Landscape Astrophotography - Horrid Noise (K100D Super)

Wolzal · 07-27-2011, 09:04 PM

For a while I've been doing long exposure star trail photos with a Spotmatic II, but decided for a change of pace to try and capture the milky way.

Rather than burn through cash on film, I borrowed a K100D Super off a friend.

What I'm finding though is I am getting a horrendous amount of noise in my shots. I've read around and understand the basics of taking a star shot (high iso, 10-30sec exposure, wide apeture) however regardless of the settings I use the images are coming out very noisy:

(ISO1600, f/3.5, 18mm, 30secs)

When I've tried to take the ISO down I've understandably had issues getting a decently exposed image.

Am I doing something fundamentally wrong, or is this camera not up to the task?

maltfalc · 07-28-2011, 12:04 AM

do you have long exposure noise reduction turned on?

calsan · 07-28-2011, 01:59 AM

Need an equatorial mount.

Montoya · 07-28-2011, 02:01 AM

Did you by chance take a dark frame after taking this photo?

oliver939 · 07-28-2011, 03:35 AM

I'm an astrophoto guy and had a k100Ds and I can tell, although I love this camera, it is not veyr fit for astrophoto.
It always make a lot of noise (I tried whithout NR and then apply a dark but not enough) and banding.
But still, in your case, I would try to reduce the iso to 400, disable NR, make a dark and stack several image together,

in my case, now, I have K5 and it's like night and day.

But anyway, in general for astrophoto, you need to pp your pictures, they'll never look very nice without proper processing.

regaridng the equatorial mount, it's another subject (to avoid star trails) and will not improve the noise.

Wolzal · 07-28-2011, 05:26 AM

Originally posted by maltfalc:

do you have long exposure noise reduction turned on?

Wasn't aware of this setting. Dug out the manual, and found out where it was, and yes it seems it was on. A lot of the astrophoto tutorials suggest turning any in camera NR off, so I'll see if there's any difference with it off.

Originally posted by calsan:

Need an equatorial mount.

Only if I want to use Bulb and have the stars stationary. It's something I'm looking at for the Spotmatic II.

Originally posted by Montoya:

Did you by chance take a dark frame after taking this photo?

I've tried it a couple of times (save to 32 bit TIFFs, layer dark frame above shot, set dark layer to Difference) but it seems to have minimal effect.

Quote:

I'm an astrophoto guy and had a k100Ds and I can tell, although I love this camera, it is not veyr fit for astrophoto.
It always make a lot of noise (I tried whithout NR and then apply a dark but not enough) and banding.
But still, in your case, I would try to reduce the iso to 400, disable NR, make a dark and stack several image together,

in my case, now, I have K5 and it's like night and day.

But anyway, in general for astrophoto, you need to pp your pictures, they'll never look very nice without proper processing.

Funny you should mention banding, because I found quite a bit in this shot:

As far as PP goes, I lose heart (and admittedly, patience) when I see this much noise. I'm a graphic designer by trade, but even these are beyond my capabilities. The most improvement I've seen is with a image stack, but there's only so many you can stack and realign before the movement in the sky is too great.

Hopefully I can find a sweet spot setup-wise that minimizes the damage.

Wolzal · 07-28-2011, 07:14 AM

Just had another go with NR turned off and white balance set to meter spot rather than whole frame. There seemed to be some improvement, found I was able to get down to ISO400.

Also had another go at working a 5 shot stack (ISO1600, f/4, 15sec, 23mm) in photoshop;

Original

PP

Finding I also get better results when I compose the shot with some landscape in it, rather than just pointing straight up.

kenafein · 07-28-2011, 07:34 AM

I think that looks pretty decent after the PP. I have never attempted anything like this though. How does it compare to your film shots?

Wolzal · 07-28-2011, 07:59 AM

My scans are on my old PC, so this is taken out of my facebook gallery.

Just on standard 400ISO film, with a Vivitar 28mm lens. Can't remember the rest of the settings unfortunately, but judging by the trail length I the exposure time was probably 15-20mins.

Next roll, yet to be finished, is on FujiFilm 200ISO.

maltfalc · 07-28-2011, 08:15 AM

as far as the banding is concerned, i've noticed that if i have my camera set to continuous mode, the second or third shot will usually have a lot less banding than the first.

ytterbium · 07-28-2011, 01:03 PM

It's K100d's sensor. It had one of the worst dark/leak current at that time. While not too big issue for normal shooting, it starts to show at higher ISO's and is main long exposure noise source.

k200d does a leap in this area, but in addition has much better (stronger) IR filter, that can be bad for AP.

This guy has quite nice illustration:
K100D is way noisier than the K200D | Flickr - Photo Sharing!
k200d noise stays nearly flat, while k100d rises exponentially.

07-27-2011, 09:04 PM	#1
Wolzal New Member Join Date: Jul 2011 Posts: 5	Landscape Astrophotography - Horrid Noise (K100D Super) For a while I've been doing long exposure star trail photos with a Spotmatic II, but decided for a change of pace to try and capture the milky way. Rather than burn through cash on film, I borrowed a K100D Super off a friend. What I'm finding though is I am getting a horrendous amount of noise in my shots. I've read around and understand the basics of taking a star shot (high iso, 10-30sec exposure, wide apeture) however regardless of the settings I use the images are coming out very noisy: (ISO1600, f/3.5, 18mm, 30secs) When I've tried to take the ISO down I've understandably had issues getting a decently exposed image. Am I doing something fundamentally wrong, or is this camera not up to the task?

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07-28-2011, 12:04 AM	#2
maltfalc Veteran Member Join Date: May 2010 Location: Winnipeg Photos: Albums Posts: 396	do you have long exposure noise reduction turned on?

07-28-2011, 01:59 AM	#3
calsan Pentaxian Join Date: Nov 2008 Location: Perth, Australia Photos: Gallery Posts: 1,548	Need an equatorial mount.

07-28-2011, 02:01 AM	#4
Montoya Forum Member Join Date: Nov 2006 Location: New Mexico Photos: Gallery Posts: 103	Did you by chance take a dark frame after taking this photo?

07-28-2011, 03:35 AM	#5
oliver939 Senior Member Join Date: Dec 2009 Location: europe Posts: 156	I'm an astrophoto guy and had a k100Ds and I can tell, although I love this camera, it is not veyr fit for astrophoto. It always make a lot of noise (I tried whithout NR and then apply a dark but not enough) and banding. But still, in your case, I would try to reduce the iso to 400, disable NR, make a dark and stack several image together, in my case, now, I have K5 and it's like night and day. But anyway, in general for astrophoto, you need to pp your pictures, they'll never look very nice without proper processing. regaridng the equatorial mount, it's another subject (to avoid star trails) and will not improve the noise.

07-28-2011, 05:26 AM	#6
Wolzal New Member Join Date: Jul 2011 Posts: 5 Original Poster	Originally posted by maltfalc: do you have long exposure noise reduction turned on? Wasn't aware of this setting. Dug out the manual, and found out where it was, and yes it seems it was on. A lot of the astrophoto tutorials suggest turning any in camera NR off, so I'll see if there's any difference with it off. Originally posted by calsan: Need an equatorial mount. Only if I want to use Bulb and have the stars stationary. It's something I'm looking at for the Spotmatic II. Originally posted by Montoya: Did you by chance take a dark frame after taking this photo? I've tried it a couple of times (save to 32 bit TIFFs, layer dark frame above shot, set dark layer to Difference) but it seems to have minimal effect. Quote: I'm an astrophoto guy and had a k100Ds and I can tell, although I love this camera, it is not veyr fit for astrophoto. It always make a lot of noise (I tried whithout NR and then apply a dark but not enough) and banding. But still, in your case, I would try to reduce the iso to 400, disable NR, make a dark and stack several image together, in my case, now, I have K5 and it's like night and day. But anyway, in general for astrophoto, you need to pp your pictures, they'll never look very nice without proper processing. Funny you should mention banding, because I found quite a bit in this shot: As far as PP goes, I lose heart (and admittedly, patience) when I see this much noise. I'm a graphic designer by trade, but even these are beyond my capabilities. The most improvement I've seen is with a image stack, but there's only so many you can stack and realign before the movement in the sky is too great. Hopefully I can find a sweet spot setup-wise that minimizes the damage.

07-28-2011, 07:14 AM	#7
Wolzal New Member Join Date: Jul 2011 Posts: 5 Original Poster	Just had another go with NR turned off and white balance set to meter spot rather than whole frame. There seemed to be some improvement, found I was able to get down to ISO400. Also had another go at working a 5 shot stack (ISO1600, f/4, 15sec, 23mm) in photoshop; Original PP Finding I also get better results when I compose the shot with some landscape in it, rather than just pointing straight up.

07-28-2011, 07:34 AM	#8
kenafein Veteran Member Join Date: May 2011 Location: Southern California Photos: Albums Posts: 4,082	I think that looks pretty decent after the PP. I have never attempted anything like this though. How does it compare to your film shots?

07-28-2011, 07:59 AM	#9
Wolzal New Member Join Date: Jul 2011 Posts: 5 Original Poster	My scans are on my old PC, so this is taken out of my facebook gallery. Just on standard 400ISO film, with a Vivitar 28mm lens. Can't remember the rest of the settings unfortunately, but judging by the trail length I the exposure time was probably 15-20mins. Next roll, yet to be finished, is on FujiFilm 200ISO.

07-28-2011, 08:15 AM	#10
maltfalc Veteran Member Join Date: May 2010 Location: Winnipeg Photos: Albums Posts: 396	as far as the banding is concerned, i've noticed that if i have my camera set to continuous mode, the second or third shot will usually have a lot less banding than the first.

07-28-2011, 01:03 PM	#11
ytterbium Veteran Member Join Date: Jan 2008 Posts: 1,076	It's K100d's sensor. It had one of the worst dark/leak current at that time. While not too big issue for normal shooting, it starts to show at higher ISO's and is main long exposure noise source. k200d does a leap in this area, but in addition has much better (stronger) IR filter, that can be bad for AP. This guy has quite nice illustration: K100D is way noisier than the K200D \| Flickr - Photo Sharing! k200d noise stays nearly flat, while k100d rises exponentially.