[sealonsf]

I am going to the Yukon in Canada soon to possibly photograph the Northern Lights and would like opinions on which lens I should use. I don't exactly have the lens I think would work best so among these, which would you use? I have a Pentax K-5.

Sigma 10-20 f4-5.6
Pentax DA 40mm f2.8
Sigma 28mm 1.8 (I would normally think that this is the clear winner but it's not really 28mm on my camera so it's closer to 40mm - I bought it used not knowing that it's only 28mm on a full frame camera - should have done my homework!)

And then, I have a Pentax 18-135 f3.5-5.6

And if you have suggestions for a cheap (under $200) lens I could look for used, please let me know.

Your thoughts? I haven't done this type of photography ever so it's all new to me. Thanks!

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Last edited by sealonsf; 12-10-2017 at 12:41 PM.

[bassek]

You need wide. So the Sigma 10-20 would do with a tripod and a long exposure time.

Seb

[skierd]

My choice would be the 18-135 followed by the 28 followed by the 10-20. The 18-135 is probably wide enough and faster than the 10-20. Toss up between the 28 and the 10-20 honestly, because the faster lens will get you much cleaner files because you can shoot at lower iso’s

Tripod, 2sec shutter delay, manually set the lens at infinity focus, and compose with the viewfinder. Turn your screen colors red to protect your night vision. I usually start at wide open apetures, 8s exposure, and 800 iso.

[photoptimist]

The best lens depends on where the Northern Lights are relative to you (which isn't easy to control). The more overhead they are, the wider the optimal lens. But if the lights are further away, then a longer focal length might be better. Moreover, there's often the issue of finding a nice foreground or landscape to go with the Northern Lights and that means picking a focal length that frames the landscape well and includes the sky & Lights.

Personally, I'd be ready to use both the 10-20 and the 28. The 28 has a 2-stop advantage in light gathering power and will give you brighter stars.

Good luck & have a great trip.

[nocturnal]

The widest angled lenses will gather less light, significantly less so than your DA40 Ltd. which I use myself for astrophotography.

For example, your Sigma at 10mm @ f4 has a 2.5mm diameter aperture, your DA40 @ f2.8 has a 14.3mm aperture to suck in all those beautiful faint aurorae!!!

DA40 will gather more than 32 times, yes 32x times the light from the Sigma at 10mm.

Your Sigma 28mm f1.8 will gather a bit more light again than the DA40 but the DA40 is sharp wide open at f2.8

Don't use UWA lenses for aurorae as they are less sensitive than the human eye.

If you are confused read about 'clear aperture' .

😀

[robjmitchell]

You are going to need something wide and fast. I would try and get a good copy of the tamron 17-50/2.8 which is 300 US. Sigma 17-50/2.8 is another option. The Samyang 14/2.8 and 16/2.0 are also suitable.
Consider selling some of your other lenses to fund it. Its crazy to go on an expensive trip without the right equipment for the sake of a few hundred dollars.

---------- Post added 12-11-2017 at 08:48 AM ----------

The widest angled lenses will gather less light, significantly less so than your DA40 Ltd. which I use myself for astrophotography.

For example, your Sigma at 10mm @ f4 has a 2.5mm diameter aperture, your DA40 @ f2.8 has a 14.3mm aperture to suck in all those beautiful faint aurorae!!!

DA40 will gather more than 32 times, yes 32x times the light from the Sigma at 10mm.

Your Sigma 28mm f1.8 will gather a bit more light again than the DA40 but the DA40 is sharp wide open at f2.8

Don't use UWA lenses for aurorae as they are less sensitive than the human eye.

If you are confused read about 'clear aperture' .

😀

That’s not how physics works. The lenses T-stop is what determines how much light reaches the sensor, which is simply F-stop minus transmission losses. My DA14/2.8 is great for faint Aurora. The Human eye struggles to pick up the colour of Auroa due to the insensitivy of the color cone cells.

[JensE]

Don't use UWA lenses for aurorae as they are less sensitive than the human eye.

Aurorae are not a small and dark deep-space phenomenon, for which this is important. As stated previously, it really depends on your desired field of view. The angle of the aurora structures in turn varies with how close to or how far under the oval you will be. See e.g. Homepage | NOAA / NWS Space Weather Prediction Center. I would expect Yukon right below the oval most of the time, even more than Lofoten. This mean you'd ideally have something starting really wide for structures taking up most of the sky, up to maybe 'normal' perspective, roughly 35mm on a K-5.

See Pentax DA 35mm f/2.4 on a k1? and for examples from Lofoten at the extremes of focal lengths which I found useful on a recent trip. Taken on a K-1, so you have to divide focal length by a factor of 1.5 to get the focal length for the same field-of-view on a K-5. My daughter shot side-by-side with me with less 'fast' zooms using a K-50 with some great results at f/3.5 to f/5.6 (using mostly the 8-16mm Sigma, the DA 18-135mm, an FA50/1.7), even though with somewhat longer exposure times, which means fast-moving structures appear a little softer.

For your extra budget, one of the fast (APS-C) Samyang/Rokinon ultra-wides (esp. the 10mm) may get you less noise - if you can find them at that price. The inexpensive 8mm fisheye is unfortunately not so great fully open, even though I have shot some decent night skies using it on my K-5 at f/4.5, none posted though.

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Last edited by JensE; 12-10-2017 at 03:02 PM.

[Simen1]

The focal length 28 mm are 28 mm any way you measure that distance. Changing sensor size doesnt change the focal lenght, it just changes the field of view you get out of that focal length.

I would recommend to try to get shutter speeds less then a couple of seconds. Northern light moves quite fast and you would want the contrasty and interessting patterns, not fuzzy long exposures.

Check the weather and aurora forecasts to get an idea of what to expect. If you are lucky you might get good 1/2s exposures with ISO 100 and f/2.8. If you are unlucky you might not see anything even with 30s, ISO 1600 and f/1,8. Usually you should get something in between. The northern lights changes quite fast so keep your equipment ready. It can change from barely visible to a bright outburst in minutes. Often the interessting patterns breakes up into a diffuse glow after an outburst.

[Na Horuk]

You can check some of the northern lights threads on this forum or look for northern lights photos on sites like Flickr, 500px,.. and then look at which lenses they used. That usually shows you a trend, or it can inspire you to change things and go against the tide.
If its a trip of a lifetime you might think about buying a lens, even if you buy it used and sell it later, that fits northern light photos. One of the ultra wides like Samyang 14mm, Irix 15mm, Venus 15mm..

I mostly just suggest you learn how to manually focus to exact infinity in the dark before your trip. Sometimes the infinity mark might be a little off. Doing some tests wide open of starry skies can help clear things up

[krazny]

Just to iterate what others have already said.

Two things you (typically) want in a lens for northern lights. Wide field of view and wide aperture. With your current setup it's either 10mm at f4 or 18mm at f3.5.

I guess your cheapest alternative option is probably the Tamron 17-50 2.8 used, it is usually cheaper than the Sigma 17-50 variant. Wider than that would be the 10mm f2.8 Samyang/Rokinon the price is higher, 3-400 $ I guess. Personally 17-18 mm is the narrowest focal length I would go for with northern lights but I suppose it depends on the landscape. The higher you can aim your camera, while still having a foreground to the northern lights, the narrower you can go I guess.

You will want to be able to shoot with as short of a shutter time as possible, especially if the lights start dancing on the sky. Otherwise you'll just end up with a green smudge on half the frame.

You could get away with the 28 mm but it would require very good framing on your part.

Edit: I guess the 14mm rokinon is available for less than 300$ if you are US based.

[aslyfox]

No advice on what to use but check out rental options once you decide

You may be able to rent the equipment you want and save $

[sealonsf]

Original poster here ---- Thanks everyone. Lots of information.

[Cthulhugan]

The best aurora shots I’ve seen all include significant foreground elements that place them in context. You want to go very wide for that, especially if the aurora is higher in the sky. I bet the new DA* 11-18/2.8 would be great. Too bad it won’t be out “soon”, and may well be a budget buster. The Rokinon/Samyang 14/2.8 has a good reputation for astrophotography, and is inexpensive, although it is manual focus (AF will likely be useless for aurora, but might effect your choice for other uses). The DA 14/2.8 is AF, and is less desirable for astro because of coma (points getting stretched/smeared towards the edge of the frame), but that would be less of an issue for aurora. It’s also more expensive than the Samyang (but not star-lens expensive). If you are buying a lens, one of the 14/2.8s should work well, or maybe one of the wider Samyangs, or kick the ISO up a stop or two and shoot with your 10-20 and spend a little money on noise reduction software.

FYI, my ultra-wide is the Sigma 8-16, which is plenty wide, but it is harder to find, more expensive, and slower.

---------- Post added 12-11-17 at 03:02 AM ----------

Oh, and be sure to shoot RAW. You are better able to recover highlights and shadows from a RAW image, and have complete control over white balance in post-processing.

[nocturnal]

You are going to need something wide and fast. I would try and get a good copy of the tamron 17-50/2.8 which is 300 US. Sigma 17-50/2.8 is another option. The Samyang 14/2.8 and 16/2.0 are also suitable.
Consider selling some of your other lenses to fund it. Its crazy to go on an expensive trip without the right equipment for the sake of a few hundred dollars.

---------- Post added 12-11-2017 at 08:48 AM ----------



That’s not how physics works. The lenses T-stop is what determines how much light reaches the sensor, which is simply F-stop minus transmission losses. My DA14/2.8 is great for faint Aurora. The Human eye struggles to pick up the colour of Auroa due to the insensitivy of the color cone cells.

Sorry mate this is not correct, I used to think (like almost everybody) that your explanation was the case, it is the classical error beginners in astrophotography make (I did it too!). Post your comment above on any astro forum and see the response... but basically a big hole lets more light through than a small hole... telescopes with larger apertures see fainter objects in the night sky... This is how the physics works.

Aurorae come in many different colours and are clearly visible to the human eye in high latitudes.

Unless you are living in Alaska you are obviously using the DA14/2.8 for longish exposures which blurs them, the shorter the exposure using longer focal lengths captures better images and not a green blurred line across the screen. Try one of your longer lenses at f2.8 against your DA14, and try it with any deep space object, MW, M31, the Pleides etc.

Seeing is believing and most internet info about this subject is fake news.

[photoptimist]

P.S. Whatever lens you use, make sure your remove any UV or protective filter from the front of the lens. If you don't, an optical interaction between the pure monochromatic light of the aurora and the flat surfaces of the filter glass will induce a subtle but obnoxious pattern of concentric rings in the image. (See Learn how to photograph the northern lights for more on that issue and lots more about photographing auroras.)