Alfred Tan's PST etalon tests with SW150mm scope

this is the main message area for anything solar :)
Post Reply
User avatar
Valery
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 3052
Joined: Sun Nov 18, 2012 3:13 pm

Alfred Tan's PST etalon tests with SW150mm scope

Post by Valery » Mon Apr 16, 2018 8:52 pm

Hi all

Here are the results of the PST etalon tests. This etalon was selected during last two years of extensive selecting among more than 30pc of earlier PST telescopes. This is the second best I was able to find and it is 100% same narrow and same luminous (very good fidelity) as my own PST etalon. My one is just a tad more smooth (rotation) in the bendpass shift. After testing so many of PST scopes I finally gave up because I lost my hope to find a better sample.
These two etalons deliver better, more contrasty and more uniform pictures than I was able to take with a selected Quark with 0,4A bandpass and good CWL uniformity.

These two pictures were taken April 13 and April 15 this year. In bothh cases the etalon was used in a telecentric mode at about F/40 and 0,6x reducer prior to the camera with IMX174 chip. In a native collimated mode it shows even better contrast, but with a CWL shifting to the FOV edge (a sweet spot) which limits the FOV. Blocking filter was Coronado BF10.

Hope this may be interesting for those who also doing a PST mod.


Valery
Attachments
AR2794-Apr-13-2018-UT-08h-40m-150mm-PST-Alfred.jpg
AR2794-Apr-13-2018-UT-08h-40m-150mm-PST-Alfred.jpg (454.65 KiB) Viewed 870 times
AR2794-Apr-15-2018-UT-10h-39m-150mm-PST-Alfred.jpg
AR2794-Apr-15-2018-UT-10h-39m-150mm-PST-Alfred.jpg (438.91 KiB) Viewed 870 times
Last edited by Valery on Tue Apr 17, 2018 5:11 am, edited 1 time in total.
"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
MalVeauX
Im an EXPERT!
Im an EXPERT!
Posts: 497
Joined: Tue May 09, 2017 7:58 pm
Location: Florida

Re: Alfred Tan's PST etalon tests with SW150mm scope

Post by MalVeauX » Mon Apr 16, 2018 9:18 pm

Really great, I can't imagine going through so many PST etalons! :P

Very best,

User avatar
Valery
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 3052
Joined: Sun Nov 18, 2012 3:13 pm

Re: Alfred Tan's PST etalon tests with SW150mm scope

Post by Valery » Mon Apr 16, 2018 10:05 pm

MalVeauX wrote:
Mon Apr 16, 2018 9:18 pm
Really great, I can't imagine going through so many PST etalons! :P

Very best,
Several years ago, when I have heard that Jean Pierre Brahic has bought a Quark Chromosphere, I have asked him
if he is willing to part with his PST etalon. He told me "No". He also told me that all the PST he saw were all equal.
But we all know well how good his PST etalon is. It is far better than most of them. So, I take the decision to try to find
an etalon which will be as good as this one. May be my one is not as good, but at least is very close. The etalons I
have tested during these 3+ years were quite different.

Some etalons were really narrow about as my best one, but they were about 2x less bright which is a big disadvantage for
a high resolution imaging, especially in a Double Stack mode.

FYI, blocking filters are not equally good either. As well as front mount etalons. Some peoples are lucky, others need
to use a selection to find better samples. So, I was much less lucky than lucky guys!


Valery
Last edited by Valery on Tue Apr 17, 2018 4:50 am, edited 2 times in total.
"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
MalVeauX
Im an EXPERT!
Im an EXPERT!
Posts: 497
Joined: Tue May 09, 2017 7:58 pm
Location: Florida

Re: Alfred Tan's PST etalon tests with SW150mm scope

Post by MalVeauX » Mon Apr 16, 2018 10:26 pm

Valery wrote:
Mon Apr 16, 2018 10:05 pm
MalVeauX wrote:
Mon Apr 16, 2018 9:18 pm
Really great, I can't imagine going through so many PST etalons! :P

Very best,
Several years ago, when I have heard that Jean Pierre Brahic has bought a Quark Chromosphere, I have asked him
if he is willing part with his PST etalon. He told me "No". He also told me that all the PST he saw were all equal.
But we all know well how good his PST etalon is. It is far better than most of them. So, I take the decision to try to find
an etalon which will be as good as this one. May be my one is not as good, but at least is very close. The etalons I
have tested during these 3+ years were quite different.

Some etalons were really narrow aboy as my best one, but they were about 2x less bright which is a big disadvantage for
a high resolution imaging, especially in a Double Stack mode.

FYI, blocking filters are not equally good either. As well as front mount etalons. Some peoples are lucky, others need
to use a selection to find better samples. So, I was much less lucky than lucky guys!


Valery
Interesting!

One of these days I'd love to build a new high res system. I recently got my hands on a 10" F10 SCT and eventually I would adore having a full aperture D-ERF on it and figured a PST etalon and a coronado blocking filter would do the job as an F10 system, and just a 2x focal extender for the high res stuff (seeing allowing that is, at 5000mm focal length). The etalon is inexpensive enough, but as you and others have pointed out, not every PST etalon is equal. So while it would be costly to get the DERF & blocking filter, it would simply take a lot of time to get a good etalon...

Very best,

User avatar
Valery
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 3052
Joined: Sun Nov 18, 2012 3:13 pm

Re: Alfred Tan's PST etalon tests with SW150mm scope

Post by Valery » Tue Apr 17, 2018 5:07 am

MalVeauX wrote:
Mon Apr 16, 2018 10:26 pm

So while it would be costly to get the DERF & blocking filter, it would simply take a lot of time to get a good etalon...

Very best,
Marty,

It should be understandable that an ultimate system always require additional money/time and very often a luck.
But the results are well worth of these additional efforts and time. Only a randomly lucky guys can pay much less
for such a system. Still the main factors are: aperture and... patience! Patience is required for hunting for the best
seeing moments. For a high res imaging I'd better own an 11" telescope with a 0,5A etalon (often among PST's) than
a 150mm telescope with a 0,3A etalon.
"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
yltansg
Almost There...
Almost There...
Posts: 1157
Joined: Sat Jun 14, 2014 9:33 am
Contact:

Re: Alfred Tan's PST etalon tests with SW150mm scope

Post by yltansg » Tue Apr 17, 2018 12:39 pm

Hi Valery,

I have tested 4 out of my collection of 5 PST etalons. All 4 fall into the 80% category (average PST). The images that I am getting is world of a difference from yours without a top 10% PST etalon. I will post my images in another posting. Can't wait to get my hands on this PST etalon. It is definitely worth the wait on my part. And thanks a million for finding it!

Alfred

User avatar
marios i.
Im an EXPERT!
Im an EXPERT!
Posts: 325
Joined: Sun Nov 09, 2014 8:38 am
Location: Cyprus

Re: Alfred Tan's PST etalon tests with SW150mm scope

Post by marios i. » Tue Apr 17, 2018 1:23 pm

Excellent!

Marios

User avatar
marktownley
Librarian
Librarian
Posts: 24534
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: Alfred Tan's PST etalon tests with SW150mm scope

Post by marktownley » Tue Apr 17, 2018 7:01 pm

You're lucky to be able to test so many etalons Valery - 30+ PST etalons would cost £15k second hand here. Even more new price...
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: 3052
Joined: Sun Nov 18, 2012 3:13 pm

Re: Alfred Tan's PST etalon tests with SW150mm scope

Post by Valery » Wed Apr 18, 2018 12:55 am

marktownley wrote:
Tue Apr 17, 2018 7:01 pm
You're lucky to be able to test so many etalons Valery - 30+ PST etalons would cost £15k second hand here. Even more new price...

Mark,

I didn't test all these 30+ etalons right here at my home in my own telescope! But most were sent to me prior to be sold here in Ukraine after purchase from the AstroMart and e-bay etc by two guys who sell a used astroequipment. Of course I paid all these post services and pay enough my time and efforts in testing them. Often the process was tedious (especially in a winter time) and not cheap.

I remember, that many years ago Markus Ludes offers such a service - PST telescopes pre-selection with best telescopes sold at a higher price. Too bad I was not in a solar imaging at that time!
"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: 3052
Joined: Sun Nov 18, 2012 3:13 pm

Re: Alfred Tan's PST etalon tests with SW150mm scope

Post by Valery » Wed Apr 18, 2018 2:01 am

Here are two images taken with PST etalon in a single stack (SS) and a double stack (DS) configurations. Both on a 150mm telescope and in a collimated beam configuration. The collimated configuration (with PST native optics) gives the most narrow bandwidth and highest contrast.
Attachments
150mm-PST-SS.jpg
Single stack
150mm-PST-SS.jpg (296.68 KiB) Viewed 762 times
150mm-PST-DS.jpg
Double stack
150mm-PST-DS.jpg (293 KiB) Viewed 762 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: 24534
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Contact:

Re: Alfred Tan's PST etalon tests with SW150mm scope

Post by marktownley » Wed Apr 18, 2018 5:13 am

The gap between an excellent single stack etalon and the double stack isn't that big. But I bet the difference in exposure time is!
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: 3052
Joined: Sun Nov 18, 2012 3:13 pm

Re: Alfred Tan's PST etalon tests with SW150mm scope

Post by Valery » Wed Apr 18, 2018 6:14 am

marktownley wrote:
Wed Apr 18, 2018 5:13 am
The gap between an excellent single stack etalon and the double stack isn't that big. But I bet the difference in exposure time is!
Yes, this difference looks much less in such active areas and for big apertures it is almost worthless to use a DS for the imaging of such active and full of dramatism areas on the sun. We loss the speed in the exposure time and need to increase the recording cadence. But in less dramatic areas, for dark filaments with lower contrast, for near limb landscapes a double stack is a must. The more desert like the landscape we do imaging, the more we can win with a DS.
But, of course, not all DS are equally bright and most are too dark to use them with larger apertures. But this DS was really bright enough to support the exposures between 5-7ms. As you know well the exposures are greatly depends of how luminous a blocking filter, camera sensitivity etc etc.
"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
Carbon60
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 5491
Joined: Wed Mar 07, 2012 12:33 pm
Location: Lancashire, UK

Re: Alfred Tan's PST etalon tests with SW150mm scope

Post by Carbon60 » Wed Apr 18, 2018 6:38 am

Stunning images, Valery.

Stu.
Lunt LS60THa B1200 PTFT
150mm H-alpha Solar telescope with Lunt35 mod
DMK41, Basler acA1920-155
NEQ6 Pro-mount
Fluxgate Magnetometers (1s and 150s Cadence)
More images at http://www.flickr.com/photos/solarcarbon60/

User avatar
MapleRidge
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 5168
Joined: Fri Jan 13, 2012 11:58 pm
Location: Cambray, ON Canada

Re: Alfred Tan's PST etalon tests with SW150mm scope

Post by MapleRidge » Thu Apr 19, 2018 12:49 am

These test images are outstanding Valery...excellent work capturing and processing :bow

Brian
Brian Colville

Maple Ridge Observatory

Cambray, ON Canada

Post Reply

Who is online

Users browsing this forum: No registered users and 3 guests