Any interest in this part? LS50C modkit

Frankenscope? Let's see it!***be advised that NOTHING in this forum has been safety tested and you are reading and using these posts at your own peril. blah, blah, blah... dont mess around with your eyesight when it comes to solar astronomy. Use appropriate filtration at all times...
Post Reply
User avatar
MalVeauX
Im an EXPERT!
Im an EXPERT!
Posts: 493
Joined: Tue May 09, 2017 7:58 pm
Location: Florida

Re: Any interest in this part?

Post by MalVeauX » Sun Oct 28, 2018 8:32 pm

Looking forward to seeing how this works out. I would be super interested if a working application is produced.

Very best,

User avatar
marktownley
Librarian
Librarian
Posts: 24527
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: Any interest in this part?

Post by marktownley » Mon Oct 29, 2018 9:43 am

What fitting is the Baader universal flange?
Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!

FlankerOneTwo
Ohhhhhh My!
Ohhhhhh My!
Posts: 65
Joined: Wed Oct 11, 2017 8:11 pm

Re: Any interest in this part?

Post by FlankerOneTwo » Wed Oct 31, 2018 2:52 am

If it works well and is for the 50c rather than the FHA, I would also be really interested.

User avatar
Valery
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 3050
Joined: Sun Nov 18, 2012 3:13 pm

Re: Any interest in this part? LS50C modkit

Post by Valery » Wed Oct 31, 2018 10:03 am

I have experimented with these etalons (LS50FHa and LS35FHa). They worked in a _collimated beam_ scheme, not in a telecentric.
The images Apollo reproduced were taken with LS35 worked in a collimated beam.

My results with these etalons worked with Baader TZ3 and TZ4 were rather negative, significantly worser than with a collimated beam.

Valery
"Solar H alpha activity is the most dynamic and compelling thing you can see in a telescope, so spend accordingly." (c) Bob Yoesle.

Largest full size 185 - 356mm Dielectric Energy Rejection Filters (D-ERF) by ARIES Instruments.

User avatar
marktownley
Librarian
Librarian
Posts: 24527
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: Any interest in this part? LS50C modkit

Post by marktownley » Thu Nov 01, 2018 9:38 am

Does the 'unit' itself support the weight of the camera / eyepiece etc behind it, or, it the weight supported by the etalon housing Apollo?
Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!

User avatar
Valery
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 3050
Joined: Sun Nov 18, 2012 3:13 pm

Re: Any interest in this part? LS50C modkit

Post by Valery » Thu Nov 01, 2018 11:06 am

TheSkyBurner wrote:
Thu Nov 01, 2018 6:39 am
Valery wrote:
Wed Oct 31, 2018 10:03 am
I have experimented with these etalons (LS50FHa and LS35FHa). They worked in a _collimated beam_ scheme, not in a telecentric.
The images Apollo reproduced were taken with LS35 worked in a collimated beam.

My results with these etalons worked with Baader TZ3 and TZ4 were rather negative, significantly worser than with a collimated beam.

Valery
Valery, can you re-elaborate your statement. I am finding conflicting information based on another post you made where you placed the PST etalon in a telecentric.

viewtopic.php?f=4&t=25248

If you are getting this very great result with a telecentric pst etalon, how would a negative result become of the lunt mod in a telecentric? Do you have a way to retest the lunt etalon with your new telecentric?
I can confirm, that my results with that sample of PST etalon were great. But this sample is really very narrow (less than 0,3A) and has a very high fidelity and a very high transmission. I know only two more such samples - owned by JP Brahic and Alfred Tan.
I doubt one will be lucky finding such an etalon without a special selection like I have done during 4 years.
Also, this etalon is only 20mm size and it is more or less uniform accross it's aperture. This is unlikely for larger sizes.

Stu's scheme works great, but he uses a collimated beam scheme. This is absolutely another story with the CWL shifts due to a large field angle.

All in all I gave up with these experiments with any etalons in a collimated beam. The best is a solid spaced etalons in near focus position. My results with three samples of Quarks convinced me that there are no competitors for these H-a eyepiece sized etalons.


Valery.
"Solar H alpha activity is the most dynamic and compelling thing you can see in a telescope, so spend accordingly." (c) Bob Yoesle.

Largest full size 185 - 356mm Dielectric Energy Rejection Filters (D-ERF) by ARIES Instruments.

User avatar
Valery
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 3050
Joined: Sun Nov 18, 2012 3:13 pm

Re: Any interest in this part? LS50C modkit

Post by Valery » Fri Nov 02, 2018 10:58 am

Collimated beam scheme with LS50FHa.

I would not reccommend to other peoples to go this way unless they have a fun in the experimenting, efforts, time and money wasting.

All these Lunt etalons are so inconsistent in it's native CWL, bandwidth, finesse and places where peoples use them are so different (typical barometric pressure and temperature), that there is no any warranty that even two etalons, taken from the same batch, will work not say identically, but at least similarly! This is the reason I gave up with cheaper alternatives to Lunt 152mm telescope.

What bad things can we expect in the implementation of this scheme?

1. Sweet spot. The larger the ratio of a telescope diameter to an etalon diameter, the smaller a sweet spot is.
2. Sweet spot banding is the most annoying. It depends of required tilt of an etalon we need to apply to come to the H-a core.
The farther the etalon CWL from the H-a core WL, the more tilt required, the more pronounced banding will be in such a telescope.
3. High sensitivity of the banding problem to a barometric pressure.

Here some photos which illustrate all the above bad things.

On a final note about collimated beam: one need a pressure tuned etalon to get rid of most problems. Better to use Lunt pressure tuned etalons (for example, DS modules) than trying to get good results with tilt turnable air-spaced etalons.
Attachments
Ed's LS50FHa banding.jpg
Full FOV of the 150mm F5 + LS50FHa
Ed's LS50FHa banding.jpg (295.47 KiB) Viewed 607 times
15 07 13 8h 39.png
15 07 13 8h 39.png (826.58 KiB) Viewed 607 times
banding  150 F5 LS50FHa #1+ #2  DS.png
banding 150 F5 LS50FHa #1+ #2 DS.png (1.06 MiB) Viewed 607 times
banding 2 150mmF5 LS50FHa.png
banding 2 150mmF5 LS50FHa.png (553.3 KiB) Viewed 607 times
banding 150mm F5 LS50FHa #2.png
banding 150mm F5 LS50FHa #2.png (778.92 KiB) Viewed 607 times
LS50FHa #2 3.png
LS50FHa #2 3.png (618.4 KiB) Viewed 607 times
sweet spot 150F5 + LS50FHa.png
sweet spot 150F5 + LS50FHa.png (402.65 KiB) Viewed 607 times
"Solar H alpha activity is the most dynamic and compelling thing you can see in a telescope, so spend accordingly." (c) Bob Yoesle.

Largest full size 185 - 356mm Dielectric Energy Rejection Filters (D-ERF) by ARIES Instruments.

User avatar
marktownley
Librarian
Librarian
Posts: 24527
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: Any interest in this part? LS50C modkit

Post by marktownley » Fri Nov 02, 2018 1:41 pm

A TZ3 is on my shopping list too...
Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!

User avatar
Valery
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 3050
Joined: Sun Nov 18, 2012 3:13 pm

Re: Any interest in this part? LS50C modkit

Post by Valery » Fri Nov 02, 2018 5:02 pm

marktownley wrote:
Fri Nov 02, 2018 1:41 pm
A TZ3 is on my shopping list too...
What the etalon you will use with this TZ3 ?
"Solar H alpha activity is the most dynamic and compelling thing you can see in a telescope, so spend accordingly." (c) Bob Yoesle.

Largest full size 185 - 356mm Dielectric Energy Rejection Filters (D-ERF) by ARIES Instruments.

User avatar
Valery
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 3050
Joined: Sun Nov 18, 2012 3:13 pm

Re: Any interest in this part? LS50C modkit

Post by Valery » Sat Nov 03, 2018 10:00 am

Apollo,

You didn't read my post with enough attention. I told exactly the following: without a special selection one can't WARRANT that the system will work fine. If only the etalon you do plan to use in such a configuration has a bit more than absolute minimal CWL shift to the red wing, then it will require too much tilt to come to H-a core and so, will produce the banding of the swet spot and instead of a round sweet spot you will get a more or less curved band which is in Ha and the rest FOV will be not. See the very first picture in my post. This picture shows how the randomly taken LS50FHa etalon works in a collimated beam. It require too much tilt to come to Ha core.

The only single LS50FHa etalon which worked OK was my very first etalon. That time I think that all the LS50FHa are the same and will work same OK. But the reality was and is quite different. I have tested may be 10 or 12 such etalons and only one of them was OK for required minimal tilt, but it was too wide (may be 0,9A) and of a very low contrast. Practically useless. All other etalons have too much CWL shift red and require too much tilt and produce unacceptable sweet spot banding.

The images you saw as good examples of my works were taken in a DS and within the banded sweet spot. They are quite small vs full FOV. Your intention to get a large 46mm useful field is a dream, no more. You will not get such a field in a collimated scheme. Lunt 152mm scope use a larger, 60mm clear aperture etalon and still have about 1/2 to 2/3 sun disk in Ha and the rest FOV is out of Ha.

You can get a full FOV in Ha and more or less uniform (depends of the etalon own uniformity) in a telecentric scheme. However, for this you need one of two cases:

1. Very rare luck that your 50C etalon is very narrow, very uniform and require no or very minimal tilt to come to the Ha core at the F/D of your TZ.
2. You need carefully select such an etalon up to the moment you will find an etalon according to requirements from case 1.

Even if you will get such a perfectly matched to your needs etalon you will see that it works differently in diffeernt weather conditions.

Instead of all these hassles I just found a good sample of Quark - uniform enough and narrow enough. It does not require even a star diagonal - just put it in the back of a SCT or any telescope F/7 to F/11 and you are ready to go. Depends of a camera used you will or will not need a focal reducer. This is much easier and cheaper than the way you offering to try. Been there done that! I can compare from the first hands.

And if I will show the comparision images taken with LS35 in a telecentric mode and images taken with Quark, anyone will immediately see which is better. And how much better and for which money and efforts invested. The only competitor to a good Quark is a very good selected PST etalon in a collimated scheme with it's one optics. But still not as good and with narrower FOV.


Valery
"Solar H alpha activity is the most dynamic and compelling thing you can see in a telescope, so spend accordingly." (c) Bob Yoesle.

Largest full size 185 - 356mm Dielectric Energy Rejection Filters (D-ERF) by ARIES Instruments.

User avatar
marktownley
Librarian
Librarian
Posts: 24527
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: Any interest in this part? LS50C modkit

Post by marktownley » Sat Nov 03, 2018 3:46 pm

Valery wrote:
Fri Nov 02, 2018 5:02 pm
marktownley wrote:
Fri Nov 02, 2018 1:41 pm
A TZ3 is on my shopping list too...
What the etalon you will use with this TZ3 ?
I will use it with my Quark (without the 4.3x telecentric) and also want to try it with my CaK setup.
Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!

User avatar
MalVeauX
Im an EXPERT!
Im an EXPERT!
Posts: 493
Joined: Tue May 09, 2017 7:58 pm
Location: Florida

Re: Any interest in this part? LS50C modkit

Post by MalVeauX » Sun Nov 04, 2018 2:29 pm

What about a potential modular piece that can accept most popular filters ranging from the PST etalon to something like the Lunt 35 & 50 or even Calcium filters like the Lunt CaK module and/or PST CaK filters? A universal USA available modular filter chamber maybe?

Very best,

User avatar
marktownley
Librarian
Librarian
Posts: 24527
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: Any interest in this part? LS50C modkit

Post by marktownley » Sun Nov 04, 2018 8:43 pm

TheSkyBurner wrote:
Sun Nov 04, 2018 4:58 am
So here is a peak at how simple this really is going to be.

If anybody wants to help, all you have to do is help. <----(thank you for the f/8 suggestion Ken Harrison!)


If someone wants to poke holes in this; I encourage you to draw something with ms paintbrush.exe, it requires zero skill and wont cost you a single cent.
If there are no diagrams to follow, then you get nothing to follow. If you help, then your name is written in stone as a person that helped!

90mm f/8.8 refractor to f/32 four element
f8.8 to f32 collimator system.PNG


150mm F8 refractor to f/32 two element
150 f8 to f32 collimator system.PNG

160mm F10 refractor to f/30 two element
160 f10 to f30 collimator system.PNG

203mm F10 SCT to F/30 two element
203mm f10 to f30 collimator system.PNG
Hey Apollo,

Just an observation; the first 50mm diameter lens you have sat 50mm from the focal point. Wouldn't that lens focal length have to be the same focal ratio as the objective lens to give a collimated beam?

Mark
Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!

User avatar
marktownley
Librarian
Librarian
Posts: 24527
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: Any interest in this part? LS50C modkit

Post by marktownley » Sat Nov 17, 2018 12:45 pm

Looks like you're making good progress there Apollo.
Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest