Forum der Vereinigung der Sternfreunde

Forum of the German Amateur Astronomy Association
Aktuelle Zeit: 17. November 2018, 19:00:24 PM

Alle Zeiten sind UTC+02:00




Ein neues Thema erstellen  Auf das Thema antworten  [ 18 Beiträge ] 
Autor Nachricht
 Betreff des Beitrags:
BeitragVerfasst: 03. Dezember 2012, 12:46:57 PM 
Offline
Meister
Benutzeravatar

Registriert: 19. August 2006, 11:45:20 AM
Beiträge: 2713
Wohnort: 66907 Glan-Münchweiler
Zitat:
To make the adjustment I fix the injection unit (I have a small workbench), and I put in front of the hole a white LED - too fixed, so that the illumination is constant. I take up a fiber from the injection unit and to the other end of the fiber, I put a camera of guide (Watec, or Lumenera, for example). I have an adapter which allows to take up the fiber on a frame C (you can tinker an equivalent?). Well on this point, i've changed for using the eshell flat lamp and a windows frame around a bright order. fast refreshment, with live statistics, are the key. - The alignment is rather simple: it is necessary to find the positioning of the cylinder (by playing on 3 screws in 120 °) which gives the maximum illumination onto the camera (statistics in the window). The final adjustment is very fine (that takes place on the pressure of tightening of screw, but with little practice, that does very well.

Hello Thierry,


Thank you very much for explaining in detail. But I am anxious to do this. Do you have some pictures about this process? This would help me. You write, that you illuminate the fiberinjection with an LED lamp. You put away the 50µm fiber from the injection and you have installed a ccd on the 50µm fiberconnector of the fiberinjection? Is this correct so? Or have you left the 50µm fiber on the injection and you put the CCD on the other end of the 50µm fiber?

As already said, some pictures would be helpfull for me. perhaps you could send some as pm

cheers

berthold


Nach oben
   
 Betreff des Beitrags:
BeitragVerfasst: 03. Dezember 2012, 14:08:11 PM 
Offline
Dauernutzer
Benutzeravatar

Registriert: 30. Juli 2010, 02:16:09 AM
Beiträge: 178
Wohnort: Melbourne, Australia
Hi Berthold,

I am also anxious to check and adjust the output fibreoptic head alignment and my understanding of the method Thierry described is shown in the attached photo. The 200um fibreoptic cable from the calibrator box brings the LED illumination to the FIGU input at 'A'. Some simple adapter will be required to ensure the fibreoptic connector is axially aligned to the reflector plate hole.
The normal 50um fibreoptic cable brings the light from the plate hole (connector at B) to either a CCD or video/webcam. Again, a simple adapter will be needed to couple the fibreoptic to the camera.

I think an alternative, simpler to connect, method would be to reverse the flow ... connect the LED fibre at 'B' (the connector already exists) and put the imaging camera at 'A' (a simpler adapter needed). Any reason why this would not work as well?

If there are any problems with either of these methods please (Berthold and Thierry) let me know as I want to check my alignment soon.

Cheers, Bernard


Dateianhänge:
FIGU-1.jpg
FIGU-1.jpg [ 194.04 KiB | 12090 mal betrachtet ]

_________________
Quicquid Nitet Notandum
Nach oben
   
 Betreff des Beitrags:
BeitragVerfasst: 03. Dezember 2012, 15:25:13 PM 
Offline
Meister

Registriert: 13. August 2009, 17:04:50 PM
Beiträge: 262
Wohnort: Maienfeld, Schweiz
Hallo Bernard,

your proposed method with illuminating the output fiber in reverse works quite well. I have used used it, as you can see from the attached report. I used the guide cam with a C-mount to T2 adapter to image the hole in the mirror.
In addition it also helped in my case, to clean the fiber ends with a cotton tip and alcohol.

Regards,

Martin


Dateianhänge:
Dateikommentar: alignment of fiber to mirror hole
FIGU fiber alignment.doc [292 KiB]
204-mal heruntergeladen
Nach oben
   
 Betreff des Beitrags:
BeitragVerfasst: 03. Dezember 2012, 19:00:13 PM 
Offline
Meister
Benutzeravatar

Registriert: 19. August 2006, 11:45:20 AM
Beiträge: 2713
Wohnort: 66907 Glan-Münchweiler
Hi Bernard and Martin,

many thanks for so detailed information and for the pictures!!!

To take away the hood it seems on your picture I only have to loose 4 srews? Is it correct? Thierry write I have to loosen 4 screws and "4 others". On your picture I don't see the electrical part of the fiberinjection ..the electrical flip mirror....and so on. Is this part in the hood?


thank you and cheers

Berthold


Nach oben
   
BeitragVerfasst: 03. Dezember 2012, 19:02:11 PM 
Offline
Dauernutzer

Registriert: 25. August 2010, 15:29:29 PM
Beiträge: 63
Wohnort: Montpellier
Very fine Martin !I work on flux on a spectral order of a tungsten lamp instead of direct image of the hole. I try to maximise the flux in real condition, IGU attached to prime focus, indirect illumination of telescope aperture and playing with the screw at 120°.


Thierry 

2012/12/3 Martin Dubs <fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)>
Zitat:
Hallo Bernard,

your proposed method with illuminating the output fiber in reverse works quite well. I have used used it, as you can see from the attached report. I used the guide cam with a C-mount to T2 adapter to image the hole in the mirror.
In addition it also helped in my case, to clean the fiber ends with a cotton tip and alcohol.

Regards,

Martin





_________________
Thierry Garrel
Observatoire de Fontcaude, Montpellier, France
SpectroBlog http://gabalou.canalblog.com/


Nach oben
   
 Betreff des Beitrags:
BeitragVerfasst: 03. Dezember 2012, 23:43:27 PM 
Offline
Dauernutzer
Benutzeravatar

Registriert: 30. Juli 2010, 02:16:09 AM
Beiträge: 178
Wohnort: Melbourne, Australia
Hi Berthold,

You are correct, only four screws need to be reoved and four loosened (as shown in my updated photo below) ... I removed all eight but that isn't necessary. Yes, the guide mirror and solenoid are all self-contained inside the cover. Once the screws are removed/loosened the cover easily slides off (to the right as shown in my photo ... there are no other electrical or mechanical links between the two parts.


Hi Martin, Thierry,

As you agree the 'reverse' light injection method will work, which is what Martin has done, then I now think that ... to make connections easier ... it should be possible to use the guidecam in its usual position (see photo below). For this to work the cover would need to be put back ater every alignment adjustment, to allow the guidecam to be used to check the results. This should not be a problem as it is very easy and fast to slide the cover on and off. The advantage of this method is that no special adapters are needed. What do you think?

Maybe we can ask this forum's administrator to move this 'off topic' discussion to a separate location?


Cheers,
Bernard


Dateianhänge:
FIGU-2.jpg
FIGU-2.jpg [ 194.23 KiB | 12050 mal betrachtet ]

_________________
Quicquid Nitet Notandum
Nach oben
   
 Betreff des Beitrags:
BeitragVerfasst: 04. Dezember 2012, 01:17:44 AM 
Offline
Meister
Benutzeravatar

Registriert: 19. August 2006, 11:45:20 AM
Beiträge: 2713
Wohnort: 66907 Glan-Münchweiler
Thank you Bernard for the new information!

Berthold


Nach oben
   
 Betreff des Beitrags:
BeitragVerfasst: 04. Dezember 2012, 01:31:35 AM 
Offline
Meister

Registriert: 13. August 2009, 17:04:50 PM
Beiträge: 262
Wohnort: Maienfeld, Schweiz
Hi Bernard,

I agree to move the topic to an instrument section (I suggest Technik - LWL).
Looking into the guidecam port as you suggest does not work, since the turning mirror is placed so that it misses the cone of light in the object path (from telescope to hole to fiber or the reverse). In the guidecam you only see the hole but you miss the lightcone with reverse illumination!
In addition to remove the cover after each adjustment is very inconvenient. With a videocam you want to see the change when you turn the screws. This is much faster and more precise.
The adapter I used is a standard C-mount to T2 converter.

Regards,

Martin


Nach oben
   
 Betreff des Beitrags:
BeitragVerfasst: 04. Dezember 2012, 02:55:48 AM 
Offline
Dauernutzer
Benutzeravatar

Registriert: 30. Juli 2010, 02:16:09 AM
Beiträge: 178
Wohnort: Melbourne, Australia
Hi Martin,

So you are the 'power behind the throne' :wink: Yes, I think moving the discussion to that Technik forum would be good.

A good point about the guidecam not seeing the light cone, I should have realised, so now back to 'plan B' :(

Did you get your C-T2 adapter from Baader or Teleskop service?

Cheers, Bernard

_________________
Quicquid Nitet Notandum


Nach oben
   
 Betreff des Beitrags:
BeitragVerfasst: 04. Dezember 2012, 03:11:54 AM 
Offline
Dauernutzer
Benutzeravatar

Registriert: 30. Juli 2010, 02:16:09 AM
Beiträge: 178
Wohnort: Melbourne, Australia
Hi Martin,

Is the '3-screw' section of your guidecam adapter the one that comes with the FIGU on the guidecam port, moved to the input port, or a component you added?

Cheers, Bernard


Dateianhänge:
Adapter.jpg
Adapter.jpg [ 23.64 KiB | 12024 mal betrachtet ]

_________________
Quicquid Nitet Notandum
Nach oben
   
 Betreff des Beitrags:
BeitragVerfasst: 04. Dezember 2012, 05:41:22 AM 
Offline
Dauernutzer
Benutzeravatar

Registriert: 30. Juli 2010, 02:16:09 AM
Beiträge: 178
Wohnort: Melbourne, Australia
Hi Martin,

A follow-up to my last question: I assume you used the existing guidecam '3-screw' adapter on the input port (it certainly looks like it), with a C-2T adapter, but what type is it? The male thread on the guidecam adapter is 25tpi but a normal C-mount is 32tpi, so is there a 25tpi C-mount to 2T adapter available ... or did you use some other coupling?

Cheers, Bernard

_________________
Quicquid Nitet Notandum


Nach oben
   
 Betreff des Beitrags:
BeitragVerfasst: 04. Dezember 2012, 11:27:43 AM 
Offline
Meister

Registriert: 13. August 2009, 17:04:50 PM
Beiträge: 262
Wohnort: Maienfeld, Schweiz
Hi Bernard,

well observed, the threads are different. I did not realize it, because the female C-mount is slightly larger and fits for about two turns and sits tightly..
Perhaps not the solution for the fine mechanic, but I am more into quantum mechanics, where this seems to work with the help of Heisenberg.
The adapter is from the LISA guide cam connection for an ATIK Titan attached to the original guide unit camera adapter.

Regards, Martin


Dateianhänge:
Dateikommentar: adapter
IMG_2197s.jpg
IMG_2197s.jpg [ 32.2 KiB | 12008 mal betrachtet ]
Nach oben
   
BeitragVerfasst: 04. Dezember 2012, 15:36:46 PM 
Offline
Dauernutzer
Benutzeravatar

Registriert: 30. Juli 2010, 02:16:09 AM
Beiträge: 178
Wohnort: Melbourne, Australia
Hi martin,

That is what I guessed was the solution ... long live Heisenberg

Thanks, Bernard

From: Martin Dubs (fg-spek-convento@vds-astro.de)
Sent: Tuesday, December 04, 2012 8:27 PM
To: fg-spek-convento@vds-astro.de (fg-spek-convento@vds-astro.de)
Subject: [fg-spek] Re: Request for observations of the 2mag star delta Orionis




Hi Bernard,

well observed, the threads are different. I did not realize it, because the female C-mount is slightly larger and fits for about two turns and sits tightly..
Perhaps not the solution for the fine mechanic, but I am more into quantum mechanics, where this seems to work with the help of Heisenberg.
The adapter is from the LISA guide cam connection for an ATIK Titan attached to the original guide unit camera adapter.

Regards, Martin






No virus found in this message.
Checked by AVG - www.avg.com
Version: 2013.0.2793 / Virus Database: 2634/5933 - Release Date: 12/02/12


Dateianhänge:
wlEmoticon-smile[1].png
wlEmoticon-smile[1].png [ 1.02 KiB | 11992 mal betrachtet ]

_________________
Quicquid Nitet Notandum
Nach oben
   
 Betreff des Beitrags:
BeitragVerfasst: 05. Dezember 2012, 16:20:38 PM 
Offline
Dauernutzer
Benutzeravatar

Registriert: 30. Juli 2010, 02:16:09 AM
Beiträge: 178
Wohnort: Melbourne, Australia
I have now checked the alignment of my eShel fiber-optic cable to the mirror hole using the 'back to front' setup shown below. I was expecting / hoping for a significant misalignment, as that would probably explain my poor SNR, but found very little, which is comforting in its own way. I played around with the alignment screws (needs 1.5mm allen key), to familiarise myself with how they affect the amplitude, but only needed to make small adjustments. I used Maxim DL (see screen capture below) which has good parameter measurements, graphic displays and live video. De-focusing the hole image helped avoid saturation and made it easier to see brightness changes. I had to run the Watec videocam at its shortest exposure to avoid saturation (255 ADU) with the light from the tungsten calibrator lamp. As I don't yet have a C(F)-T2(M) adapter I made a temporary adapter (a 1.25" nose), which worked reasonably well.
I also took the opportunity to clean the optic cable ends with a Q-tip and alcohol.

I now need to look for some other explanation / cause for my low SNR problem.

Cheers, Bernard


Dateianhänge:
align setup.jpg
align setup.jpg [ 151.59 KiB | 11906 mal betrachtet ]
best focus align.jpg
best focus align.jpg [ 165.82 KiB | 11906 mal betrachtet ]

_________________
Quicquid Nitet Notandum
Nach oben
   
 Betreff des Beitrags:
BeitragVerfasst: 05. Dezember 2012, 16:29:01 PM 
Offline
Meister
Benutzeravatar

Registriert: 31. Juli 2006, 16:43:32 PM
Beiträge: 3188
Wohnort: Köln
Hi together! Great that you are so active for this campaign. Just a reminder: You are meanwhile discussing technical issues for the Eshel and not the campaign. Remember that this is the ConVento thread which is going to all registered professionals, as well. Even I do not understand the details you presently describe. So, I recommend to move this discussion to the category "Technique".

Cheers, Thomas


Nach oben
   
 Betreff des Beitrags: eShel fiber-optic alignment
BeitragVerfasst: 05. Dezember 2012, 23:26:40 PM 
Offline
Dauernutzer
Benutzeravatar

Registriert: 30. Juli 2010, 02:16:09 AM
Beiträge: 178
Wohnort: Melbourne, Australia
(This is transferred from the Convento group's delta Orionis topic)

I have now checked the alignment of my eShel fiber-optic cable to the mirror hole using the 'back to front' setup shown below. I was expecting / hoping for a significant misalignment, as that would probably explain my poor SNR, but found very little, which is comforting in its own way. I played around with the alignment screws (needs 1.5mm allen key), to familiarise myself with how they affect the amplitude, but only needed to make small adjustments. I used Maxim DL (see screen capture below) which has good parameter measurements, graphic displays and live video. De-focusing the hole image helped avoid saturation and made it easier to see brightness changes. I had to run the Watec videocam at its shortest exposure to avoid saturation (255 ADU) with the light from the tungsten calibrator lamp. As I don't yet have a C(F)-T2(M) adapter I made a temporary adapter (a 1.25" nose), which worked reasonably well.
I also took the opportunity to clean the optic cable ends with a Q-tip and alcohol.

I now need to look for some other explanation / cause for my low SNR problem.

Cheers, Bernard


Dateianhänge:
best focus align.jpg
best focus align.jpg [ 165.82 KiB | 11782 mal betrachtet ]
align setup.jpg
align setup.jpg [ 151.59 KiB | 11782 mal betrachtet ]

_________________
Quicquid Nitet Notandum
Nach oben
   
 Betreff des Beitrags:
BeitragVerfasst: 05. Dezember 2012, 23:38:52 PM 
Offline
Dauernutzer
Benutzeravatar

Registriert: 30. Juli 2010, 02:16:09 AM
Beiträge: 178
Wohnort: Melbourne, Australia
Hi Thomas,

I fully agree that this eShel related techhnical discussion needs to be moved elsewhere and did suggest this a few posts back. I have copied my last posting to the new topic "eShel fiber-optic alignment" in the Technik-LWL section and suggest any further discussion go there. We also need to move the relevant existing postings there and assume the Administrator can do this but how do we contact him?

Cheers,
Bernard

_________________
Quicquid Nitet Notandum


Nach oben
   
 Betreff des Beitrags: Re: eShel fiber-optic alignment
BeitragVerfasst: 19. September 2018, 12:10:35 PM 
Offline
Meister
Benutzeravatar

Registriert: 19. August 2006, 11:45:20 AM
Beiträge: 2713
Wohnort: 66907 Glan-Münchweiler
Hi Bernard,

now " suddenly" I have the same problems with poor efficiency and I am playing with the idea to test my fiberinjection for exact alignment. Could you help me please?

Near the mirror there are 3 alignment screws and there are once more three alignment far of the mirror screws. What function do they have please?

I have to look if the distance of the fiber to the pinhole is correct. How one can adjust it? Then I have to look if the fiber is exactly aligned to the pinhole ,ok? Which screws must I turn for this? They near to the mirror or they far to the mirror?

What did you have found causing the poor efficiency you also have had?

Best Regards
berthold


Nach oben
   
Beiträge der letzten Zeit anzeigen:  Sortiere nach  
Ein neues Thema erstellen  Auf das Thema antworten  [ 18 Beiträge ] 

Alle Zeiten sind UTC+02:00


Wer ist online?

Mitglieder in diesem Forum: 0 Mitglieder und 1 Gast


Du darfst keine neuen Themen in diesem Forum erstellen.
Du darfst keine Antworten zu Themen in diesem Forum erstellen.
Du darfst deine Beiträge in diesem Forum nicht ändern.
Du darfst deine Beiträge in diesem Forum nicht löschen.
Du darfst keine Dateianhänge in diesem Forum erstellen.

Suche nach:
Gehe zu:  
Powered by phpBB® Forum Software © phpBB Limited
Deutsche Übersetzung durch phpBB.de