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Longer exposures??
Mad Hatter Imagery wrote: no but the difference would be minor unless of course as stated earlier there is movement in the frame Jul 29 14 07:22 pm Link Jul 29 14 07:25 pm Link Ok, so I set up my tripod and pointed a camera at something black. I dialed it up to ISO H2 (aka unusable) and then I metered it. It turned out to be 1/250, so at 1/8000 I would have to take 6 shots to get the same amount of light. I then took six shots at 1/8000 and six shots at 1/250. Then I wrote a python script to sum and average the jpegs into new jpegs. No wimpy WYSIAG image editing programs for me! It was 34 lines, including blank lines and the #! comment at the start. I could make it shorter, but it is short enough I think. I posted my experiment at https://infohost.nmt.edu/~schlake/imgmerge/ The two subdirectories have the original jpegs, and resulting jpeg. The top level directory has the source code. The jpegs are small jpegs out of my camera. The sum of six underexposed images is primarily noise with some rough shapes similar to what the picture really looks like. The average of six properly exposed, but high-noise, images is a cleaner rendition of the image with less noise. Jul 29 14 10:13 pm Link Ok. My point is I don't have a camera that can be exposed for an extended amount of time and I'd like to see night star streaking across the sky for maybe an hour's time or maybe produce an image composed of all light passing through a given scene in 24 hours. If I could rely on shorter exposures I won't need a neutral density filter during day hours. Jul 30 14 12:53 pm Link Mad Hatter Imagery wrote: I work in a building full of astronomers. When I mentioned to one my little experiment last night, I got a tremendous amount of information on this kind of stuff. Apparently this kind of thing is as common to them as caution tape is to us. For what you say you are doing, head to an astro forum and see if you fare better. Jul 30 14 02:10 pm Link Herman Surkis wrote: Can you pay pal me $100? If not, you'll have to steal it. Jul 30 14 02:22 pm Link Mad Hatter Imagery wrote: I guess you might be in luck. You probably do NOT want to run a 60 minute exposure. instead, you'll want 60, 1-minute exposures. Jul 30 14 02:28 pm Link Christopher Hartman wrote: He is talking about stacking the exposures up digitally and adding them all together digitally. Seems easy enough to test. Jul 30 14 02:55 pm Link Mad Hatter Imagery wrote: ya know you could have just said that in beginning, yes you can do it, many night time photographers do this to get long star trails and avoid noise from sensor heat up. there are ton of tutorials about how to do it. Including best time of month where to point your camera, settings on camera and post photo shop work Jul 31 14 09:21 pm Link is something moving...well, the long exposure will give that and have a different blur then a combination of exposures..if it is a static shot, and going for hdr, well again a different effect...light, and exposure 101....this shot gets the clouds, this one gets the details...what are you going for...have fun and experiment ...beauty of digital...Mo Jul 31 14 09:34 pm Link Mad Hatter Imagery wrote: Easily done! Aug 01 14 06:11 pm Link Mad Hatter Imagery wrote: The difference is that one is called "Long Exposure" and the other is called "Multiple Exposures." Aug 01 14 07:21 pm Link |
