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Sony's latest a7r IV also appears to have Star Eater issues

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#1 Coconuts

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Posted 17 September 2019 - 06:19 AM

Sony had a big launch event in NYC back in July for their new a7r IV, which uses the smallest (yet full frame) of their latest and greatest triad of back illuminated CMOS sensors, with 61 Mpx.  This is essentially the same sensor as the IMX455 used in the just-launched QHY600 cooled astrocamera, but with phase detect autofocus pixels added for the consumer camera market.  The technical part of the launch video is worth watching; they claim 15 stops of dynamic range, implying either really low read noise, a large full well, or a combination of both.  The a7r IV also has on-chip 16 bit ADCs.  Here's a link to a video of Sony's NYC launch event:

https://www.youtube....h?v=U9TENA7dOEY

I have been eyeing Sony's new triad of cutting-dege BSI CMOS sensors since they first appeared on Sony's roadmaps a few years ago.  While the a7r IV is pricey at $3500, that is still well under the $5000 for the upcoming "Photographic" version of the QHY600M/C, and so the a7r IV had the potential to be a really great camera for astrophotography.

 

While retail a7r IV's are not yet shipping in the US, with general availability here "in September", a number of advance copies have made it out to reviewers and some folks in other countries.  On September 14th, one user, Jim Kasson, went to the effort to check for any star eating issues.  He reports a dramatic change in behavior once the exposure time reaches or exceeds 2.5 seconds.  You can read his report here:

https://blog.kasson....s-shutter-speed

Petapixel also picked up on this yesterday:

https://petapixel.co...er-speed-report

 

That's a real shame.  Sony hasn't listened to the needs of the astro imaging market to date, and seems to be bent on continue to ignore it.  All it would take is a firmware option to turn off this feature (for us, bug).  With no cameras yet shipping in the US, and no manual online, its remotely possible that such an option is buried in their menus, but I wouldn't count on it.

 

Jim Kasson's blog not only checked into the star-eating issue for the new a7r IV, but he also tested a LOT of other aspects, many of which are relevant to astrophotography.  You can check out his full set of testing here:

https://blog.kasson.com/category/a7riv

Kasson goes deep in deriving full well capacity and read noise vs ISO setting, fixed pattern noise, read noise versus self-heating, and a number of other parameters that we care about.  I'm still digging through all of his findings, but it does seem clear that Sony's claim of 15 stops of dynamic range is essentially marketing nonsense, and that the actual dynamic range of the a7r IV is only marginally better than its a7r III predecessor, although both are still quite good in DR compared to other cameras.

 

I mentioned at the outset that the a7r IV is based on the smallest of Sony's latest triad of impressive BSI CMOS sensors.  They may well retain commercial camera use of the full frame model for their own cameras, but for the larger two, they are offering them to other camera makers.  Fuji, in particular, will be launching their GFX 100 in November; this uses a variant of the 55 mm diagonal IMX 461, but with autofocus pixels added for consumer camera use.  It is much more expensive ($10K), but still way below the price of other medium format cameras from Phase One and Hasselblad.  That large diagonal will challenge optical systems, but Tak and others could handle it with ease.  I have a TMB 130 f/6 APO with a Riccardi large 0.75X reducer that could do so as well. 

 

Star eating is a camera software issue, not anything intrinsic to the sensor, so these new Sony BSI CMOS sensors may yet find use in astro imaging.  In a PM from a CN poster with a Fuji GFX 50 (earlier Sony sensor generation), he states: "I can tell you that the Medium Format is a total game changer and that the color reproduction is second to none. Fujifilm in generally are really pushing their system for astro imaging, especially in Japan.".  That is encouraging, and jives with what I am hearing that Fuji's stock IR filter lets in a lot of Ha.  So there's still hope, but at a price.  In the meantime, Sony needs to hear from us to add a disable feature for "star eater".

 

All the best,

 

Kevin


Edited by Coconuts, 17 September 2019 - 06:51 AM.


#2 sg6

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Posted 17 September 2019 - 08:52 AM

Sony hasn't listened to the needs of the astro imaging market to date, and seems to be bent on continue to ignore it.

Sony are not making astrphotography cameras. They are producing DSLR's for the more usual photography market, portrait, landscape, sports, holiday memories and whatever

 

One person who asked why his images were not as good as a serious AP'er was told bluntly:

A DSLR is for holiday snaps, not AP.

That was the end of that conversation, but unfortunately more or less correct.

 

We happen to be able to use a DSLR at least initially for AP, that however does not make it an AP Camera.

A DSLR is not mono, it is not cooled, we have to rip filters out, we have to override things like Noise Reduction.


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#3 Coconuts

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Posted 17 September 2019 - 09:28 AM

"A DSLR is for holiday snaps, not AP". 

 

I suspect Wei-Hao Wang and many others here would disagree.  This is, after all, the "DSLR and Digital Camera Astro Imaging and Processing" forum.

 

All the best,

 

Kevin


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#4 DubbelDerp

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Posted 17 September 2019 - 11:44 AM

I was going to comment here, but then I thought... nah, don't feed the trolls.

 

I use Canon cameras, so I don't have a horse in this race, but I think the original post is worthy of discussion. The sensor does sound incredible, but that much data would bring my workstation to its knees!



#5 Coconuts

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Posted 17 September 2019 - 01:11 PM

DD:  "that much data would bring my workstation to its knees!"

 

AMD has a CPU for you... 2018's twelve-core Threadripper 1920X is now only $200.

 

https://www.pcworld....-cheap-200.html

 

All the best,

 

Kevin



#6 aeroman4907

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Posted 18 September 2019 - 05:01 PM

Technically speaking the AR7 iv is a mirrorless camera and not a DSLR. I have one back ordered but I intend to use it for fine art landscape photography and not for astrophotography. I completed my whole Milky Way imaging project with my Canon 5d mk2 and a 24 mm Rokinon lens. Truth be told the astrophotography probably helped wear out my sensor which necessitates its replacement with the Sony. Canon unfortunately is falling far behind on the camera front.

#7 t_image

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Posted 18 September 2019 - 09:55 PM

The Sony listening thing methinks is a chicken-egg dilemma.

 

AP'ers aren't buying the latest Sony MILCs. Sony isn't a bunch of dummies....

The customers who are buying the latest Sony cameras are the population that Sony listens to [and Sony does--they change features per request all the time, pretty easy to see this history],

because they are who Sony sees as customers......

 

So ironically AP'ers have stopped buying Sony for AP, and thus Sony doesn't see they should be concerned about non-customers,

while AP'ers complain Sony doesn't listen to them, duh.....

 

AP'ers that stopped buying see it as a non-negotiable,

the customer base that gets heard and Sony fulfills feature request for all the time are the ones where the features are NOT non-negotiables....

so that is the main difference....

 

The issue isn't a secret,

If Sony engineers really did put a toggle,  they would have announced it,

it won't be something we have to discover......

 

Someone on DPR asked about star eater.

An interesting reply mentioned "the internet effect."

Then ironically the internet effect happened in that very thread......

 

Seriously, put yourself in their shoes.

The people who don't care are consistent customers.

The people who say "I'm never buying a Sony camera again" were the chief complainers of star-eater.

You have limit time and energies in a market which is dying because cellphones will soon replace dedicated cameras anyways(to Sony's sensor division's great profit).........

Who are you going to 'listen to?"



#8 SandyHouTex

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Posted 19 September 2019 - 09:35 AM

The Sony listening thing methinks is a chicken-egg dilemma.

 

AP'ers aren't buying the latest Sony MILCs. Sony isn't a bunch of dummies....

The customers who are buying the latest Sony cameras are the population that Sony listens to [and Sony does--they change features per request all the time, pretty easy to see this history],

because they are who Sony sees as customers......

 

So ironically AP'ers have stopped buying Sony for AP, and thus Sony doesn't see they should be concerned about non-customers,

while AP'ers complain Sony doesn't listen to them, duh.....

 

AP'ers that stopped buying see it as a non-negotiable,

the customer base that gets heard and Sony fulfills feature request for all the time are the ones where the features are NOT non-negotiables....

so that is the main difference....

 

The issue isn't a secret,

If Sony engineers really did put a toggle,  they would have announced it,

it won't be something we have to discover......

 

Someone on DPR asked about star eater.

An interesting reply mentioned "the internet effect."

Then ironically the internet effect happened in that very thread......

 

Seriously, put yourself in their shoes.

The people who don't care are consistent customers.

The people who say "I'm never buying a Sony camera again" were the chief complainers of star-eater.

You have limit time and energies in a market which is dying because cellphones will soon replace dedicated cameras anyways(to Sony's sensor division's great profit).........

Who are you going to 'listen to?"

So one of the serious complaints Sony has continued to not address for daytime users is menu organization.  As in there is none.  So it's not just us.



#9 t_image

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Posted 19 September 2019 - 10:53 AM

So one of the serious complaints Sony has continued to not address for daytime users is menu organization.  As in there is none.  So it's not just us.

I either don't understand the specifics of your point or I think you have your facts incorrect.

Have you played with a menu from the original a7s and a new mark 3/4 model and it's menu system? It is different.

And if you reply that users still aren't happy--it's an impossible requirement unless you stipulate a concrete way that the menu is supposed to operate that a whole quorum of users want.

There are too many diversified feature request on this subject matter. Prove me wrong otherwise. Show me video after video and post after post that stipulate a unified way the menu should work.

 

Sony even through the a7xx line has adjusted the menu system organization a few times.

Just like the algorithm that results in Star-eater has been adjusted a few times as well (however IMO the menu system got better, the star removal got worse (happens in more settings) and different -turns small stars green).....

 

To your initial point "not just us,"

a better example of a still-to-be addressed feature request:

4:2:2 10bit 4K video recording (and 4K 60p) which would be very easy to demonstrate more influencers and users and a greatly larger user audience than astro are desiring this feature......

Of course, if one looks,

Sony isn't afraid to address this:

https://www.youtube....1&v=sTU-pVeRdhY

 

Observe how the influencer succeeded in getting an audience with Sony Senior Staff and asked them about such,

instead of just posting complaints on some forum......

Notice Sony staff spend about 3 minutes addressing the example above that they haven't fulfilled yet....



#10 SandyHouTex

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Posted 22 September 2019 - 08:54 PM

I either don't understand the specifics of your point or I think you have your facts incorrect.

Have you played with a menu from the original a7s and a new mark 3/4 model and it's menu system? It is different.

And if you reply that users still aren't happy--it's an impossible requirement unless you stipulate a concrete way that the menu is supposed to operate that a whole quorum of users want.

There are too many diversified feature request on this subject matter. Prove me wrong otherwise. Show me video after video and post after post that stipulate a unified way the menu should work.

 

Sony even through the a7xx line has adjusted the menu system organization a few times.

Just like the algorithm that results in Star-eater has been adjusted a few times as well (however IMO the menu system got better, the star removal got worse (happens in more settings) and different -turns small stars green).....

 

To your initial point "not just us,"

a better example of a still-to-be addressed feature request:

4:2:2 10bit 4K video recording (and 4K 60p) which would be very easy to demonstrate more influencers and users and a greatly larger user audience than astro are desiring this feature......

Of course, if one looks,

Sony isn't afraid to address this:

https://www.youtube....1&v=sTU-pVeRdhY

 

Observe how the influencer succeeded in getting an audience with Sony Senior Staff and asked them about such,

instead of just posting complaints on some forum......

Notice Sony staff spend about 3 minutes addressing the example above that they haven't fulfilled yet....

It’s under the subheading “Bad”, bullet 4:

 

https://kenrockwell....sony/a7s-ii.htm



#11 Alen K

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Posted 22 September 2019 - 09:46 PM

Technically speaking the AR7 iv is a mirrorless camera and not a DSLR. I have one back ordered but I intend to use it for fine art landscape photography and not for astrophotography. I completed my whole Milky Way imaging project with my Canon 5d mk2 and a 24 mm Rokinon lens. Truth be told the astrophotography probably helped wear out my sensor which necessitates its replacement with the Sony. Canon unfortunately is falling far behind on the camera front.

Okay, I'll bite. How did your astrophotography help wear out your sensor? And how do you know it is "worn out?" 




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