7 replies to this topic

[lviatour]

Images were taken with the Skywatcher Esprit 120ED refractor at 860mm focal length mounted on an AZ-EQ6. The Nikon Z7 camera was modified for astrophotography and equipped with an IDAS NBZII filter. Total integration time was 4 hours and 30 minutes, divided into 45 x 6-minute exposures. 45 dark, 45 flat, and 45 bias frames were also captured. The setup was controlled using an ASIair Plus.

The image was taken in Hamois, Belgium on August 6, 2024. Processing was done in HOO for the nebulae and RGB for the stars. Software used: Siril, Starnet, darktable, and GIMP under Linux.

[Bruce K]

AMAZING  and lovely, thanks for sharing this one.

 

Bruce

[james7ca]

That's a very nice looking image.

 

Have you ever noticed or had any problems with the often reported colored, concentric rings artifact that seems to occur on all recent Nikon cameras (including, the Z7)? If not, perhaps your signal levels are so high that the artifact becomes "swamped" by the signal.

[lviatour]

That's a very nice looking image.

 

Have you ever noticed or had any problems with the often reported colored, concentric rings artifact that seems to occur on all recent Nikon cameras (including, the Z7)? If not, perhaps your signal levels are so high that the artifact becomes "swamped" by the signal.

It's strange, I've taken lots of pictures with the Z7 and never realized this.

[james7ca]

Thanks for the quick update. That's another nice image.

 

It's been said that if you haven't noticed this issue with the concentric rings then you should NOT go looking for it. That said, I've never been fully convinced that we know all there is about suffering from this "defect" or not. I've seen it on both my Z30 and Z8 but I'm shooting under Bortle 7+ skies and I generally use fairly short exposures and my total integration times are typically under one or two hours.

 

May I ask how you take your flats and what ISO you use? Higher ISOs may reduce this problem, I typically use either ISO800 or ISO1600. It's generally believed that this is a firmware issue but there have been some suggestions that it may vary somewhat from camera to camera. I wonder if anyone has considered that it may have something to do with the IR rejection filters that Nikon is using. Odd thing is that some Canon cameras that are used by the same people that have had problems with the Nikons don't seem to have this issue.

Edited by james7ca, 08 August 2024 - 08:38 AM.

[lviatour]

Thanks for the quick update. That's another nice image.

 

It's been said that if you haven't noticed this issue with the concentric rings then you should NOT go looking for it. That said, I've never been fully convinced that we know all there is about suffering from this "defect" or not. I've seen it on both my Z30 and Z8 but I'm shooting under Bortle 7+ skies and I generally use fairly short exposures and my total integration times are typically under one or two hours.

 

May I ask how you take your flats and what ISO you use? Higher ISOs may reduce this problem, I typically use either ISO800 or ISO1600. It's generally believed that this is a firmware issue but there have been some suggestions that it may vary somewhat from camera to camera. I wonder if anyone has considered that it may have something to do with the IR rejection filters that Nikon is using. Odd thing is that some Canon cameras that are used by the same people that have had problems with the Nikons don't seem to have this issue.

I'm capturing lights at 800 ISO, darks at 800 ISO, bias at 800 ISO, and flats at 64 ISO.
I've captured 45 lights at 360 seconds each.
I'm using an ASIair Plus, and the photos aren't being saved to the camera's SD card (there's no SD card in the camera). Instead, the images are directly saved as 16-bit FITS files to a USB drive.

[james7ca]

Okay, thanks for those details. However, I'd really like to know how you take your flats. Are these sky flats or you using an artificial light source (LED panel or something else).

[lviatour]

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Okay, thanks for those details. However, I'd really like to know how you take your flats. Are these sky flats or you using an artificial light source (LED panel or something else).

flat panel Lacerta