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cconstantine | 1 year ago
For a little bit of context for how impressive this is, here's my take on it with a consumer grade 8" Newtonian telescope from my backyard: https://www.astrobin.com/full/w4tjwt/0/
cconstantine | 1 year ago
For a little bit of context for how impressive this is, here's my take on it with a consumer grade 8" Newtonian telescope from my backyard: https://www.astrobin.com/full/w4tjwt/0/
rkuester|1 year ago
Edit: Oh, you can click through the image and see technical details. Very cool.
seabass|1 year ago
1. The scope they used is roughly equivalent to shooting with an 800mm telephoto lens. But the fact that it's 8" wide means it can let in a lot of light.
2. The camera [2] is a cooled monochrome camera. Sensor heat is a major source of noise, so the idea is to cool the sensor to -10deg (C) to reduce that noise. Shooting in mono allows you shoot each color channel separately, with filters that correspond to the precise wavelengths of light that are dominant in the object you're shooting and ideally minimize wavelengths present in light pollution or the moon. Monochrome also allows you to make use of the full sensor rather than splitting the light up between each channel. These cameras also have other favorable low-light noise properties, like large pixels and deep wells.
3. The mount is an EQ6-R pro (same mount I use!) and this is effectively a tripod that rotates counter to the Earth's spin. Without this, stars would look like curved streaks across the image. Combined with other aspects of the setup, the mount can also point the camera to a specific spot in the sky and keep the object in frame very precisely.
4. The set of filters they used are interesting! Typically, people shoot with RGB (for things like galaxies that use the full spectrum of visible light) or HSO (very narrow slices of the red, yellow, and blue parts of the visible spectrum, better for nebulas composed of gas emitting and reflecting light at specific wavelengths). The image was shot with a combination: a 3nm H-Alpha filter captures that red dusty nebulosity in the image and, for a target like the horsehead nebula, has a really high signal-to-noise ratio. The RGB filters were presumably for the star colors and to incorporate the blue from Alnitak into the image. The processing here was really tasteful in my opinion. It says this was shot from a Bortle-7 location, so that ultra narrow 3nm filter is cutting out a significant amount of light pollution. These are impressive results for such a bright location.
5. They most likely used a secondary camera whose sole purpose is to guide the mount and keep it pointed at the target object. The basic idea is try to put the center of some small star into some pixel. If during a frame that star moves a pixel to the right, it'll send an instruction to the mount to compensate and put it back to its original pixel. The guide camera isn't on the technical card, but they're using PHD2 software for guiding which basically necessitates that. The guide camera could have its own scope, or be integrated into the main scope by stealing a little bit of the light using a prism.
6. Lastly, it looks like most of the editing was done using Pixinsight. This allows each filter to be assigned to various color channels, alignment and averaging of the 93 exposures shot over 10 hours across 3 nights, subtraction of the sensor noise pattern using dark frames, removal of dust/scratches/imperfections from flat frames, and whatever other edits to reduce gradients/noise and color calibration that went into creating the final image.
[1] https://www.astrobin.com/w4tjwt/0/
[2] https://astronomy-imaging-camera.com/product/asi294mm-pro/
VikingCoder|1 year ago
I'm sorry, but this is making me laugh so hard. I don't know a lot about astrophotography, but one thing I've experienced so far is that astrophotographers love to talk about their equipment and process.
It's like asking a grandparent, "Oh, do you have pictures of your grandkids?" It kind of makes their day. :)
_akhe|1 year ago
supernovae|1 year ago
cconstantine|1 year ago
aronhegedus|1 year ago
cconstantine|1 year ago
peeters|1 year ago
xcv123|1 year ago
Here's the full resolution image:
https://www.esa.int/var/esa/storage/images/esa_multimedia/im...
cconstantine|1 year ago
notdang|1 year ago
It's consumer level, but not cheap at all.
Vox_Leone|1 year ago
noneeeed|1 year ago
dudeinjapan|1 year ago
xcv123|1 year ago