Lens choice for K-50 astrophotography

Spindrift · 07-11-2020, 01:59 PM - **1 Like**

Well, I now have my shiny new Samyang 16mm F2 lens and was going out tonight and try and capture the Neowise comet. Ha! Sodding British weather. I live practically at sea level in the flattest part of the UK, with huge horizons and relatively little light pollution, but the sky? The sky is now just a mass of clouds.

I said that would happen.

**jatrax** · 07-13-2020, 08:11 AM

Originally posted by Spindrift

The sky is now just a mass of clouds.

Two years ago I planned a trip to a dark sky area in the western US. Complete desert area, dry lake bed. Rains maybe 5 inches annually. We were there 4 days. It rained two of them and was completely cloud covered the rest of the time. We set up the first night and I got 2 shots of the Milkyway Way before I noticed the stars gradually disappearing as the clouds moved in.

It always happens.

**MossyRocks** · 07-13-2020, 09:04 AM

Originally posted by jatrax

Two years ago I planned a trip to a dark sky area in the western US. Complete desert area, dry lake bed. Rains maybe 5 inches annually. We were there 4 days. It rained two of them and was completely cloud covered the rest of the time. We set up the first night and I got 2 shots of the Milkyway Way before I noticed the stars gradually disappearing as the clouds moved in.

It always happens.

The joys of astrophotography. That almost sounds like all of last year for me I was only able to make it out 4 time to photograph something other than the moon. We got so much rain last year it wasn't funny and when it didn't rain it wanted to stay cloudy for days. This year has been a lot better for astro shooting.

Vithar · 08-14-2020, 01:18 AM

Originally posted by Spindrift

OK, so I went for the Samyang 16mm f2, guided I admit by the fact that I found one online at a significant discount.

Would you be able to share where you got it from? I'm looking to get one as well and a lot of places that had them for a reasonable price are out of stock.

Spindrift · 08-21-2020, 02:25 PM - **1 Like**

Originally posted by Vithar

Would you be able to share where you got it from? I'm looking to get one as well and a lot of places that had them for a reasonable price are out of stock.

Hi Vithar,

It was on Amazon, via their Global Store, so I don't know the actual vendor. All I can tell you is that it came from the US (I live in the UK). Sorry I can't be of more help.

**psoo** · 09-03-2020, 08:58 AM

Originally posted by johngs

I only tried night sky astro photography a few times with my K-50.

The lens I used was a Sigma 10-20mm f4-5.6 EX DC
I got the best results with the lens at 10mm, using ISO 1600 and f4 and 30 seconds exposure.
My Milky Way shots with this set up were pretty good for a beginner like me!
I'll try to attach one of my shots taken with the above setup and settings ...

It's great to see that a 30 second exposure doesn't blur the image due to the earth's rotation. How long an exposure have you used before the image is blurred for shots of the stars and constellations?

**MossyRocks** · 09-03-2020, 01:27 PM

Originally posted by psoo

It's great to see that a 30 second exposure doesn't blur the image due to the earth's rotation. How long an exposure have you used before the image is blurred for shots of the stars and constellations?

30 seconds is really getting towards the upper end of what can be done for not too noticeable star trails. There is a general rule that one should use 300/(focal length) to get your maximum untracked exposure time. This is often good enough but you will have pretty oval stars with this rule and if the lens has a lot of distortion there may be more trailing in the corners. Using 200/(focal length) will produce much better results and will most of the time produce nice round stars. With ultrawides you can push it a bit but 50% is really over that unless the lens is soft or really bloats stars. I will run my 12mm at 20 seconds and get some very nice stars.

**psoo** · 09-03-2020, 04:51 PM

Originally posted by MossyRocks

30 seconds is really getting towards the upper end of what can be done for not too noticeable star trails. There is a general rule that one should use 300/(focal length) to get your maximum untracked exposure time. This is often good enough but you will have pretty oval stars with this rule and if the lens has a lot of distortion there may be more trailing in the corners. Using 200/(focal length) will produce much better results and will most of the time produce nice round stars. With ultrawides you can push it a bit but 50% is really over that unless the lens is soft or really bloats stars. I will run my 12mm at 20 seconds and get some very nice stars.

Thanks Mossy, appreciate your advice.

07-11-2020, 01:59 PM - 1 Like	#16
Spindrift New Member Join Date: Mar 2020 Location: Wisbech, Cambridgeshire, UK Posts: 12 Original Poster	Maybe I'm a wether forecaster. Well, I now have my shiny new Samyang 16mm F2 lens and was going out tonight and try and capture the Neowise comet. Ha! Sodding British weather. I live practically at sea level in the flattest part of the UK, with huge horizons and relatively little light pollution, but the sky? The sky is now just a mass of clouds. I said that would happen.

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07-13-2020, 08:11 AM	#17
jatrax Site Supporter Join Date: May 2010 Location: Washington Cascades Photos: Gallery \| Albums Posts: 12,991	Originally posted by Spindrift The sky is now just a mass of clouds. Two years ago I planned a trip to a dark sky area in the western US. Complete desert area, dry lake bed. Rains maybe 5 inches annually. We were there 4 days. It rained two of them and was completely cloud covered the rest of the time. We set up the first night and I got 2 shots of the Milkyway Way before I noticed the stars gradually disappearing as the clouds moved in. It always happens.

07-13-2020, 09:04 AM	#18
MossyRocks Loyal Site Supporter Join Date: Nov 2017 Location: Minnesota Photos: Gallery \| Albums Posts: 2,982	Originally posted by jatrax Two years ago I planned a trip to a dark sky area in the western US. Complete desert area, dry lake bed. Rains maybe 5 inches annually. We were there 4 days. It rained two of them and was completely cloud covered the rest of the time. We set up the first night and I got 2 shots of the Milkyway Way before I noticed the stars gradually disappearing as the clouds moved in. It always happens. The joys of astrophotography. That almost sounds like all of last year for me I was only able to make it out 4 time to photograph something other than the moon. We got so much rain last year it wasn't funny and when it didn't rain it wanted to stay cloudy for days. This year has been a lot better for astro shooting.

08-14-2020, 01:18 AM	#19
Vithar Closed Account Join Date: Aug 2020 Posts: 2	Originally posted by Spindrift OK, so I went for the Samyang 16mm f2, guided I admit by the fact that I found one online at a significant discount. Would you be able to share where you got it from? I'm looking to get one as well and a lot of places that had them for a reasonable price are out of stock.

08-21-2020, 02:25 PM - 1 Like	#20
Spindrift New Member Join Date: Mar 2020 Location: Wisbech, Cambridgeshire, UK Posts: 12 Original Poster	Originally posted by Vithar Would you be able to share where you got it from? I'm looking to get one as well and a lot of places that had them for a reasonable price are out of stock. Hi Vithar, It was on Amazon, via their Global Store, so I don't know the actual vendor. All I can tell you is that it came from the US (I live in the UK). Sorry I can't be of more help.

09-03-2020, 08:58 AM	#21
psoo Site Supporter Join Date: Jan 2012 Location: Long Island, NY Posts: 485	Originally posted by johngs I only tried night sky astro photography a few times with my K-50. The lens I used was a Sigma 10-20mm f4-5.6 EX DC I got the best results with the lens at 10mm, using ISO 1600 and f4 and 30 seconds exposure. My Milky Way shots with this set up were pretty good for a beginner like me! I'll try to attach one of my shots taken with the above setup and settings ... It's great to see that a 30 second exposure doesn't blur the image due to the earth's rotation. How long an exposure have you used before the image is blurred for shots of the stars and constellations?

09-03-2020, 01:27 PM	#22
MossyRocks Loyal Site Supporter Join Date: Nov 2017 Location: Minnesota Photos: Gallery \| Albums Posts: 2,982	Originally posted by psoo It's great to see that a 30 second exposure doesn't blur the image due to the earth's rotation. How long an exposure have you used before the image is blurred for shots of the stars and constellations? 30 seconds is really getting towards the upper end of what can be done for not too noticeable star trails. There is a general rule that one should use 300/(focal length) to get your maximum untracked exposure time. This is often good enough but you will have pretty oval stars with this rule and if the lens has a lot of distortion there may be more trailing in the corners. Using 200/(focal length) will produce much better results and will most of the time produce nice round stars. With ultrawides you can push it a bit but 50% is really over that unless the lens is soft or really bloats stars. I will run my 12mm at 20 seconds and get some very nice stars.

09-03-2020, 04:51 PM	#23
psoo Site Supporter Join Date: Jan 2012 Location: Long Island, NY Posts: 485	Originally posted by MossyRocks 30 seconds is really getting towards the upper end of what can be done for not too noticeable star trails. There is a general rule that one should use 300/(focal length) to get your maximum untracked exposure time. This is often good enough but you will have pretty oval stars with this rule and if the lens has a lot of distortion there may be more trailing in the corners. Using 200/(focal length) will produce much better results and will most of the time produce nice round stars. With ultrawides you can push it a bit but 50% is really over that unless the lens is soft or really bloats stars. I will run my 12mm at 20 seconds and get some very nice stars. Thanks Mossy, appreciate your advice.