Long exposure shots...what am I doing wrong?

[skillz03]

I've recently tried to take long exposure pictures in the night, but they seem to turn out blurry all the time. I've tried pictures of stars, buildings in a distance, but it never seems to work. What am I doing wrong? Pictures are shot with a Nikon D3100 and a 35mm f1.8 lens: DSC_1028 | Flickr - Photo Sharing!

Any help would be appreciated!

 

[ShaneF]

off the top of my head some things i can suggest are:

- Tripod and if its windy possibly a weight if its a lighter tripod. A sand bag or grocery bag with something heavy in it will work.
- Remote shutter trigger or cable so u dont move the camera when pushing the trigger
- Use the mirror lock up function if your camera has it.
- Make sure your lens is set to infinity if your shooting the stars
- Experiment with aperture/fstop/iso and exposure times

 

[Seventen]

How long was the shutter time for ?
with 35mm on a crop sensor camera will be about 55mm so its about 15 seconds you can have shutter open for before earths rotation will cause the objects to start to leave trails behind.
Sturdy tripod and a remote shutter release is needed. If you dont have a remote shutter release use the 10 second timer you have even on a light weight mount will give enough time to settle down.
In the Flickr image it is not in focus so make sure you have it set to infinity.

Edited 25 to 15

 

[shefjr]

I took a look at your photo stream and it appears to me that your photos are all OOF and not motion blur. As stated already make sure your lens is focused to infinity or in some cases you infinity may be a bit too much and you'll want to be just slightly adjusted back from infinity.

Here are a couple of great references that have been made on the forum that give step by step instructions. I highly recommend checking them out.

By, Sw1tchFX
http://www.thephotoforum.com/forum/articles-interest/276016-shooting-night-pictures-stars-stuff.html

By, Manaheim
http://www.thephotoforum.com/forum/...naheims-ultimate-guide-night-photography.html

Have fun and hope this helped!

 

[Dinardy]

A good way to not miss is to focus in on the brightest available light source. If you have a decent LCD screen this shouldn't be too hard while using the zoom function.

 

[zombiemann]

How long was the shutter time for ?
with 35mm on a crop sensor camera will be about 55mm so its about 25 seconds you can have shutter open for before earths rotation will cause the objects to start to leave trails behind.
Sturdy tripod and a remote shutter release is needed. If you dont have a remote shutter release use the 10 second timer you have even on a light weight mount will give enough time to settle down.
In the Flickr image it is not in focus so make sure you have it set to infinity.

I would LOVE to know where you came up with 25 seconds. 25 seconds on a crop sensor at 35mm... will leave definite trails.


For shooting the night sky, the Rule of 500 is a good "rule of thumb". It isn't perfect but it will certainly help. Essentially the rule of 500 is thus: The time you can expose before trails begin to form is 500/effective focal length of your lens. If you are shooting with crop sensor it, effective focal length is the mm of the lens (in this case 35) times whatever the crop factor is on your sensor. I *think* nikon uses a 1.5 crop. So 35X1.5 gives us 52.5. 500 divided by 52.2 tells us you can expose for roughly 9.5 (round down to 9) before trails start to show up.

Google will provide more detailed information, but make sure you include "astrophotography" in your search or you will get more information about diabetes than you ever wanted.

 

[runnah]

I would LOVE to know where you came up with 25 seconds. 25 seconds on a crop sensor at 35mm... will leave definite trails.


For shooting the night sky, the Rule of 500 is a good "rule of thumb". It isn't perfect but it will certainly help. Essentially the rule of 500 is thus: The time you can expose before trails begin to form is 500/effective focal length of your lens. If you are shooting with crop sensor it, effective focal length is the mm of the lens (in this case 35) times whatever the crop factor is on your sensor. I *think* nikon uses a 1.5 crop. So 35X1.5 gives us 52.5. 500 divided by 52.2 tells us you can expose for roughly 9.5 (round down to 9) before trails start to show up.

Going to call BS on this one. Same lens and this was 30 second exposure. You can start to see the beginning of some blurring but not as much as it ruins the sharpness.


sky2 by runnah555, on Flickr

 

[Gavjenks]

One thing that I didn't see anybody mention was to make sure your image stabilization or vibration reduction or whatever they call it is turned OFF when the camera is on a tripod. If not, the camera will enter weird feedback loops and it will have the effect of making things look out of focus.

 

[zombiemann]

Going to call BS on this one. Same lens and this was 30 second exposure. You can start to see the beginning of some blurring but not as much as it ruins the sharpness.

You know, you're right. I have absolutely no clue what I am talking about

 

[runnah]

Going to call BS on this one. Same lens and this was 30 second exposure. You can start to see the beginning of some blurring but not as much as it ruins the sharpness.

You know, you're right. I have absolutely no clue what I am talking about

View attachment 52623

Maybe the stars move faster in your area?

I don't know what to tell you. I take a 30 second exposure of stars with a crop sensor camera and a 35mm lens and I don't get star trails. End of story.

 

[Braineack]

I call BS on all you--I got trails with an 3sec exposure :greenpbl:

Shame about some of those shots, had you focused, it looks like you could of had a couple of good captures.

 

[Gavjenks]

^ It depends on where in the sky you're shooting. At the equator, with an image closer to one of the poles of the earth, the stars are moving MUCH MUCH slower in the sky than if you shoot straight up or right toward the east or west horizons. And as your position moves more extremely north or south, this changes of course. Near the north pole, the stars straight up will be moving slowest, and the stars on any horizon will be moving fastest.

We're talking about easily 1 maybe 2 orders of magnitude here. So depending on which part of the sky you shoot, 10 seconds might be needed to show a trail, whereas somewhere else, 2-3 minutes might be needed to show a trail.

In fact, you can calculate it exactly. Look up the travel distance of a star of interest in your area, see how much it moves during one night, then divide out the number of hours it was visible for to get the star's speed. Compare to the distance shown in your viewfinder to figure out speed in terms of pixels/second. Then you can determine if blur would be visible or not.

< about 1-2 pixels over the course of your exposure = no noticeable trails.
> 1-2 pixels = noticeable trails.

For a very wide angle shot, calculate several stars at the edges and center of the frame and take the fastest moving one as the limiting factor.


Annoying how astronomy matters for astrophotography, isn't it? But anyway, you could both be right.

 

[Seventen]

Thanks for noticing my mistake, Was supposed to be 15. At least where I live i can get away with 55mm at 15 seconds admittedly if you zoom right in you can see slight trails but normal picture its un-noticable but I am a beginner and my work isnt great but i love the look of it.

 

[Patrice]

You can increase your exposure times significantly with a simple made at home barn door tracker. They can be complicated or very simple but the simple ones made with about $10 worth of materials work quite well.

 

[DiskoJoe]

You can increase your exposure times significantly with a simple made at home barn door tracker. They can be complicated or very simple but the simple ones made with about $10 worth of materials work quite well.

Kid was shooting like 30 sec exposures. But yeah, everything is out of focus. For most of these shots you could have just focused to infinite and lowered the aperture to like f22 and got a decent shot. Adjust the white balance too, its running hot which is why the one shot is really yellow.