eShel + IMX455 Sony

Design, construction, tuning of spectroscopes
Information and discussion about softwares (telescope remote, autoguiding, acquisition, spectral processing ...)
James Foster
Posts: 439
Joined: Sun Jan 24, 2016 7:14 am

Re: eShel + IMX455 Sony

Post by James Foster »

RE:"Une mise à jour assez complète de ma page sur l'optimisation de eShel :

http://www.astrosurf.com/buil/asi6200mm/

(but still in French for the moment, really sorry)."

I had Microsoft Edge make a English translation and output to .PDF for us "French" challenged eShel fans!
http://astroimage.info/files/eShel%20an ... 20ENG2.pdf

James
James Foster
eShel2-Zwo ASI6200MM Pro
Lhires III (2400/1800/600 ln/mm Grat) Spectroscope
LISA IR/Visual Spectroscope (IR Configured)
Alpy 200/600 with Guide/Calibration modules and Photometric slit
Star Analyzer 200
Stu Todd
Posts: 21
Joined: Mon Mar 21, 2016 6:29 am
Location: Dunedin, New Zealand

Re: eShel + IMX455 Sony

Post by Stu Todd »

Great stuff James,

Thanks for taking the time to put that up.

Another fantastic essay from Christian too!

Regards,

Stu
Christian Buil
Posts: 1431
Joined: Mon Sep 26, 2011 6:59 pm
Contact:

Re: eShel + IMX455 Sony

Post by Christian Buil »

Thanks James!

Tom, some out of the topic, but... here a part of my presentation for the ASW2020 Spectroscopy Workshop, the November 8:

Image

Image

An excellent solution also for Lhires III spectrograph, I confirm.

Christian Buil
Tom Love
Posts: 64
Joined: Sun Apr 21, 2019 5:57 am

Re: eShel + IMX455 Sony

Post by Tom Love »

Most interesting,
Last edited by Tom Love on Sun Nov 01, 2020 11:37 am, edited 1 time in total.
-------------------------------------------------
Martinborough, New Zealand. Alpy, Lhires RC12
Tom Love
Posts: 64
Joined: Sun Apr 21, 2019 5:57 am

Re: eShel + IMX455 Sony

Post by Tom Love »

Most interesting, thankyou Christian, as always! I think this confirms my view that a fast newtonian has a lot to recommend it.

The AAVSO workshop has some really fascinating presentations, but the time of day is terrible for this side of the world (this isn't a complaint - I know you can't accommodate everybody with one time), so for Australians and New Zealanders it's probably best to wait until they put up the recordings of the sessions afterwards.
-------------------------------------------------
Martinborough, New Zealand. Alpy, Lhires RC12
Peter Somogyi
Posts: 420
Joined: Sun Jul 13, 2014 8:56 am

Re: eShel + IMX455 Sony

Post by Peter Somogyi »

Thank you for the APM 2.7x Barlow test, Christian!
So the 65mm backfocus (yellow arrows in the picture) is your modified recommendation in order to achieve 2x rather than 2.67x ? (APM specs saying "Backfocus: 105 mm from Center last Lens" and "Resulting focal length: - 62.9 mm")
Peter
Christian Buil
Posts: 1431
Joined: Mon Sep 26, 2011 6:59 pm
Contact:

Re: eShel + IMX455 Sony

Post by Christian Buil »

Yes Peter, the change from 105 mm to 65 mm is to achieve the 2x. The Barlow work well at 2.7x but also at 2x (my optical simulation and test on the sky) at the center of the field.

Christian
Joan Guarro Flo
Posts: 611
Joined: Thu Nov 03, 2011 8:50 pm

Re: eShel + IMX455 Sony

Post by Joan Guarro Flo »

Bonjour Christian,
The results that you have achieved are really spectacular, incredible to do times ago, congratulations for that !
With this system you make observations with hardly any noise in them and I need 5 times more time than you for similar results !

You know that most of the echelle observers we use in our instruments the ATIK460EX that you know very well. One "little" problem is the price of these cameras that have the IMX 455, so many of us will use the ATIK for a few or long time.

But following your instructions, I have made this Vega target with a reduction test by CMOS system with hopeful results.
 
Telescope Schmidt-Cassegrain. ATIK460EX, ISIS 6.03                     

Phase 1 : All frames in binning 1x1                                      

Phase 2 : 7 Vega frames, Thor and Tung pretraitement- make BIAS and DARK  subtraction, ( I have not known how make the FLAT ).                                       
Phase 3 : 7 Vega frames, Thor and Tung have passed for CMOS treatment, median filter 5x5 and binning 2x2.
                   
Phase 4 : Classic treatment with ISIS 6.03,  "Function de blaze lisseé" and "Order merging adjustment" activated.

Have I followed the appropriate way ? Is it possible to achieve good results with our ATIK460EX with this reduction system ?I think there are three many problems, the resolution down from 10000 to 8000, ripples appeared in some regions and it is possible that the noise in the violet could be improved.
What is your opinion about that ?

Cordialement, Joan.
Attachments
_ VEGA TEST1.png
_ VEGA TEST1.png (21.49 KiB) Viewed 4421 times
_VEGA TEST 3.png
_VEGA TEST 3.png (15.54 KiB) Viewed 4421 times
_VEGA TEST 2.png
_VEGA TEST 2.png (24.52 KiB) Viewed 4421 times
Olivier GARDE
Posts: 1243
Joined: Thu Sep 29, 2011 6:35 am
Location: Rhône Alpes FRANCE
Contact:

Re: eShel + IMX455 Sony

Post by Olivier GARDE »

Hello Joan,

I don't understand why you want to proceed CCD data with a CMOS process ?

CMED in ISIS V6 is only for a CMOS camera because CMOS camera have telegraph noise, not CCD.

It's normal that you decrease resolution of your spectrum with CMED process because you use a median filter and binning factor on your raw images.
With an ATIK 460ex your pixel size is 4,54µm, with the CMED process your pixel size grow at 9,08 µm
With an IMX 455 the pixels size is 3,8µm, with the CMED process your pixel size grow at 7,6 µm

The best process to reduce CCD data is the "classical" method.
LHIRES III #5, LISA, e-Shel, C14, RC400 Astrosib, AP1600
http://o.garde.free.fr/astro/Spectro1/Bienvenue.html
Robin Leadbeater
Posts: 1926
Joined: Mon Sep 26, 2011 4:41 pm
Contact:

Re: eShel + IMX455 Sony

Post by Robin Leadbeater »

Joan Guarro Flo wrote:Bonjour Christian,

With this system you make observations with hardly any noise in them and I need 5 times more time than you for similar results !
I cannot believe a change from CCD to CMOS with different processing can make that much difference. The must be some other problem (or "magic" !) here

Cheers
Robin
LHIRES III #29 ATIK314 ALPY 600/200 ATIK428 Star Analyser 100/200 C11 EQ6
http://www.threehillsobservatory.co.uk
Post Reply