njbphoto Posted October 18, 2004 Share Posted October 18, 2004 I was out shooting this past weekend and noticed some of the sky shotsI took with the sun in them had a really weird flare. It's completelylinear and varies from white to slightly green. At any rate, I waswondering if anyone has an explanation (I'd like to know whether I didsomething wrong that I can fix, or if this is an inherent problem withdigital, or whether my camera may need to be repaired). Thanks so muchfor any help! Here's an example: (oh and any pointers on how to "fix"it in photoshop would be much appreciated! =) <img src="http://img.photobucket.com/albums/v481/nbabs219/DSC_1319.jpg"> Link to comment Share on other sites More sharing options...
phule Posted October 18, 2004 Share Posted October 18, 2004 To the best of my knowledge your CCD should not be blooming like that. You may need to get it looked at. Link to comment Share on other sites More sharing options...
EricM Posted October 18, 2004 Share Posted October 18, 2004 are you by chance using any skylight or uv filters? Link to comment Share on other sites More sharing options...
grepmat Posted October 18, 2004 Share Posted October 18, 2004 This is common effect associated with "blooming" - it is an problem inherent with most CCD's. The thing is that you had the sun directly in your field of view. The sun, of course, is incredibly bright - so bright that it can cause temporary problems for the sensor. If you have it in your field of view, you are likely to see effects like this. Even a bright reflection can cause it. It is not a good thing, but it is normal. By the way, it being directional like that has to do with how the charge is shifted out of the CCD. Cheers. Link to comment Share on other sites More sharing options...
phule Posted October 18, 2004 Share Posted October 18, 2004 << This is common effect associated with "blooming" - it is an problem inherent with most CCD's >> This is only a problem with CCDs not outfitted with anti-blooming gates. While I have no direct knowledge regarding the CCD on the D70, the fact that my Canon A80 has such a gate does lead me to believe that the D70 would as well. The fact that this camera blooms would indicate a possible malfunction of either the gate or the CCD chip. Link to comment Share on other sites More sharing options...
masque Posted October 18, 2004 Share Posted October 18, 2004 My D70 does not exhibit the vertical band that yours does. I have not shot many frames like this, however... perhaps five? Perhaps six? Maybe further testing is required. And maybe someone else will do it. :) Link to comment Share on other sites More sharing options...
bill_chiarchiaro Posted October 18, 2004 Share Posted October 18, 2004 The D70 is known to produce effects like that green stripe when shooting the sun. One way to avoid them is to use smaller apertures (larger f numbers) to get slower shutter speeds. The problem apparently is due to the D70's electronic shutter, which it uses at speeds faster than 1/250 or so. At slower speeds, the mechanical shutter controls the exposure. Your image was shot at ISO 800, f/16, and 1/2500 with a 28-300mm lens. You could have dropped the ISO setting to 200, and I'm guessing your lens could go one more stop to f/22. That would have given you a shutter speed of 1/320, which might not have been quite slow enough. Still, think "low ISO" and "small aperture" the next time you're shooting the sun. Good luck, --Bill Link to comment Share on other sites More sharing options...
grepmat Posted October 18, 2004 Share Posted October 18, 2004 To clarify: Even sensors with anti-blooming technology will bloom with enough light. These technologies help, but are not cure-alls. Cheers. Link to comment Share on other sites More sharing options...
grepmat Posted October 18, 2004 Share Posted October 18, 2004 Another point, if people are wondering: An electronic shutter can be overwhelmed by too much light as well. While "closed", it is trying to keep the charge erased, but it can be swamped to the point that the pixel still saturates and blooms. A physical shutter is, of course, essentially immune to this. Hence, the previous poster's suggestion to use a shutter speed that relies solely on the mechanical shutter. Cheers. Link to comment Share on other sites More sharing options...
njbphoto Posted October 18, 2004 Author Share Posted October 18, 2004 Thanks so much to everyone for the info! You guys are great! One question though: Bill, how did you know my camera's seetings? Are they perserved even when the image is uploaded? Very nice! Thanks again... looks like I'll have to remember to slow the camera down next time. Link to comment Share on other sites More sharing options...
bill_chiarchiaro Posted October 18, 2004 Share Posted October 18, 2004 "Bill, how did you know my camera's seetings? Are they perserved even when the image is uploaded?" Nick, Evidently, they were. Some image processing programs preserve the EXIF data, and others don't. There are several freely available programs that will read and display the EXIF data. Currently, my favorite is exiftool (http://www.sno.phy.queensu.ca/~phil/exiftool/). I saved a copy of your photo, ran exiftool on it, and out came the data. --Bill Link to comment Share on other sites More sharing options...
larry_tudor1 Posted October 18, 2004 Share Posted October 18, 2004 I don't know but...shooting the direct sunlight with a digital camera isn't really healthy for the sensor...I think.Film is another story. Link to comment Share on other sites More sharing options...
streetlevel Posted October 18, 2004 Share Posted October 18, 2004 How to fix - lots and lots of careful clone tool. You could even do a color range select to help protect the surrounding area, but feather the heck out of it. No easy fix that I can think of though... Link to comment Share on other sites More sharing options...
phule Posted October 18, 2004 Share Posted October 18, 2004 << shooting the direct sunlight with a digital camera isn't really healthy for the sensor >> Generalizations are worth very little. Link to comment Share on other sites More sharing options...
juan_parm_nides1 Posted October 21, 2004 Share Posted October 21, 2004 If the light does not hurt your very sensible retina (you do not feel pain in your eyes) it hardly can hurt your CCD. But you must use high "f" numbers, I mean ,f22 or higher, to eliminate undesirable effects. In an DSLR the CCD is only exposed to light at the moment you press the shooter. Link to comment Share on other sites More sharing options...
larry_tudor1 Posted October 21, 2004 Share Posted October 21, 2004 How about the LCD then...I'm asking this because I have spot metering on my P&S camera so,I adjust the exposure for how I like it on the LCD and then,reframe so that's why I should be real carefull not to include the sun since my exposure is lock,the diaphragm don't close down so there would be a lot of light reaching the LCD. Link to comment Share on other sites More sharing options...
larry_tudor1 Posted October 21, 2004 Share Posted October 21, 2004 Thinking about it...isn't a P&S CCD<always exposed to the light since...that is what provide you with an image on the LCD...right? Link to comment Share on other sites More sharing options...
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