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Topics - Jordi Gallego

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Hi all,
I have had a very low participation on the forum in the last months as I am on a very busy professional situation at the moment and unfortunately I have not much time for astrophoto :sad: :sad:
Anyway I promised some time ago to make a presentation on noise reduction in astrophotography using PixInsight, and I did it finally last weekend.
If you would like to have it a look, you can download the powerpoint file from my webpage:

There are Spanish and English versions. I already ask your indulgence for the quality if the English translation (It is quite a bit heavy file, 17 Mb, as it contains some images with a reasonable resolution).
Unfortunately this time I did not have records of my speech so you may found that some slides seem incomplete or difficult to understand without the verbal explanation.
Best regards

Gallery / NGC6914, VdB 131, 132 and surrounding area
« on: 2011 August 10 10:10:28 »
Hi all,

I have just finished processing of my last image. It is a widefield image in Cynus with NGC6914 nebula in the center.
Image taken with TOA-150 and STL11k. Exposure:  9x20 min RGB + 9x30 min Halpha (Astrodon filters).

This is the image at 800 pixel wide:

This is link to a higher resolution (66%) version:

and this is a close-up of central nebulosity (ay 100%):

Best regards

Gallery / NGC3718, NGC3729, Hickson56
« on: 2011 April 25 13:30:01 »
Hi all,

Today I had the opportunity to finish the latest image that I have been working on.
It is a bit different from what I usually do (mostly nebulae) and really this field asks for a longer focal length, but in any case this is the field with NGC3718, NGC3729, ARP322 group (Hickson 56) and a few more.
Please take into account that the image is presented as a crop at 100%

This is version at “forum size” (800 pixel):

And this is the 100% version (1075 pixel)

The image is an LRGB composition with more than 12 hour accumulated exposure. Taken with TOA-150 and STL-11000 (thus 1070 mm focal length and 1.69”/pixel) on EM-400 mount.
I am reasonably satisfied with the detail on the galaxy (especially when compared to other images taken with higher apertures and focal lengths).
This image has been complicated to process because, being a deep image, there was a lot of information on the background, and the noise reduction stage (always a complex task for me) caused a lot of problems.
Treatment has been possible thanks to noise reduction tools of PixInsight and thanks to the advice of Juan Conejero, who I would like to thank  (the advice for sure was good, the implementation if wrong it is only my fault  :D)


General / Good performance of ImageIntegration
« on: 2011 March 12 03:41:43 »
Hi all,

My last image, a widefield of NGC2170 region in Monoceros, has been a bit difficult to process.
When I saw the first couple of images downloaded from the camera I thought that I had a problem in the STL: both images had a group of parallel vertical traces in the same place of the frame (over NGC2170). A more close inspection showed me that the vertical lines changed from frame to frame, so no problem on the CCD, they were really satellite traces. Astonish I saw that image after image (I collected 14x20 minutes for each R,G and B channel over November to February) all images had the traces (and all of the over the more interesting object on the field!!!). All frames had a minimum of 3 traces and a maximum of 7 on a very narrow path. You can see some of the frames (not at all the worst) here:

This a first try of a pure average combination on the green channel, showing the result.

However, after several trial and error tests ImageIntegration did a very nice job and achieved to eliminate all of them. This is, I think, a remarkable proof of the good implementation and function of the rejection algorithym (winsorized sigma clipping on this case) as it must be noted that in total I had 14 images x 3 channel x 5 average number of traces = 210 traces in a very narrow space!
Obviously I had to push the limits of the algorithym  so I also get an integrated image with a noise level higher than the one I expected with 14 exposures. Maybe because of this I am not especially happy of my processing results, but in any case this is the final result I got (and with no traces!) 8)

And this is a link to a higher resolution version:


Hola a tod@s      English below

He incluido en el apartado artículos de mi web :

una presentación sobre integración de imágenes con la herramienta ImageIntegration de PixInsight. Es un archivo powerpoint (20 MB) y también hay un pdf con notas de la exposición oral.
La página artículos y las presentaciones que contiene están en castellano


Hi all,

I have updated the articles page on my website with a presentations on integration of images with ImageIntegration tool of PixInsight. It is a powerpoint file (20MB) and a pdf file with notes on the oral presentation..

The web page is in english but presentations are in spanish (except this last presentation on integration of images that is also in english language.)


Gallery / NGC1333
« on: 2010 November 30 11:19:54 »
Hola a tod@s,   english below

Esta es una imagen que me ha costado bastante en tener acabada pues ha acumulado unos cuantos problemas....

En primer lugar el tiempo no nos ha acompañado mucho este año. La primera exposición la hice el 10 de Septiembre y la última el 14 de Noviembre. En medio quedan un buen número de subidas a Àger desaprovechadas por culpa de las nubes :-(:-(

Otro problema es que esta imagen, al no ser el objeto principal tan tenue como los últimos objetos Van den Bergh que he fotografiado, la había planificado como RGB y al final ha sido LRBG. Sucedió que la primera noche (un viernes) llegué reventado al observatorio, programé CCDComander y, por error, solo puse tomas de Luminancia. Cuando me desperté varias horas despues ya tenía unas cuantas tomas hechas y para aprovecharlas cambié a LRGB.

Por último, durante el procesado de esta imagen llegué a un punto en que me atasqué en un aspecto en concreto. Entonces decidí pedir consejo a Vicent Peris y él me lo dió, y por eso quiero decirlo aquí y agradecérselo públicamente.

Bueno al final, esto es lo que ha salido. Se trata de una toma con 20 exposiciones de luminancia de 15 minutos cada una, y 10 exposiciones de 30 minutos en R, G y B (binning 1x1) con TOA-150 y STL-11000. Esta es la imagen a "tamaño de foro":

y aquí la teneis a bastante mayor resolución:

A ver que os parece


Hi all,

This is an image that has been difficult to finish due to several reasons..........

First, weather has not been much friendly this year. First exposure was taken on September 10th and last was in November 14th. In the middle ther are several 170 km trips to my observatory to find only clouds.... :-(

Another problem was that this image was planned to be RGB, but due to a mistake from my side ended as LRGB.

Last, during processing, I arrive to a point that blocked me. I the ask for advice to Vicent Peris who kindly helped me. I want to thank him here.

Well at the end this is what I get. Exposure is 20 x 15 min in Luminance and 10x30 min in R,G and B (unbinned), with TOA-150 and STL-11000. This is the picture at "forum size":

And this is a higher resolution version:

let us see what do you think

Gallery / Summer work on Cepheus
« on: 2010 September 18 12:14:55 »
This summer I have been dedicated to image widefield nebulosity areas on Cepheus, that include objects from Sidney Van den Bergh’s catalogue.
I have completed 3 images, and all of them have been totally and exclusively processed in PixInsight . The equipment used is Takahashi TOA-150 (with flattener 67-FL) and SBIG STL-11000.

Van den Bergh 141 (Ghost nebula)

This is last image with near 13 h of accumulated (LRGB) exposure (and with  a non definitive processing):

link to a higher resolution version (66%):

and a detail at 100% of the “ghosts”:

Van den Bergh 155 & Sharpless 2-155 (Cave nebula)

11 h accumulated (RGB) exposure:

Link to a higher resolution version (66%):

Van den Bergh 152: a very interesting region with a lot of different objects inside

I have already posted this image on the forum, so to avoid repeating me, this is the link to the original post:

Thanks for taking a look ;)

Best regards

Gallery / Van den Bergh 152 and surronding area
« on: 2010 August 25 02:30:35 »
After a while posting images here I would like to show this image of Van den Bergh 152 and surronding area. The field includes several interesting objects, VdB 152 itself, planetary nebula  DeHt 5, B175, LBN 538, etc.

This time, as target was somewhat dim I left RGB strategy used in recent shots and returned to to LRGB:
Luminance: 22x15 minutes
Color: R: 5x30 min,  G: 5x30 min, B: 6x30 min 
Witht TOA-150 and STL-11000
Enterely processed with PixInsight 1.6

This is full field at web size:

A higher resolution version (66%):

and a detail at 100%

Best regards

Nota: para una versión en castellano por favor ver este post en el foro FotografiaAstronómica:

Hi all,

I must say in first place, as apologize, that work reasons (and also bad weather) keep me away a lot from astrophotography and from forum participation on recent times.

On the other hand, this post may be is a bit off-topic but as at the end it talks about two CCD images and both have been processed with PixInsight, I have included it here anyway.  ;)

I have just updated my website with a news on the publication of an study on "Arp's loop", supported by Instituto de Astrofísica de Canarias and coordinated by Dr. David Martínez-Delgado, which uses between other resources , images from three amateur astrophotographers, Ray J. Gabany, Tony Hallas and myself.

Paper has been presented and already accepted for publication at Astronomy & Astrophysics journal and because of this we can talk about it.

To be honest, my contribution to the work has been very modest and mainly means the use of one of my previous M81 - M82 images (the one that was APOD on 2008):

and the fact of this image being used (by the way, in negative and heavily stretched, as is usual on this kind of scientific works) has allowed me to be presented as co-author of the study :D

Although this kind of collaboration with the professional world is not new (and we have great examples here on this forum) it is really new to me and I cannot hide that it is indeed a personal gratification. In first place for having my name on a scientific publication related to my astrophoto work and secondly because my name appears between the names of two world known astrophotographers as Gabany and Hallas are.
It is also relevant to me as I also participated on other works of this kind that did not achieve the objective (although they required a lot of hours of dedication) and I was a bit discouraged.

Well, in any case here is the link:

If you would like to have more information on the study you can download a complete copy (PDF) here:

Regarding the images, on my web site, first image (the old one taken with FSQ-106N) was mainly processed with PixInsight 1.0 (I did calibration and alignment at that time with other package) and was one of the first where I processed by separated, following Vicent Peris lessons, Large Scale and Small Scales. In any case it is hard to think today on not having, Deconvolution, HDRWavelets, ImageIntegartion, Color Calibration tools...... and many other tools that have been included in PixInsight on these years ::)

I started new image, taken with TOA-150 in February. (At this time I even completely forgot that the paper on Arp’s loop was on its slow way to publication) , and this image is, frankly speaking.......... unfinished :-[
It is unfinished because terrible bad weather (and some mistakes from my side) prevented me to collect enough exposure time. But I could not resist the temptation of show it as is my intention to "finish it" on oncoming weeks, and then I will display at full resolution.
A few comments regarding this new image. It will be again a pure RGB image and this time my target (I am using a smaller image scale) is more to get galaxy detail rather than show up IFN. And this image will be the first that will be processed from the beginning to end, from calibration to resizing for web display in PIxInsight (1.6) :D

Thanks and I apologize for the long post


Bug Reports / Problem with Open Image Files window
« on: 2010 April 01 06:03:48 »

I have a small problem with Open Image Files window (I do not use native files dialogs): I am not able to clearly see information (month, day) on Date Modified field :

I can see year and time (hours and minutes) but it is not possible, at least to me, "expand" Date modified field width  to clearly see month and specially date.

This is in PI Win x64 (latest release). I am not 100% sure but I think that this did not happen with my old machine runnig 32 bit version of PI


General / A couple of doubts about ColorCalibration
« on: 2010 January 10 07:57:15 »
Hi Juan and everybody,   (castellano abajo)

I have a couple of doubts and/or questions regarding ColorCalibration tool.

First, how should one interpret that the white reference mask is a color image instead of a grayscale image? I do not understand how such a mask works. Can you please explain this?

Second, (this is maybe more a request than a question), why the color calibration factors, Kr, Kg, Kb, that are displayed on the processing console after the application of the process, are higher than one?. I know that is a current practice on other software packages but this is, I believe, against PixInsight philosophy. Is it possible to change these coefficients to the normalized range 0 -1?, or alternatively, if this is not possible or desirable, is it possible then to change the presentation of the manual color correction sliders to accept numbers higher than one?

Thanks in advance

Tengo un par de dudas y/o preguntas acerca de la herramienta ColorCalibration.

En primer lugar, ¿cómo se debe interpretar que la máscara white reference sea una imagen de color en lugar de escala de grises?. No comprendo como trabaja una máscara así. Juan, puedes explicarlo por favor?

En segundo lugar (ésto es más una petición que una pregunta), ¿Porque los factores de calibación de color que aparecen en la processing console tras la aplicación del proceso, son mayores de uno?. Ya sé que esto es práctica habitual en otras aplicaiones, pero entiendo que esto va en contra de la filosofía de PixInsight. ¿Es posible cambiar la presentación de estos coeficientes para que queden dentro del rango normalizado 0-1?, o alternativamente, si esto no es posible o deseable, se puede cambier la presentación de los manual color correction sliders, para aceptar números mayores de uno?

Gracias anticipadas

Hola a tod@s      english below

He actualizado mi web con una página que recoge algunas presentaciones que he ido realizando sobre temas de astrofotografía. Las dos últimas hacen referencia al procesado de imágenes RGB y al uso de varias herramientas de PixInsight. La página y las presentaciones están en castellano:


Hi all,

I have updated my website with a few presentations on astrophotography topics. The two more recent are devoted to RGB image processing and the use of several tools on PixInsight. The presentations are unfortunatly only in Spanish


Gallery / NGC7023 Iris Nebula
« on: 2009 September 08 12:36:18 »
Hola a tod@s,         Hi all (english below) )

Os pongo aquí mi última toma. Se trata de NGC7023, la nebulosa Iris y sus alrededores, un campo que siempre me ha agradado mucho y hasta ahora no había tenido ocasión de fotografiar.

Este es el campo completo:

link a una copia de mayor resolución (66%):

Recorte de la Iris:

TOA-150 y STL-11000. Son 10 tomas de 15 minutos por canal (RGB) recogidas en dos noches de Agosto excepcionalmente cálidas: en una están tomadas con la cámara a -10ºC y en la otra a -5ºC. Nunca había tenido que llegar a esa temperatura y se nota en el ruido (y en el tratamiento necesario para eliminarlo claro, que está un poco pasado de rosca).


This is my last shot. NGC7023, the Iris nebula and surronding area, a zone that I had always liked a lot but until now I did not have had the opportunity to image.

This is full field:

link to a higher resolution version (66%):

Iris crop:

TOA-150 and STL-11000. 10 exposures of 15 minutes per channel (RGB) taken during two extremely warm nights of August: one night I had to shot at -10ºC and the other at -5ºC. I had never used the camera at this temperature, and this is perceptible in the noise (and in the treatment given to reduce it, of course, that is a bit excessive).


Gallery / M33 del año pasado M33 from last year
« on: 2009 June 06 00:48:25 »
Hola a tod@s,          english below

Sigo sacando tomas del baúl. Ésta está hecha entre Octubre y Diciembre del año pasado. Está hecha por tanto con el FSQ. Tiene en total casi 9 horas de exposición (9 x15min R, 9 x 15min G, 7 x 20min B, 4 x 30min Halfa).
La toma está procesada con PixInsight 1.51 (incluyendo el nuevo módulo de deconvolución de 1.5.2.)

Esta es la imagen (al 66%):

y este es un link para la imagen al 100% y con un poco más de campo:

Un saludo

I still have some images that are pending of processing. This is taken between October - December last year and has about 9 hours of accumulated exposure (9 x15min R, 9 x 15min G, 7 x 20min B, 4 x 30min Halfa).
Processed with PixInsight 1.51 (including new 1.5.2 deconvolution module)

This is the image (at 66%)

and this is a link to the 100% version (with a slightly wider field):

Best regards

English below

No estoy seguro si esto es exactamente un bug, pero en todo caso .......
Durante el procesado de la última imagen, al salir una vez del programa me apareció un mensaje de error de PixInsight (lo siento pero no me acuerdo exactamente de que decía, pienso que era el típico mensaje de error estilo windows que dice si quieres comunicarlo o no, pero no estoy seguro.)
Cuando, volví a entrar al programa noté esto:
- “File tool bar” (save, save as,….) no aparece en la barra de herramientas (y antes estaba!!)
- El menú de la barra de herramientas está deshabilitado!!!

Para mirar de solucionarlo, primero reseteé los ajustes de PixInsight y luego desinstalé y volví a instalar el programa, pero la situación sigue igual

¿Qué puedo hacer??  :o


I am not sure if this is exactly a bug, but in any case…….

During processing of last image, when I exit the program I noticed a message error from PixInsight (sorry but I do not remember the exactly contents, I think that was the typical, windows style error message telling you if you want to communicate or not, but I am not sure.

When, later, I enter again I noticed that:

- File tool bar (Save, Save as, …) was not shown on tool bar, and before it was
- Tool bars menu is now disabled!!!

In order to solve this situation I reset PixInsight settings and also uninstall and install again, but situation is still the same.

What can I do??   :o


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