bwana Loc: Bergen, Alberta, Canada

Milky Way: I normally use a 35mm lens and stitch the shots together into a panorama. Use the '500 Rule' to reduce star trailing. That said, I've also used a 14mm and a 50mm for Milky Way shots.

Aurora Borealis: 95% with a 14mm lens, 5% with a 6.5mm (fisheye) lens.

Use the fastest lens you have. And it goes without saying, use a tripod or, better yet, a tracking mount.

Enjoy!

bwa

slcarn Loc: Draper, Utah USA

The smaller the mm the longer your exposure time can be without star trails. I shoot 14mm at 20 seconds with ISO 4000. It is extremely important you have your focus figured out on your lens before it gets dark. Not all lenses stop at infinity. You can have everything right but if the focus is off it's a waste of time.

Samyang has relatively inexpensive lenses with a f/2.8 that work well.

Check out the Astronomy Section of UHH there are great tutorials there.

Don't kick the tripod.

Steve

ORpilot Loc: Prineville, Or

I use a Samyang 14mm f2.8 manual focus lens. Don't let the low price deter you. It is an excellent lens. To do any better would cost you almost twice the price if not more. Prime lenses are generally better than zooms. Although I have used my Sigma 14-24mm f2.8 Art lens with good results. Manual lenses are preferred because you are going to focus manually anyway. I have also used a very low cost 7Artisans 7.5mm f2.8 manual lens on my APS-C camera. Wide angle lenses are preferred for MilkyWay and Northern lights photos. There are many reasonably priced lenses out there that work pretty good. I have tested so old Film lenses by Nikon and Zeiss that are comparable to modern lenses but much lower in price. Don't rule out good point and shoot cameras. My Sony RX100v did very well with star shots.

7Artisana 7.5mm on Sony a6500


Sony RX100v at 24mm f1.8

jlg1000 Loc: Uruguay / South America

The 500 rule was for cameras under 12 MPX.

Use this instead: https://sahavre.fr/wp/regle-npf-rule/

I shot that yesterday night. The Milky Way can be seen.

bwana Loc: Bergen, Alberta, Canada

Regardless of which rule you care to use there will always be some degree of star trailing unless you use a tracking mount.

The '500 Rule' is a simple approach. You want better stars, use the '300 Rule'...

bwa

amfoto1 Loc: San Jose, Calif. USA

The main reason you want a large aperture actually isn't for the exposure, although you may need it at times. You will probably instead stop down a bit for sharper shots. Most lenses are not a t their sharpest wide open. They do better stopped down one or two stops. You'll have to play with this to see what exposures work for your particular purposes.

The primary reason you want a large aperture lens for night sky photography is to brighten up an optical viewfinder. This largely only applies to DSLRs. Most mirrorless have an electronic viewfinder that can be brightened to help with composition and focus.

Often a "slower" lens... say f/4 versus f/2.8, or f/2.8 versus f/1.8... is sharper and better corrected than a faster one.

In many cases a prime lens will work better than a zoom lens.

Focal length is whatever properly frames the image you're making. Most likely it will be a normal to wide lens... less likely a telephoto. But ya never know until you get into it!

You'll need to study the lenses available for your system. Look for reviews, test results, MTF charts, etc. You can probably narrow it down to just a few candidates pretty quickly. Once you have a short list, you might want to come back here and ask for peoples' experience with those specific lenses.

If you end up shopping for a lens, for this purpose I'd recommend considering both manual focus and autofocus lenses. You'll probably be turning off AF anyway.

Oh, and infinity doesn't always mean infinity on modern lenses! Some lenses have an accurately calibrated stop at infinity focus, but most now don't. Many actually allow focus to go past infinity slightly. This doesn't matter with autofocus, but can be a consideration when focusing manually. With manual focus don't assume that you can just spin the focus ring all the way to the infinity stop.

cjc2 Loc: Hellertown PA

I really have to thank all the folks who posted here. Some folks assumed this info was for me and my equipment as listed here. Actually, this info was for a friend with a Nikon 5600 body and a few lenses. I will probably advise them to buy a used 20, 35 or 50 1.8 DX lens to begin experimenting. I also do not know how well versed they are in PP, or even what they use, but I will find out. I was also thinking an older, manual focus lens might fit the bill as well. Again, thanks to all. Please continue to comment based on this additional information as you wish. Chris

gouldopfl

It depends on what you are trying to do. I use a Tamron 15-30 f/2.8. You can take a long day 30 minute single shot or multiple 30 second shots and merge them together. I purchased a MSM star tracker during it's Kickstarter campaign and if this isn't something you are doing every night 365 it is quite handy and allows for very sharp and detailed pictures.

ecobin Loc: Paoli, PA

Personally I use my 16-35mm at 16mm. I've also used 24mm. It depends on where you are and whether you want to capture anything in the foreground.

Redrocks Loc: New Castle Indiana

Read anything by Royce Bair and you will have a good start. He has a book out that has great steps for beginners.

Traveller_Jeff

Instead of the remote shutter release, set your timer to open the lens 10 seconds after you've pressed the shutter. I use a 35mm lens on a Nikon D5 to get the larger constellations. What is it you're looking for? If it's star trails, then keep the shutter open for a couple of minutes; if it's constellations, then make the exposure a lot shorter and brighten it up in post. Keep the ISO low enough to minimize noise; i use no higher than 400. Topaz denoise on the NEF file can also reduce whatever noise does remain.

bwana Loc: Bergen, Alberta, Canada

I suspect a '30 minute single shot' would be very badly blown out!?

bwa

R.G. Loc: Scotland

Sorry - still not saying it right . For any given shutter speed, the wider the angle, the smaller the star trails.

Trying to get a good exposure by raising ISO above a certain point (depends on the camera) will be counterproductive. You need to capture as much light as possible, but the longer the exposure, the longer the star trails. A low f-stop gives you more light without any down side. And a wide angle lens gives you smaller star trails without a down side. Using the lowest f-stop means you won't be using the lens's sweet spot, but in this situation that's a minor consideration.

JimH123 Loc: Morgan Hill, CA

Depending upon the lens, the lowest f-stop setting may not be a minor consideration. Some lenses are just plain awful when wide open and doing stars. And others are quite good. Doesn't take much effort to find out.

Focusing stars is critical too. As a star moves out of focus, in either direction, it turns into an expanding disk that rapidly dims as the same amount of light is spread over a much larger area. In fact, the dimmer stars just disappear from site.

The best way to focus stars is live view. Start with a bright star and focus the best you can. As that bright star comes into focus, pick a dimmer star and then watch for it to be at the brightest point you can find. That will be perfect focus.

Then take some pictures at different shutter times and different apertures and see what you get. If you have a good lens, wide open may look good. If not that good of a lens, you may want to stop down a bit. The results will let you know what the lens can do. Be sure to magnify and look at stars in the corners. Be prepared to not like what you see if the lens is not so good.

Just because a lens looks good on terrestrial objects is no guarantee that it will look good with stars. Stars are good at exasperating all the deficiencies of a lens. Maybe sometime in the future we will get AI software that corrects lens distortions. But right now, we don't have that. When (if) it comes, maybe it will be called NoComo AI or NoAstigmatism AI or NoCA AI or NoLensOffset AI? Hopefully they are all bundled into one product.

mr1492 Loc: Newport News, VA

Go as wide as you can with an f stop of 2.8 or better (a 1.4 is wonderful.) Remember, you are trying to capture as much light as you can in as short a time as you have.