APOD: Orion in Gas, Dust, and Stars (2014 Nov 11)

[geckzilla]

Astronomical imagery is a strange art form trying to balance science and aesthetics. In traditional art there is a strategy to not reveal everything in so much detail that works very well. For instance, it's ok to have someone's face obscured in shadow. In astronomy, the opposite is true. I notice a lot of astrophotographers desire to reveal everything and make it as clear as possible. Sometimes extreme measures are taken in order to reveal more and more. The spread of a star is undesirable, especially a very bright one, so work is done to minimize its impact. In the quest to bring out the dimmer things, a little noise becomes an epic maelstrom of bright and dark pixels and futile battles are waged against it.

[Chris Peterson]

I see your point. I really do.

But for me, a lover of stars, I often feel that the stars are treated very strangely in astronomical imagery. For example, as Bruce wrote:

BDanielMayfield wrote:
The star Alnitak right above the Flame nebula has been quite notably dimmed. It's really about as bright as the other two belt stars, but here it's so dim it doesn't stand out at all.

That phenomenon is extremely common in images focusing on the Horsehead region, if they also include Orion's Belt.

Every bright star in a deep exposure is photometrically incorrect, because each is, by necessity, exposed to saturation (at which point intensity is meaningless). So the only remaining indicator of intensity is apparent diameter, and that's not always very reliable. Also, many deep images are made using narrowband filters, which also results in unexpected (but not incorrect) stellar brightnesses.

[Nitpicker]

BDanielMayfield wrote:
The star Alnitak right above the Flame nebula has been quite notably dimmed. It's really about as bright as the other two belt stars, but here it's so dim it doesn't stand out at all.

That phenomenon is extremely common in images focusing on the Horsehead region, if they also include Orion's Belt.

Ann

Funny, but I don't perceive Alnitak to be much different in brightness from Alnilam or Mintaka (in the APOD or any other image I can recall). Alnitak is much more in the thick of the nebulous glow than the other two belt stars, however, so maybe that makes it stand out less against its surroundings when the nebulosity is amped up. (And yes, Chris has a point, too.)

Astronomical imagery is a strange art form trying to balance science and aesthetics. In traditional art there is a strategy to not reveal everything in so much detail that works very well. For instance, it's ok to have someone's face obscured in shadow. In astronomy, the opposite is true. I notice a lot of astrophotographers desire to reveal everything and make it as clear as possible. Sometimes extreme measures are taken in order to reveal more and more. The spread of a star is undesirable, especially a very bright one, so work is done to minimize its impact. In the quest to bring out the dimmer things, a little noise becomes an epic maelstrom of bright and dark pixels and futile battles are waged against it.

Interesting. With the rise of photographic technology, but well before the digital age, the traditional art of painting responded by moving into new areas of representing things that couldn't be done easily with photography. And the art of "photo realistic" painting became more of a niche market. I think my own personal aesthetic as it pertains to deep sky astrophotography is still forming, but I think it is leaning towards realism with as much contrast stretching (applied uniformly to the whole image) as the S/N ratio reasonably allows, and with little other intervention. (I am a simple man.) To my mind, this APOD is somewhat akin to a map or a diagram rather than a realistic representation, which is fine, but perhaps not entirely to my taste.

[DavidLeodis]

The image of the blue cat that was brought up through the 'blue' link in the "bright blue stars" made me . As also did the 'h' in the 'The' in "The brightest three stars on the far left" where just the 'h' was the link to an APOD, not the whole "The".

[starsurfer]

I'm surprised no one has mentioned M78, peeking in from the lower left corner of the image. M78 is the lonely one out in Orion; it must surely know how it feels to be M92.

What about NGC 1999 to the right? Won't anyone spare a thought for M107?

[starsurfer]

A labeled version of Fabian Neyer's mosaic of the region: http://www.starpointing.com/ccd/orion_labeled.html