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02/01/2011 09:39:10 AM · #1 |
As some folks may have seen here, the challenge is to take a photograph which looks like it was taken during daylight hours, but was actually taken at night/in the dark.
Special rules:
No sunrises or sunsets (moon is quite ok)
Include at least one element in the photograph which shows it is night.
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Message edited by author 2011-02-01 09:42:23. |
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02/01/2011 10:18:10 AM · #2 |
I love the idea, and would like to see more shots like these.
Here's a recent entry of mine that would have been nice for this.
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02/01/2011 11:32:09 AM · #3 |
Great idea. Would be best to allow us to shoot just before, during or just after a full moon.
An alternate, color version of my 4 AM submission.  |
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02/01/2011 11:35:32 AM · #4 |
How is this done? Just a long exposure?
I like the idea.
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02/01/2011 12:25:44 PM · #5 |
Originally posted by NiallOTuama:
How is this done? Just a long exposure?
I like the idea. |
Mine was 935s. Waning gibbous 64% moon, which is optimal for lighting night landscape without washing out star trails. Tripod. Remote shutter release cable. It takes some experimentation to let the ambient light paint the scene, fill the shadows, without blowing out highlights. |
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02/01/2011 01:38:45 PM · #6 |
| any tips for reducing digital grain in these types of images? ive tried this before, but the old 6.3mp d100 is a hot bed of icky pixels... i was shooting at iso 200 (the lowest it will go) with exposures at around the 3-5 minute mark, in camera long exposure noise reduction on.... |
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02/01/2011 02:07:04 PM · #7 |
Originally posted by disassociation:
any tips for reducing digital grain in these types of images? ive tried this before, but the old 6.3mp d100 is a hot bed of icky pixels... i was shooting at iso 200 (the lowest it will go) with exposures at around the 3-5 minute mark, in camera long exposure noise reduction on.... |
In order to do better that the in-camera long-exposure NR, it's necessary to adopt a rather complex approach. You basically have to do what astrophotographers do:
- Turn in-camera long-exposure NR *off*
- Take several "dark frames" (lens cap on) with the same exposure time and ISO as for your images
- Take several image frames
- Take several more dark frames
- Average all your dark frames
- Combine all your image frames (there is more than one way to combine; if not doing star trails, averaging works well
- Subtract your combined dark frame from the combined image frame
There is both science and art to this procedure. The results can be worth the effort, but there is one heck of a learning curve.
For reference, the dark frame subtraction takes care of one type of noise (fixed-pattern noise) while averaging image frames takes care of the other type (random noise). The noise improvement scales with the square root of the number of images. Averaging four images reduces random noise by a factor of two, averaging sixteen images reduces noise by a factor of four, etc.
It's necessary to average dark frames as well so that we don't "add back" the random noise from a single dark frame.
Make sense? ;-) |
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