E-M5 does hand held infrared and tripod astro with 12mm lens in the Aussie outback

Started May 23, 2012 | Discussions thread
Gary_Oz
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Re: Thanks!
In reply to kenw, May 23, 2012

Hi Ken, I haven't looked at at long exposure thermal noise of the E-M5 sensor yet, as I used the E-M5's NR to automatically subtract the dark frame noise from the long exposures.

The thermal noise can be expected to be modified by ambient temperature as well as sensor and camera-induced temperature changes from how much use the sensor has been used prior to the shot.

Perhaps a more critical aspect for wide field astrophotography with the 12mm lens will be to take flat frames and subtract those to address the vignetting wide open although I am yet to see if the E-M5's automatic vignetting correction actually works well enough to avoid requiring flat frames to be taken.

Flat frames are exposures at the aperture being used of a uniformly lit subject in the hope that when used to subtract from your image it can reduce vignetting more accurately than basic vignetting correction controls in Lightroom or Photoshop.

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Olympus OM-D E-M5
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