# How to get stars in focus?



## peanut170 (Aug 6, 2011)

Was camping and woke up in middle of night and there's were amazing amount of stars, figured I'd tryn get a cool night picture, it was really dark so even a 5 min exposure was barely visible, but could see that the stars were not in focus, so tried to refocus and went for a 10 min exposure and it was more visible but still out of focus. Finally after 45 mins of being cold i gave up, so any tips you have, would be very helpful. I'm going on a cool hike in the middle of nowhere and should be some cool night photos to be had. Thanks for any help.


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## KmH (Aug 6, 2011)

The Earth makes a complete rotation on it's axis every 24 hours. Any shot made of the stars that is longer than about 30 seconds will blur the star (star trail) from the motion of the Earth turning.

In Vancouver, you and your camera are moving from west to east at about 650 mph. At the equator the speed is higher, about 1050 mph. If you stand right next to the north or south pole, it takes 24 hours to move about 6 feet..

A motor driven equitorial camera mount is designed to counter act the Earth's rotation, but such a device is not inexpensive.

You can open the aperture wide, increase the ISO and use a substantially quicker shutter speed and make sharply focused star or wide sky shots without equitorial camera mount.


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## peanut170 (Aug 6, 2011)

That's good info but I need a little more help than that please. How do I get them in focus? I've seen star trail photos that are in focus, also pics of stars and other weird colors in the sky, how is this achieved?


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## CCericola (Aug 6, 2011)

Unless you have an equitorial mount on your camera they won't be. Sharp pictures of stars can only be made if the camera is tracking the stars, counteracting Earth's rotation. Read this: Photography techniques: Equatorial mounts for astrophotography


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## molested_cow (Aug 6, 2011)

Wait, what do you mean "in focus"? Do you mean blurry trails? If so just set your focus to infinity. I never use AF when doing night shots.


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## KmH (Aug 6, 2011)

peanut170 said:


> That's good info but I need a little more help than that please.


Self help provides many un-antisipated benefits.

In the course of doing your own research, you discover other information you didn't know you need to/or want to know.


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## Railphotog (Aug 6, 2011)

You need a star filter.  They are available in many sizes.


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## OrionsByte (Aug 6, 2011)

What kind of camera are you using?  Can you post some of the photos so that we can tell you if they're out of focus or simply blurred from motion?

As far as focusing on them, don't try to use the camera's autofocus - it's too dark for it to work properly.  You could try setting the lens' focus at infinity, but what I usually do is focus at infinity and then pull back just a hair.  Better yet, if you have a lens that has distance markings on it then you can figure out the lens' hyperfocal distance and use that.


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## analog.universe (Aug 6, 2011)

On many autofocus lenses, the lens will actually focus past infinity.  You can try autofocusing on a ground object that is very far away..   you can also use live view to manually focus on an object you can see.  If the moon is out you can use that.

Alternatively you could figure out where infinity actually is on your lens, during the day... and then remember how far to pull back from the maximum focal distance.


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## peanut170 (Aug 6, 2011)

KmH said:


> peanut170 said:
> 
> 
> > That's good info but I need a little more help than that please.
> ...


Yea sorry for asking for help on a beginners forum. Maybe you should spend less time, not answering the question, and more time in the spelling forum. To everyone else, thanks for the input, maybe it was just focusing past infinity, I'll give it another go.


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## Compaq (Aug 6, 2011)

I set my camera on a tripod and tried to focus on the stars, and I found that they are no in focus at infinity, but just before. Make good use of your live view, and zoom in to 5x, or even 10x.


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## Jarmo (Aug 6, 2011)

Use live view and find a star or a far away light source and get it manually in focus.


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## lyonsroar (Aug 6, 2011)

Manually zoom to infinity, rotate back a touch.  Shoot.  Review.  Back or forward a touch more to taste.  Shoot.  Review.  Repeat.

Seriously, not that hard.


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## johnh2005 (Aug 6, 2011)

Also, with most modern lens turning the focus ring all the way to the end is "past" infinity and will not have the stars in focus.  You will need to back up a little.  As stated above you should use live view and zoom in either the 5x or 10x.  That should help.


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## Edsport (Aug 7, 2011)

I don't have live view so what i do is use high ISO and wide aperture so exposure time is short and adjust the focus so i'm close then take a shot. Look at the photo zoomed in. If needed i refocus a bit and keep checking until i have good focus. Then set ISO and other settings to what i want and take the shot...


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## Jarmo (Aug 7, 2011)

Edsport said:


> I don't have live view so what i do is use high ISO and wide aperture so exposure time is short and adjust the focus so i'm close then take a shot. Look at the photo zoomed in. If needed i refocus a bit and keep checking until i have good focus. Then set ISO and other settings to what i want and take the shot...


When I didn't have live view on my previous camera I just used the view finder and got a far away lamppost in focus.


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