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Is Sony Really Alpha?

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#2176 tsk1979

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Posted 15 April 2021 - 02:05 PM

DSOs don’t have small one pixel stars, or you just don’tnotice it?

Not noticeable in the images. Infact I have to remove stars



#2177 calypsob

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Posted 16 April 2021 - 12:28 AM

Not noticeable in the images. Infact I have to remove stars

I can see it occurring in your image, you need to understand what it looks like. Share the raw data and it will be a 100% determinable factor. 


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#2178 tsk1979

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Posted 16 April 2021 - 05:11 PM

I can see it occurring in your image, you need to understand what it looks like. Share the raw data and it will be a 100% determinable factor. 

RAW data you mean individual fits? Or final stacked image. For post stacked images, I have too many stars, want to remove some

 

Example

20200225-St-avg-8562.0s-MSC_1_3.0_none-x


Edited by tsk1979, 16 April 2021 - 07:32 PM.


#2179 calypsob

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Posted 17 April 2021 - 07:54 AM

The stacked sub is fine, you can manipulate stars any time. You cannot manipulate what the camera decided for you to filter out
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#2180 erictheastrojunkie

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Posted 17 April 2021 - 01:32 PM

The people that deny the star eater and its affects on astro images crack me up, listen, I love using my A7s for time lapse and its sensor is perfect for that, but there is absolutely no denying that when paired with a sharp lens and shot in bulb mode the firmware absolutely obliterates stars and fine detail. Here's a prime example, shot this last weekend with my Voigtlander 50mm APO, a 3.5 minute tracked single exposure at ISO 800 and f2.8 with zero editing done, second shot is just a screengrab of the exposure with a zoom in the center of the image:

 

https://imgur.com/gallery/pXUaTfJ

 

A field full of garbled stars, green and pink remnants with donuts all over the place, absolutely destroyed detail. ANY amount of zooming in shows how bad the effect is on an image like this, the firmware's affects are real and it negatively harms astro images, it nobody any amount of good to deny this and it certainly does not help our cause as astrophotographers trying to improve the quality of cameras for our use.


Edited by erictheastrojunkie, 17 April 2021 - 01:33 PM.

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#2181 tsk1979

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Posted 17 April 2021 - 03:35 PM

The people that deny the star eater and its affects on astro images crack me up, listen, I love using my A7s for time lapse and its sensor is perfect for that, but there is absolutely no denying that when paired with a sharp lens and shot in bulb mode the firmware absolutely obliterates stars and fine detail. Here's a prime example, shot this last weekend with my Voigtlander 50mm APO, a 3.5 minute tracked single exposure at ISO 800 and f2.8 with zero editing done, second shot is just a screengrab of the exposure with a zoom in the center of the image:

 

https://imgur.com/gallery/pXUaTfJ

 

A field full of garbled stars, green and pink remnants with donuts all over the place, absolutely destroyed detail. ANY amount of zooming in shows how bad the effect is on an image like this, the firmware's affects are real and it negatively harms astro images, it nobody any amount of good to deny this and it certainly does not help our cause as astrophotographers trying to improve the quality of cameras for our use.

I never denied the affects. Infact I specifically said its an issue in milky way shots. All I am saying is that when I stack, it does not matter from a practical standpoint.

I often use star removal in post (starnet++ etc.,)



#2182 erictheastrojunkie

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Posted 17 April 2021 - 06:29 PM

I think you're failing to grasp the basic importance of the topic, it does matter from a practical standpoint, what you are stacking is not raw data and the image quality does suffer from the firmware. What you are stacking is not high quality exposures when done in bulb mode, maybe you do not notice the ill effects or you do not care, but from your image I can tell you I personally would not be satisfied with that result. And whether or not you do star removal is not the point, the artifacts left behind and the degradation in detail caused by the firmware filtering is unacceptable. 


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#2183 tsk1979

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Posted 18 April 2021 - 02:47 PM

I think you're failing to grasp the basic importance of the topic, it does matter from a practical standpoint, what you are stacking is not raw data and the image quality does suffer from the firmware. What you are stacking is not high quality exposures when done in bulb mode, maybe you do not notice the ill effects or you do not care, but from your image I can tell you I personally would not be satisfied with that result. And whether or not you do star removal is not the point, the artifacts left behind and the degradation in detail caused by the firmware filtering is unacceptable. 

Oh, from that POV now I get it. 

 

I guess my images would have been better if I did not have sony's weird star removal thingy. Wondering if A7III has the same issue or to a lesser extent.

 

Another thing is that this issue has gotten so much press, and its easily fixable in firmware. I am wondering why is Sony silent or not offering any remedy



#2184 sharkmelley

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Posted 18 April 2021 - 05:32 PM

Oh, from that POV now I get it. 

 

I guess my images would have been better if I did not have sony's weird star removal thingy. Wondering if A7III has the same issue or to a lesser extent.

 

Another thing is that this issue has gotten so much press, and its easily fixable in firmware. I am wondering why is Sony silent or not offering any remedy

The history of this is quite confusing.

 

The A7, A7R and A7S all applied the original raw data filtering (a.k.a. star eater) in bulb mode only.

 

The Mark 2 versions of the cameras applied raw data filtering to all exposures of 4sec and longer. Because of complaints Sony then updated the algorithm for the Mark 2 versions and all subsequent versions.  The updated algorithm still kicks in for all exposures of 4sec and longer but is slightly less destructive.  Typically it no longer deletes small tightly focused stars but it turns them green instead because the revised algorithm removes fewer green pixels than the previous version of the algorithm.

 

So the A7III does apply raw data filtering but it is less destructive than the A7S.

 

Mark


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#2185 DanielJStein

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Posted 19 April 2021 - 05:51 AM

The history of this is quite confusing.

 

The A7, A7R and A7S all applied the original raw data filtering (a.k.a. star eater) in bulb mode only.

 

The Mark 2 versions of the cameras applied raw data filtering to all exposures of 4sec and longer. Because of complaints Sony then updated the algorithm for the Mark 2 versions and all subsequent versions.  The updated algorithm still kicks in for all exposures of 4sec and longer but is slightly less destructive.  Typically it no longer deletes small tightly focused stars but it turns them green instead because the revised algorithm removes fewer green pixels than the previous version of the algorithm.

 

So the A7III does apply raw data filtering but it is less destructive than the A7S.

 

Mark

Thanks for summarizing this Mark. Does the A7RIII and IV have the same filtering as the A7III? 



#2186 sharkmelley

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Posted 19 April 2021 - 06:05 AM

Thanks for summarizing this Mark. Does the A7RIII and IV have the same filtering as the A7III? 

Yes:

https://www.sonyalph...he-a7riii-does/

 

Mark


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#2187 DanielJStein

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Posted 19 April 2021 - 06:48 AM

Ah that makes sense, thanks for clarifying Mark... and the comments section on that thread was uhhhh interesting. To say the least laugh.gif


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