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photographing night sky

walter_j

New member
I'm considering a panasonic or a nokton 25mm lens. I tried photographing the night sky before - with poor results. I tried with a olympus 12mm and got much better results then I've had before. I'm now looking for a 25mm lens, and wonder if F.95 to F1.4 is a big step in night sky photography. Will F.95 allow a much shorter exposure time then F1.4? The longer the exposure the more the stars will move. I'd prefer AF and the lighter weight of panasonic, but will the 1/2F stop make a big difference?
 

Riley

New member
not really my area, but 1/2 a stop, probably not
youve got about 20 secs to make an exposure before the dots of stars become lines
so you end up fighting two variables

1) limited exposure times
2) ability of a lens to shoot wide open

In any event you will have to raise the ISO, in which case not you fight noise as well. Of course people that shoot this stuff all the time use a device called a planetary drive, which gives the camera the same view of the sky by moving with the rotation of the Earth. Then they stack images enabling them to reduce noise.

Another technique they use is to use filters, theres a video of that here:
How to make narrowband filter deep sky images with a DSLR and clip filter for astrophotography - YouTube

anyway fwiw I didnt do any of that and this was my result

Panasonic GH2, 15 secs, 800ISO
Panasonic Leica Summilux 25/1.4, f/1.4​
 

walter_j

New member
Thanks Riley. Thats just the sort of picture I'm looking to take, so the Panasonic will work I'm still curious as to how much less time your picture would take with a nokton. Australia has exceptionally clear night skies compared to northern canada I think, so I'm unsure how this would affect exposure time. I'll try tonight with my 12mm m.zuiko and olympus omd at 800iso and 15sec and see how that turns out.
 

GrahamWelland

Subscriber & Workshop Member
You'll definitely pick up more light with the faster lens although you need to temper that with the potential for distortion / coma with many of the optimised faster lenses.

I noticed in your initial note that you were looking to use AF for star field photography. In my experience this'll be an exercise in frustration and you are far better off using manual focus and live view to dial in sharp focus. Unfortunately it's not as simple as dialing in the lens at infinity (you'd think it would be) but most AF lenses will focus beyond infinity and so using live view to get your stars to render as sharp points is needed. That said, not all live views are equal - I shoot stars primarily with my Nikon D600 (or D800) or my Fuji X-Pro1. Both of these have noisy live view and so aren't great for this - at least compared to Canon. I'd recommend trying your Panasonic and see how well you get on. When I shot Olympus E-P3 I tried this and it wasn't great.

Good luck with your endeavours. :thumbs:
 

Riley

New member
Thanks Riley. Thats just the sort of picture I'm looking to take, so the Panasonic will work I'm still curious as to how much less time your picture would take with a nokton. Australia has exceptionally clear night skies compared to northern canada I think, so I'm unsure how this would affect exposure time. I'll try tonight with my 12mm m.zuiko and olympus omd at 800iso and 15sec and see how that turns out.
one of the things is, metering tries to make an 18% grey out of an otherwise dark night sky. So the camera left to its own devices will try to overexpose.

An OMD should be around a stop less noisy than my GH2, so thats a plus. Personally I think that higher focal length lenses might be more fun than wider optics, b/se it all gets a bit tiny

I live rurally, so the skies are as good here as anywhere in the world. As temperatures come back up theyre brilliant clear skies from horizon to horizon
 

Riley

New member
You'll definitely pick up more light with the faster lens although you need to temper that with the potential for distortion / coma with many of the optimised faster lenses.

I noticed in your initial note that you were looking to use AF for star field photography. In my experience this'll be an exercise in frustration and you are far better off using manual focus and live view to dial in sharp focus. Unfortunately it's not as simple as dialing in the lens at infinity (you'd think it would be) but most AF lenses will focus beyond infinity and so using live view to get your stars to render as sharp points is needed. That said, not all live views are equal - I shoot stars primarily with my Nikon D600 (or D800) or my Fuji X-Pro1. Both of these have noisy live view and so aren't great for this - at least compared to Canon. I'd recommend trying your Panasonic and see how well you get on. When I shot Olympus E-P3 I tried this and it wasn't great.

Good luck with your endeavours. :thumbs:
AF? no way, theres nothing to focus on.

Even MF is a bit frustrating
Especially if like me you try to set shutter speed first and use liveview to focus. I had to set 15 seconds in order to see the image focus,
but in doing so you adjust the focus and wait 15 seconds to see where you are at!

quite frustrating but ultimately do-able if you are patient
 

tbhv55

New member
I'm considering a panasonic or a nokton 25mm lens. I tried photographing the night sky before - with poor results. I tried with a olympus 12mm and got much better results then I've had before. I'm now looking for a 25mm lens, and wonder if F.95 to F1.4 is a big step in night sky photography. Will F.95 allow a much shorter exposure time then F1.4? The longer the exposure the more the stars will move. I'd prefer AF and the lighter weight of panasonic, but will the 1/2F stop make a big difference?
The difference between f/1.4 and f/0.95 is actually 1.12 stops (if you're interested, the formula can be seen here - page down to heading "Number of Stops Between Two Stop Numbers").

Regarding how this might affect long-exposure shots, I don't know, since I have little experience in this type of photography. However, I thought that this information might help with your decision.:)
 

walter_j

New member
One site suggests 1 F stop less needs 1/2 the shutter speed. A F0.95 is 2 stops less then my F2 lens, and therefore require 1/4 shutter speed. A 12 second exposure taken with my 12mm lens will take 3 seconds with the nokton. wow
 

tbhv55

New member
One site suggests 1 F stop less needs 1/2 the shutter speed. A F0.95 is 2 stops less then my F2 lens, and therefore require 1/4 shutter speed. A 12 second exposure taken with my 12mm lens will take 3 seconds with the nokton. wow
In the days of film photography, "reciprocity failure" needed to be factored-in for long exposure shots. In this phenomenon, the reciprocal relationship between shutter speed and aperture went somewhat awry as exposure times got longer.

I believe that this factor is less of a concern with digital photography - though I'm uncertain on the extent to which this might be the case. Nonetheless, I would suggest Googling the term "reciprocity failure" and obtaining a good understanding of the effect (useful background knowledge, if nothing more:)), and trying to find out how things have changed in the digital world, in this regard.

Hope this helps... it would be good to see the resulting night-sky images, when you have them.
 

walter_j

New member
My first attempt. The stars aren't very bright but the mountains (Roche de Boule) are well lit. From my deck! I got better images of the stars, but the mountains are in silhouette
 

tbhv55

New member
My first attempt. The stars aren't very bright but the mountains (Roche de Boule) are well lit. From my deck! I got better images of the stars, but the mountains are in silhouette
It's showing now!

I'd say that's a pretty good start... however, if the stars are better in the other shot, why not combine the two images in Photoshop (provided that the other shot is identically framed) to give the best parts of each? If you're new to PS, and therefore unfamiliar with the process, I'm sure that we can talk you through it.:)
 
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