Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Topics - vicent_peris

Pages: 1 [2] 3 4 ... 6
16
Hi all,

We've announced this event by email but I forgot to announce it on the forum. So I'm posting this event now, specially because we still have one seat. This PixInsight intensive workshop will take place in Katonah, New York, USA, from March 11th to 17th, 2015.

This workshop aims at giving a comprehensive operational/technical understanding of PixInsight to a small group of participants (5-10) over the course of 7 concentrated working days. The workshop will take place in a mid-century modern, private home in Katonah, near New York city.

Participants will bring all their own unprocessed data sets which will be processed during the week. The structure of the seminar will allow participants an in-depth view of Pixinsight, with the goal of having a total immersion in the process of the image creation.

For more information about the workshop, please visit the dedicated webpage at pixinsight.com:

https://pixinsight.com/workshops/katonah-2015/

Due to its singular characteristics, we are limiting this workshop to 10 seats. We still have one seat.

This workshop is being sponsored by Pleiades Astrophoto and the Astronomical Observatory of the University of Valencia.


See you in Katonah!
Vicent.

17
Dear all,

I'm glad to announce a PixInsight workshop that will take place in Alcanalí, Alicante, Spain, from February 1st to 7th. This workshop aims at giving a comprehensive operational/technical understanding of PixInsight to a small group of maximum 10 participants over the course of 7 concentrated working days. The workshop will take place in a private, mediterranean villa, where we will all sit around a dining table and immerse ourselves in processing data.

Participants will bring all their own unprocessed data sets which will be processed during the week. The workshop will be also centered in several examples which will be worked from start to finish. The seminar will allow participants an in-depth view of PixInsight, from a beginners level to an expert level, with the goal of having a total immersion in the process of the image creation. This workshops also introduces a new documentation for the attendees.

For more information about the workshop, please visit the dedicated webpage at pixinsight.com:

https://pixinsight.com/workshops/alicante-2015/

Due to its singular characteristics, we are limiting this workshop to 10 seats.

This workshop is being sponsored by Pleiades Astrophoto and the Astronomical Observatory of the University of Valencia.

See you in Alcanalí!
Vicent.

18
Workshops and Conferences / European PixInsight Conference 2014
« on: 2014 September 26 14:07:24 »
Hi all,

One week ago we announced the first European PixInsight Conference (EPIC). People is registering quickly and we have only 10 places left.

The first European PixInsight Conference will take place in Munich, Germany, on next October 31st to November 2nd. This year, Carlos Milovic and me will be both teaching in the workshop.

We are also introducing some important innovations in our teaching methodology, like the flow charts, which will help you in your image processing work at home, and three specific workshop levels to meet the needs of all the people. For further details please visit the workshop's webpage:

https://pixinsight.com/workshops/epic-2014/

Our aim is to create a yearly meeting point for the European PixInsight community in Munich, so we'll be developing the EPIC with new contents and activities from now on.

This workshop is being sponsored by Astrosysteme Austria (ASA) and the Astronomical Observatory of the University of Valencia.


See you in Munich!
Vicent.

19
Gallery / Barnard 150
« on: 2014 August 06 10:15:15 »
Hi all,

Just finished a new work, this time Barnard 150 in Cepheus:



Here at full resolution.

It has been done with a 20" Planewave and a Finger Lakes Proline 16803 at the Observatorio Astronómico de Aras de los Olmos. The image has nearly 19 hours of integration time. I did the exposures with RGB and Sloan z' filter. The last filter was used to enhance the emission of dust-reddened stars inside the nebulae, as it transmits light in the infrared from 800 nm. Here you have a crop of the RGB and RGBz images:


RGB:




RGBz:



The use of the z' filter enhances the star reddening and also shows new faint sources inside the nebulae. It also shows redder absorption nebulae because they emit light in the infrared.


Hope you like it.
Best regards,
Vicent.

20
Release Information / Superbias: a practical example
« on: 2014 July 18 15:35:33 »
Hi all,

I want to describe the technique I designed for master bias generation. I decided to design this technique when I was working with the old camera at Calar Alto. This camera had terrible column defects which were a challenge to correctly calibrate the light image. A master bias shows these defects:



This is the sensor used to produce most of the images I released from Calar Alto (and more coming). The idea I had in mind was how to produce the best master bias with the higher possible signal to noise ratio. The main problem I had was the extremely low readout time -3 min.- because it was not possible to have a large amount of bias frames to integrate. I made an experiment with a Finger Lakes camera having a Truesense CCD sensor and found that, by integrating a high number of bias frames, the master bias was well characterized by two different structures:

- A small scale pattern consisting of vertical lines.
- A large scale pattern consisting of soft gradients.

The goal of the superbias is to reconstruct a model -based on these two discrete structure types- of the bias signal with a low quality master bias image. First, take a look at this small crop of a bias signal. The vertical strip contains several integrations from a 200-frame data set:



See that, even integrating 20 frames, the read noise dominates over the column pattern. As we integrate more frames, the column structuture starts to appear. Take into account that this cannot be done simply by averaging column values because in most bias images there are large scale structures that are not vertically distributed. We can see these structures in the below image of two different sensors. I deliberately posterized the images to clearly show the gradient orientation:



Therefore, the superbias is a combination of both characteristic scale structures. Let's see the superbias calculated from a 20-frame master bias:



If we compare this superbias to another superbias built from the full data set, the main difference between both images is the increased signal to noise ratio of the large scale structures:



Please take into account that these images are heavily stretched; see the single bias image in vertical strip, which has the same stretching, to have a comparison point with the actual read noise of the camera. When we look at these images at full resolution, the reconstructed colum pattern is very similar in both images:



The superbias technique was designed for cameras with a bias signal where the only significative small scale structures correspond to the vertical pattern. In this case (a Truesense KAF16803 sensor), we can actually demonstrate that the residual, not modelled part of the image is random noise. When we subtract a superbias image from the original, integrated master bias, the result shows a uniform, random distribution:



Assuming that this residual is random white noise, its intensity should decrease by the square root of the number of integrated images. If there is a fixed pattern—the same pixel-to-pixel variations that we can find, for instance, in dark and flat frames—, then the decrease in noise intensity won't follow this law because the pattern has a fixed, constant intensity.

We are going to do this test by subtracting the superbias generated from the 200-frame master bias. We are also going to test if the superbias technique works well with lower quality master bias images, so we are doing the same noise measurement taking as reference a superbias generated from a 25-frame master bias. We'll subtract these superbias images from a set of master bias frames, which are the integrations of 25, 50, 75, 100, 125, 150, 175 and 200 randomly selected images.

The results of this experiment are summarized in the table below:



Table values are expressed in units of 10-5. The first column indicates the master bias used to get the residual image. The second and third columns are the noise intensities measured on the residuals after subtracting the superbias images from the 25- and 200-frame master bias, respectively. To evaluate noise intensities, we have used the Qn scale estimator of Rousseeuw and Croux.[1] The last column is the theoretical noise increase computed from the square root of the number of integrated frames. We can see clearly that the residual image is purely random noise, which demonstrates that the column pattern and medium-scale structures of the bias signal is very well modelled with the superbias technique in this case.


[1] P.J. Rousseeuw and C. Croux (1993), Alternatives to the Median Absolute Deviation, Journal of the American Statistical Association, Vol. 88, pp. 1273–1283.



You can download the set of master bias images here.
Best regards,
Vicent.

21
Hi,

I'm glad to announce a PixInsight workshop that will take place in Katonah, NY (USA), on September 7th to 13th. The workshop will be given by Vicent Peris, astrophotographer of the Astronomical Observatory of the University of Valencia (OAUV), Spain, and a principal member of the PixInsight Development Team.

This workshop aims at giving a comprehensive operational/technical understanding of Pixinsight to a small group of participants (m) over the course of 7 concentrated working days. The workshop will take place in a mid-century modern, private home, where we will all sit around a dining table and immerse ourselves in processing data.

Participants will bring all their own unprocessed data sets which the class will share as examples to work on. The images will be worked from start to finish; therefore, the seminar will allow participants a never-before-offered view of Pixinsight, from a beginners level to an expert level, with the goal of having a total immersion in the process of the image creation.

For more information about the workshop please visit the dedicated webpage at Pixinsight.com:

https://pixinsight.com/workshops/katonah-2014/

Due to its singular characteristics we are limiting this workshop to 10 seats.

This workshop is being sponsores by Pleiades Astrophoto and the Astronomical Observatory of the University of Valencia.


See you in Katonah!
Vicent.

22
Hi all,

I'm glad to announce a PixInsight workshop that will take place at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, USA, on June 28th and 29th.

This workshop has been conceived with a special focus on the active participation of the attendees. Each registered participant will be provided with a personal account on our file servers, where he or she will be able to upload raw data that will be worked out during the workshop. In this way the participants will have the opportunity to apply and understand the concepts and techniques described in the context of their particular imaging conditions.

The topics covered will be, among others, the graphical user interface, elementary techniques of astronomical image processing, image delinearization and dynamic range compression, and narrowband imaging.

This workshop includes a tour to visit Harvard's famed 15-inch Great Refractor telescope, a key instrument for the development of astronomy in the 19th Century.

For more information about the workshop there are two dedicated webpages. The webpage hosted at harvard.edu contains general information, including lodging and a map of local restaurants:

http://hea-www.cfa.harvard.edu/piworkshop/

The webpage at pixinsight.com contains more technical information about the workshop contents, as well as the registration info:

https://pixinsight.com/workshops/cfa-2014/

This workshop is being sponsored by Astrosysteme Austria (ASA) and the Astronomical Observatory of the University of Valencia.

I want to publicly thank Joe DePasquale for their help on the organization, we're making this workshop reality thanks to his collaboration.


See you in Cambridge!

Vicent.

23
Gallery / Large Magellanic Cloud
« on: 2013 December 05 10:23:20 »
Hi,

After the Chile workshop I was invited by Daniel Verschatse to Hacienda Los Andes (www.haciendalosandes.com) where I had the first opportunity to photograph the southern skies during 5 nights. I decided to risk my work to a single image, and made this photo of a portion of the Large Magellanic Cloud near the Tarantula nebula:



It's a two-panel mosaic made with a 14.5" f9 RCOS and a STL11K. Total exposure time is 10 hours (20 min subs) through RGB filters (no L).

For additional info and higher res versions you can visit my website:

http://astrofoto.es/Galeria/2013/LMC/LMC_en.html

I want to publicly thank Daniel for letting me to work on his telescope during these nights and I strongly recommend to visit the Hacienda if you go to Chile, skies are amazing and the place is wonderful.


Hope you like it!
Best regards,
Vicent.

24
Gallery / IC1805
« on: 2013 November 15 02:23:43 »
Hello,

Last week I made a photo at the Observatorio Astronómico de Aras de los Olmos (OAO), where I work operating the telescopes. The object is a small part of IC1805 in Cassiopeia.

I've made two different versions of this photo. The first one is black and white, including only the narrowband H-alpha data:



For higher resolution and more info visit my website:

http://astrofoto.es/Galeria/2013/IC1805_BW/IC1805_BW_en.html

The second version is a color photo where I mixed the H-alpha data with the broadband exposures:



For higher resolution and more info visit my website:

http://astrofoto.es/Galeria/2013/IC1805/IC1805_en.html

This photo was made with a Planewave 20" CDK and a Finger Lakes Proline 16803. The narrowband filters are from Omega Optical and the broadband ones from Astrodon. The total exposure time was 11.5 hours.


Hope you'll enjoy it.
Best regards,
Vicent.

25
Workshops and Conferences / Munich PixInsight workshop - Results
« on: 2013 November 05 13:05:04 »
Hi,

I want to publish here some of the results of the image processing techniques we learnt in the 2013 Munich workshop.

People showed a lot of interest on narrowband imaging so we made an in-depth review of these imaging techniques. First we reviewed how to introduce the H-alpha signal into a color image when both images are in linear state. This technique allows the H-alpha signal enhancement without affecting the color balance of continuum-emitting objects. Here you have before and after images with data by Leo Bette:



We also reviewed techniques to enhance emission-line objects in non-linear images. This is an HaRGB image with data by Velimir Popov (left RGB; right HaRGB):



We didn't have the time to review everything I prepared for the workshop. I provided n USB stick for each participant in which they have all the educational data. In this stick they have additional PixInsight projects with all the processing steps. An interesting example is the one below with M27 data by Max Bacher.

This example show at left a broadband RGB image. The middle image is a narrowband (R:H-alpha; G&B:O-III). The right one shows the mix of both to correct star colors:



A SHO example with the same data. Left the SHO image with color calibration taking as white the light of the nebula; at right the same result with corrected star colors:



Finally, an example we reviewed about dynamic range management with data of a M42 image by José Luis Lamadrid and me. Before and after images:



People got different processing examples covering techniques about LRGB composition, HDR composition and dynamic range management, star masking and narrowband imaging (7 different ways to combine narrow and broad band data).


Hope you like it ad we did. :)
Best regards,
Vicent.


26
Workshops and Conferences / Munich PixInsight workshop is over
« on: 2013 October 27 16:02:09 »
Hi,

We just finished the PixInsight workshop this afternoon. I think it came very well. I want to thank all the participants for coming to meet me, it was a really wonderful experience.

I'm sharing with you some photos of the event. This was the conference room:



Saturday lunch:



Saturday dinner:



A group photo taken today before the lunch (I think 9 people are missing in this photo):



And just two hours ago we have the last dinner with few people still in the hotel:




I look forward to meet you again next year! ;-)
Best regards,
Vicent.


Best regards,
Vicent.

27
Gallery / PANSTARRS - 2013/03/18
« on: 2013 March 20 13:47:53 »
Hi,

This is a photo of comet PANSTARRS with a 20 inch CDK and a Proline 16803 from the Aras de los Olmos Observatory:



Total exposure time is about 21 minutes (22x12 sec and 33x30 sec exposures) with Sloan r' filter. At this size, image scale is about 0.9 arcsec/pixel.


Best regards,
Vicent.

28
General / Time, 2nd part
« on: 2013 January 26 10:09:45 »
Hi!

I just published a new post in my blog, work in progress of a new Calar Alto image, as well as some reflections on our methodology:

http://astrofoto.es/blog/2013/01/time-2nd-part/


Hope you'll find it useful and interesting!
Best regards,
Vicent.

29
Announcements / Blog, Facebook and Twitter
« on: 2013 January 13 02:36:31 »
Hi,

Some weeks ago I opened my new astrophotography blog at Astrofoto.es. You can read me at this address:

http://astrofoto.es/blog

There I'm speaking about general art, astrophotography and also a bit of the science involved in the objects we use to photograph. The latest post is about gradient correction, hope you like it.

You can also find me in Facebook:

http://www.facebook.com/pages/Vicent-Peris-Astrophotography/142535982568857

And in Twitter:

http://twitter.com/vicentperis1


Best regards,
Vicent.

30
Gallery / PK164+31.1 from Calar Alto
« on: 2012 September 26 03:17:55 »
Hi!

We have added a new image to PixInsight Gallery:

http://pixinsight.com/gallery/PK164+31.1-CAHA/en.html



You can see it also in my website:

http://astrofoto.es/Galeria/2012/PK164/PK164_CAHA_en.html

It is a 28 hour HaRGB exposure acquired and processed by Jack Harvey and me. The telescope was the Zeiss 1.23 meter we have been using during the last years.

In this image we have used new techniques for integrating narrow and broadband data. I'm thinking to write a new article about them.


Best regards,
Vicent.

Pages: 1 [2] 3 4 ... 6