GoPro for astro photography?

[Dheorl]

Looking at the iFixit teardown of the new GoPro got me thing about it's possibilities for astrophotography.

As I'm sure many of you are aware, a popular low buget option for astrophotography is to modify a webcam by removing the lens and creating an eyepiece mount for it. I've done this myself using a sony cam so that the camera module itself would fit inside the eyepiece (the solar telescopes we were using had an anoying focus distance).

With the possibility of 4k video and what is seemingly quite an easy to remove lens, do you think the GoPro could be a viable upgrade from the world of webcams. It's clearly a fair amount more expensive than the average webcam, but tbh I was struggling to get the claimed fps with the webcames I tried and that was only at 720p IIRC.

Just wondering what your thought are on this? To me it seems like it could be quite a neat little camera for image stacking (if possibly a bit expensive - getting into the realms of proper astro cameras)

 

[RustierOne]

Dheorl wrote:

Looking at the iFixit teardown of the new GoPro got me thing about it's possibilities for astrophotography.

As I'm sure many of you are aware, a popular low buget option for astrophotography is to modify a webcam by removing the lens and creating an eyepiece mount for it. I've done this myself using a sony cam so that the camera module itself would fit inside the eyepiece (the solar telescopes we were using had an anoying focus distance).

With the possibility of 4k video and what is seemingly quite an easy to remove lens, do you think the GoPro could be a viable upgrade from the world of webcams. It's clearly a fair amount more expensive than the average webcam, but tbh I was struggling to get the claimed fps with the webcames I tried and that was only at 720p IIRC.

Just wondering what your thought are on this? To me it seems like it could be quite a neat little camera for image stacking (if possibly a bit expensive - getting into the realms of proper astro cameras)

The Go Pro is a nice video camera, but one I haven't used. It would be a shame to ruin it for its intended purpose. There's a lot of video cameras made for astrophotography that are about the same price or a bit more than the latest Go Pro. Some of the best are by Imaging Source - here's a link for that video camera:

http://www.theimagingsource.com/en_US/products/cameras/usb-cmos-color/

These astronomy-ready cameras are noted for low noise and high frame rates, features of great value in planetary video work. They allow capture of a large number of low noise AVI frames for stacking in Registax or other programs. Here's an example of what came be accomplished with these cameras. The link takes you to some work by Bob Pilz who uses an 8-inch reflector and Imaging Source camera:

http://www.pbase.com/bob_p/moon_8_telescope


There are other sources of astronomy video cameras - Orion Telescopes and Celestron come to mind.

That's my view on the matter for what its worth.

 

[Dheorl]

RustierOne wrote:

Dheorl wrote:

Looking at the iFixit teardown of the new GoPro got me thing about it's possibilities for astrophotography.

As I'm sure many of you are aware, a popular low buget option for astrophotography is to modify a webcam by removing the lens and creating an eyepiece mount for it. I've done this myself using a sony cam so that the camera module itself would fit inside the eyepiece (the solar telescopes we were using had an anoying focus distance).

With the possibility of 4k video and what is seemingly quite an easy to remove lens, do you think the GoPro could be a viable upgrade from the world of webcams. It's clearly a fair amount more expensive than the average webcam, but tbh I was struggling to get the claimed fps with the webcames I tried and that was only at 720p IIRC.

Just wondering what your thought are on this? To me it seems like it could be quite a neat little camera for image stacking (if possibly a bit expensive - getting into the realms of proper astro cameras)

The Go Pro is a nice video camera, but one I haven't used. It would be a shame to ruin it for its intended purpose. There's a lot of video cameras made for astrophotography that are about the same price or a bit more than the latest Go Pro. Some of the best are by Imaging Source - here's a link for that video camera:

http://www.theimagingsource.com/en_US/products/cameras/usb-cmos-color/

These astronomy-ready cameras are noted for low noise and high frame rates, features of great value in planetary video work. They allow capture of a large number of low noise AVI frames for stacking in Registax or other programs. Here's an example of what came be accomplished with these cameras. The link takes you to some work by Bob Pilz who uses an 8-inch reflector and Imaging Source camera:

http://www.pbase.com/bob_p/moon_8_telescope

There are other sources of astronomy video cameras - Orion Telescopes and Celestron come to mind.

That's my view on the matter for what its worth.

 

[bondiblue]

There are four issues with using a camera such as the GoPro, and it is a bad choice on all scores...

a. The tiny sensor means its pixel spacing is far too dense to be suitable for telescope optics, in comparison to the size of the diffraction disk of stars, and the size of the useful focal plane of the optics (most of it is wasted because the sensor is too small).

b. The sensor isn't cooled, which means its low-light capabilities are limited by thermal noise. this is related to pixel size - sensors with small pixels are very noisy, sensors with big pixels perform far better

A GoPro is about the worst choice you could make on that score.

c. While you can remove the lens, you can't remove the Bayer filter and the UV/IR filters (I expect it has one of these too).

The astronomical-grade sensors have the Bayer filter removed so they shoot black & white, and at the full resulotion this provides. To do colour, use three shots through coloured filters, and the exposures in each colour are adjusted according to the sensor calibration to give correct colour.

For monochrome, if you use these cameras on an all-reflecting astrograph such as a Ritchey-Chretien, Newtonian, Cassegrain or the Schmidt or Maksutov variants, these accurately focus all the incoming radiation from IR to UV. So there is a big advantage if your have a camera that can image this extended spectrum.

In comparison any consumer-grade camera with a Bayer sensor is at a huge disadvantage - including the GoPro.

d. Lastly, resolution.

Bayer sensors as in the GoPro use a matrix in which blocks of four sensor pixels are aggregated (one red, one blue, two green) to make a single "colour pixel".

The downside is that the number of "colour pixels" in the final image image from it has one quarter as many pixels as the sensor actually has, and the resolution is halved. The resolving power is actually worse than that, as the Bayer filter degrades the resolution too.

OTOH the GoPro is very good for what it was designed for - video of fast action in full sunlight.