At 02:11 AM 3/24/2007, Robert M wrote: >All, > >I'm sure lots of people now have more experience with the "Self Cleaning >Sensor". I am interested in these people's opinion on this feature.
I highly recommend people take a look at this site: http://pixinfo.com/en/articles/ccd-dust-removal/ for one test on the effectiveness of dust cleaning systems. Bottom line is they don't do that much. I would put my money the most on anti-static methods. This site's results confirm my own experience, especially that the Olympus E-1 dust cleaning has more to do with the distance the dust is held away from the sensor, which is easier to do with smaller than FF sensors. I have tried many methods of cleaning the sensor and the two most effective I have found are the CO2 Duster (not a standard compressed air which can splatter other stuff onto the sensor) and a pecpad wrapped around a piece of plastic (like shaped credit card) and some ethanol. The same as the above article implies. I have yet to try the electrostatic ionizer approach: http://www.fovegraphy.com/IonizerE.php Unless you tend to shoot at high F-stops (F11-F16 and higher) dust is not likely to be "too" much of an issue unless you go looking for it. In my experience, the best dust removal system is the operator of the camera, a CO2 Duster, and occasional cleaning. I have not seen any definitive results that dust removal works. The cameras that seal the sensor chamber, or keep dust farthest away from the sensor are the best. The CO2 duster gets the big stuff. The fine stuff requires more effort, but is also less visible except at the high F-stops. And I quote one of my previous emails: At 03:52 PM 2/8/2007, you wrote: >At 12:47 PM 2/8/2007, Robert asked: >><snip> >>The main reason I would wait for the next release is for the self cleaning >>sensor. Does anybody have experience with it? How well does it work? > >I've had experience with the Olympus E-1 and the 5D. The effectiveness >of the E-1 is in part, keeping the dust further from the sensor, such that >the shadows cast by the dust are less sharp. Hence it appears that the >dust shakers work, in part because the dust is held further from the sensor, >which is easier to do on non-FF sensors. (This applies to really fine dust) >The F-stop needs to be F-11 or higher before the fine dust is an issue >(macro photography suffers the most from Dust issues). > >Second, the DOF required for a FF sensor is smaller (higher F-stop) >than a reduced frame sensor, and hence will sharpen the dust shadow. > >Third, the most difficult dust (or oil or contaminants) are the really small >ones that seem to be un-affected by the shaker. To be most effective >some sort of ionizer needs to discharge the static charge or no amount >of shaking will eliminate the fine dust. > >On the 5D, the worst dust occurred, for me, during the summer when >I fired the camera after it had been sitting in the hot car. I believe that >oil from the shutter splattered onto the sensor, and only some sort of >solvent would remove it. I also have a permanent dust particle from >manufacturing, as it is between the sensor and the AA filter. > >For the random large dust, the dust shakers help, but so does a >CO2 Duster, for that type of dust. Both the E-1 and my 5D required >cleaning for the fine particulate, which shows up at high F-stops. > >For those who want to see the dust in their cameras, set the F-stop to >at least F22, or the highest it will go. Then take a photo, Un-Focused at >a blue monitor background, or blue sky, or any uniform light. Then boost >the contrast of the image. Dust in the image that is upper right, will be >in the lower right as you look into the camera from the front (if you are >trying to wipe or clean the sensor). > >Again, the hardest dust to remove will appears as fine specs. Larger dust >tends to be fibrous and many techniques can remove it fairly easily. The >fine stuff is really difficult for the shakers without some sort of ionizer >to discharge it. > >Some links: >http://www.bythom.com/cleaning.htm >http://www.pbase.com/image/15473243 >http://americanrecorder.com/catalog/index.php?cPath=10 >http://www.fovegraphy.com/IonizerE.php > >My favorite method uses a PEC*PAD wrapped around stiff plastic >(like old credit card) with some methanol (eclipse). Cut plastic to >nearly the width of the sensor. > >I've tried the VisibleDust brush, the SensorSwab, the CO2 Duster, and >the PecPad on plastic with methanol. The CO2 duster and the PecPad >works the best for me. I have yet to try the ionizer approach. And I just >can't seem to the the VisibleDust brush to do much, at least for the >fine particulate. > >If you do macro photography (or any high F-stop), dust is a real pain. Wayne S * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
