I don't understand how the aperture relates to how the rate of flicker beats with the frame rate. Allen > -----Original Message----- > From: piclist-bounces@mit.edu [mailto:piclist- > bounces@mit.edu] On Behalf Of Sean Breheny > Sent: Wednesday, May 15, 2013 9:11 AM > To: Microcontroller discussion list - Public. > Subject: Re: [EE] High Speed Camera (especially Mike > Harrison if he is around) >=20 > Hi Bruce, >=20 > Thanks for the suggestion. It shows this banding even if the > aperture is > completely closed so I do not think it has to do with flicker of > the light > sources around. >=20 > Sean >=20 >=20 >=20 > On Wed, May 15, 2013 at 4:33 AM, Bruce Douglas > wrote: >=20 > > Just to make sure, have you tested this camera under > sunlight as well? > > High speed cameras have flicker and maybe banding > under many types of > > artificial light. > > > > On Tue, May 14, 2013 at 12:52 PM, Sean Breheny > wrote: > > > > > OK, more interesting information: > > > > > > First, I looked at the auction photos again and I realized > that I > > > overstated the degree of evidence that this thing was > working before > > > shipment. I notice that the image shown is very blurry. It > does not seem > > to > > > have the bands of noise but it is not certain. > > > > > > I also noticed in my playing with the camera that focusing > the lens > > didn't > > > seem to make any difference in the image. Not only was > it noisy but > > always > > > blurry. > > > > > > So, I opened up the camera itself. I discovered that the > CCD had a light > > > blue IR cut filter glued to the top and that this filter had > some kind of > > > residue on BOTH the outside and the CCD-facing > surfaces which made it > > very > > > clouded. I was able to clean the front surface but I could > not clean the > > > inner one. Given that this sale was as-is, no returns, I > took the risk, > > cut > > > through the glue beads, and popped the filter off the > top of the CCD. > > Thank > > > God, it came off cleanly and indeed there is another > piece of glass under > > > it covering the sensor and that is clear. > > > > > > I have yet to reassemble and try the camera again but I > suspect that this > > > will make the image much better - although of course it > will not do > > > anything about the banding. > > > > > > Any idea how this would have happened? It almost looks > to me like the > > glue > > > used to attach the filter eventually outgassed and > clouded the filter. > > That > > > seems strange, though, unless someone modified the > camera to add this > > > filter and used the wrong kind of adhesive. > > > > > > Last night I removed the main board from the control > unit and looked for > > > any evidence of failed capacitors, debris, flux residue, > etc. I also > > > inspected the several reworks to make sure they were > not damaged. I > > > re-seated all connectors and socketed ICs. No difference > in system > > > behavior. > > > > > > I scoped the power supply input to the main board (+5 > and +12V from an > > SMPS > > > which is an external module) and it is clean. There is a > DC-DC converter > > > implemented with discrete components and a > transformer on the main board > > - > > > I have not yet verified whether that is working properly. > > > > > > The image on the screen has a menu bar to the right and > that is crisp and > > > clear - the banding is only within the actual image from > the camera. This > > > makes me suspect that it is not a problem with the main > power supply or > > > with the CRT driver board but rather something in the > processing of the > > > image or the power supply to the camera. > > > > > > Sean > > > > > > > > > > > > On Mon, May 13, 2013 at 4:54 PM, Mike Harrison > > > > wrote: > > > > > > > On Mon, 13 May 2013 16:42:46 -0400, you wrote: > > > > > > > > >Yes, thank you, I have already seen those. > Unfortunately, the innards > > do > > > > >not seem all that close to mine but I still say that the > device is > > > similar > > > > >because the user interface is identical and the outer > appearance of > > the > > > > >case is similar. Also, the PCB inside the controller is > silk-screened > > > > >"Redlake Imaging" so it must be that Olympus hired > Redlake to design > > > this > > > > >model. > > > > > > > > > >Sean > > > > > > > > Seems like there has been lot of re-badging and > company takeovers over > > > the > > > > years in the HS video > > > > business > > > > > > > > -- > > > > http://www.piclist.com/techref/piclist PIC/SX FAQ & > list archive > > > > View/change your membership options at > > > > http://mailman.mit.edu/mailman/listinfo/piclist > > > > > > > -- > > > http://www.piclist.com/techref/piclist PIC/SX FAQ & list > archive > > > View/change your membership options at > > > http://mailman.mit.edu/mailman/listinfo/piclist > > > > > -- > > http://www.piclist.com/techref/piclist PIC/SX FAQ & list > archive > > View/change your membership options at > > http://mailman.mit.edu/mailman/listinfo/piclist > > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list > archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .