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03-09-2019, 07:17 AM   #1
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Sigma 8-16 for star photography?

I realise the Sigma 8-16 is a bit slow but is it a complete loss for star photography?

03-09-2019, 07:34 AM - 1 Like   #2
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QuoteOriginally posted by Arbalist Quote
I realise the Sigma 8-16 is a bit slow but is it a complete loss for star photography?
I've used it before, but my star photography is pretty primitive, and I've bought the Rokinon 14 2.8, which one astro-photography site deemed the best astro-photography lens ever for all systems, not just for Pentax. I just thought, "it's not that expensive, give yourself a chance."
03-09-2019, 09:29 AM   #3
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No lens is a complete loss for star photography but lesser lenses require darker skies, longer exposures, more stacking, more post-processing, and tracking mounts to get decent images.

One major issue with astrophotography is that the physical aperture (focal length divided by f-stop) really matters in terms of bring out the stars against the backdrop of the sky. By that measure the Rokinon 14/2.8 gathers nearly 8 times as much star light as the Sigma 8/4.5.
03-09-2019, 10:52 AM   #4
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No, nothing is ever a complete loss. What you are doing, is essentially trading Field of View width, for aperture (collecting light). There are a number of things that you can do to recover. Bottom line is that with astro, collecting light is paramount, because there is so precious little of it from the stars (with no moon).

Take a look at this website Using - crop: 1.5, megapixel: 16, focal length: 8, pixel tolerance: 4 you can get 20seconds of exposure. Just lock the mirror up and using an external shutter release, just lock-it in continuous and take a number of images back to back. Then use Sequator (free download) to stack them.

You can also use the O-GPS1 startracer and get up to about 60 seconds of exposure. You can also stack those images too.

There are ways around the limitations. You will just essentially get dimmer stars, and these are ways to gather additional light to make them brighter.



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