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jrw11
professor emeritus
Reged: 06/09/07
Posts: 501
Loc: U.S.A.
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The area where I take my photos is probably better than a lot of urban areas. The houses are about a half mile (or more) from the main street. The houses are to the south of where I set up. The houses have their garages jut out from the house. And each one has the standard 100 watt bulb on the side of the garage. To the north west, there is one street lamp at about 10 to 10:30 o-clock. Is there a filter that can be used with film to cut down the extra light? While there is that one street light, I've seen alot of people who live on the main streets, that have several. So, I'm lucky in that regard. Thanks!
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Celestron C6n -HD Reflector
dual axis drive motors added
Orion 80mm Short tube refractor
Skyscout
Early 70's Pentax 7x50
Garrett Optical 12x60
Garrett Optical 15x70
Oberwerk 20x80 Standards
Canon Rebel Ti (film)
4 Minolta Srt cameras
Mamiya RB67 Pro-s with 180 lens
127mm KL lens for RB, Bellows hood for RB67
120 and 220 film backs
Cambo SCII 4x5 view camera
over 50 other film cameras
several eyepieces
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1965healey
Carpal Tunnel
Reged: 06/23/07
Posts: 2846
Loc: San Antonio, TX
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Oh Clownfish, where are you?
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1965Healey (Karen)
Woodlawn Lake Observatory
Celestron CPC 800/FT MIcro/APT Wedge
SV NHNG 80mm #0261/CG5-GT
Celestron Omni 150 XLT
Losmandy rails/rings
Starizona CWeight system
Celestron Neximage
Sony a100 DSLR/ZigView S2
Meade DS60's w/Autostar (2)
Meade LPI/Meade DSI-C/DSI ProII
750cc Honda Shadow Spirit (Thanks Dad!)
1965 Austin Healey 3000 MKIII
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ClownFish
Post Laureate
Reged: 04/26/05
Posts: 5600
Loc: Islamabad, Pakistan
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I know your pain! I live in a secured compound with 4 other homes, surrounded by high walls, electric fence, and 250 watt security floodlights on every side of each of the four homes, plus all along the wall. It is a virtual daylight here after sunset.
Light Pollution Filters, come in several flavors and work by cutting back specific areas of the spectrum. For narrow spectral range targets, these filters can help by increasing contrast between the background glow and the target's own light. But many objects that use star light to illuminate themselves (stars, reflection nebula, galaxies) will not benefit, and in fact, be worse off.
Also, the filters work best in the central portion, thus if you use a wide angle lens you will see banding and other artifacts from using the filters.
And with all filters - they do not transmit 100% of the energy passed through them. Since film already suffers from reciprocity failure, even slight light intensity decreases will cause a much greater loss of exposure. You will need to compensate 2 to 3 times the exposure.
With all that said, the IDAS Light Pollution Suppression (LPS) filter from Hutech is one of the best filters for color film. I hope others can chime in with your experiences too!
Another filter option that works in light polluted areas in the Ha filter. This produces a deep red image, so you will want to convert the color image into a B&W when post processing. This filter blocks just about everything EXCEPT Hydrogen Alpha, which many large emission nebula shine at. Examples include the North American, California, Rosette, Lagoon, Crescent, Eagle, Swan, and many others. This filter looks almost black, and you can't see anything through it. But Ha light passes - and if you have a film that is very sensitive to Ha light then it will work. Kodak E200 and old Tech-Pan B&W film does nicely with this - although unfortunately Tech-Pan is no longer being manufactured.
CF
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Learn all about POLAR ALIGNMENT with my Drift Method Tutorial and simulator!! Or visit my Foreign Service Blog!
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jrw11
professor emeritus
Reged: 06/09/07
Posts: 501
Loc: U.S.A.
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Thanks CLOWNFISH ! Those photos in the film forum that I called "east of jupiter" were taken in that location.
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Celestron C6n -HD Reflector
dual axis drive motors added
Orion 80mm Short tube refractor
Skyscout
Early 70's Pentax 7x50
Garrett Optical 12x60
Garrett Optical 15x70
Oberwerk 20x80 Standards
Canon Rebel Ti (film)
4 Minolta Srt cameras
Mamiya RB67 Pro-s with 180 lens
127mm KL lens for RB, Bellows hood for RB67
120 and 220 film backs
Cambo SCII 4x5 view camera
over 50 other film cameras
several eyepieces
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