Stars with tails even at 30 seconds?

[battletone]

Is this right? I have like 5 photos I took at night with my new tripod, and even with a 30 second exposure the stars are motion blurred.

I think they are 2x-3x as long as they are wide.

Really kind of ruins the photos.

 

[dmatsui]

I havent been able to try this myself but most people trying to capture the nightsky, or milky way without the sky trails do so with a maximum shutterspeed of 30 seconds. Slight star trails are visible if you zoom in a believe but they should be relatively unnoticable when resized to say 800px for the web. but yes i wouldnt recommend using a shutterspeed of more than 30" if you dont want star trails (as you've noticed)
I dont know to what extent your stars have traveled or if in certain regions in the world it is more noticeble than others.

 

[battletone]

Here are a couple 100% croppings. Both are at 30 seconds.

 

[chammer]

i see you shot at iso 800. as you're on a tripod, and shooting a long exposure anyway, you really can back it down to iso 100. would really cut down on the noise in the images.

 

[astrostu]

It all depends on the lens (field of view). With a 35 mm lens on a 1.6x crop body (56 mm equiv.), star trails will start to show after about 20 seconds.

 

[battletone]

i see you shot at iso 800. as you're on a tripod, and shooting a long exposure anyway, you really can back it down to iso 100. would really cut down on the noise in the images.

Well based on looking at the settings, the crop with the roof was 400. But the other was 800 with reduction on.

I had just bought a remote too, but it wasn't with my gear. The 100 wasn't allowing enough exposure at 30 seconds for what I was trying to do. It was f9 for the roof crop and f11 for the other. I probably could have used a much lower f stop but I was experimenting, so maybe next time. :thumbup: I wanted the forground to be in focus though as there was trees and a grain bin I wanted with the clouds moving. The stars were something I wanted to experiment with too, but these pics I honestly wasn't expecting the tail issues I had read about.

iso800, f11, 30 seconds

iso400, f9, 30 seconds (this is an edited RAW with exposure and stuff)

 

[Josh66]

The 100 wasn't allowing enough exposure at 30 seconds for what I was trying to do.

I think that what charmmer was trying to say is that since you're already using a 30 second exposure, why stop there?

Drop the ISO down to 100 and expose for 240 seconds (4 minutes).
This would be the exact same exposure as your 800 ISO 30 sec shot.
[EDIT]Although, since it's a longer exposure - the star trails will be longer and you will capture more movement in the clouds.[/EDIT]

(You will have to use Bulb to do this.)

 

[astrostu]

Unless your roof was within ~10 meters/yards of the camera, it's doubtful that it would be out of focus even at f/2.0. The image below (not meant to thread-jack, just as an example) was taken for 15 sec, f/1.4 at ISO 200. Camera was on a stationary mount about 10 m from the brown roof, maybe 20 m from the dome, and 20-30 from the trees. They're in focus even when the image is printed as a 12"x18".

 

[battletone]

Points taken.

My remote I bought wasn't with my camera so I was limited to 30 seconds.

 

[Garbz]

As a very rough rule of thumb you can consider the maximum exposure allowable for NO star trails to be 600/EFL. So say you have a 20mm lens on a D200, the equivalent focal length for 35mm becomes 20x1.5 = 30mm. So 600/30 = 20 seconds. Anything beyond 20 seconds on this very wide angle will cause very clear star trails.

You can adapt this formula so you don't need to remember your EFLs just make it 900/focal length for Nikon non-fullframe cameras, or 960/focal length for Canon non-fullframe cameras.

As always these rules are based on standard viewing practices. If you zoom in at 100% you'll probably note that there are very slight trails, however at any normal viewing they should not be noticeable.

 

[Hellrot]

at least, with nikon, you can use any infrared device as a remote, as well. So you can use the remote shutter function. I use my comcast remote, personally

 

[Josh66]

at least, with nikon, you can use any infrared device as a remote, as well. So you can use the remote shutter function. I use my comcast remote, personally

:lmao:

Really?

I'm going to try that (Canon)... Any certain button you have to push, or does any button work?

 

[molested_cow]

Funny that I am always looking opportunities to capture star trails.

You definitely need wide aperture and fast film speed to achieve what you want. It also depends on exactly what you want to shoot vs the light condition. If there is an object that you want to illuminate without artificial light source, you will have to count on the time of the day or the moon. Otherwise, it will be very tricky to obtain a good exposure without star trails, unless if you take two separate shots and p-shop them together.

 

[Turnerea]

at least, with nikon, you can use any infrared device as a remote, as well. So you can use the remote shutter function. I use my comcast remote, personally

:lmao:

Really?

I'm going to try that (Canon)... Any certain button you have to push, or does any button work?

Doesn't work with canon... tried on my XTi. Got some weird looks from the roomates...haha

 

[henrycooke]

at least, with nikon, you can use any infrared device as a remote, as well. So you can use the remote shutter function. I use my comcast remote, personally

Any device? Your saying my phone can set of my D40?
HOW.