JeffGreenberg

astrophotography: properly exposed ISO 100 & yet insane noise!!!

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Sony RX10-III, f4, ISO 100, 24mm equivalent;

5-10 minute single exposure; JPG made from DNG;

have since been told astrophotography must be series of short exposure flattened layers;

but was there any camera setting that would have eliminated this overwhelming noise???

 

www.photosphotos.net/FL171212017.jpg

Edited by JeffGreenberg

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All APN are not suitable for astrophotography, but your exposure time is too big. Light pollution can produce the noise you see on your photo but for long exposure you need systems cooling your sensor (like this one http://www.centralds.net/cam/?p=7911 for a SONY A7); Try an exposure time between 15 and 30s and stack at least 10 images to optimise you signal to noise ratio.

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Has Jeff discovered a way to identify dark matter as it passes through the earth? ;)

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6 minutes ago, funkyworm said:

Has Jeff discovered a way to identify dark matter as it passes through the earth? ;)

 

Unless it is the dark energy that causes the expansion of its sensor...

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12 minutes ago, funkyworm said:

Has Jeff discovered a way to identify dark matter as it passes through the earth? ;)

Jeff's no wimp.

 

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The red spots are overheating sensor - I get them when I do longer exposures to get moving clouds. For astro, I use 20 seconds at 3200 ISO which gives me this

 

the-milky-way-in-dark-skies-in-kouchibouguac-national-park-in-new-H3N7EX.jpg

 

if you want star trails then you have to do a whole load of shorter exposures and then stack them. There are quite a few good astro stack software packages available and there are a few basic ones that are free. DeepSkyStacker is free, but Windows only. www.startrails.de is also pretty good. I used it a few times and works well for the basic task of stacking to give trails - it doesn't have all the fancy functions of the expensive deep sky astronomy software.

Edited by Colin Woods
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Jeff, I'd say the noise you've got is relatively normal and you can fix it with say... DENOISE projects 2 professional - very good for noise for astro shots.

 

But you are right - the best results you can get with short exposures and then stacking them in Photoshop if you want star trails. Usually I'm using ISO 3200 or 6400 and exposure between 15 and 30 secs depending on the focal length. Here is a result.

 

milky-way-over-the-pinnacles-desert-namb

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On 10.1.2018 at 21:25, JeffGreenberg said:

Sony RX10-III, f4, ISO 100, 24mm equivalent;

5-10 minute single exposure; JPG made from DNG;

have since been told astrophotography must be series of short exposure flattened layers;

but was there any camera setting that would have eliminated this overwhelming noise???

 

www.photosphotos.net/FL171212017.jpg

Topaz denoiser is also worth a try :) but the exposure times seems to long

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11 hours ago, Colin Woods said:

The red spots are overheating sensor - I get them when I do longer exposures to get moving clouds. For astro, I use 20 seconds at 3200 ISO which gives me this

 

the-milky-way-in-dark-skies-in-kouchibouguac-national-park-in-new-H3N7EX.jpg

 

if you want star trails then you have to do a whole load of shorter exposures and then stack them. There are quite a few good astro stack software packages available and there are a few basic ones that are free. DeepSkyStacker is free, but Windows only. www.startrails.de is also pretty good. I used it a few times and works well for the basic task of stacking to give trails - it doesn't have all the fancy functions of the expensive deep sky astronomy software.

Just had to say, a really beautiful photo! well done :)

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5 hours ago, arcticphotoworks said:

Just had to say, a really beautiful photo! well done :)

Thank you, it was taken in a dark sky area in New Brunswick. When I see photos like this it reminds me how good our cameras really are. In film days we had just a couple of ASA 3200 choices and both were so limited in their dynamic range and so grainy that their use was very limited. How much do I love my D750? It was taken with the Tamron 15-30mm f2.8 which also a reminder of how good the third party lenses are these days.

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@Ilya and @Colin : stuning images ! Good job. I dream of a dark sky in my place... I can find it in the open sea, but to do a long exposure it will be a little difficult ....

 

Colin, almost all my lens are Tamron f2.8 (17-50mm, 70-200mm, 90mm macro)  

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I found exactly the same thing when photographing the moon recently - taken at 100 ISO but looked more like 16000.

Edit: OK, reading back I realise I had a different problem - but still, couldn't understand why the quality seemed so poor with 'normal' exposures, just because it was the moon at night.

 

Edited by Phil Robinson

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4 hours ago, Phil Robinson said:

I found exactly the same thing when photographing the moon recently - taken at 100 ISO but looked more like 16000.

Edit: OK, reading back I realise I had a different problem - but still, couldn't understand why the quality seemed so poor with 'normal' exposures, just because it was the moon at night.

 

 

You don't have to use a long exposure time to shoot the moon .

Here 2 shoots at 200 ISO

super-moon-at-moonrise-over-the-mountain1st-quarter-of-the-moon-in-the-sky-of-pr

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1 hour ago, Southmind said:

 

You don't have to use a long exposure time to shoot the moon .

Here 2 shoots at 200 ISO

super-moon-at-moonrise-over-the-mountain1st-quarter-of-the-moon-in-the-sky-of-pr

Exactly - I was using a short shutter speed and low ISO but it still came out looking like it was shot at 16000. I've tried more than once and I'm always disappointed by the results.

 

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Those (2) ISO 3200 Milky Way images,

if possible a slice of pre-NR version for comparison...?

If willing, mention how noise reduced & detail maintained???

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Jeff

I use DxO Optics for my RAW conversion, I use its Prime NR which is its noise reduction for high ISO files and it works wonders. The NR is done at the RAW conversion stage. If you like, I could email you the RAW file to have a play with.

Colin

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On 1/15/2018 at 12:24, JeffGreenberg said:

Those (2) ISO 3200 Milky Way images,

if possible a slice of pre-NR version for comparison...?

If willing, mention how noise reduced & detail maintained???

I didn't use any NR software or technique at all. I've got Nikon D800 and ISO 3200 and 30sec exposure are accepted by Alamy without any issues. I'll try to post 100% crop later when I get to my computer.

On a side note - ISO 3200 but just a handheld shot from Fujifilm X-E2 was accepted as well.

 

If I need to reduce the noise I'm using Dfine from Nik Software (free software right now).

 

In your case I'd try to use something like 30secs shots and then stack them in one of the apps available: http://www.rogergroom.com/astronomy-deep-sky-stacking-software/  (depending on your OS etc)

Edited by Ilya Genkin

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