Astro not going so well

[Kyle21]

So I've been trying to do some astro and I'm not very happy with my results. I have a d5200 using a 55-300 4.5-5.6g. I'm at 55mm f5.0 30sec 6400 ISO on this shot. I know it's blurry I didn't use a remote for the shot but I'm just trying to get more starlight. Am I at the limits of my lens or should I try something else? Any help is appreciated.

 

[Tailgunner]

Hum...the ISO seems way high to me but I'm still trying to figure this out my self. I would try it much lower, like ISO 200 but nothing over ISO 800. Again, I'm still experimenting myself.

 

[GaryT]

From what i have been reading you need faster glass for astro. If you are any way serious about night shots full frame seems to be the way to go for the better high iso performance. Did you have long exp nr switched on?

 

[yo13dawg]

With your lens its probably going to be hard to get a lot of detail. Ideally you want a faster and wider lens. I usually take star shots at 11mm at f2.8-f3.5. You can always bump the ISO even more but then you will be at an even bigger trade off of more stars vs noise. Only other option I could think if is to get a star tracker mount to counter the rotation for star trails.

 

[Kyle21]

Thanks for the reply's I was thinking much the same about needing a faster lens. I guess I should have asked what I can do to lower my Iso and still get a good starfield.

 

[Kyle21]

here is everything the same except 3200iso

 

[yo13dawg]

Another option would be to get to a dark remote area, away from city lights and pollution.

Do you have anything wider than a 55mm? Look up the rule of 600, which gives you a rough idea on how long you can leave your shutter open without producing visible star trails.

 

[TruckerDave]

Using the "rule of 600" your max shutter speed would have been about 7.25sec in order to prevent star trails. (55mm x 1.5 (crop factor) and divide 600 by that number for shutter speed).
The 600 rule is not perfect but it is a good starting point.

 

[GaryT]

If you do a bit of a google you will find all you need to know, the lads covered two of the main points in the posts above. If you don't want star trails you can make your own 'barn door tracker' for little or nothing.
If you have no wide angle fast glass maybe a 35mm 1.8 would be a good option as it is pretty cheap and seems to get great reviews. Failing that there are cheap third party 20mm and 24mm primes but I think they are mostly 2.8.

I can't speak from experience, just from what I have been reading up on. I am saving for a D3/700 or D3s as I think some of the milkyway shots i have been looking at are mind blowing. There are also quite a few vids on YouTube that should answer any queries you have.

Im sure somebody that is experienced in the field will be along to throw some light on it soon enough!

 

[runnah]

Naw son, you just need a remote shutter remote and patience.

Shoot low ISO to get less noise and high fstop to get nice crisp focus.

Exposure times are going to be long and after a couple mins exposure the stars will start to move. Try to find the balance between exposure time and fstop settings.

 

[GaryT]

Naw son, you just need a remote shutter remote and patience.

Shoot low ISO to get less noise and high fstop to get nice crisp focus.

Exposure times are going to be long and after a couple mins exposure the stars will start to move. Try to find the balance between exposure time and fstop settings.

But that will give you star trails, he doesn't want trails. Does he?!

 

[TruckerDave]

Minutes???? Even with a 10mm wide angle using the 600 rule it only works out to about 40sec before you see movement. If you are going for minutes you are going to get long star trails. Don't be afraid to dial up the iso either, with the short exposure times you will need higher iso. Plus you want to open your lens up as wide a possible to get as much light as you can. A tripod and shutter release are a must. Get away from light pollution as well. If you want the Milky Way you need to know where it is. Depending on the time of year and location you might not be able to see it at night. (I have an app called planets. Simple yet effective).

 

[runnah]

But that will give you star trails, he doesn't want trails. Does he?!

Depend on how long the exposure is for. 1-2 isn't too bad. Anything more and you'll start to see alot of movement. Work with your apature to find the happy medium.

 

[GaryT]

With that lens at 55mm you can see its starting to show trails already and that's only a 30 sec exposure. As truckerdave said there is a basic equation based on focal length to eliminate the trails, this involves having to use a high ISO to keep your exposure time fairly slow. This is how you can get a crisp milkyway shot showing many stars but yet keeping them as sharp points of light.

If the op wants trails maybe stacking images would give a better result than a single exposure. The program to stack is available for free if you don't have ps.