Astrophotography with the Powershot G7X ?

[mermaidkiller]

Two weeks ago I got this camera, just as a simple and compact secondary beside my bulky 6d.

I tried it on the sky last week and was amazed what this cute camera can capture. It does not match the 6d (or any SLR), but for such a small sensor (8.8x13.2mm: 37% of the size of FF) the results are promising for quick AP.


Hydra-Gemini-Taurus 15sec f/4 8.8mm (FOV 75º), single exposure in RAW, postprocessed in PSD CC.

And it is taken in a rather light polluted area, so I used only f/4 instead of f/1.8.

Fumbling with manual settings and remote, I found out that remote control with the app is rather limited, but it is possible to enable Continuous shooting, M(anual) mode, Manual focus, T=30sec, RAW, and ISO up till 3200 combined. But .... it can only be done when manually holding down the shutter button for several minutes when making frames for a stack.

So I made a bracket from aluminum strip which I put over the front of the camera which keeps the shutter button down. Due to lack of clear skies (horrible climate in NW Europe) I tried it as a dry run and it worked !


The bracket forcing the shutter button down.

My 6d remains my main AP cam, that is for sure, but I keep this cam for simple AP for situations the 6d is unsuitable.

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Ricoh KR-5 ... Pentax ME Super ... Canon T90 ... ... ... 40d ... 7d ... 6d

 

[W5JCK]

It should work okay. I have a Sony RX100 III with a 1" sensor and pretty fast and good lens. I use it for satellite trail capture and general nightscapes. The lens is the biggest factor in my opinion. I have no clue how well the G7X lens does. Several years ago I had the original mark I G1X and that was really very good for AP tasks like meteor capture, satellite trail capture, and general nightscapes. But the G1X had a sensor almost as big as the APS-C. Canon started using inferior lenses in their subsequent versions. Does the G7X have a port for a wired remote? If so I recommend using an intervalometer. Manually holding down the shutter works, but it is a clunky solution and you could run into memory cache issues after a long shoot. You will likely be okay with multi-second shutters though. Cache issues on some cameras occur more frequently with very short shutters. Another option is CHDK . I looked at their Wiki page and an alpha version is available for the G7X. Once that gets to a stable spot, it might be a good option.

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Best Regards,
Jack
Website: http://w5jck.com/nightscapes-gallery.html
Flickr: https://www.flickr.com/photos/jackswinden
Sony RX100M3, a6000, and a7

 

[bmike]

I have the MK2. This is my favorite image with stars in it:

Cupola and Stars