Hello everyone!
I am a history undergraduate currently writing a research project on the effects of light pollution on the night sky. The project is part of a unit I am taking which deals with modern histories of darkness and night-time, and requires us to locate and analyse primary source material.
If anyone on this forum has any photography they have taken in the last 30 years which they don't mind me using in the essay, I would be immensely appreciative! I have begun trying to document some myself, but I figured someone on here may have already taken some more evocative ones using a DSLR. The essay will only be shown internally to my tutor for marking, and your work would be credited in the references. This can also be kept anonymous if you wish!
I am particularly interested in the negative effects that light pollution has on wildlife and the visibility of the night sky.
Please feel free to ask any questions.
Best wishes,
Will
Undergraduate student seeks amateur photography detailing the effects of light pollution on the night sky
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RMSteele
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Re: Undergraduate student seeks amateur photography detailing the effects of light pollution on the night sky
I have been an active amateur astronomer since about 1970 and I have lived in the same house on the outskirts of Leeds since 1981. At that time, according to my contemporary variable star notes, the faintest star usually visible to my unaided eye at the zenith was stellar magnitude 4.5. It is now regularly brighter than magnitude 3.0. The brightness ratio of magnitude 3.0 to 4.5 is almost 4:1 which means that for me, an exclusively visual observer as opposed to a photographic or electronic imager, the artificial illumination of an area of the night sky at the zenith has increased between 4 and 5* times. This of course relates to the area directly overhead, but the effect of the (predominant LED) pollution is much greater at altitudes farther from the zenith.
Best wishes, Bob
*I estimate that I have lost half a magnitude on account of physiological ageing factors ( between ages 28 and 70), which leads me to suspect that light pollution has actually increased by at least 4.0 to 4.5 times.
Best wishes, Bob
*I estimate that I have lost half a magnitude on account of physiological ageing factors ( between ages 28 and 70), which leads me to suspect that light pollution has actually increased by at least 4.0 to 4.5 times.
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David Frydman
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Re: Undergraduate student seeks amateur photography detailing the effects of light pollution on the night sky
In the last 40 years I think that the faintest stars visible locally are 5 to 6 times brighter allowing for the loss from aging eyes.
On many nights no stars or just one or two are visible to the unaided eyes.
The Commission for Dark Skies may allow the use of their photos comparing 30 years ago to now.
You have to ask.
What is strange is that using the Canon G16 with no tripod but jammed on the window frame using Programme a 0.5 second or 1 second exposure at f/1.8 at 3200 ISO reveals many more stars than visually using good 8x32 or 8.5x44 binoculars.
There are many stars shown on the photos with sometimes no stars seen in the binoculars.
The situation here is already probably beyond saving, except with a very rare total electricity blackout which happened once about 15 years ago.
Moths are fewer, birds fewer, but more people and foxes.
I have not seen the milky way for over thirty years.
I used to see M33 in Margate standing under a lit street light without optical aid in windy transparent skies.
11 Pleiades was normal with sometimes 13 with unaided eyes at sea level.
Now almost none.
The only thing I regularly observe now are Jupiter's moons with 18x50 binocular.
And the Moon.
Regards,
David
On many nights no stars or just one or two are visible to the unaided eyes.
The Commission for Dark Skies may allow the use of their photos comparing 30 years ago to now.
You have to ask.
What is strange is that using the Canon G16 with no tripod but jammed on the window frame using Programme a 0.5 second or 1 second exposure at f/1.8 at 3200 ISO reveals many more stars than visually using good 8x32 or 8.5x44 binoculars.
There are many stars shown on the photos with sometimes no stars seen in the binoculars.
The situation here is already probably beyond saving, except with a very rare total electricity blackout which happened once about 15 years ago.
Moths are fewer, birds fewer, but more people and foxes.
I have not seen the milky way for over thirty years.
I used to see M33 in Margate standing under a lit street light without optical aid in windy transparent skies.
11 Pleiades was normal with sometimes 13 with unaided eyes at sea level.
Now almost none.
The only thing I regularly observe now are Jupiter's moons with 18x50 binocular.
And the Moon.
Regards,
David
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David Frydman
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- Joined: Mon Jan 18, 2010 9:25 am
- Contact:
Re: Undergraduate student seeks amateur photography detailing the effects of light pollution on the night sky
One has to be careful comparing film photos to digital images.
Fast colour film was 400 ASA.
800 ASA was available but not very good.
About 5 year ago my Sony A7S gave good photos at 100,000 ISO. 200,000 and 400,000 ISO were not useful.
1/13th second at f/1.4 at 100,000 ISO with a secondhand 85mm Samyang lens showed 7th or possibly 8th magnitude stars in light pollution.
So photographic evidence may not be reliable and even less so compared to visual results.
From cities I could see mag 5.9 stars in light pollution, although mag 6.4 from Helsinki near the sea in very clean air but full city lights.
In Lyme Regis harbour mag 6.7 and mag 6.8 nearby. The street lights were rather subdued.
On La Palma at 7,800 ft in 1988 the zenithal limiting magnitude was 7.2 on a poor night with Saharan dust in the air.
M33 was easily seen with direct vision with unaided eyes.
Also 15 or 16 Pleiads.
In a national park near Tampere Finland there were so many stars above the forest I could not recognise the constellations.
I suppose the stars seen were around mag 7.0.
I can probably see mag 3 stars now at the zenith on a good night.
Regards,
David
Fast colour film was 400 ASA.
800 ASA was available but not very good.
About 5 year ago my Sony A7S gave good photos at 100,000 ISO. 200,000 and 400,000 ISO were not useful.
1/13th second at f/1.4 at 100,000 ISO with a secondhand 85mm Samyang lens showed 7th or possibly 8th magnitude stars in light pollution.
So photographic evidence may not be reliable and even less so compared to visual results.
From cities I could see mag 5.9 stars in light pollution, although mag 6.4 from Helsinki near the sea in very clean air but full city lights.
In Lyme Regis harbour mag 6.7 and mag 6.8 nearby. The street lights were rather subdued.
On La Palma at 7,800 ft in 1988 the zenithal limiting magnitude was 7.2 on a poor night with Saharan dust in the air.
M33 was easily seen with direct vision with unaided eyes.
Also 15 or 16 Pleiads.
In a national park near Tampere Finland there were so many stars above the forest I could not recognise the constellations.
I suppose the stars seen were around mag 7.0.
I can probably see mag 3 stars now at the zenith on a good night.
Regards,
David
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RMSteele
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Re: Undergraduate student seeks amateur photography detailing the effects of light pollution on the night sky
Corrected version of my earlier post.
Having re-examined my contemporary sky notes for 1981 more extensively, I find that I recorded the limiting magnitude at the zenith at magnitude 4.0 on 10 nights, magnitude 4.5 on 15 nights, and magnitude 5.0 on 11 nights. I therefore correct my earlier text as follows;
"I have been an active amateur astronomer since about 1970 and I have lived in the same house on the outskirts of Leeds since 1981. At that time, according to my contemporary variable star notes, the faintest star visible to my unaided eye at the zenith was stellar magnitude 5.0 on 1 in three clear nights. It is now regularly brighter than magnitude 3.0. The brightness ratio of magnitude 3.0 to 5.0 is 6.31:1 which means that for me, an exclusively visual observer as opposed to a photographic or electronic imager, the artificial illumination of an area of clear night sky at the zenith has increased at least 6 times*. This of course relates to the area directly overhead, but both cloud cover and increasing distance from the zenith will amplify the effect of artificial lights."
Best wishes, Bob
*These figures do not take into account the estimated loss of up to half a magnitude on account of physiological ageing factors (between ages 28 and 70).
Having re-examined my contemporary sky notes for 1981 more extensively, I find that I recorded the limiting magnitude at the zenith at magnitude 4.0 on 10 nights, magnitude 4.5 on 15 nights, and magnitude 5.0 on 11 nights. I therefore correct my earlier text as follows;
"I have been an active amateur astronomer since about 1970 and I have lived in the same house on the outskirts of Leeds since 1981. At that time, according to my contemporary variable star notes, the faintest star visible to my unaided eye at the zenith was stellar magnitude 5.0 on 1 in three clear nights. It is now regularly brighter than magnitude 3.0. The brightness ratio of magnitude 3.0 to 5.0 is 6.31:1 which means that for me, an exclusively visual observer as opposed to a photographic or electronic imager, the artificial illumination of an area of clear night sky at the zenith has increased at least 6 times*. This of course relates to the area directly overhead, but both cloud cover and increasing distance from the zenith will amplify the effect of artificial lights."
Best wishes, Bob
*These figures do not take into account the estimated loss of up to half a magnitude on account of physiological ageing factors (between ages 28 and 70).