I'd llike to shoot the milky way.

[AndrewPDX]

What is the best lens to use?

A lot of people on flickr use short focal lengths with wide apertures (seems obvious enough). See example here. So, knowing that, any recommendations for a good Nikon lens to shoot the milky way? I've got a D5000 body which seems to handle the low, natural light fairly well (sure, it's no D3...). Thanks for the tips!

-Andrew

[tonyniev]

do you have a tracking mount? if not do you know how to stack your images....the milky way will need long exposures and non tacking mounts will start having star trails beyond 1 minute of exposures.

[AndrewPDX]

Ahh, I do not have a tracking mount. I've attempted the shot a few times and would always get star trails with the longer exposures. Shorter exposures wouldn't show the galaxy at all. I thought it was a problem with not using the right lens.

Image stacking is an option, but it looks like people get better results with the tracking mount. I'm researching that now. Any recos?

[tonyniev]

you can take shorter exposures and then stack them say take 10 x 30 seconds then that would almost be equal to 5 minutes of exposures...you may need to do more...you also need to be in a dark sky with little ambient light.

[ElCapitan]

Originally Posted by tonyniev

you can take shorter exposures and then stack them say take 10 x 30 seconds then that would almost be equal to 5 minutes of exposures...you may need to do more...you also need to be in a dark sky with little ambient light.

I have a little trouble figuring this out. If every shot has the exact same exposure settings, is it any different than just taking 1 photo and then duplicating the background layer and set the blending to screen?

[inkista]

Yes. The iso noise will move around from shot to shot to shot, so stacking will also decrease noise.

Andrew: suggest you google "barn door tracker astrophotography".

[ElCapitan]

Any special tricks to stacking? I've heard of using some program called hugins, but could you just use photoshop as well?

[ravncat]

one of the reasons for using wider lenses - is that the angular change of the earth rotation is smaller. Think about it the same way as the 1/focal length shutter speed rule.

If you have an area of 90 degrees in your finder, and things move half a degree - it`s much less noticable than if you have 2 degrees in your viewfinder. This is why alot are with short focal length lenses.

The moment you head towards telephoto astrophotography - you need a clock drive as above.

As for stacking shots - that`s something I haven`T done. I suspect there are a few ways to do it - one of which would be to put them into layers, and use an overlay type of blend mode (as per photoshop)

I`d be interested in hearing about other methods (otherwise I`ll have to go off and do my own research ;D )

[inkista]

Originally Posted by ElCapitan

Any special tricks to stacking? I've heard of using some program called hugins, but could you just use photoshop as well?

Yes, you can use photoshop, but stacking software like DeepSkyStacker might be better. The biggest trick is to align the shots perfectly, and that's where Hugin might help as a front end (although, mostly, I've heard of it being used for focus stacking with macro photography, since enfuse can be set to stack via contrast or HDR/enfuse exposure stacking). The other trick is to include dark frames, rather than using the in-camera "long exposure noise reduction" setting. Saves you a bit of time.

You want to do dark frames because with longer exposures, an additional form of noise appears, due to heat across the sensor. "Hot pixels", unlike iso noise, do NOT move about from shot to shot. Taking a dark frame (i.e., an exposure of the same length/aperture/iso but with the lens cap on) will pinpoint hot pixels, and allow for their removal in the final image. That's why when you use the setting in-camera, you're doubling your exposure time.

Understand, please I only know about all this stuff theoretically from reading too many webpages. I've never actually done any of this.

[Aegea]

The other pre-requisite is of course really dark skies. Stacking images won't reduce skylight from light pollution!