Startrails with lit lighthouse in foreground

kswier · 06-27-2011, 06:00 PM

Next week, I am going on a camping trip on a small island in the northern part of Lake Michigan (South Manitou Island).

This particular island was an important part of the shipping industry. It houses one of the few natural harbors in Lake Michigan, but has also proved to be one of the more dangerous places for ships to navigate. Because of the danger, they built a lighthouse (yes, this is my long winded way of saying there is a lighthouse on the island). When I went camping on this island 7 years ago, work was being done to restore the island's lighthouse. A bit of that work has been completed, and it sounds like there is now a replica of the original light that is lit during summer nights.

I have always been interested in photographing startrails, but do not get away from city lights that often. Thus, I have been reading a lot about star trail photography online. However, it is difficult to find sources that talk about taking star trails with bright lights in the foreground (Thus the reason for this post). My end goal would be a photo with a lit foreground and startrails in the sky.

I am constrained to using the kit lens or the Pentax A 50mm f/2.0 (I wanted to rent the da 15mm limited, but it was too expensive). At the moment I think the kit lens sounds like the best choice due to focal length, but am concerned about getting flare from the lighthouse light. I plan on stacking images rather than using one long exposure, to try and keep from completely blowing out the lighthouse's light. It looks like the minimum time to get any descent star trail is ~1 hour. I also plan on finding the north star to help with composition.

I am looking for any available advice, but I particularly interested in the following topics:

How do I keep the lens from flaring?
What aperature/iso shoudl I use to get startrails (I have pentax k200d, so high ISO is not ideal)?
Should I be concerned about the lens fogging up in the summer?
How do I balance the light from the lighthouse with the goal of having a lit foreground?

Thank you in advance for any advice.

adr1an · 06-27-2011, 06:14 PM

I can't help you with anything much, other than to share that Lens Flare is wholly predictable and thus can be 'worked with' to an extent. Flare will always appear inversely-opposite of the light source that creates it... so if its a light source in the bottom-far-right, the flare will appear top-far-left...

So depending on composition, you can frame it so that any flare can be masked out more easily in PS...

And regarding the startrails themselves and low-iso etc - heres another thing I've gleaned around here :
Think different. Don't go for one uber-long exposure - use an application such as Startrails application to stack multiple 30Second ISO100 exposures... you can end up with say a 1hr ISO10 equivalent image... Just make sure to turn off the "Noise Reduction" features in-camera (if the K200's have that)

**pixelsaurus** · 06-27-2011, 06:42 PM

A read of this may prove useful. Your Complete Guide For Photographing Star Trails | DIYPhotography.net
Unless it is really humid, or cold, I can't see dew being a problem during summer. If the ground gets wet, and/or dew drips off the camera, lens or tripod, then there is a good chance the lens surface will dew up. You can use a portable hair dryer to keep it clear or perhaps put an toeloess sock over the lens barrel and stuff one of those "boil in the bag" pocket warmers in it to keep the lens warm. Maybe one for the cam to keep the water out of the electronics, unless your cam is weather sealed. Good luck.

deckroid · 06-27-2011, 06:55 PM

Hey there

I found this site here... to be REALLY helpful.

I have done one or two and I found that if you get the first shot right the stacking program does the rest. I did a star trail for an hour with a 20 second shutter at f/3.5 with my kit lens at ISO 100 on my K10D just as the last pinkness was in the sky. I will try to find it. But it came out great because by the last shot, the silhouette I had with the tree line was one with the black sky. But the program works with the first shot then stacks from there.

Really interesting. I want to try more.

mysticcowboy · 06-27-2011, 09:13 PM

One possible problem will be the humidity. Since you are on an island there may be some mist in the air that will cause some light bleed from the lighthouse. That's more likely a problem than flare.

The lights in lighthouses are very bright and can overpower stars, especially with the long exposures necessary for trail shots. A test exposure will tell you if that is the case. If it is, you may have to shoot with the lighthouse behind you or around a point of land.

Aperture is only important if you want the foreground in good focus. Unless you have a current Pentax a Kx, Kr or K-5, you will want as low an ISO as possible. Older Pentax's had a fair amount of dark area noise at higher ISOs. Another thing to remember is that Pentax includes a noise reduction scheme on longer exposures. That effectively adds a time equal to the exposure in processing, which will leave gaps in your star trails. I think only the K-5 allows that to be turned off.

**pixelsaurus** · 06-27-2011, 10:35 PM

Originally posted by mysticcowboy

Another thing to remember is that Pentax includes a noise reduction scheme on longer exposures. That effectively adds a time equal to the exposure in processing, which will leave gaps in your star trails. I think only the K-5 allows that to be turned off.

My *ist DS also allows for noise reduction to be turned off. A trick astrophotogs use is to make a series of dark frames (same ISO and exposure as the intended shots) and to subtract them in PP. This will remove a lot of the noise. In fact Startrails seems to allow for dark frames to be added to the image list for batch processing. DeepSkyTracker also allows for dark,bias and offset frames to be added to the mix to reduce noise.http://deepskystacker.free.fr/english/index.html

**mattb123** · 06-28-2011, 12:38 PM

It might work to stack the shots up like a regular star tails photo because if the lighthouse light rotates, you will get some darkness time in which the stars could be captured. It may take some trial and error and probably some luck but it could end up pretty interesting If the frames you take while the light is pointing at you add too much light, you could try excluding them from your stack. Seems like there might be a happy medium in there somewhere.
Good luck and have fun!

**jbinpg** · 06-28-2011, 02:31 PM

All lighthouses have a beacon with a fixed rotation speed. You should be able to do some onsite calculations to find that number in seconds. Then figure out the exact angle you would like the light to be shining in your image, set the appropriate interval in your camera's interval timer (interval has to be longer than the exposure + NR time if any), and then start the interval run at the exact point where it meets your angle. This way you could avoid any shots with the light angle in the wrong place and have lots of images to stack if necessary. A tripod is a requirement.

Jack

kswier · 06-28-2011, 05:12 PM

Thank you all for the advice.

I do plan on stacking images, but had not thought the the light on the lighthouse may be rotating. I am wondering if the best approach might be to take the foreground image first, and then take the star trail series after. In post processing, get rid of the sky in the foreground picture, and use the startrail sky instead. That way I would only have to worry about the rotation of the light when taking the foreground pictures. I also wonder if combining a couple foreground pictures into some kind of (realistic looking) HDR photo would help keep the lighthouse light from being blown out.

Northern Soul · 06-29-2011, 02:27 AM

I'd do as you've suggested - get an image of the lighthouse you are happy with, then cut out the sky and drop in your trails.

In fact your thread has had me mulling over how I might shoot a lighthouse I know next time I am there - I'm hoping that with a bit of sea mist you'll be able to see the shape of the light beam from the lighthouse, and if so I'm going to experiment with getting an image showing the beam either side of the lighthouse by covering the lens for part of the lights rotation, if that makes sense.

mysticcowboy · 06-29-2011, 07:50 PM

Originally posted by jbinpg

All lighthouses have a beacon with a fixed rotation speed. You should be able to do some onsite calculations to find that number in seconds. Then figure out the exact angle you would like the light to be shining in your image, set the appropriate interval in your camera's interval timer (interval has to be longer than the exposure + NR time if any), and then start the interval run at the exact point where it meets your angle. This way you could avoid any shots with the light angle in the wrong place and have lots of images to stack if necessary. A tripod is a requirement.

Jack

Sorry, Jack but most lighthouses now use strobes that fire in unique patterns. I live two miles from a lighthouse, and on clear nights can see two others. I wouldn't want to try to time star trail shots around the patterns.

mysticcowboy · 06-29-2011, 07:52 PM

Originally posted by pixelsaurus

My *ist DS also allows for noise reduction to be turned off. A trick astrophotogs use is to make a series of dark frames (same ISO and exposure as the intended shots) and to subtract them in PP. This will remove a lot of the noise. In fact Startrails seems to allow for dark frames to be added to the image list for batch processing. DeepSkyTracker also allows for dark,bias and offset frames to be added to the mix to reduce noise.http://deepskystacker.free.fr/english/index.html

That's a great idea. I'll check out the link and give that a go when our skies clear. The Pacific Northwest isn't the best place for anytime star photography.

**jbinpg** · 06-29-2011, 11:12 PM

Pity. I loved the rotating beacons. I remember when they changed the one out when I was stationed at Cape St James. It turned the other way and it threw all of us for a while until we got used to it

**pixelsaurus** · 06-30-2011, 07:01 AM

Originally posted by mysticcowboy

That's a great idea. I'll check out the link and give that a go when our skies clear. The Pacific Northwest isn't the best place for anytime star photography.

Thanx. The following link has details about the various calibration frames that can be used for cleaning up noise from astrophotos. The article is slanted towards the use of IRIS, a freeware software app designed specifically for astro. I can't vouch for IRIS even though I have it installed, seems to have a real steep learning curve, and my brain is already full. However the article does contain info which may be useful. astro.ai-software.com

06-27-2011, 06:00 PM	#1
kswier Veteran Member Join Date: Dec 2009 Posts: 426	Startrails with lit lighthouse in foreground Next week, I am going on a camping trip on a small island in the northern part of Lake Michigan (South Manitou Island). This particular island was an important part of the shipping industry. It houses one of the few natural harbors in Lake Michigan, but has also proved to be one of the more dangerous places for ships to navigate. Because of the danger, they built a lighthouse (yes, this is my long winded way of saying there is a lighthouse on the island). When I went camping on this island 7 years ago, work was being done to restore the island's lighthouse. A bit of that work has been completed, and it sounds like there is now a replica of the original light that is lit during summer nights. I have always been interested in photographing startrails, but do not get away from city lights that often. Thus, I have been reading a lot about star trail photography online. However, it is difficult to find sources that talk about taking star trails with bright lights in the foreground (Thus the reason for this post). My end goal would be a photo with a lit foreground and startrails in the sky. I am constrained to using the kit lens or the Pentax A 50mm f/2.0 (I wanted to rent the da 15mm limited, but it was too expensive). At the moment I think the kit lens sounds like the best choice due to focal length, but am concerned about getting flare from the lighthouse light. I plan on stacking images rather than using one long exposure, to try and keep from completely blowing out the lighthouse's light. It looks like the minimum time to get any descent star trail is ~1 hour. I also plan on finding the north star to help with composition. I am looking for any available advice, but I particularly interested in the following topics: How do I keep the lens from flaring? What aperature/iso shoudl I use to get startrails (I have pentax k200d, so high ISO is not ideal)? Should I be concerned about the lens fogging up in the summer? How do I balance the light from the lighthouse with the goal of having a lit foreground? Thank you in advance for any advice.

06-27-2011, 09:13 PM	#5
mysticcowboy Veteran Member Join Date: Apr 2009 Location: port townsend, wa Photos: Albums Posts: 968	One possible problem will be the humidity. Since you are on an island there may be some mist in the air that will cause some light bleed from the lighthouse. That's more likely a problem than flare. The lights in lighthouses are very bright and can overpower stars, especially with the long exposures necessary for trail shots. A test exposure will tell you if that is the case. If it is, you may have to shoot with the lighthouse behind you or around a point of land. Aperture is only important if you want the foreground in good focus. Unless you have a current Pentax a Kx, Kr or K-5, you will want as low an ISO as possible. Older Pentax's had a fair amount of dark area noise at higher ISOs. Another thing to remember is that Pentax includes a noise reduction scheme on longer exposures. That effectively adds a time equal to the exposure in processing, which will leave gaps in your star trails. I think only the K-5 allows that to be turned off. Last edited by mysticcowboy; 06-27-2011 at 09:27 PM.

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06-27-2011, 06:14 PM	#2
adr1an Veteran Member Join Date: Sep 2010 Location: Canberra Photos: Gallery \| Albums Posts: 739	I can't help you with anything much, other than to share that Lens Flare is wholly predictable and thus can be 'worked with' to an extent. Flare will always appear inversely-opposite of the light source that creates it... so if its a light source in the bottom-far-right, the flare will appear top-far-left... So depending on composition, you can frame it so that any flare can be masked out more easily in PS... And regarding the startrails themselves and low-iso etc - heres another thing I've gleaned around here : Think different. Don't go for one uber-long exposure - use an application such as Startrails application to stack multiple 30Second ISO100 exposures... you can end up with say a 1hr ISO10 equivalent image... Just make sure to turn off the "Noise Reduction" features in-camera (if the K200's have that)

06-27-2011, 06:42 PM	#3
pixelsaurus Site Supporter Join Date: Jul 2007 Location: Te Kuiti, NZ Photos: Gallery \| Albums Posts: 986	A read of this may prove useful. Your Complete Guide For Photographing Star Trails \| DIYPhotography.net Unless it is really humid, or cold, I can't see dew being a problem during summer. If the ground gets wet, and/or dew drips off the camera, lens or tripod, then there is a good chance the lens surface will dew up. You can use a portable hair dryer to keep it clear or perhaps put an toeloess sock over the lens barrel and stuff one of those "boil in the bag" pocket warmers in it to keep the lens warm. Maybe one for the cam to keep the water out of the electronics, unless your cam is weather sealed. Good luck.

06-27-2011, 06:55 PM	#4
deckroid Forum Member Join Date: Jan 2008 Location: Homedale, ID Photos: Albums Posts: 80	Hey there I found this site here... to be REALLY helpful. I have done one or two and I found that if you get the first shot right the stacking program does the rest. I did a star trail for an hour with a 20 second shutter at f/3.5 with my kit lens at ISO 100 on my K10D just as the last pinkness was in the sky. I will try to find it. But it came out great because by the last shot, the silhouette I had with the tree line was one with the black sky. But the program works with the first shot then stacks from there. Really interesting. I want to try more.

06-27-2011, 10:35 PM	#6
pixelsaurus Site Supporter Join Date: Jul 2007 Location: Te Kuiti, NZ Photos: Gallery \| Albums Posts: 986	Originally posted by mysticcowboy Another thing to remember is that Pentax includes a noise reduction scheme on longer exposures. That effectively adds a time equal to the exposure in processing, which will leave gaps in your star trails. I think only the K-5 allows that to be turned off. My *ist DS also allows for noise reduction to be turned off. A trick astrophotogs use is to make a series of dark frames (same ISO and exposure as the intended shots) and to subtract them in PP. This will remove a lot of the noise. In fact Startrails seems to allow for dark frames to be added to the image list for batch processing. DeepSkyTracker also allows for dark,bias and offset frames to be added to the mix to reduce noise.http://deepskystacker.free.fr/english/index.html

06-28-2011, 12:38 PM	#7
mattb123 Site Supporter Join Date: Apr 2010 Location: Colorado High Country Photos: Gallery Posts: 10,872	It might work to stack the shots up like a regular star tails photo because if the lighthouse light rotates, you will get some darkness time in which the stars could be captured. It may take some trial and error and probably some luck but it could end up pretty interesting If the frames you take while the light is pointing at you add too much light, you could try excluding them from your stack. Seems like there might be a happy medium in there somewhere. Good luck and have fun!

06-28-2011, 02:31 PM	#8
jbinpg Site Supporter Join Date: Mar 2008 Location: Prince George, BC Photos: Gallery \| Albums Posts: 3,546	All lighthouses have a beacon with a fixed rotation speed. You should be able to do some onsite calculations to find that number in seconds. Then figure out the exact angle you would like the light to be shining in your image, set the appropriate interval in your camera's interval timer (interval has to be longer than the exposure + NR time if any), and then start the interval run at the exact point where it meets your angle. This way you could avoid any shots with the light angle in the wrong place and have lots of images to stack if necessary. A tripod is a requirement. Jack

06-28-2011, 05:12 PM	#9
kswier Veteran Member Join Date: Dec 2009 Posts: 426 Original Poster	Thank you all for the advice. I do plan on stacking images, but had not thought the the light on the lighthouse may be rotating. I am wondering if the best approach might be to take the foreground image first, and then take the star trail series after. In post processing, get rid of the sky in the foreground picture, and use the startrail sky instead. That way I would only have to worry about the rotation of the light when taking the foreground pictures. I also wonder if combining a couple foreground pictures into some kind of (realistic looking) HDR photo would help keep the lighthouse light from being blown out.

06-29-2011, 02:27 AM	#10
Northern Soul Veteran Member Join Date: Feb 2008 Location: The North of England Photos: Albums Posts: 494	I'd do as you've suggested - get an image of the lighthouse you are happy with, then cut out the sky and drop in your trails. In fact your thread has had me mulling over how I might shoot a lighthouse I know next time I am there - I'm hoping that with a bit of sea mist you'll be able to see the shape of the light beam from the lighthouse, and if so I'm going to experiment with getting an image showing the beam either side of the lighthouse by covering the lens for part of the lights rotation, if that makes sense.

06-29-2011, 07:50 PM	#11
mysticcowboy Veteran Member Join Date: Apr 2009 Location: port townsend, wa Photos: Albums Posts: 968	Originally posted by jbinpg All lighthouses have a beacon with a fixed rotation speed. You should be able to do some onsite calculations to find that number in seconds. Then figure out the exact angle you would like the light to be shining in your image, set the appropriate interval in your camera's interval timer (interval has to be longer than the exposure + NR time if any), and then start the interval run at the exact point where it meets your angle. This way you could avoid any shots with the light angle in the wrong place and have lots of images to stack if necessary. A tripod is a requirement. Jack Sorry, Jack but most lighthouses now use strobes that fire in unique patterns. I live two miles from a lighthouse, and on clear nights can see two others. I wouldn't want to try to time star trail shots around the patterns.

06-29-2011, 07:52 PM	#12
mysticcowboy Veteran Member Join Date: Apr 2009 Location: port townsend, wa Photos: Albums Posts: 968	Originally posted by pixelsaurus My *ist DS also allows for noise reduction to be turned off. A trick astrophotogs use is to make a series of dark frames (same ISO and exposure as the intended shots) and to subtract them in PP. This will remove a lot of the noise. In fact Startrails seems to allow for dark frames to be added to the image list for batch processing. DeepSkyTracker also allows for dark,bias and offset frames to be added to the mix to reduce noise.http://deepskystacker.free.fr/english/index.html That's a great idea. I'll check out the link and give that a go when our skies clear. The Pacific Northwest isn't the best place for anytime star photography.

06-29-2011, 11:12 PM	#13
jbinpg Site Supporter Join Date: Mar 2008 Location: Prince George, BC Photos: Gallery \| Albums Posts: 3,546	Pity. I loved the rotating beacons. I remember when they changed the one out when I was stationed at Cape St James. It turned the other way and it threw all of us for a while until we got used to it

06-30-2011, 07:01 AM	#14
pixelsaurus Site Supporter Join Date: Jul 2007 Location: Te Kuiti, NZ Photos: Gallery \| Albums Posts: 986	Originally posted by mysticcowboy That's a great idea. I'll check out the link and give that a go when our skies clear. The Pacific Northwest isn't the best place for anytime star photography. Thanx. The following link has details about the various calibration frames that can be used for cleaning up noise from astrophotos. The article is slanted towards the use of IRIS, a freeware software app designed specifically for astro. I can't vouch for IRIS even though I have it installed, seems to have a real steep learning curve, and my brain is already full. However the article does contain info which may be useful. astro.ai-software.com