Timeline for Is a Celestron telescope filter useful for photography?
Current License: CC BY-SA 3.0
9 events
| when toggle format | what | by | license | comment | |
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| Aug 4, 2015 at 13:21 | comment | added | user13451 | If you are after night sky photographs to try to get colors we don't see, you may instead want to consider a broad 'sky glow' filter such as telescope.com/Accessories/Telescope-Eyepiece-Filters/… which blocks the frequencies of light that terrestrial sources give (and reflect back). However, I would strongly suggest you read up on astronomy and emission nebulae. Also note that the colors in the photographs are not the ones in nature. | |
| Aug 4, 2015 at 13:17 | comment | added | user13451 | @fabriced If you are using a narrow band filter, you will have trouble seeing any color (especially with an exposure that is less than several minutes). The areas of color in the night sky, with a few exceptions tend to be just arcminutes across (there are 60 arc minutes in a degree - a 400mm lens on full frame has a 6.2 degree fov). The Horsehead Nebula is 8 arcmin x 6 arcmin. The Eagle Nebula is 7 arcmin. Outside of these nebulae, the sky is black. | |
| Aug 4, 2015 at 9:54 | comment | added | MicroMachine | I guess what I was trying to ask, underlying in my question, is whether or not it would be possible technically, to take pictures of the sky in which colors that are hard to see with the human eye would appear. Not necessarily zoomed pictures, but landscapes or still life or portraits in which the sky is visible. | |
| Aug 3, 2015 at 4:16 | comment | added | user13451 | Imagine taking all your photographs using only the light from a low pressure sodium vapor lamp - i.sstatic.net/CvIjo.jpg and that is the type of color you would get with a bandpass filter. Though this one would happen to be in the blue-green part of the spectrum rather than the yellow. Black and white photographers use such filters - but not narrow bandpass. The green filter that a B&W photographer uses (a 58 or 61) has a bandpass of ~150nm. Others tend to be long pass. photo.net/learn/optics/edscott/cf000010.htm - try those instead of a narrow band pass. | |
| Aug 3, 2015 at 4:12 | history | edited | user13451 | CC BY-SA 3.0 |
Add true color image.
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| Aug 3, 2015 at 4:09 | comment | added | user13451 | The color of the first image is a false color composite, as explained in mcwetboy.com/mcwetlog/2010/04/… . The second (now third) image is a gray scale because using color data isn't meaningful when there is such a narrow band of color. I would suggest going and borrowing a R25 filter and shooting a few frames through it (and its not a narrowpass filter - you'll get more 'color' data out of it). The filter is designed for capturing a very particular color of light and taking photographs that have exposures of several minutes. | |
| Aug 3, 2015 at 3:55 | comment | added | MicroMachine | Thanks @MichaelT for your help in understanding this complex concept. Sorry if I sounded like a noob, I definitely know that we need a lot of filters all the time :) What I don't understand is: why would the second photo be B&W but not the first one? Wouldn't a camera be able to reproduce what the eye sees, including colors? Also, my question was, simply, if you used this filter for regular photography (i.e. long pose portraits under a night sky), would it pull out "more" details and colors from the sky than not using a filter? I built adapters & lenses before; so Ø of thread is not important. | |
| Aug 3, 2015 at 3:48 | vote | accept | MicroMachine | ||
| Aug 2, 2015 at 17:02 | history | answered | user13451 | CC BY-SA 3.0 |
