for the next 4500 million years :mrgreen:
The results of H-alpha do look interesting, but I am more interested in observing the sun how it “looks” e.g. what can be seen (safely) of the photosphere and not indirectly from the chromosphere above, so to see the structure and detail in and around sunspots.
Wait and see ... :lol: :lol: :lol:


regards Rainer

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Re: Starting white light solar

Post by DeepSolar64 » Tue Dec 29, 2020 10:58 pm

Can I assume that a Barlow is safe to add after the wedge?_Simon
Perfectly safe. That's the way I use it.

The sun has been active more than you might think lately. The southern hemisphere is ramping up rather fast this soon after solar minimum and yes it is noticeable in white light.


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Re: Starting white light solar

Post by Montana » Wed Dec 30, 2020 1:23 pm

Simon, don't worry about using the wedge, follow the instructions very carefully and you will not damage anything. Never put anything before the wedge (apart from the telescope), then put any barlow etc after the the wedge and ND filters and you can't go wrong. Remember to have lens caps for view finders and the main telescope when not using it for a while. You can leave it tracking the Sun but if the telescope cover is on it stops unnecessary heat while changing barlows, eyepieces etc.

For safety I always do a systems check (like an aircraft pilot), then do the hand test. Your eye has no pain receptors but your palm does. If you place your palm over the eyepiece and it is cold you know it will be safe for your eye. I have tested several components with the palm test to see how much heat comes from various filters, it is interesting. However you would be foolish to stick your palm at the exit of a telescope with no filters at all!! I find it will give you confidence because like you, I didn't quite trust anything to start with :)

Alexandra



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Re: Starting white light solar

Post by SimonM » Thu Dec 31, 2020 10:49 pm

Montana wrote:
Mon Dec 28, 2020 4:25 pm
Unless you have an amazing refractor you must use a UV/IR filter to image with as the out of focus UV/IR will make the image blurry but not necessary for visual technically as you can't see it but I would be cautious with the eyes so it is up to you (technically safe). However, with my TEC140 I have no need to add one as it is well corrected naturally. The Continuum filter does pass UV/IR so must be used with a cut filter in most cases. Try with and without to satisfy yourself.
I'm waiting for my Baader Wedge to arrive and so I have time to "worry" about the UV/IR that is a potential concern (for me) for visual use! Whilst I should be sensible, I probably shouldn't worry unduly.

I should add, that putting my eye to an EP will take quite some "nerve" since we are always told never to do this. I doubt that Baader takes any chances with their Wedge "kit" and they have had time to ensure it is safe to use. Even so, is there a checklist to confirm everything is as it should be e.g. looking through the prism at a bright light before first use, looking at the reflection of filters from both sides, using it with a camera before using your (one set) of eyes, tracking the sun for an extended period with a camera first?

Does everyone have anxiety for their first-time use? If the postman takes too long, I will have convinced myself that this was all a bad idea (which I'm sure it isn't). Solar film in front of the scope is considered very safe, but there are many combinations. The advantage of the wedge (with ND3 and Solar Continuum) is that it is a "package" - until something is swapped out, it is (should be) working as designed e.g. it is the complete solution. The original SUN EP filters that have the potential to "crack" probably give wedges with ND filters unnecessary concerns. The prism attenuates visible, UV, and IR in equal amounts e.g. passing 5% of each (there is no magic to remove IR as it "only" reflects off the top surface into the EP)?

The UV/IR thing does worry me a bit because it isn't something that can be easily measured e.g. if the image was too bright, then you know to look away, but the IR is a "silent" thing. It has already been suggested that using an extra ND filter is preferable to a polarising filter. This makes sense to me because each ND filter cuts the visual and IR down but two crossed polarising filters only attenuate visual light and are useless at IR reduction. In effect, if IR isn't being eliminated by the Solar Continuum filter then using the polarising filter at more than a minimal setting ensures that more IR than is realized is going through? I know Baader changed their Solar Continuum filter so that in the new "thinner" filter mount, this version is (supposed) to attenuates in IR as well or better than a UV/IR filter, but dealer websites are slow/reluctant to change the advice given.

FWIW, I will have:

EP with polarising filter, UV/IR cut filter --> 1.25" adapter --> (Baader ND 3.0, Solar Continuum filter, Wedge) --> Objective --> target.

Or (better) as suggested (without the need for a polarising filter):

EP with UV/IR cut filter --> 1.25" adapter with ND 0.6 or 0.9 filter --> (Baader ND 3.0, Solar Continuum filter, Wedge) --> Objective --> target.

In time, I will probably dispense with the UV/IR filter (as suggested).

Simon

PS I now have copies of "The Sun and How to Observe It" by Jamey L. Jenkins and also "Solar Observing Techniques" by Chris Kitchin, whilst waiting for Mr. Postman...
Last edited by SimonM on Sun Jan 03, 2021 7:12 pm, edited 1 time in total.



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Re: Starting white light solar

Post by DeepSolar64 » Thu Dec 31, 2020 11:25 pm

Just use the wedge as directed and you will be perfectly safe. The polarizing filter and ND3 filter will arrest the majority of what passes through the wedge. You can use a UV-IR cut filter for added safety but I believe the risk is minimal for the wedge and the other two filters work very well. Other filters like a 540nm green continuum filter can really improve contrast on the disc.

Enjoy your new wedge.

James
Last edited by DeepSolar64 on Fri Jan 01, 2021 6:31 pm, edited 1 time in total.


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Re: Starting white light solar

Post by rsfoto » Fri Jan 01, 2021 4:18 pm

SimonM wrote:
Thu Dec 31, 2020 10:49 pm
Montana wrote:
Mon Dec 28, 2020 4:25 pm
Unless you have an amazing refractor you must use a UV/IR filter to image with as the out of focus UV/IR will make the image blurry but not necessary for visual technically as you can't see it but I would be cautious with the eyes so it is up to you (technically safe). However, with my TEC140 I have no need to add one as it is well corrected naturally. The Continuum filter does pass UV/IR so must be used with a cut filter in most cases. Try with and without to satisfy yourself.
I'm waiting for my Baader Wedge to arrive and so I have time to "worry" about the UV/IR that is a potential concern (for me) for visual use! Whilst I should be sensible, I probably shouldn't worry unduly.

I should add, that putting my eye to an EP will take quite some "nerve" since we are always told never to do this. I doubt that Baader takes any chances with their Wedge "kit" and they have had time to ensure it is safe to use. Even so, is there a checklist to confirm everything is as it should be e.g. looking through the prism at a bright light before first use, looking at the reflection of filters from both sides, using it with a camera before using your (one set) of eyes, tracking the sun for an extended period with a camera first?

Does everyone have anxiety for their first-time use? If the postman takes too long, I will have convinced myself that this was all a bad idea (which I'm sure it isn't). Solar film in front of the scope is considered very safe, but there are many combinations. The advantage of the wedge (with ND3 and Solar Continuum) is that it is a "package" - until something is swapped out, it is (should be) working as designed e.g. it is the complete solution. The original SUN EP filters that have the potential to "crack" probably give wedges with ND filters unnecessary concerns. The prism attenuates visible, UV, and IR in equal amounts e.g. passing 5% of each (there is no magic to remove IR as it "only" reflects off the top surface into the EP)?

The UV/IR thing does worry me a bit because it isn't something that can be easily measured e.g. if the image was too bright, then you know to look away, but the IR is a "silent" thing. It has already been suggested that using an extra ND filter is preferable to a polarising filter. This makes sense to me because each ND filter cuts the visual and IR down but two crossed polarising filters only attenuate visual light and are useless at IR reduction. In effect, if IR isn't being eliminated by the Solar Continuum filter then using the polarising filter at more than a minimal setting ensures that more IR than is realized is going through? I know Baader changed their Solar Continuum filter so that in the new "thinner" filter mount, this version is (supposed) to attenuates in IR as well or better than a UV/IR filter, but dealer websites are slow/reluctant to change the advice given.

FWIW, I will have:

EP with polarising filter, UV/IR cut filter --> 1.25" adapter --> (Baader ND 3.0, Solar Continuum filter, Wedge) --> Objective --> target.

Or (better) as suggested (without the need for a polarising filter):

EP with UV/IR cut filter --> 1.25" adapter with ND 0.6 or 0.9 filter --> (Baader ND 3.0, Solar Continuum filter, Wedge) --> Objective --> target.

In time, I will probably dispense with the UV/IR filter (as suggested).

I bought myself an (Apple Book) copy of "The Sun and How to Observe It" but Jamey L. Jenkins whilst waiting for Mr. Postman...

Simon
Hi Simon,

I think you can save your money and not buy an additional UV/IR blocking filter.

I found this posting here and it is from 2015. I guess Baader is now delivering the new Solar Continuum filter with a much better UV/IR blocking.

viewtopic.php?t=16944

Rainer


regards Rainer

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Re: Starting white light solar

Post by Highbury Mark » Fri Jan 01, 2021 5:07 pm

It’s all perfectly safe - if you just follow the instructions. You can find the Baader Coolwedge manual online if you want to do some reading ahead of taking delivery. No reason for any nervousness ahead of your first observation! Just relax and enjoy it.
It will probably take some time to find out your preferred set up for visual, and for activity and good seeing to coincide. But you are starting at the perfect time - we have big hopes for 2021.


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Re: Starting white light solar

Post by SimonM » Fri Jan 01, 2021 6:40 pm

rsfoto wrote:
Fri Jan 01, 2021 4:18 pm
I think you can save your money and not buy an additional UV/IR blocking filter.

I found this posting here and it is from 2015. I guess Baader is now delivering the new Solar Continuum filter with a much better UV/IR blocking.

viewtopic.php?t=16944

Rainer
Thanks Rainer.

I already have a 1.25" Baader UV/IR cut filter. My imaging camera 294MC only has AR coated and needs the UV/IR to prevent bloated stars.

I also found the same topic and comparing the old with the new, shows a marked improvement. I like Baader Planetarian "stuff" as it is well made and does what it claims to do very well. The company also responds very quickly to emails and questions - an obvious question to ask is what is the overall attenuation across all the UV, IR and visible wavelengths - I'm sure they will reply after the bank holiday.

Logically, there is no reason for the Solar Continuum filter not to have the additional coatings that a UV/IR filter has so that it can perform both functions. Most likely this is what they have done. If there had been a "problem" with UV/IR transmission without the filter, then they could have modified the design to include a third filter simply by extending the collar at the top of the wedge housing. As it is, you can put three filters in-line with the wedge although this reduces the number of threads for the ClickLock to attach - the last thing you want is for it to come off!

The reason I asked was that space for filters is limited. I have Baader Hyperion EPs and they are with a combined 1.25" and 2" barrel. With an ordinary BH 2" Clicklock dielectric prism, they can all fit using the 2" barrel with one filter. With the Solar Prism, there isn't room for the 1.25" part, so I have to use a 1.25" adapter. Since this has a filter thread on the bottom, I can easily use the additional ND filters. On the EP, I will use a 1.25" polarising filter (ordered one). Without a 2" ND filter, I could also use my 1.25" UV/IR filter. I too, think it is not needed. If I wanted to use the ND filter then something has to "give" and it probably will be the UV/IR filter.

The ND 3.0, 1.8, 0.9, and 0.6 filters are all cutting visible and IR anyway. So unless the UV/IR is markedly better than any of the ND filters, there is no point in using it. A camera can see IR e.g. with a 0.9 ND filter, by increasing the exposure 10x but your eye hasn't been exposed to the IR. That's why I am leaning towards using ND filters and not the polarising filter as a "cut" of visual is also with the IR using an ND filter.

Simon
Last edited by SimonM on Fri Jan 01, 2021 7:40 pm, edited 1 time in total.



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Re: Starting white light solar

Post by SimonM » Fri Jan 01, 2021 6:57 pm

Highbury Mark wrote:
Fri Jan 01, 2021 5:07 pm
It’s all perfectly safe - if you just follow the instructions. You can find the Baader Coolwedge manual online if you want to do some reading ahead of taking delivery. No reason for any nervousness ahead of your first observation! Just relax and enjoy it.
Thanks Mark.

The Baader website (great for info and for asking questions too) has a link to the 2010 version of the manual and there is also a "new" 2019 version that is much longer and has much more information.

The Baader K-Line Filter 1¼" (double stacked) also looks very interesting. Notice on their website their chart for how it attenuates UV and IR extends from 300nm to 1500nm. If the Solar Continuum chart was similar then these discussions would be unfounded. Of course, the K-Line is close to being invisible for the eye to see. I think it would be wrong to say it introduces problems, rather without the filter, it wouldn't be possible to detect visible light to alert to a potential problem, so ND 3.0 + 1.8 + K-Line equals nothing to see (but also no potential issues either).

The K-Line filter does look interesting. It is also rather expensive. The BH notes only show it with a KaK filter as well as the K-Line. So that doesn't show how useful it is e.g. you might show a UV/IR filter and see that it reveals more than the Continuum - it is all down to what other filters are used.

It probably does provide a different perspective. Being double-stacked does increase its effectiveness, but the big weakness is that it only has a response limited to 8nm, so it can never be the same as a specialist EP filter. A better comparison can probably be provided so that it can be judged if the cost is justified?

I was all set to buy the Quark EP until I realized that many units were not to spec. In the UK, FLO has said that they check all the Quarks and only sell the ones which "pass" their criteria. So no buying 8 and returning 6 of them... Like all things (K-Line included), I will probably get one (resigned look and lowered bank balance). For now, I'm interested in white light.

Simon



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Re: Starting white light solar

Post by Highbury Mark » Fri Jan 01, 2021 10:24 pm

One other thing Simon - to see fine detail around Sunspots and granulation, it’s best to crank up the magnification. And that requires well corrected eyepieces in fast scopes like the F/5.5 Esprit, otherwise you can get softer views, particularly towards the edge of the fov. Hyperions can struggle with fast scopes, so if you’re not getting the sharpness you’re looking for, you might get better results with another EP. I find orthoscopics and TeleVue Plossls work well - together with a high quality barlow. Just something to bear in mind when you’re testing the wedge.


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Re: Starting white light solar

Post by DeepSolar64 » Fri Jan 01, 2021 11:05 pm

And of course if seeing allows high magnification. Winter seeing here at my location is generally not that great.


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Re: Starting white light solar

Post by SimonM » Sun Jan 03, 2021 5:34 pm

Highbury Mark wrote:
Fri Jan 01, 2021 10:24 pm
One other thing Simon - to see fine detail around Sunspots and granulation, it’s best to crank up the magnification. And that requires well-corrected eyepieces in fast scopes like the F/5.5 Esprit, otherwise, you can get softer views, particularly towards the edge of the FOV. Hyperions can struggle with fast scopes, so if you’re not getting the sharpness you’re looking for, you might get better results with another EP. I find orthoscopic and TeleVue Plossls work well - together with a high-quality Barlow. Just something to bear in mind when you’re testing the wedge.
Thanks, you have some good points which I was thinking about - using other EPs and the right size of Barlow for my scope...

When you say "crank up the magnification", how far can I push it? There are Barlow converters with much bigger than a 2x ratio available that I haven't tried. Will using a Barlow also help with imaging or is there only so much info available that is available for my camera (178 mono) with its small pixels?

I also have a Tele Vue 10.5mm Plössl EP and a Tele Vue 2x Barlow which might be worth trying. Doesn't an EP react well to being used with a Barlow, so at f/11 the BP EPs should be OK? My EPs are 5mm, 8mm, and 10mm and also the bigger versions.

My starting point with the Esprit, being f/5.5 isn't ideal and my BP Hyperion EPs used with my SCT are also not ideal for the refractor. I do however like the BP Hyperions because they offer good eye relief and (for me) easy to "look into". My understanding is that they are an EP and a Barlow combined and like a Barlow, by varying the spacing, different FL can be achieved (not attempted).

Combine that with my imperfect eyesight (not getting any younger) and it is almost a "Recipe for Disaster" :band. I do however also derive pleasure from imaging and (almost) EEA.

Granulation was something else I was interested in - at a later date I may want to try switching the Continuum filter out for the K-Line one for imaging too.

Simon
Last edited by SimonM on Sun Jan 03, 2021 5:39 pm, edited 1 time in total.



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Re: Starting white light solar

Post by marktownley » Sun Jan 03, 2021 5:38 pm

Hi Simon.

I think that 10mm tV plossl, and the 2x barlow, with your wedge and 100mm Espirit would make for a lovely WL setup. I use the TV plossls, they're great!

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Re: Starting white light solar

Post by SimonM » Sun Jan 03, 2021 10:00 pm

Montana wrote:
Wed Dec 30, 2020 1:23 pm
For safety I always do a systems check (like an aircraft pilot), then do the hand test. Your eye has no pain receptors but your palm does. If you place your palm over the eyepiece and it is cold you know it will be safe for your eye. I have tested several components with the palm test to see how much heat comes from various filters, it is interesting. However you would be foolish to stick your palm at the exit of a telescope with no filters at all!! I find it will give you confidence because like you, I didn't quite trust anything to start with :)
That is a good plan and final check. I get the message that because one’s eyes are sensitive to ordinary light, but not aware of the hidden dangers of IR, that you have to check, and check again, before proceeding.

I think I will also be able to verify that the scope is in focus by the size/intensity of the spot on the back of the wedge, and obviously not simply obscured by fleeting clouds, with the hand check to look for visible but not a hidden source of heat, before (finally) bringing the eyes to the EP... :cat

Simon



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