rhawidantas
Offline
• •
Upload & Sell: Off
|
 p.1 #2 · p.1 #2 · Star Eater Algorithm and getting in contact with Sony | |
Hello Sony,
I am writing with great concern about the so-called “Star Eater” problem affecting Sony Alpha cameras.
Most of the latest Sony Alpha cameras employ a spatial filtering noise reduction algorithm when using Bulb mode. This noise reduction targets hot pixels. It affects RAW files and cannot be turned off, even when using Uncompressed RAW. The primary issue with the spatial filtering is that it greatly affects astrophotography: dimmer stars that occupy only a few pixels are erased, essentially “mistaken” for noise by the filtering algorithm. The result is an astrophoto with greatly reduced visibility of dim stars and an overall appearance of reduced resolution.
This issue affects all recent Sony alpha mirrorless cameras including the a6000, a6300, a6500, a7S, a7R, a7, a7II, a7SII and a7RII. It likely affects more models, too. The issue has been thoroughly discussed and analyzed by others in the community, particularly on the DPReview forums and on Jim Kasson’s Last Word blog. References are at the bottom of this email.
The blog, lonelyspeck.com, focuses specifically on accessible landscape astrophotography for beginners and I’ve personally been a big fan of Sony cameras up until now. While the spatial filtering on Sony Alpha cameras has been documented for a long time, it didn’t really affect the simpler forms of astrophotography that do not require shutter times longer than 30s. If we used these cameras in M mode and let the camera time the exposure up to 30s long, the camera would not apply the problematic spatial filtering. For most cases in landscape astrophotography, night sky exposures almost never exceed 30s in order to reduce star trailing.
But I’ve recently learned through Sony Alpha Rumors, as well as the DPReview forums and Jim Kasson’s blog, that Sony has issued firmware updates to at least the a7RII and a7SII (3.30 and 2.10, respectively) that now forces the same “Star Eater” spatial filtering on all exposures that exceed 3.2s in shutter time, even when not in Bulb mode. What was once a problem that only affected the niche case of Bulb exposures now affects ALL reasonable untracked astrophotography exposure times for common focal lengths.
Personally, learning of this change (and verifying the issue for myself) has led me to question my desire for future Sony camera bodies and has made me very skeptical of future firmware updates. I hate the thought of having recommending a camera to someone only to learn that something has changed that would have me question my original recommendation. These aren’t cheap tools. As a result, I’m no longer recommending and will be forced to discourage the use of current and future Sony cameras on my blog, unless we see a fix.
I’m reaching out because I believe Sony has the capability to fix this issue to win back the support of so many loyal fans. We have already seen Sony make improvements and fixes to the a7 series when DPReview published about the original issues with Sony’s compressed RAW artifact problems. As a result, Sony issued firmware updates for the a7II, a7SII, and a7RII that enabled uncompressed RAW. It was a fix that was favorably commended by many in the photography community. Now, we need another fix.
Sony, please fix the “Star Eater” spatial filtering issue via a firmware update… the problem was introduced/exacerbated with firmware so it’s obvious it can be fixed with firmware. At the very least, make it a selectable option in the menu such that it can be disabled when desired. Adding the option to disable it for Bulb mode would just be icing on the cake.
This letter is available publicly as a blog post on lonelyspeck.com, documenting the issue for their readers. I’ve recommended the a7SII and a7RII to so many people for landscape astrophotography and it would feel disingenuous to not tell them about this issue.
For reference, here are a number of online sources that discuss the “Star Eater” problem:
DPReview:
https://www.dpreview.com/forums/post/58709160https://www.dpreview.com/forums/post/55841466
Cloudy Nights:
https://www.cloudynights.com/topic/498339-sony-a7s-star-eater-algorithm/https://www.cloudynights.com/topic/505754-another-real-world-example-of-sonys-star-eater-problem /https://www.cloudynights.com/topic/558230-star-eater-in-action-sony-a7rii/
SAR:
http://www.sonyalpharumors.com/specific-a7sii-astrophotography-fix-request/#disqus_thread
Sony Community:
https://community.sony.com/t5/Alpha-NEX-Cameras/Star-eater-in-bulb-mode/td-p/508740
From Jim Kasson:
http://blog.kasson.com/the-last-word/spacial-filtering-of-raw-images-by-sony-a7s-a7ii/http://blog.kasson.com/the-last-word/sony-a7rii-long-exposure-spatial-filtering-with-fw-3-30 /http://blog.kasson.com/the-last-word/16486/http://blog.kasson.com/the-last-word/lenr-and-sony-a7rii-fw-3-30-lowpass-filteering /http://blog.kasson.com/the-last-word/reverse-engineering-the-sony-a7rii-long-exposure-spatial-filtering/http://blog.kasson.com/the-last-word/sony-a7rii-bulb-spatial-filtering/
Sincerely,
|
