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Topics - vicent_peris

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31
Wish List / Blink information please
« on: 2012 June 08 11:15:38 »
Hi,

A very nice improvement for the Blink module would be to display also some information about the displayed image, like some FITS keywords (objetc name, filter, exposure, and so on). I really need it.


Thanks. Best regards,
Vicent.

32
Hi,

This is a very short tutorial. We're working now with one of our latest images acquired at CAHA. The photographed object is PK164+31.1, a planetary nebula in Lynx. The original RGB image looks like this:



While thinking about how to calibrate the color of this image, I saw the tiny spiral galaxies at right. So I decided to try to use these galaxies as the white reference of the image. Take into account that these galaxies are significantly redshifted, as well as all the other background objects. So, to me, this would have sense from a documentary point of view. The reference galaxies are these ones:



After applying the color calibration routine, we get this result:



And this is the image after raising the color saturation:



Of course, the H-alpha emission is somewhat muted because we are giving less weight to the red channel. But this can be solved because we have H-alpha data as well. This is a close comparison of the reference galaxies before and after the color calibration process, and after the color saturation curve:



Now these galaxies have blue-cyan spiral arms and orange bulges. :) See also the we can now appreciate much better the color of the spiral arms of the tiny galaxy inside the PN.


That's all.
Best regards,
Vicent.

33
Announcements / APOD for Leonardo Julio & Carlos Milovic
« on: 2012 March 06 01:51:20 »
Hi,

My greetings for Leonardo and Carlos! Today's APOD is for him.

It is the area sorrounding NGC 2170, acquired with a Taka Epsilon180ED and a Canon 5D Mark II. This image have been revised by Carlos at the PixInsight Workshop in Argentina.

IMO this image has some very good points, specially the dinamic range control around the stars. Never will stop saying how important this is; moreover I would say that, historically, this defines the point where astronomical image processing enters into the modernity.


My best wishes to both.
V.


34
Image Processing Challenges / ALHAMBRA Survey, field 7
« on: 2012 March 05 08:14:55 »
Hi all,

I have just uploaded a set of images of the ALHAMBRA Survey. This is a cosmological survey containing about 600.000 galaxies down to mag 26.5 in four square degrees of the sky, acquired with the 3.5 meter Zeiss telescope at Calar Alto Observatory. The data set is composed of 23 images which have been registered and flux equalized. 20 out of the 23 are midband image acquired with 30 nm wide filters; these images have been acquired with LAICA camera. This camera has four, 16 megapixel sensors located at the prime (f3.9) focus, and these images correspond to the ones acquired by one of these four sensors. The filter system is described in page 5 of this PDF article. The other three images have been acquired with Omega2000, a 4 megapixel infrared camera, with the standard wideband J, H and K filters.

The challenge here is to combine a RGB image. Good luck!
Vicent.

35
Off-topic / Eris occultation in Nature
« on: 2011 October 27 06:08:54 »
Hi,

Today Nature published a letter where I am coauthor about the results of an observation of a star occultation by TNO Eris. You can read the abstract here:

http://www.nature.com/nature/journal/v478/n7370/full/nature10550.html

Dr Jan Fabregat and myself contributed with an observation from the observatory of the University of Valencia. We observed the target star with a 60 cm RC and a Watec videocamera. Finally the occultation band passed across South America, so we didn't see any decrease in brightness of the star here in Spain.

From these observations we conclude that the size of Eris is almos the same as Pluto's. It is also very interesting the measurement of the albedo: 0.96. This means that Eris reflects the light of the Sun as an astronomical mirror.  :D This is surely due to a frozen atmosphere on the surface of the dwarf planet..


Best regards,
Vicent.

36
Gallery / Image Release: Messier 31 - Calar Alto
« on: 2011 September 16 09:49:45 »
Hi all,

We have released a new photo acquired at Calar Alto Observatory with the 1.23 and 3.5 meter Zeiss telescopes. You can see it at 800 pixel wide here:



You can see the more information about the image and a full resolution version by following this link:

http://astrofoto.es/Galeria/2011/M31/M31_CAHA_en.html

Direct link to the full resolution image:

http://astrofoto.es/Galeria/2011/M31/M31_CAHA_full.html

And a direct link to the full resolution image with the emission line objects:

http://astrofoto.es/Galeria/2011/M31/M31_CAHA_emission_full.html

We used seven filters to make this photo. In the 3.5 meter telescope we acquired data with four, 30 nm wide filters centered at 458, 489, 551 and 644 nm. The 458 and 551 contained mostly continuum data, while the 489 and 644 contained emission from O-III, H-beta and H-alpha. Thanks to this filter combination it has been possible to separate the emission objects from the rest of the galaxy. You can see in my website both versions of the image (with and without emission line object enhancement). The RGB exposures with the 1.23 meter telescope were used for the mid and large scale structures of the image, giving to the photo a more "broadband color".

Hope you like it.
Best regards,
Vicent.

37
Tutorials and Processing Examples / Dynamic Range and Local Contrast
« on: 2011 September 16 08:36:04 »
Hi all,

I've just published a tutorial about processing techniques concerning dynamic range and local contrast. Although it's an advanced tutorial, I think some sections can be easily followed. In this article I describe some techniques that are extremely important for me at this moment. I recommend to take a closer look to the star dynamic range compression section that speaks about the techniques I am using now to restore the Gaussian profile of the stars. Follow the below link to read the article:

http://pixinsight.com/tutorials/NGC7023-HDR/en.html


Hope you like it!
Best regards,
Vicent.

38
Gallery / Image Pre-Release: NGC 7023 - Calar Alto
« on: 2011 September 16 08:25:09 »
Hi all,

I want to present our lastest work from the Descubre / CAHA / OAUV / DSA collaboration: NGC 7023 - the Iris Nebula. This image was acquired and processed by Jack Harvey, Steve Mazlin and me. Total exposure time is about 23 hours - with 20 min subs - through Baader RGB filters. For the central, 7th magnitued star we made an HDR integration with exposures of 1 min, 5 sec and 0.3 sec.

Here you have the image at 600 pixel wide:



You can see the more information about the image and a full resolution version by following this link:

http://astrofoto.es/Galeria/2011/NGC7023/NGC7023_CAHA_en.html

Direct link to the full resolution image:

http://astrofoto.es/Galeria/2011/NGC7023/NGC7023_CAHA_full.html


This is a truly important work for me because it summarizes the state of some of the techniques that I have been developing throughout the last 10 years. For this reason, along with the image,I've just published a tutorial about processing techniques concerning dynamic range and local contrast. Although it's an advanced tutorial, I think some sections can be easily followed. In this article I describe some techniques that are extremely important for me at this moment. I recommend to take a closer look to the star dynamic range compression section that speaks about the techniques I am using now to restore the Gaussian profile of the stars. Follow the below link to read the article:

http://pixinsight.com/tutorials/NGC7023-HDR/en.html


Hope you like it!
Best regards,
Vicent.

39
Tutorials and Processing Examples / NGC 6914 processing notes
« on: 2011 January 13 16:27:41 »
Hi all,

this is to say that some days ago we put some processing notes on our NGC 6914 in the processing examples section of PixInsight's website. Here is the link:

http://pixinsight.com/examples/NGC6914-CAHA/en.html

I describe here some techniques that link data acquisition and processing. For example, I describe the observational techniques to supress blooming, or to correct residual gradients to make a better mosaic assembly.

This article is only a summary of the employed techniques. I will describe deeply some of them in the near future.


Hope you find interesting this article.
Best regards,
Vicent.

40
Hello all,

this is to announce that I will be giving a two hour PixInsight workshop at CEDIC 2011. I will give also a lecture about my professional work at the Astronomical Observatory of the University of Valencia and at Calar Alto Observatory. CEDIC is the first international astro-imaging conference in Europe, and will take place on March 18th and 20th. Information about CEDIC can be found here:

http://cedic.at/

Workshop program will include:

- PixInsight working philosophy and user inteface introduction.
- Image processing with PixInsight:
     - High dynamic range image composition with the HDRComposition tool.
     - Non-linear transformations of the image (histograms, curves...).
     - Dynamic range compression with the HDRWaveletTransform tool.
     - Color calibration.


More information and updates will be posted here and at CEDIC website. Stay tuned.

Best regards,
Vicent.

41
Hello all,

this is to announce that I will be giving a three hour PixInsight workshop at NEAIC 2011. I will give also a lecture about my professional work at the Astronomical Observatory of the University of Valencia and at Calar Alto Observatory. NEAIC is one of the most important astro-imaging conferences in the USA, and will take place on April 14th and 15th.  Information about NEAIC can be found here:

http://www.rocklandastronomy.com/NEAIC/index.html

Workshop program will include:

- PixInsight working philosophy and user inteface introduction.
- Image processing with PixInsight:
     - High dynamic range image composition with the HDRComposition tool.
     - Non-linear transformations of the image (histograms, curves...).
     - Dynamic range compression with the HDRWaveletTransform tool.
     - Color calibration.


More information and updates will be posted here and at NEAIC website. Stay tuned.

Best regards,
Vicent.

42
Gallery / Image Prerelease: NGC6914 at CAHA
« on: 2010 October 14 09:36:59 »
Hi all,

this is our last image acquired at Calar Alto Observatory on July; we finished processing it just today. It's a two panel mosaic of NGC6914 in Cygnus with the 1.23 meter Zeiss telescope. The field of view is 15x27 arcminutes. Each panel has about 11 hour total exposure time through Baader RGB and H-alpha filters. As we use to do, no luminance exposures were acquired, so (as you will see) color deepness is very good. Here you have the image:


Image credits: CAHA, Descubre Foundation, DSA, OAUV, Vicent Peris, Jack Harvey, Juan Conejero.
Full resolution here: http://www.astrofoto.es/astrofoto/foros/ngc6914c.jpg

With this true RGB image set, we were able to go extremely deep into the darkness of the central area of the photo, where we can show you faint reflection nebulas. It is important also to note that color calibration was made taking as white reference the integrated light of M51 through this imaging system. The RGB weights for this galaxy were applied to this image, knowing accurately the atmospheric extinction for both images.

To increase the contrast of the H-alpha structures, we processed separately the H-alpha image and blended it with the R channel with an "overlay" opperation in PixelMath, as described here:
http://pixinsight.com/forum/index.php?topic=2409.msg16165#msg16165


Hope you like it!
Vicent.

43
Hello all,

last weekend we did a 12 hour PixInsight workshop at the Adler Planetarium (Chicago):




Although there were only 8 attendees, things went smoothly and we reviewed a lot of concepts and techniques. Apart from learning processing techniques, we discussed the observational techniques required to use the upcoming PixInsight tools for superflat and color calibration.

This is a small photo gallery:


A photo of the attendees in front of the sun dial. The downtown in the background:


A larger version here: http://astrofoto.es/astrofoto/foros/workshops/Adler-2010/2_Group1_large.jpg

From left to right: Geoffrey Stone, Cleon Wells, Larry Van Vleet, David Illig, Max Mirot, Joe De Pasquale, Robert Hurt and Philip de Louraille.


A second group photo with me (I'm att the center of the frame) taken by a tourist:


A larger version here: http://astrofoto.es/astrofoto/foros/workshops/Adler-2010/3_Group2_large.jpg


The conference room:




On saturday, five of us went to a "spanish" restaurant in the downtown:





Best regards,
Vicent.



44
Gallery / APOD for Jack and Steve
« on: 2010 August 05 15:07:19 »
Hi,

see today's APOD :)

http://apod.nasa.gov/apod/ap100805.html


Congratulations!
Vicent.

45
Hello all,

just yesterday the Adler set up the registration webpage:

https://adlerplanetarium.wufoo.com/forms/astrophotography-workshop-with-vicent-peris/


In very short we will publish official agenda, hotel info and FTP details.


Thanks you very much for your interest.
Best regards,
Vicent.

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