37 replies to this topic

[sharkmelley]

In short,  what you call a fault is 'not a bug, but a feature.'   Even likely its patented.  

I've no doubt that this in-camera processing is done with the best of intentions for the average photographer.  But it screws things up for serious deep-sky astrophotography.  It's the law of unintended consequences, I guess.

[unimatrix0]

Then the obvious  deduction is that  the rings are created by bad flats.  A very common problem for 'amateur astrophotographers' images.   To blame the camera maker for making a bad camera not designed for astro imaging is clearly bogus and misleading.   If they chose to pay attention to you or others complaints like this to them, and reply to your 'findings', Nikon could sue you for slander & libel  and you'd lose in a heartbeat.  You're lucky that Its a waste of their time to reply to these bogus conclusions.  

 

In short,  what you call a fault is 'not a bug, but a feature.'   Even likely its patented.  

Can you be less prejudice? 

 

I have plenty of images taken with all sorts of cameras and the only one that gives an unavoidable rings is the Nikon D5600 and previously the D5300. I also had Canon 60D, Canon T7, Pentax K70 and Canon T5i. Beside those, I have /had  QHY183C , Meade IV mono, 533mc pro, and currently 533mm pro. 

 

None gave me rings beside the Nikons, so don't worry about my flat taking procedure, I'm somewhat confident that I can handle it. 

 

You are welcome to look at my images, so while they are not picture of the day master shots, I think I have taken enough images and processed 100s of them to know how ot take flats. 

Pictures on this forum gallery
https://www.cloudyni...ms&section=user

 

Pictures on Astrobin

https://www.astrobin...s/frankszabo75/

 

 Mark has done an extensive research from samples provided from several people who use these cameras and he is arriving to the same conclusion with the Nikon does raw pre-processing (which cannot be excluded) and of course astrophotographers were never considered as priority by Nikon. 

At least, it's good to know that this problem exists and advise others before they buy a camera for this specific use, that they might gonna encounter this issue. 

Edited by unimatrix0, 21 February 2024 - 02:52 PM.

[Rlakjdlsj]

Can you be less prejudice? 

 

I have plenty of images taken with all sorts of cameras and the only one that gives an unavoidable rings is the Nikon D5600 and previously the D5300. I also had Canon 60D, Canon T7, Pentax K70 and Canon T5i. Beside those, I have /had  QHY183C , Meade IV mono, 533mc pro, and currently 533mm pro. 

 

None gave me rings beside the Nikons, so don't worry about my flat taking procedure, I'm somewhat confident that I can handle it. 

 

You are welcome to look at my images, so while they are not picture of the day master shots, I think I have taken enough images and processed 100s of them to know how ot take flats. 

Pictures on this forum gallery
https://www.cloudyni...ms&section=user

 

Pictures on Astrobin

https://www.astrobin...s/frankszabo75/

 

 Mark has done an extensive research from samples provided from several people who use these cameras and he is arriving to the same conclusion with the Nikon does raw pre-processing (which cannot be excluded) and of course astrophotographers were never considered as priority by Nikon. 

At least, it's good to know that this problem exists and advise others before they buy a camera for this specific use, that they might gonna encounter this issue. 

Don't know what your smoking but In your rant, there are problems with your accusation of my bias.  1st.  I said I have seen  both makers cameras have made plenty of good and great astro images, with no rings or donuts.  2nd  

 

It was Mark who said  the rings were created by bad (overexposed) flats.  But then he blamed Nikon that it "screws things up" in astro images with it manipulation of its firmware that is never designed for astro-imaging.  Well you can't expect a pig to fly can you?   Only crazy people or those with some other 'agenda' will argue the pig should be able to fly and then blame the pig farmer. 

 

 I've never had any of these rings from my Canons, that Mark also accuses of making rings, either because I follow the basic rules when taking flats   I know not to overexposure or underexpose or I don't 'over manipulate my data like he does.  

 

 Its pretty simple unless you don't pay attention to the Gaussian curve, what artifacts your optics might produce or overthink the whole process.  Maybe your Nikon camera is producing the rings from its firmware manipulation. But Mark says its not.  If you want to sue Nikon, thousands of Nikon owners won't agree with you.  Nikon Is not 'catering' to astro-imagers and finding Nikon at fault are bordering on 'crazy' at best.   IMO, "Frankly my dear I don't give a dam."  And you make it clear why Nikon agrees with me.  

Edited by Ron359, 21 February 2024 - 04:56 PM.

[Rlakjdlsj]

Can you be less prejudice? 

 

 

 

 Mark has done an extensive research from samples provided from several people who use these cameras and he is arriving to the same conclusion with the Nikon does raw pre-processing (which cannot be excluded) and of course astrophotographers were never considered as priority by Nikon. 

At least, it's good to know that this problem exists and advise others before they buy a camera for this specific use, that they might gonna encounter this issue. 

As Unimatrix 0, you should be the first to recognize that is a good example of "hive mind thinking."  IDIC is more logical.  

Edited by Ron359, 21 February 2024 - 05:05 PM.

[unimatrix0]

Ok, so I'm not smoking anything, but your reply came down as "You guys don't know what you're doing, stop making up stuff".  That's all. 

This is isn't like a one time occurence and not with just one person or just bad flats.

Regarding the flats they are "auto flats", measured by software to the correct ADU.  That's the problem that Mark was saying. That maybe my subframes didn't have the ring (this time), but my flats did, because I did correct flats. 

 

That's the point he was making, that the perfect flats and the perfect exposure time just doesn't want to work with this camera. According to him, we have to under expose both the subs and the flats. They cannot be the ordinary flats that every other camera needs. And then maybe then the circles won't show up. 

 

But beside the flats  I can give you 10s of aborted images that have circles in them and not just me, Mark himself gets them and so do other people, mainly Nikon owners. The issue existed long before I noticed, because I was looking for answers and I found the concentric topic here in this forum and it was immediately identified that the circle isn't caused by bad exposure or bad coma corrector or bad ______insert anything that cause aberrations, but it's in-camera processing of the raw files and there is little we can do about it, beside play around our exposure levels to avoid them.  Some others don't get them, so it's an ongoing investigation how to avoid them or what really triggers it to appear, but Mark knows more about that since he has been collecting samples for months or years and analyzing them. Trust me I'm the most skeptical person and I tried this camera on 4 different type /size/ style scopes and with and without filters and with and switching correctors and flatteners around and it's just not the gear or the glass, it's really the camera that causes the issue. 

And it's not just my opnion, others came to the same conclusion. There are some flukes of course, those who has other issues and misidentify the problem and blame the bad image on the circles, but they are easily identified. 

Edited by unimatrix0, 21 February 2024 - 06:20 PM.

[FrankieT]

To blame the camera maker for making a bad camera not designed for astro imaging is clearly bogus and misleading. 

Nikon seem to promote the use of their equipment for astrophotography at nikonusa.com. I think it would be very helpful if you could point out where Nikon state which of their cameras are not designed for "astro imaging" or perhaps not suitable for some astrophotography use cases.

[Rlakjdlsj]

Nikon seem to promote the use of their equipment for astrophotography at nikonusa.com. I think it would be very helpful if you could point out where Nikon state which of their cameras are not designed for "astro imaging" or perhaps not suitable for some astrophotography use cases.

For a couple decades now, Nikon has been 'accused' by Mark and many others here and other internet forums of manipulating the camera raw data.  Should be pretty clear, to any 'serious astro imager', the camera that doesn't produce a 'clean' unmanipulated raw file is not designed specifically for astro imaging.  I won't even mention (apparently cured ?) Nikon's former problems of "star eating." or sometimes faulted for producing green stars.  

 

I don't have first hand knowledge of 'DSLR Nikons, asI switched from 30+ yrs of Nikon film cameras and lenses mainly because of what 'the experts' said about the "star eaters", - a good friend is one of the 'experts' having been a professional for decades. '  

 

But I see Nikon fan good pics and appreciate they are overall decent cameras for DSLR astro images.   My original comment on Mark's test, was more about his 'off-base' conclusion.   I will point out his testing methods seem to find many rings in many different cameras of all makers but few of his claims can be reproduced consistently.  

 

Even his own images get inconsistent results.   Despite the fact that  "baked in" sensor firmware is no doubt the same in all cameras of the maker and model produced in the 10s of thousands. Yet  he blames all of these rings on firmware "baked-in monkeying."   In science if you can't reproduce the findings of a theory or a test, you have to revise your conclusions or test methods. Not keep claiming you're right and they're wrong.  I give him credit for his finding this OP problem was in bad flats.

 

 The OP seems to find that means the camera firmware is 'bad.'  My take on that, is you often have to adjust your 'settings' according to "best practices" that users over time figure out.  An e.g., is the diff  of best ISO settings for Nikon' is in low hundreds.  For Canon the often recommended ISO are from 800-1600.  And of course exceptions to these 'rule of thumbs' are used by some astro-imagers because they may have different criteria or values of what they like to see in their images. Same goes for color balance subjective interpretation.  Nightscape astro-imagers often work 'outside' the expert 'rules.'    Again, these are features that give us a lot of flexibility,  and are not bugs you should blame the maker for.  

 

If the OP would send his cam in for a repair to Nikon,  seems very likely they will tell him it works within their specs and doesn't have a problem they can find.  Many of us have bought lenses from 'aftermarket' Korean lens makers and getting a "good copy" is always a challenge for it to be "good" for astro cause of coma at the edges.  You learn you better buy it and test it and then have a good return policy to either forget it or get another lens to try.  Camera firmware is what it is.  Its not subject to quality control misses in 'some batches' and not in others.  Firmware code is simply copied.    If you send it back for a repair telling them its a  bad firmware,  they will tell you its within their specification.  You can always try a new version or re-loading it.  It might be a buffalo or pig,  but you didn't pay for a pig or buffalo with wings that can fly day or night for hours in all extreme weather conditions. 

Edited by Ron359, 22 February 2024 - 11:18 AM.

[sharkmelley]

For anyone new to the discussions about raw-data manipulation, you can find my test procedures documented here:

• Diagnosing Raw Data Filtering (a.k.a. "star eater")
• Diagnosing Baked-In Concentric Rings

A list of artefacts associated with various camera models can be found here:

• DSLR/Mirrorless Artefact Summary

I'm always happy to analyse test files from camera models not on the above list.

 

I'm also happy to receive constructive criticism about the methodology employed and to provide further explanations where necessary.

 

Mark

Edited by sharkmelley, 22 February 2024 - 01:56 AM.

[FrankieT]

I don't have first hand knowledge of 'DSLR Nikons, asI switched from 30+ yrs of Nikon film cameras and lenses mainly because of what 'the experts' said about the "star eaters", - a good friend is one of the 'experts' having been a professional for decades. '  

Well, it's a real shame for Nikon that you switched brands after so many years as a customer! I guess you will not be the last though - it seems that some manufacturers are able to improve their products for astrophotography, e.g see this thread. It appears that DLSR/MILCs with Sony sensors can provide clean raw images for the serious astro imager after all.

 

In the end, no camera is perfect and, as you mentioned, there are always issues to work around. Credit to Mark, Frank (unimatrix0) and other experts like your good friend who give up their own time and expertise to test, analyze and provide their first-hand experiences and workarounds in good faith, which benefits the whole community. In this case, their combined efforts might have led to some tangible product improvements too. Who knows, Nikon might even follow Sony's lead and give you a reason to switch back!

 

Anyway, this post has gone off topic now so I'll stop here.

 

 

 

 

[Rlakjdlsj]

Well, it's a real shame for Nikon that you switched brands after so many years as a customer! I guess you will not be the last though - it seems that some manufacturers are able to improve their products for astrophotography, e.g see this thread. It appears that DSR/MILCs with Sony sensors can provide clean raw images for the serious astro imager after all.

 

In the end, no camera is perfect and, as you mentioned, there are always issues to work around. Credit to Mark, Frank (unimatrix0) and other experts like your good friend who give up their own time and expertise to test, analyze and provide their first-hand experiences and workarounds in good faith, which benefits the whole community. In this case, their combined efforts might have led to some tangible product improvements too. Who knows, Nikon might even follow Sony's lead and give you a reason to switch back!

 

Anyway, this post has gone off topic now so I'll stop here.

Got too much 'invested' in Canon now to switch back.   I still occasionally use some of my 'old' Nikon glass on my Canon bodies. Which you can't even use on newer Nikon bodies...  oh the irony.  ; )  

 

I've said many times, I see many good astro-images taken with Nikons these days.  Its too bad some users just have much higher expectations.  Its just one of the 'givens' of DSLR cameras they are NOT dedicated astro-imaging cameras.   To give you a 'local  metaphor', they are great  'Swiss-Army" knives!   ; )  

Edited by Ron359, 22 February 2024 - 03:25 PM.

[Spaceman 56]

 

i have plenty of images taken with all sorts of cameras and the only one that gives an unavoidable rings is the Nikon D5600 

 

 it's good to know that this problem exists and advise others before they buy a camera for this specific use,

Ok. Nothing personal here, but I have a Nikon D5600, and I have used it sucessfully for over a year for AP.

 

I have never seen any problems in any of my images.  

 

why that is, I don't know, but I can only relate my experiences.

 

You have seen my images Unimatrix, but for others who may not frequent the Deep Sky forum, I will post some.

 

 

 

 

 

 

Where are the Unavoidable Rings, you are discussing in my images ?

[sharkmelley]

 

Ok. Nothing personal here, but I have a Nikon D5600, and I have used it sucessfully for over a year for AP.

 

I have never seen any problems in any of my images.  

You shoot under pristine skies and that makes a huge difference

 

The rings only start to appear when the background pixel values hit a certain level.  It is quite possible that the background in your lights is so dark that the rings are never triggered.    In addition you don't need to "force" the data as much to reveal faint details and so if there are any rings (for instance in your flats) you are much less likely to see them revealed in your final image.

 

I would certainly be interested in seeing a raw light and a raw flat from one of your sessions.

[Spaceman 56]

 

The rings only start to appear when the background pixel values hit a certain level. 

 

It is quite possible that the background in your lights is so dark that the rings are never triggered.    

I see Shark.

 

the rings are in there, but don't show up because of my sky conditions.

 

I can accept that.