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#1
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better way of seeing noise before image is printed?
I like to print photos of images I've taken during planetary imaging
sessions. I have been printing images for several years, but I always have the same problem: I can't seem to see the noise very well until after an image is printed. Many, many times I have wasted initial prints because noise rears its ugly head in the image. Then I have to go back and try to gaussian blur the image at the risk of loosing sharpness when the image is reprinted. My question is this: is there any easy way to see noise in images before they are printed? If I zoom in 200% or better and readjust brightness/ contrast, this helps somewhat, but I am usually still disappointed once the image is printed. There must be a better way of seeing/ predicting noise that will show up in photos. Any help would be greatly appreciated. Thanks in advance, Jason |
#2
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better way of seeing noise before image is printed?
On Mar 4, 3:43�pm, "Jason Albertson" wrote:
I like to print photos of images I've taken during planetary imaging sessions. *I have been printing images for several years, but I always have the same problem: *I can't seem to see the noise very well until after an image is printed. *Many, many times I have wasted initial prints because noise rears its ugly head in the image. *Then I have to go back and try to gaussian blur the image at the risk of loosing sharpness when the image is reprinted. *My question is this: *is there any easy way to see noise in images before they are printed? *If I zoom in 200% or better and readjust brightness/ contrast, this helps somewhat, but I am usually still disappointed once the image is printed. *There must be a better way of seeing/ predicting noise that will show up in photos. *Any help would be greatly appreciated. Thanks in advance, Jason Some of the soft ware routines, (i.e. Max DL or AIP4WIN?) alow you to measure the statistics in a specific and controlled region of the image. Pick a region of the dark sky and measure the std. dev. Hope this helps. |
#3
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better way of seeing noise before image is printed?
Use Film.
-- There are those who believe that life here, began out there, far across the universe, with tribes of humans, who may have been the forefathers of the Egyptians, or the Toltecs, or the Mayans. Some believe that they may yet be brothers of man, who even now fight to survive, somewhere beyond the heavens. The Lone Sidewalk Astronomer of Rosamond Telescope Buyers FAQ http://home.inreach.com/starlord Sidewalk Astronomy www.sidewalkastronomy.info The Church of Eternity http://home.inreach.com/starlord/church/Eternity.html "Jason Albertson" wrote in message ink.net... I like to print photos of images I've taken during planetary imaging sessions. I have been printing images for several years, but I always have the same problem: I can't seem to see the noise very well until after an image is printed. Many, many times I have wasted initial prints because noise rears its ugly head in the image. Then I have to go back and try to gaussian blur the image at the risk of loosing sharpness when the image is reprinted. My question is this: is there any easy way to see noise in images before they are printed? If I zoom in 200% or better and readjust brightness/ contrast, this helps somewhat, but I am usually still disappointed once the image is printed. There must be a better way of seeing/ predicting noise that will show up in photos. Any help would be greatly appreciated. Thanks in advance, Jason |
#4
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better way of seeing noise before image is printed?
On Mar 4, 3:19 pm, "Starlord" wrote:
Use Film. -- Film?! For the planets?! Uhh..."no thanks." ;-) The lowliest Quickcam planetary shot is better than the best film planetary shot. WAY better. Unk Rod |
#5
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better way of seeing noise before image is printed?
wrote in message ps.com... Some of the soft ware routines, (i.e. Max DL or AIP4WIN?) alow you to measure the statistics in a specific and controlled region of the image. Pick a region of the dark sky and measure the std. dev. Hope this helps. Can Photoshop show noise statistics? I can see how a certain level of noise in the form of a number could be beneficial for printing purposes. Jason |
#6
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better way of seeing noise before image is printed?
I have seen planetary photos done with film that would blow away most ccd
ones. remember, one pic with film has over 3 megs of data in it. -- There are those who believe that life here, began out there, far across the universe, with tribes of humans, who may have been the forefathers of the Egyptians, or the Toltecs, or the Mayans. Some believe that they may yet be brothers of man, who even now fight to survive, somewhere beyond the heavens. The Lone Sidewalk Astronomer of Rosamond Telescope Buyers FAQ http://home.inreach.com/starlord Sidewalk Astronomy www.sidewalkastronomy.info The Church of Eternity http://home.inreach.com/starlord/church/Eternity.html "RMOLLISE" wrote in message ps.com... On Mar 4, 3:19 pm, "Starlord" wrote: Use Film. -- Film?! For the planets?! Uhh..."no thanks." ;-) The lowliest Quickcam planetary shot is better than the best film planetary shot. WAY better. Unk Rod |
#7
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better way of seeing noise before image is printed?
On Mar 4, 5:34 pm, "Starlord" wrote:
I have seen planetary photos done with film that would blow away most ccd ones. I never have. Period. Unk Rod |
#8
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better way of seeing noise before image is printed?
On Sun, 4 Mar 2007 15:34:56 -0800, "Starlord"
wrote: I have seen planetary photos done with film that would blow away most ccd ones. remember, one pic with film has over 3 megs of data in it. Then you've never seen any good digital images. They are so far beyond film there's no comparison. Film itself is lower resolution, lower dynamic range, lower sensitivity, and higher noise. Good planetary imaging requires taking many (ideally, hundreds) of very short exposure images (to reduce seeing), and summing them (to reduce noise). Film isn't sensitive enough for the short exposures, and even if it were, scanning and stacking that many images for noise control would be a nightmare. People with webcams are routinely producing planetary images these days that are far superior to the best film shots ever made, by anybody. _________________________________________________ Chris L Peterson Cloudbait Observatory http://www.cloudbait.com |
#9
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better way of seeing noise before image is printed?
On Sun, 04 Mar 2007 20:43:54 GMT, "Jason Albertson"
wrote: I like to print photos of images I've taken during planetary imaging sessions. I have been printing images for several years, but I always have the same problem: I can't seem to see the noise very well until after an image is printed. Many, many times I have wasted initial prints because noise rears its ugly head in the image. Then I have to go back and try to gaussian blur the image at the risk of loosing sharpness when the image is reprinted. My question is this: is there any easy way to see noise in images before they are printed? If I zoom in 200% or better and readjust brightness/ contrast, this helps somewhat, but I am usually still disappointed once the image is printed. There must be a better way of seeing/ predicting noise that will show up in photos. Any help would be greatly appreciated. I'm a bit suspicious of your display system. Any reasonable monitor has more dynamic range than a print, and should show noise better. I usually see subtle noise on the screen that doesn't show up in prints, not the other way around. Of course, you should be working at 100% for all critical processing (not 200%, at least not in Photoshop). Is your monitor reasonably calibrated with a gradient scale, such that you aren't losing range off one end or the other? In Photoshop, you should be able to see the difference between a black and a 95% K region, and you should also be able to tell the difference between a white and a 5% K region. You should never have to adjust the brightness or contrast away from what matches your output. _________________________________________________ Chris L Peterson Cloudbait Observatory http://www.cloudbait.com |
#10
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better way of seeing noise before image is printed?
On Mar 4, 3:52�pm, wrote:
On Mar 4, 3:43?pm, "Jason Albertson" wrote: I like to print photos of images I've taken during planetary imaging sessions. ?I have been printing images for several years, but I always have the same problem: ?I can't seem to see the noise very well until after an image is printed. ?Many, many times I have wasted initial prints because noise rears its ugly head in the image. ?Then I have to go back and try to gaussian blur the image at the risk of loosing sharpness when the image is reprinted. ?My question is this: ?is there any easy way to see noise in images before they are printed? ?If I zoom in 200% or better and readjust brightness/ contrast, this helps somewhat, but I am usually still disappointed once the image is printed. ?There must be a better way of seeing/ predicting noise that will show up in photos. ?Any help would be greatly appreciated. Thanks in advance, Jason * * Some of the soft ware routines, (i.e. Max DL or AIP4WIN?) alow you to measure the statistics in a specific and controlled region of the image. *Pick a region of the dark sky and measure the std. dev. *Hope this helps. As a specific example consider AIP4WIN. Go to the Measure\pixel tool. Choose a circle diameter of 60 pixels in the dark sky region. In one case the mean is 3.77 with a sdt dev of 9.66. This operation is about as fast as looking at the image. |
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