Stars and night sky lens etc

[wasnapper]

I would like to have a go at star or milky way photography. I have an f8 mirror lens or 18-55 and 55-250 or 70-300 zooms with widest aperture of 3.5.

What would be the best lens and exposure for this?

[wasnapper]

Hmmmm

[Granville]

I have no idea, but I do have the same question. Waiting to see what responses this brings.

[Allann]

Your 18-55 will prob be best as you'll get more of the sky in. But you want your fastest lens as you iso will be high and your shutter slow. Just do a quick search on here, or check previous posts in the night/astro forum for what others have already posted.

[Allann]

Can even check out the learning section for hints.

[wasnapper]

Thanks John. I'll have look at the learning section after work

[Granville]

This is what I am struggling with at the moment, and one of the reasons I want to get a fast, wide lens. For Milky Way and Night sky shots I am pretty much stuck with a shutter speed that avoids start trailing. So, 30 seconds or so. In order to gather more light I need a higher ISO, or a wider aperture. The higher ISO has a bit of a small ceiling on a D3100, so the choice comes down to wider aperture on as wide an angle lens as is practical. I have the standard Nikon kit lenses, a 50mm 1.4 (too narrow) and also a Tamron 18-270 3.5 -6.4(?) PZD. I have been thinking about a Tokina 11-14 2.8 but they aren't cheap. I know I would use it for landscape photography as well, but I am naturally slow to make decisions, so it waits for a while.

Having said that, I have taken Milky Way shots at 18mm 3.5, but my PP skills with Lightroom, which I have only just purchased, are not good enough to know whether or not I can enhance what I have with sufficient quality. They might be perfectly acceptable if I learn Lightroom well enough.

[wasnapper]

Granville, Perhaps you could post one of your shots and ask if someone can give you a workflow for lightroom. I don't use it myself

[Allann]

I use a 17mm f4 lens for most of mine, so what you have should be fine. best advice i can give, make some new images, share them here and ask for specific advice.

A85U2215-Edit.jpg

ISO 3200 17mm f4 30sec

All processing was done in Lightroom so that should give you an idea of what is possible. I don't by any stretch of the imagination call myself good at this sort of image but like you I'm dabbling in this stuff too.

[RJD]

I use a 17-50mm f2.8 Tamron, at the wide end obviously, and I have found that to be a really good lens for that and landscapes, as well as indoors when I can't use a flash.

[wasnapper]

Thanks for the info. I have ordered a fisheye lens but might have a go with the kit lens (when the sky clears lol) pretty poor in Perth just now

[Granville]

Thanks all. I'll see if I get one of my old photos and post it up. Or perhaps I have an excuse now to get out in he bush a bit and take some fresh ones. Must find that fishing rod. Honey! We're going camping.

[wmphoto]

I went as low as 8mm at f4.5 (Sigma 8 -16) which isn't particularly sharp at 8mm and wide open. I found my best results were at 17mm f4 (Canon 17-40). As a rough guide for exposure time to avoid star movement, the formula is 500 / (mm * crop factor) = seconds. i.e..

Crop body factor 1.6
Focal length 17mm

So = 500 / (17*1.6) = 18.4 seconds exposure.

I actually ended up going 25secs and still got good results. Shoot wide open and bump up the ISO as high as noise levels let you. I went ISO1600 on my 450D and ISO3200 on my 7D before the noise became too much.

Edit - turn off IS, sturdy tripod and no wind are a must.