Sony & The “Star Eater” problem

Started May 24, 2017 | Discussions thread
Navman Regular Member • Posts: 372
Re: STAR EATER - HOW BAD REALLY IS IT ???
2

I've just carried out what I regard as a reasonably robust quantification of the effect of Sony's star-eater algorithm on an A7RII, as follows:

1. Take two sets of ten images of the same set of the Milky Way, exposed a minute or so apart, and with the first set exposed using 3.2 second exposures (no star-eater) and the second set exposed using 4 second exposures (with star-eater);

2. Separately load each set of images into DeepSkyStacker as raw files, setting the raw-read brightness setting in DSS to compensate for the difference in exposure, i.e., to 4.0 for the 4 second exposures, and to 4.8 for the 3.2 second exposures.  That is the 20% increase in read brightness for the 3.2 second exposures compensates for their 20% shorter exposure compared to the 4 second exposures.

3. Set the star detection threshold to 90%, register each set, and calculate the average number of stars detected.

4. The results:
     - average number of stars for the 3.2 second set - 640.3;
    - average number of stars for the 4.0 second set - 472.8;

5. The conclusion: Sony star-eater reduces the number of detectable stars in this equivalent images by 167 or by about 26%.

It's time for a solution, Mr Sony!

-John

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