6Apr - ARIES 214mm D-ERF + C8 + PST etalon testing

[yltansg]

This setup is part of my testing of collected PST etalons for C8 and C14 ARIES H-Alpha - 214mm ARIES D-ERF + C8 + PST etalon + BF + X3 barlow + Basler acA1920-155um.







I am testing the 4th of my collection of 5 PST etalons. This 4th PST etalon showed the best results.


6 Apr was very cloudy day and I had only managed adjusting the tilt of the etalon, moving around the sun disk and focusing. Then I had to stop the session. It was in the evening that I noticed I had inadvertently turned the recording on. There were lots of recording of clouds and some solar features. I used Virtual Dub to extract the best single frames of nice features. Here they are:

Proms:


Proms with gain turned up:


A inconsequential portion of the disk:


This is the best of 4 PST etalons that I have tested. To highlight that these are single-frame captures. What do you think about its quality?

Alfred

[MapleRidge]

Hi Alfred...

The setup looks great, and lucky that you captured some of the test videos. They look promising considering that they are single frames...a stack will tell more. I’m looking forward to seeing more form this setup.

Brian

[Merlin66]

Whoooo You're very lucky to be able to test so many PST etalons!
In my experience over the past ten years, the PST etalon has a 10/80/10 quality distribution.
10% should never have left the factory
80% are, well, "OK" and do the job - just!
10% are excellent and give tremendous potential for mods.
Just my 2c

[Valery]

Whoooo You're very lucky to be able to test so many PST etalons!
In my experience over the past ten years, the PST etalon has a 10/80/10 quality distribution.
10% should never have left the factory
80% are, well, "OK" and do the job - just!
10% are excellent and give tremendous potential for mods.
Just my 2c

Hi Ken,

Hah! Your distribution curve reflects my experience. I have looked through many PST and I tried more than 30 of them to find the one which is as good as our friend Jean Pierre Brahic works with. And I found 3 samples that are excellent. One of them is same good as two others, but not so luminous - requires about 2x longer exposure time which is very critical to image with high resolution with a larger aperture telescope(s).
Two others from these three leave nothing to wish better - unless they will be just larger in aperture! These are very luminous and with my older BF10 Coronado (somewhat rusted), DERF, 2x Barlow, IMX174 and on a typical SCT - allows 2-2,5ms exposures with a mild gain. This is enough for high resolution - short enough to freeze the seeing and quick enough to get a good fps speed - enough frames within a movie cadence.
These two may be still not as narrow as Jean Brahic's one, but very close behind. I was not able to find better than these two.
And one of them is for Alfred Tan - here is the picture taken with this etalon installed on my C11 telescope. It is easily seen how narrow this etalong and how good it's finesse. Too bad Meade can make all the PST etalons this good.


Valery

[yltansg]

Hi Alfred...

The setup looks great, and lucky that you captured some of the test videos. They look promising considering that they are single frames...a stack will tell more. I’m looking forward to seeing more form this setup.

Brian

Thanks Brian. No chance to do it this weekend. It was clouded out most of the time.

Alfred

[yltansg]

Whoooo You're very lucky to be able to test so many PST etalons!
In my experience over the past ten years, the PST etalon has a 10/80/10 quality distribution.
10% should never have left the factory
80% are, well, "OK" and do the job - just!
10% are excellent and give tremendous potential for mods.
Just my 2c

Thanks Ken for sharing your experience. Thanks also for sharing the document on "Modifying a Coronado PST Hα Solar Telescope" with me some years ago. Locally I have bought and extracted the etalons from 3 PSTs and bought 2 PST etalons from a gentleman in US. So far the tests showed that they belong to the 80% lot.


This was how I removed the etalon fom the PST.

Alfred

[yltansg]

Hi Ken,

Hah! Your distribution curve reflects my experience. I have looked through many PST and I tried more than 30 of them to find the one which is as good as our friend Jean Pierre Brahic works with. And I found 3 samples that are excellent. One of them is same good as two others, but not so luminous - requires about 2x longer exposure time which is very critical to image with high resolution with a larger aperture telescope(s).
Two others from these three leave nothing to wish better - unless they will be just larger in aperture! These are very luminous and with my older BF10 Coronado (somewhat rusted), DERF, 2x Barlow, IMX174 and on a typical SCT - allows 2-2,5ms exposures with a mild gain. This is enough for high resolution - short enough to freeze the seeing and quick enough to get a good fps speed - enough frames within a movie cadence.
These two may be still not as narrow as Jean Brahic's one, but very close behind. I was not able to find better than these two.
And one of them is for Alfred Tan - here is the picture taken with this etalon installed on my C11 telescope. It is easily seen how narrow this etalong and how good it's finesse. Too bad Meade can make all the PST etalons this good.


Valery

Hi Valery,

Having purchased 5 PST etalons, I can appreciate how much hard work and also having lady luck to be on your side are needed to get hold of the very good etalons. I am looking forward to the delivery of the 356mm D-ERF and that super PST etalon

Alfred

[Carbon60]

Nice setup, Alfred.

I admire your confidence that you won't accidentally drop it off the edge of the building there

Good luck with the new etalon and ERF.

Stu.

[yltansg]

Nice setup, Alfred.

I admire your confidence that you won't accidentally drop it off the edge of the building there

Good luck with the new etalon and ERF.

Stu.

Hi Stu,

Come to think of it, I took a big risk without realising it

It was mounted on an iEQ45 earlier.

[Derek Klepp]

Good luck Alfred.

[yltansg]

Thanks Derek. The weather forecast for next week is rain for every day Nevertheless I will look out for gaps of good weather

Alfred

[pedro]

I have a mod PST that belong to the 10% that never have left the factory...

[marktownley]

Good read everyone! All my PST etalons have been in the 80% category.

[yltansg]

I have a mod PST that belong to the 10% that never have left the factory...

Hi Pedro,

1 of my 5 belongs to 10% reject category.

Alfred

[yltansg]

Good read everyone! All my PST etalons have been in the 80% category.

Hi Mark,

4 of my 5 are in the 80% category. 1 belongs to the 10% reject

Looking forward to the one that is coming from Valery

Alfred

[Montana]

I was thinking exactly the same as Stu

Nice images from the PST
Alexandra

[yltansg]

Hi Alexandra,

The ledge is on the 6th floor (about 20m high). I must really be careful.....

The PST images were taken with a x3 barlow, not a good image scale. I will be using a x2 barlow in my subsequent test.

Alfred

[ffellah]

Hi Alfred: thank you for starting this very interesting thread that includes opinions on PST etalons. I have not paid much attention to mine, but I think it will have much more use in the future.

Franco

[yltansg]

Hi Alfred: thank you for starting this very interesting thread that includes opinions on PST etalons. I have not paid much attention to mine, but I think it will have much more use in the future.

Franco

Hi Franco,

I am glad to see interest in PST etalons for hi-res imaging. Currently I am testing my 5 etalons on a C8 fitted with a full aperture D-ERF. After that I will use them for students' project. They can test them under different seeing conditions and at different locations in the college using the C8 and later with the C14.

Alfred