Coolers

I get dizzy just looking at it.

AnalogMan

I was playing with my camera on a trip recently and took some long exposure photos, however, they didn't turn out as good as hoped.

I was taking pictures in the dark (national park with no light pollution), shooting the night sky and initially used ISO of 3200, f/3.5, and shutter speed of 30 seconds. The picture looked pretty decent on the camera LCD but terrible on my laptop when shown at 1:1, I saw a lot of distinct blue/green/red dots for the photo. Thinking it was noise from the camera at the high ISO setting, I changed to ISO 800 and took a shot with 87.6 seconds exposure (manually timed/controlled), but the picture doesn't really look better. The picture also looks very grainy and unlike the pictures taken in daylight.

https://picasaweb.google.com/1138409...07239217567922

My questions are:
1. Why do they look so bad, and
2. What can I do to improve pictures from similar situations with my current gear (Nikon D5000 with the kit 18-55mm lens).

Thank you

~tc~

There are two things that come to mind:

While the gain noise from ISO 800 might be well controlled in a "normal" exposure time, it's going to be exaggerated with long exposure. The whole point of long exposure is to keep the ISO down.

As the sensor heats up from a long exposure, it creates noise also. My Panasonic has a feature that takes a black frame of the same shutter speed and subtracts it to eliminate this noise. Your Nikon might have the same thing.

Yes, as always, improving one of these makes the other worse ...

chimphappyhour

You ran into two noise issues here. The first is high ISO noise. You obviously caught that and there's a few ways to go about fixing it. One is to use a lower ISO (which you did) or to just go for it and use some sort of noise reduction. The second noise issue you started to run into is called long exposure noise. When and how this sets in will vary from sensor to sensor.

You are using the D5000. You can find Thom Hogan's comments on how the sensor in that camera performs here: http://bythom.com/nikond5000review.htm I noticed he compared that sensor to the one in the D80. (Although, it is clearly not the same sensor being 12mp CMOS vs 10mp CCD of the D80.) I had the D80, it was a good camera but, yeah, the noise wasn't the best on it.

Next question is, are you shooting RAW or jpeg and if RAW, how are you processing it? Jpeg will bake in your NR settings. RAW processed on Nikon software will be there but not hard baked in necessarily. (I think LENR does get baked in, but not 100% sure.) RAW processed with other programs will require that you reapply NR in post production.

Focusing looks like it was tricky too. Looks like you were using the kit lens wide open. The 18-55 being a kit lens actually isn't all that bad but it probably isn't the best wide open. Also, working wide open will limit your depth of field, which means there is less forgiveness on your focusing. Since you're already on a tripod, I would go for f8 which is a good strong aperture. You might be able to eek out f5.6 at that given focal length.

The tripod brings up another point. Make sure you have the most stable tripod and head you can wring out of your bank account. Once you have it, stabilize it more. Weight pulling straight down through the center column helps, that's why some tripods have a hook under there. Keep anything that can cause vibration off of the camera and tripod. I remove my camera strap and when using my wired remote, that gets wrapped tightly around the base of the tripod head.

Note that certain focal lengths have a time limit before the point of light of a star becomes a trail. The wider the lens, the longer you get. Trails obviously aren't bad but I think there is a certain amount of arc that we subconsciously want to accept. It's one of those, you'll know it when you see it kind of things.

So, really, just lock it all down as much as possible and be aware of the wind/breeze. Make sure you are either using or have available proper noise reduction methods. Then it is a matter of getting your focus and settings right.

Oh, no idea if this is posted anywhere here but this is the dark sky finder I use here in the US: http://www.jshine.net/astronomy/dark_sky/ It's pretty handy.

chimphappyhour

Guess I'll go ahead and throw a couple up:


Grand Canyon by the Full Moon by chimphappyhour, on Flickr


Untitled by chimphappyhour, on Flickr

AnalogMan

Thank you ~tc~ and chimphappyhour for your tips.

The pictures didn't look different between RAW and JPEG to my untrained eyes. I haven't done any post processing yet, just using Picasa 3 to view the NEF files. "I am feeling lucky" didn't really help my star pictures

The camera was placed facing up on the picnic table at the camp site. There was no breeze and I used a remote to trigger the shutter, so the camera was pretty stable. Will keep the tips about tripod (planning to get one) and straps in mind.

Next time (will probably be a while) I'll try f8. Might also try even lower ISO but looks like it's going to be a trade off between that and long exposure noise.

Thanks again!

Photonerd71

If you are using a D5000 you should have a "long exposure NR" in the menu someplace (It was on my D90 and is on my D7000) as tc said. When turned on it will take another shot, with the shutter closed, the exact length of time after your first shot. (if you have a 30 sec exposure it will take another 30 sec shot with the shutter closed ) the camera will then compare the two and eliminate some noise.

When using a tri pod turn off the VR on you lens. Also, better glass is never a bad thing. Finally, just keep tweaking your setting until you get it the way you like it. Eventually you will hit on the right combo of ISO,shutter speed and apature for your liking.

DavenM

like the first image...looks really abstract...good composition

DavenM

Awesome second shot....like the symmetry of the shoot and coloring

pommyboi

There are some lovely photos on this thread.

I haven't done much work on the tripod but I purchased a carbon fibre travel tripod for a trip to Australia so I made sure I took a few night photos.

http://www.flickr.com/photos/pommyboi/5775187707/

http://www.flickr.com/photos/pommyboi/5764669879/

http://www.flickr.com/photos/pommyboi/5775188755/

Nothing original but I was pleased for my first attempt.

Love2Fly74

I just love the colours in this one and all the others are just fantastic! You are all making me jealous as I would love an SLR but can't afford one at the moment. Thanks all for sharing



Fireworks over the Ohio River during Thunder Over Louisville (2009) display


I believe the fireworks were shot at F/11 or F/13 with a 6-8 second exposure.[/QUOTE]

Hartmann

Dresden, Germany at Night

Circumknowitall

ISO200 f9 18mm 9 secs

Radisson Ambassador Plaza Hotel & Casino San Juan.

Circumknowitall

bloodyeyeballs

I just found this thread. There are some great photos here. Here is the Hilton Moorea at night.

http://bit.ly/wGsHS9