Deep Sky Colors - Astrophotography by Rogelio Bernal Andreo http://blog.deepskycolors.com/ Deep Sky Colors es 2010-02-09T16:25:00-08:00 Fri, 12 Mar 2010 14:16:54 GMT hourly 1 2000-01-01T12:00+00:00 ZoomBlog http://www.zoomblog.com/pics/blogs/ZoomBlog_mini.gif http://www.zoomblog.com/ Pretty pictures http://blog.deepskycolors.com/archive/2010/02/09/pretty-pictures.html http://blog.deepskycolors.com/archive/2010/02/09/pretty-pictures.html there are as many schools of thought as there are astrophotographers.

Yet, every time I see someone using the term "pretty picture" referring to the type of astrophotography that mainly focuses on the aesthetic aspects of imaging celestial objects, I wonder if the work of Ansel Adams or Art Wolfe should also be defined as nothing but "pretty pictures" as well.

Don't get me wrong, I don't really mind people using the term "pretty picture". The term is good enough to describe one of the many ways a person can embrace astrophotography (and probably easier to understand than "aesthetic astrophotography"), and when someone uses it, if they like to photograph and measure asteroids or comets, I'd just say that they like to "take pictures of rocks", and if they enjoy measuring imaging devices and optics I may friendly refer to them as "data nuts" :-)

The problem is when the concepts collide - usually in the minds of people who think art and science are rather incompatible when it comes to astrophotography. The fact is, art and science have a lot more in common than what some "data nuts" think - they just can't or simply won't embrace them simultaneously, but doing so is a skill too - just because some people lack those skills or simply reject the concept doesn't make it any less important, valuable or respectable, nor the person who does it is less capable. Many data nuts know that, but a few probably don't...

For example, not long ago, one of these data nuts (I use the term with love, the same love I'm sure others apply when they talk about pretty pictures) stated that no matter the processing, the data "underneath" is always the same, so "who cares about fancy processing", disregarding any work or creativity in the processing of astro images as something rather pointless. To me that was like saying that a chicken is a chicken no matter how you cook it, literally disregarding the work and creativity of chefs all around the world. But raw chicken doesn't feed people, right?

Which brings me to the point I really wanted to make... Probably the biggest mistake often made by some (not all!)  data nuts and rock photographers is to disregard the work of those whose goal is partly or mainly aesthetic as images that are useless for astronomy.

Useless for astronomy? Well, usually it is not observing logs, graphs or inverted monochrome linear images, but those fine (and "useless for astronomy") pictures - and the science associated to them - the ones that probably most often capture the mind of a young man or woman and spark the plug that will get them hooked into astronomy, for life. In other words, chances are that many of the astronomers of tomorrow will embrace astronomy as their lifetime work because of those "pretty pictures".

Which to me it means that "pretty pictures" may be useless for astronomers, but definitely not for astronomy.

So if your interest in astrophotography is driven mainly or in part by an aesthetic interest, keep doing what you're doing! The world needs you as much as they need everyone else - plus you will be exercising a much more diverse spectrum of disciplines, because no matter how much art-driven you are, you will still need to be a bit of a data nut ;-)

]]> 2010-02-09T16:25:00-08:00 RBA The photographer of the dust http://blog.deepskycolors.com/archive/2010/01/25/the-photographer-of-the-dust.html http://blog.deepskycolors.com/archive/2010/01/25/the-photographer-of-the-dust.html Ciel Et Espace (the most popular astronomy magazine in France AFAIK) asked me a few questions about some of my images. Two months later I received in the mail the February 2010 issue, with a nice writeup about me commenting some of those images. Perhaps one of the most exciting things, besides the 6-pages portfolio, is that out of the four stories featured on the cover, one of them is the one about my work, and they titled it "Le Photographe de la poussière", which means The Photographer of the dust, which I think it's kind of cool, despite I don't consider myself THE photographer of the dust but just one more, out of many. I feel both humbled and honored to see this article - first complete article ever about my work - on a popular magazine, but at the same time, so excited!

The article features nine images (plus one of yours truly, taken at Dinosaur Point, next to my rig), along with a short comment from me about each of them (translated to French). I hesitate to post the article in readable form here as it will infringe their copyright, but while I wait for their permission to publish it, here's the cover as posted on their web site, a non-readable "preview" of the article (permission for publishing has also been requested), and a list of the images with links to the original version here at DeepSkyColors.com.

The cover:



A reduced non-readable version of the article:



And a list of the images, linked to their original version here in DeepSkyColors.com:

The Witch Head nebula and Rigel
Orion's Belt
The Blue Horsehead nebula
The Helix Nebula
Andromeda
IC405, M38 and the Tadpoles
The Rosette and Cone area
M81/M82 and Integrated Flux nebulosity
The Leo Triplet

A big thanks goes to Emilie and Franck from Ciel Et Espace for beautifully crafting and publishing this article and giving me the honor of sharing cover space in their prestigious magazine!  ]]> 2010-01-25T11:00:00-08:00 RBA Astrophotography and conventional photography http://blog.deepskycolors.com/archive/2010/01/16/astrophotography-and-conventional-phot.html http://blog.deepskycolors.com/archive/2010/01/16/astrophotography-and-conventional-phot.html
Astrophotography is a type of photography that can be embraced with many different motivations or goals in mind. Some people do astrophotography to measure equipment (cameras, telescopes, etc), others measure celestial objects (their size, distance, etc), others hope to understand the dynamics of the universe, other do so mainly for their aesthetic appeal, etc. Some people do some or all of the above. Others may even embrace it in many other ways.

My astrophotography is mainly aesthetic, at least at this point. I don't do astrophotography to find new objects, to measure their distance, to study how they interact with other celestial objects, and I'm not in the business of measuring the performance of any given camera or telescope, although I may occasionally do it to better understand the tools I use and what to expect from them.

And yet, there are differences between how different people approach the aesthetic aspect of this hobby. In my case, at this point in my journey, one of the many things I do is to associate astrophotography to the way one would approach photography of other "daylight" objects found in nature, and I try to use the same elements a "day" photographer would use, recognizing that some elements aren't there when targeting a dim galaxy or nebula, making out for those missing elements whenever I can and I feel they could help me achieve my goal, and of course, adding to the mix all the elements only found in astrophotography. Needless to say, some typical elements of daylight photography simply cannot be applied, such as the angle (not to be confused with the framing) or perspective, and others, although they can be artificially implemented through image processing, they shouldn't be applied, as they would alter the true nature of the objects, such as the direction of light for example.

Some people may think that this approach is wrong, simply because astrophotography is very different than conventional photography. My answer to that is, yes, astrophotography is very different in so many ways, but to me, it also has many common elements with "daylight photography" and because of that, I try to apply some of those elements the best way I can, along with all the elements specific to astrophotography. If you believe that astrophotography should be embraced with only the elements that are given by this discipline, that's fine. But to me, considering and applying other elements, sometimes not very often considered, does not detract the hobby but it enriches it instead.

This may still sound silly but I will eventually write about some of these elements, and about some ways I think they can be used, at which time I would refer back to this post and then things hopefully make more sense. In fact, the main reason to start with this "concept" (not novel BTW) is not so much to make a point, but to place a reference I know I will be using in the future.

For now I will describe what I would call some of the main "principles" I use when doing astrophotography, and I will do so using a "daylight target" as an example. Keep in mind this is not the truth, just my opinion, my view, at this point in time. Say for instance that I would like to take a picture of a bunch of trees.

- As a technician or scientist, I will adjust my equipment to the best possible settings I know to achieve my goal, and apply my knowledge - whether good, bad or anything in between - to acquire the best possible data I can get, being realistic about my limitations and constrains. Here, knowledge is everything, so I will thrive to learn more and more, realizing I will never be able to "know everything" - which in a way it's a good thing: there will always be something new to learn.

- As a presenter of nature I will make sure I don't add anything to the trees that wasn't there before. I won't touch up a branch because in my image it looked "ugly" to me. I won't remove a cloud from the image because I was hoping to show a clear sky. And I won't paint a flower pink because I feel the image looks nicer than if it was showing its natural - say yellow - color.

- As a communicator I may try to craft the image so that the leaves of the trees become the main element I try to communicate with the image, or the trunks, or the forest as a whole, or even one particular tree, or perhaps that eagle that happened to fly by, or both, or why not, the whole landscape... I may highlight the "crispness" of the branches, while keeping in mind the goals I've set as a "presenter of nature", and I may adjust the color saturation of the tree leaves if that helps me emphasize the message I try to convey as a communicator, also as long as that doesn't detract me from presenting a true object.

- As a perfectionist I will seek for the comments of others to see whether I achieved my goal as well as to find out imperfections in my image. Imperfections when I applied my skills as a technician, as a presenter of nature or as a communicator. I will want to know what others think about the image, both from a technical perspective as well as knowing what they felt the image "told" them. So if I wanted to emphasize the richness of the forest, I would like to know if people was left with the impression that the forest in the image was indeed "rich" or if, on the other hand, their attention shifted to something I didn't think about, and use all that feedback to better learn what I did right and wrong.

- And as a hobbyist, I will have fun doing all of the above!

Which of these aspects I believe is more important in aesthetic astrophotography? Well, they all are important of course, but if I was to highlight one at this point, that would be communication. Why? Because I feel it's the one most forgotten.

]]> 2010-01-16T01:20:00-08:00 RBA New area: The DeepSkyColors Blog http://blog.deepskycolors.com/archive/2010/01/09/new-area-The-Deepskycolors-Blog.html http://blog.deepskycolors.com/archive/2010/01/09/new-area-The-Deepskycolors-Blog.html
This area will be available following the "Blog" link in the left menu on blog.DeepSkyColors.com.

I'm not making any commitments other than writing here every once in a while. Sometimes I might post 3 articles in a row, and then it could take me a month to write something else. The truth is, it's a lot faster to write than to take photographs of the deep night sky! But we'll see... :-) Of course, unless otherwise specified, everything I write will be my opinion, not the sacred truth . You might agree or disagree with me, but if there's something I've found is that the best way to learn is to share our thoughts, rather than lecturing as if we knew it all.

So let this be the announcement for now, and in a few minutes I'll post the first "official" post of the DeepSkyColors Blog! :-)

]]> 2010-01-09T00:00:00-08:00 RBA Widefield Rosette and Cone nebulas http://blog.deepskycolors.com/archive/2009/12/01/widefield-Rosette-and-Cone-nebulas.html http://blog.deepskycolors.com/archive/2009/12/01/widefield-Rosette-and-Cone-nebulas.html
Click here for a larger version

This project started as a H-Alpha 2x2 mosaic of the Rosette and Cone nebulas in Monoceros. The top-left pane was taken during full Moon (23 degrees away from this field).

You can see the H-Alpha image only here.

After having the Ha, I was hoping to gather LRGB to make a color image, however I could only squeeze one night for RGB before bad weather arrived, and on that night, I only had about 3 hours before the Moon would show up that night, so the only way I thought I could gather some color that I could use was by using my Canon 40D and a camera lens, and that's how I've got the color (18x10'). Not enough time to get separate RGBs and luminance, much less for a 2x2 mosaic.

Since the color data was so bad compared to the Ha, rather than combining the Ha with the RGB and getting a luminance out of that, I used the Ha as luminance - something I wouldn't recommend - then did some needed heavy surgical work to the RGB image and added it over the Ha-made-luminance, which not only created the famous salmon salad effect but also generated undesirable color blotch and other artifacts. Although I do have a version where I tried to transform the "salmon color" into the more accurate reddish color of strong Ha areas, I felt the image suffered more overall, creating even greenish-looking stars! For that reason I decided to make the version you see above - the salmon color image - the "official" image for this project. You can see the "cherry red" image here.

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]]> 2009-12-01T00:00:00-08:00 RBA Barnard's Loop and M78 http://blog.deepskycolors.com/archive/2009/11/24/barnards-Loop-and-M78.html http://blog.deepskycolors.com/archive/2009/11/24/barnards-Loop-and-M78.html
Click here for a larger version

It took me a couple of tries to get the combination of the H-Alpha image with the LRGB but in the end I'm pleased with the results. Barnard's loop is impressive, and I think in this image I framed its most attractive area.

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]]> 2009-11-24T00:00:00-08:00 RBA Flaming Star Nebula (IC 405), M38 and the Tadpoles http://blog.deepskycolors.com/archive/2009/11/21/flaming-Star-Nebula-Ic-405-M38-and-the.html http://blog.deepskycolors.com/archive/2009/11/21/flaming-Star-Nebula-Ic-405-M38-and-the.html
Click here for a larger version

This image is a widefield around the Flaming Star Nebula in the constellation Auriga, that also includes other objects such as the Tadpoles, the M38 cluster (top-left of the image), etc.

I started taking 20x10' of L and 5x5' (bin 2x2) of each RGB. This was last Saturday from the DARC Observatory.

When I started processing it, and as I was trying to pull out the fainter nebulosity, the stars started to dominate the field. I simply couldn't contain them no matter what I did. So on Monday I decided to take a short trip to Montebello and captured 6x20' of H-Alfa, to see if then, with more signal in the nebulosity and smaller stars I could better manage the image.

I added 20% of the processed luminance to the also processed Ha, but I didn't add any Ha to the color - I used only the color information from the RGBs. The Ha left the better SNR areas a bit soft but I was much more pleased with the results.

The color was originally a bit unconvincing, so I first did a color calibration by selecting an area mainly packed with white-looking stars and balance the whole image assuming the average color of the stars in that selecion was indeed white. After that I neutralized the background taking one small area as a reference.

What I realized however is that I am no longer going to take RGBs binning 2x2, unless I'm dealing with an emergency - such as not enough time and evaluating that I will definitely get better SNR if I bin 2x2. The reason is what others have mentioned and that I could really notice this time. Basically after adding the color I could notice a very obvious ringing around many stars, ringing that wasn't nearly as obvious by looking only at the luminance.

It's a very interesting field, packed with interesting objects not often seen all in the same image. I hope you like it!

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]]> 2009-11-21T00:00:00-08:00 RBA Witch Head Nebula and Rigel http://blog.deepskycolors.com/archive/2009/11/16/witch-Head-Nebula-and-Rigel.html http://blog.deepskycolors.com/archive/2009/11/16/witch-Head-Nebula-and-Rigel.html
Click here for a larger version

Here's my "November project" with the FSQ/STL11k...

In this image I first tried to put into practice a method to pull the dust out that I had been thinking these past few days, and I didn't end up too thrilled about the results. It induced some "blur/denoise-like" effects early in the processing, and it also fabricated bloated star halos in the mid-sized stars (Rigel was put where it belongs with a quick HDRWT).

So after the fact I went back and did some reprocessing from scratch treating large and small scale structures separately, then merged the results to the previous image. This helped me reduce some of the halos (I did't bother with the big ones because those are "optical presents" not the effect of bad processing), keep the stars under control, enhance the witch head a bit, etc. but didn't remove the denoise/blur effect on the background.

I still think the initial processing thingy may work, I just need to play with it a bit more and be more careful next time... Nevermind the halo aroud Rigel is purple, although that's how it came out.

The image is in fact a 2 pane mosaic with data from 3 frames, each taken from a different site, with a total exposure of almost 12 hours

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]]> 2009-11-16T00:00:00-08:00 RBA Deep Field: From California to the Pleiades http://blog.deepskycolors.com/archive/2009/10/20/deep-Field-From-California-to-the-Plei.html http://blog.deepskycolors.com/archive/2009/10/20/deep-Field-From-California-to-the-Plei.html
Click here for a larger version

This is a 4x3 mosaic captured over 6 sessions at three different places. At the time of taking this image I believe it' the deepest image of this field taken so far, and yet, as I mention in just a minute, the number of subframes to acquire this image is in fact, minimal.

The areas of the California nebula (the red nebula on the bottom left, also known as NGC 1499) and the Pleiades (the blueish area on the top-right, AKA M45) also use individual images of these objects. I took the image of M45 from Calstar on September'09, and the California nebula was captured the week after over two sessions at Henry Coe State Park, but I never published it as I was hoping to get more data for the image and instead I decided to do this mosaic.

The color is a bit "spotty" because I had very little color data. All luminance frames are 10 minutes, although each frame has a different number of subexposures (from 4 to 10 -yes, some frames are only 4 "subs", for example, the area on the left/top of M45). For the RGBs they all are 4x5' bin 2x2, not ideal, but just enough to get some signal and at least give color to the image. The different number of subexposures for the L caused some areas to be better defined than others. The reason I wasn't consistent was mainly the rush to "get something" and later run out of time to accumulate more subs.

This image was selected as NASA's Astronomy Picture of the Day on November 3rd, 2009

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]]> 2009-10-20T00:00:00-08:00 RBA Venus, Saturn, Mercury and the fog http://blog.deepskycolors.com/archive/2009/10/12/venus-Saturn-Mercury-and-the-fog.html http://blog.deepskycolors.com/archive/2009/10/12/venus-Saturn-Mercury-and-the-fog.html
Click here for the entire panorama

What you see above is just a crop. Please click on the image to see the complete panorama.

The panorama is a composition resulting from taking well over 60 different frames - no, I didn't use them all in the final image!

I think it captures the breathtaking view that is to see that huge blanket of fog over the Silicon Valley.

Venus, Saturn and Mercury can all be seen, in the far right. Venus, the brightest point in the sky is hard to miss. The also bright point below Vnus is Saturn, and even lower and a tad brighter than Saturn, is Mercury. That's their position on Saturday morning (October 10th, 2009) around 6-6:30am.

The images were taken from this vista point on Friday and Saturday morning:  in Skyline Blvd., a road that cruises along the ridge of the Santa Cruz Mountains on the west of the Silicon Valley.

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]]> 2009-10-12T19:29:00-08:00 RBA Orion's Deep Field - Belt and sword http://blog.deepskycolors.com/archive/2009/09/19/orions-Deep-Field--Belt-and-sword.html http://blog.deepskycolors.com/archive/2009/09/19/orions-Deep-Field--Belt-and-sword.html
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When a friend of mine saw the image I took of Orion's belt he was quick to suggest "Why don't you build a mosaic with this image and the one of the Horsehead and M42 you took last winter?". And I thought "That's an EXCELLENT idea!"After a bit of work putting the mosaic together, here's the result: a beautiful panorama of an area of the constellation of Orion that is anything but usual, almost resembling a true stellar landscape, from the 3 famous stars of the belt to M42.

This image was selected as NASA's Astronomy Picture of the Day on September 28th, 2009

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]]> 2009-09-19T00:00:00-08:00 RBA Orion's belt http://blog.deepskycolors.com/archive/2009/09/18/orions-belt.html http://blog.deepskycolors.com/archive/2009/09/18/orions-belt.html
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I spent the nights of Thursday 17~Saturday 19 at CalStar, an annual Star Party that takes place at Lake San Antonio in California, a site that although it isn't high at all (900 feet) it has pretty decent skies.

I spent each of the three nights after 3am on this field that surprisingly is not very commonly photographed. If you cannot recognize these three stars, you must live in a place that's always cloudy in winter, as they are visible even from very light polluted skies :-)

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]]> 2009-09-18T03:00:00-08:00 RBA Milky Way, east to west http://blog.deepskycolors.com/archive/2009/09/18/milky-Way-east-to-west.html http://blog.deepskycolors.com/archive/2009/09/18/milky-Way-east-to-west.html See Explanation. Moving the cursor over the image will bring up an image of the Milky Way the way it woud look to our eyes.Clicking on the image will bring up the highest resolution version available of the photo version.
Larger "visual" version
Larger "photo" version

The image you see above is a mosaic of 10 different frames, each of them was acquired with either 5x5 minutes (around the Milky Way) or 5x3-4 minutes for the rest of the sky. The horizons are superimposed from two 3x1' shots, but they match both what was there and the orientation.

It's interesting to note that when I started shooting at the Sagittarius area, the Pleiades weren't even above the horizon, but by the time I've got to that part of the sky, they were already all the way up there.

Now, for the fun part, if you mouse over the image, you will see a digitally altered image of what our eyes could see that night, more or less. If you move the mouse out of the image, you see what the camera could catch. The idea is for those who have never seen the Milky Way from a very dark site, to give them an idea of what it would look like - so maybe they get excited about visiting a dark site and enjoy the night sky!

Have you ever been to a very dark site? I'd like to hear what you think. Do you see the image of the "visual" Milky Way too bright compared to what you see at a very dark site? Too dark? Perhaps the image is too "glowy"? Not enough contrast? Please let me know in the comments below!

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]]> 2009-09-18T00:00:00-08:00 RBA The Pleiades (M45) http://blog.deepskycolors.com/archive/2009/09/17/the-Pleiades-M45.html http://blog.deepskycolors.com/archive/2009/09/17/the-Pleiades-M45.html
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Most classic images of M45 - also known as The Pleiades or the Seven Sisters - tend to capture the blueish reflected dust of this famous cluster. However, the region of our galaxy in this direction also has the typical reddish hydrogen gas emission. Also, some dust doesn't reflect the light from the stars so strongly, so it acquires a grayish hue. This widefield image, captured during CalStar'09, shows this peculiar dance of dust and gas, easily differentiated by their colors.

This image was selected as NASA's Astronomy Picture of the Day on October 14th, 2009

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]]> 2009-09-17T00:00:00-08:00 RBA Andromeda (M31) http://blog.deepskycolors.com/archive/2009/08/15/andromeda-M31_2.html http://blog.deepskycolors.com/archive/2009/08/15/andromeda-M31_2.html See Explanation.Moving the cursor over the image will bring up an alternate version.
Original Image

DATE
August 15 and 16, 2009

PHOTO
Exposure time:
L: 18x5' & 10x20'
RGB: 10x5' each channel
Total: 7.3 hours
Focal: 500mm, f/5

EQUIPMENT
Imaging scope: FSQ106 EDX
Camera: STL11000
Guiding camera: StarShoot Autoguider
Mount: Takahashi EM400

SITE & CONDITIONS
Henry Coe State Park, California
Seeing: Very good
Transparency: Poor

SOFTWARE
Stacking: DeepSkyStacker
Processing: PixInsight & Photoshop

COMMENTS
This is a "mouseover" image that allow us to compare the image I took of M31 with the images taken by the Ultraviolet/Optical Telescope aboard NASA's Swift spacecraft of the same object.

First you see the Swift image (not mine!) and if you move your mouse over the image, you can then see the image I took. Moving the mouse in and out of the image you can compare the two images.

I did this to see how the details in the core of my image matched those details - whenever visible - in the Ultraviolet image from the Swift spacecraft.

]]> 2009-08-15T00:05:00-08:00 RBA