<p>You'll probably need <a href="http://en.wikipedia.org/wiki/Astronomical_spectroscopy" rel="nofollow noreferrer">spectrometer</a> data to distinguish and identify spectral lines. That kind of spectrographic images look e.g. like this:  </p>

<p><img src="https://i.sstatic.net/Op3AB.jpg" alt="enter image description here"></p>

CC BY-SA 3.0
2014-01-14T20:47:16.430Z
2014-02-17T14:18:09.360Z
2014-02-17T14:18:09.360Z
Gerald
<p>No, amateur astronomy equipment is not capable of doing such an analysis. Most color CCDs use something called a <a href="http://en.wikipedia.org/wiki/Bayer_filter" rel="nofollow">Bayer filter</a> to detect color. Essentially, certain pixels detect only red photons, other pixels detect only green, and still others detect only blue. Each filter has a high transmission over some band of wavelengths (say, for red, 600 - 700 nm). Photons outside of this band are absorbed. The CCD pixels behind the red Bayer filter then count how many photons they see (they actually measure charge, but that's a detail). The point is, the CCD can't measure a photon's precise wavelength; it can only count how many it sees over some wavelength band.</p>

<p>Now, this is NOT necessarily the case when it comes to professional astronomy. To my knowledge, there do not currently exist optical CCDs that can do spectroscopy without a diffraction grating. For one thing, optical diffraction gratings work really well, so there is no reason. The other reasons are that optical photons don't generate a lot of charge in a CCD, so it would be hard to measure, and there are generally a LOT of optical photons, so you'd get a lot of <a href="http://xmm.esac.esa.int/sas/current/doc/epileupmask/node4.html" rel="nofollow">pile up</a>.</p>

<p>By contrast, X-ray CCDs often do spectroscopy, albeit not with Fourier analysis (for example, the <a href="http://cxc.harvard.edu/cal/Acis/" rel="nofollow">ACIS</a> CCDs on Chandra). There are a lot fewer X-rays than optical photons, and they deposit a lot more energy on a CCD. Unfortunately, you can't do X-ray astronomy from the ground, so even if an amateur astronomer could somehow afford one, it wouldn't do them any good. Even in the case of X-ray astronomy, you generally use an x-ray diffraction grating to get a spectrum if that is what you are interested in.</p>

CC BY-SA 3.0
2014-02-14T02:57:22.873Z
2014-02-14T21:36:35.250Z
2014-02-14T21:36:35.250Z
Scott Griffiths
<p>Are there pictures that contain high enough dynamic width, so that amateurs can use fourier spectrum analysis to observe the redshift themselves? </p>

<p>I know pictures usually are encoded using RGB and/or CMYK and therefore lose a lot of color information from a physical perspective, but I'm wondering if there exists a picture format that could store that much information, and if so, could amateurs then use fourier spectrum analysis to actually see the red-/blueshift?</p>

CC BY-SA 3.0
2014-01-14T19:29:39.993Z
Like this? http://www.rspec-astro.com/wp-content/uploads/2010/12/3C-273-Ha-Hb-Hy-color-Final.jpg
asawyer
<photography><redshift>
Can redshift be measured using fourier?
frodeborli
# Can redshift be measured using fourier?

(Asked by: username_0 on 2014-01-14)

Are there pictures that contain high enough dynamic width, so that amateurs can use fourier spectrum analysis to observe the redshift themselves?

I know pictures usually are encoded using RGB and/or CMYK and therefore lose a lot of color information from a physical perspective, but I'm wondering if there exists a picture format that could store that much information, and if so, could amateurs then use fourier spectrum analysis to actually see the red-/blueshift?

**Tags:** photography, redshift

> **Comments:**
> **username_1**: Like this? http://www.rspec-astro.com/wp-content/uploads/2010/12/3C-273-Ha-Hb-Hy-color-Final.jpg  

---

## 2 answers

### Answer by username_3 on 2014-02-14. Score: 5 | Accepted answer

No, amateur astronomy equipment is not capable of doing such an analysis. Most color CCDs use something called a [Bayer filter](http://en.wikipedia.org/wiki/Bayer_filter) to detect color. Essentially, certain pixels detect only red photons, other pixels detect only green, and still others detect only blue. Each filter has a high transmission over some band of wavelengths (say, for red, 600 - 700 nm). Photons outside of this band are absorbed. The CCD pixels behind the red Bayer filter then count how many photons they see (they actually measure charge, but that's a detail). The point is, the CCD can't measure a photon's precise wavelength; it can only count how many it sees over some wavelength band.

Now, this is NOT necessarily the case when it comes to professional astronomy. To my knowledge, there do not currently exist optical CCDs that can do spectroscopy without a diffraction grating. For one thing, optical diffraction gratings work really well, so there is no reason. The other reasons are that optical photons don't generate a lot of charge in a CCD, so it would be hard to measure, and there are generally a LOT of optical photons, so you'd get a lot of [pile up](http://xmm.esac.esa.int/sas/current/doc/epileupmask/node4.html).

By contrast, X-ray CCDs often do spectroscopy, albeit not with Fourier analysis (for example, the [ACIS](http://cxc.harvard.edu/cal/Acis/) CCDs on Chandra). There are a lot fewer X-rays than optical photons, and they deposit a lot more energy on a CCD. Unfortunately, you can't do X-ray astronomy from the ground, so even if an amateur astronomer could somehow afford one, it wouldn't do them any good. Even in the case of X-ray astronomy, you generally use an x-ray diffraction grating to get a spectrum if that is what you are interested in.


---

### Answer by username_2 on 2014-01-14. Score: 0

You'll probably need [spectrometer](http://en.wikipedia.org/wiki/Astronomical_spectroscopy) data to distinguish and identify spectral lines. That kind of spectrographic images look e.g. like this:

![enter image description here](https://i.sstatic.net/Op3AB.jpg)


---

