From: "Charles Allison"
Date: Thu Sep 13, 2001 12:42 pm Subject: Re: [VIDEOASTRO] Possible new features/mods for pc23c Hi group, I've been looking at the pc23c chip specifications again in some spare time and kicking some ideas around with a few folks and have possibly come up with some good prospects. Right now, these have not be done or verified, but they look very promising and are fairly simple for what they can do. First, There seems to be a 1 jumper mod that appears to push out the AGC/manual gain by a little bit, increasing sensitivity slightly at the expense of a little more noise. Second, and possibly fantastically, it seems possible to make a fairly small mod to allow time integration of up to several seconds, making the camera extremely sensitive compared to a normal video camera. Initially, this mod will probably require using a computer, digitizer and program to run the camera integration and only one frame or field will have the integrated image. It should be possible to build a small circuit board which can capture this integrated image and continue to output it on all frames with only a little more mod work to the camera. These should allow one to use the pc23c for a video tracker on much dimmer objects and permit better imaging of those solar system objects which are just a little too dim for video. These mods with image stacking software will possibly even be able to achieve deep sky images as well as squeezing out that last little extra bit of exposure needed to get a decent image. It's going to be a while before I can fully implement the system with synchronized frame capture software which is a requirement for my use. The basic mod to the camera requires making a couple of fairly tight connections adding a couple of resistors and cutting a land in a very easy to get to area of the board. It will also require coming up with some small prototype board with some small amount of circuitry. Anyone interested in testing the idea or in additional details, please contact me. Charles
From: "Charles Allison"
Date: Sun Sep 16, 2001 7:01 am Subject: Re: [VIDEOASTRO] Possible new features/mods for pc23c Joe, I've been discussing this on qcuiag also. The mod should work for a variety of cameras using sony chip sets. I think the pc23c with the cxd2400r offers a better solution than the newer ones with the 2463 because the 2400 can do frame integration rather than merely field integration. The net result is a full 512x460 (approx) rather than 512x230 for the 2400. The 2463 seems to only have field integration so you can do it for only 1 field since field integration sums two ccd pixel rows at a time. At present, I haven't tried to make the integration mod. Although the hw should take around an hour or two (mostly to figure out cabling and finding the connector to the camera's iris control - since that looks like a good one to use rather than drilling holes in the camera body). I have tried the frame integration mode and it seems to work. best regards, Charles
From: "Charles Allison"
Date: Thu Sep 20, 2001 3:37 pm Subject: Re: [VIDEOASTRO] Super pc23c mod test -----Original Message----- From: Charles Allison To: QCUIAG@yahoogroups.com Date: Thursday, September 20, 2001 5:36 PM Subject: Re: [QCUIAG] Modified pc23c cam > >Group, > >I finally got to try to test my mods on the pc23c video camera. The >attached images were captured to 8mm video tape and then captured to >computer via a connectrix usb video capture device at 320x240. > >The camera has my older mods of manual/auto shutter and AGC auto/manual/off >which are available on the web from more than one source. The camera was >set to E Shutter off (default 1/60th second exposure intended to use with >lenses with electric iris control. The AGC was turned off. Images were >taken with the room lights off during the day with the windows shuttered so >it was moderately dim. > >The images are preliminary using an alligator clip to control the extended >integration rather than a transistor and computer interface. > >int60fld.jpg - camera running at 1/60 second in the fld mode (normal >default camera mode) > >flfd.jpg - an image with about 1/2 to 1 second manually timed exposure in >the field mode. > >flfrm.jpg - an image in the frame mode with about 1/2 to 1 second manually >timed exposure. > >No serious attempt was made to adjust the focus or aim at a target since the >camera was in pieces on the edge of the work bench. > >The pc23c is a common under 100 $ US b&w camera available in ntsc and in pal >containing a sony ccd and a sony cxd2400 timing chip. > > >Best regards, > >Charles
From: "Charles Allison"
Date: Tue Sep 25, 2001 2:25 pm Subject: Re: [VIDEOASTRO] Possible new features/mods for pc23c Joe, It's been slow, The only photos I have so far are of the finished mods on the camera card. I've spent the last several days trying to get a new computer up and running for the wife. Hers is about to bite the dust and building up a new one is far more complex than just sticking the parts together and loading windows which was completed saturday and I'm still not quite finished. (that and moving the wife's office from upstairs to down here.) I do have some benchtop 1 sec nominal manual exposured timed images to the vcr (mostly an upside down view of the rear of my office chair and some crud on the floor in a moderately dim room taken with agc off). The mods do seem to work as expected and don't appear to negatively affect the camera in its normal operating modes. I think it will make for a really great all around b&w camera and a very fast and accurate autoguider. It's a lot less messy and complicated to work with than my cookbook camera and it should allow reasonable video quality images of just about anything the cookbook cam can do but it's not going to replace the cookbook for the ultimate best possible image and data collection capability that only one of those cooled slow data capture/transfer ccd cameras can do. I have had the camera modified with the lid on since thursday but the two transistor mod circuit to tie to the serial port that goes in my controller box has been there on the bench in pieces since thurs. Even today was a bombout since I had to go get a fan belt for the lawnmower halfway across houston and tonight is a class (3 more left). Hopefully, I've got all the blackwidow spiders killed off in my observatory hut and the horrible reign of terror from the skies (or the lawn - where ever those giant mosquitos hide) seems to also be over and I can actually go outside without losing a quart or two of blood to those little vampires. I'm beginning to feel like that guy from the lil abner cartoon strip with the cloud that perpetually stays over him raining continually. On the brighter side, I got 2 of those new Vesta Pro cams for $25 ea from Egghead sw and the mods for them on QCUIAG seems to be going great guns with images coming in to the group. At the current rate though, I'll get mine modified by the year 2220. Anyway, I have hopes of being able to finish the pc23c mods this week and put a bit into my guider program to get it running. I'll also have to try to get an option going to save the images to disk in that program. It is possible to do it to a video tape in a totally manual mode and it was not difficult to capture them to my connectrix usb capture device. Also - the new computer now has my wingotv card up and running in it so I'm back in decent video capture capability again. Hopefully, things are going to settle down some again and I'll be able to start doing some things on the bench and in the observatory soon. Best regards, Charles
From: "Charles Allison"
Date: Mon Nov 19, 2001 2:15 pm Subject: IT'S FINALLY HERE - AN INTEGRATING TIME EXPOSURE for the PC23C Hi all, I have finally gotten enough time to finish (or at least reach a useable intermediate state) my imager projects and to document them. They can be reached by going to my astronomy web page and going to the downloads page. http://home.covad.net/~cbapja/cba/astro.htm PC23C Modification What is there is an Acrobat PDF describing the modification for the PC23C video camera. Version 4 of the modifications include not only manual control over the Gain and shutter speed, but also contain a time integration mod which will allow the camera to integrate frames for quite a few seconds, either with or without a computer present. It's possible to even use a pushbutton to manually time the exposures while recording to a VCR. VideoView VideoView is a simple image capture program which will work with both the PC23C for direct video capture and it will work with Steve Chamber's long exposure Vesta Mod. The program will either run long exposures or a rather slow video stream capture from either cameras. It is possible to turn the video capture to disk on and off and to save currently captured to CAPTURE.AVI images to another file name and location. There is a TXT file describing the basic use which must be downloaded separately. Please feel free to download them and send me your comments and suggestions. I do not know when I can get back to making improvements on either but they should be functional. Best regards and Enjoy, Charles Allison
Date: Thu Jan 10, 2002 10:19 pm Subject: Fwd: Supercircuits PC-164C experiences and information Here is an initial review of the PC-164C as reported by David Dunham. Rob Robinson - VP of Occultations Services - IOTA --- In IOTAoccultations@y..., Joan and David Dunham wrote: In previous messages, usually with information about individual events, I have given some information about the amazing PC-164C camera sold by http://www.supercircuits.com for $130, less than half the cost of the similarly sensitive Watec 902H camera. The PC-164C easily recorded the 11.0-mag. star that was occulted by (712) Boliviana on December 19 when I used it with an 8-inch Schmidt-Cass and f/3.3 focal reducing lens at a rather dark site near Hancock, Maryland. Even 12th-mag. stars were faintly visible. Last night, I tried to record a graze of an 8.8-mag. spectral type M star with the same system from nearby Damascus, Maryland. It easily recorded the star at a cusp angle of about 12 degrees with the 52% sunlit Moon, which produced considerable glare with some thin clouds; that was right at the start of the graze period. Features could still be seen on the Earthlit dark side of the Moon at that first-quarter phase. Unfortunately, the clouds rapidly thickened, causing both the lunar dark side and star to disappear, so the graze was not recorded; of course, about 5 minutes later, the clouds passed and the Moon was in the clear for at least half an hour more. Next month I will record a faint-star graze with the system; there are many nearby opportunities. The PC-164C looks different from, and is smaller than, the inexpensive PC-23C camera that is made in Taiwan. The basic connections for those two cameras are the same, although the PC-164C back end connections are on wires rather than built into the body of the camera like the PC-23C. That is, the front is a C-mount, so a C-to-1.25 inch adaptor, like the one sold for about $35 from Adirondack Video, is needed to use with a telescope. The video out is a male BNC, so a female BNC-to-female RCA connector is needed to use with standard (male) RCA jacks. The 12-volt power connector available from Radio Shack is also the same as the PC-23C. My PC-164C is nearly as sensitive as my Watec 902H, with the Watec camera being only a few tenths of a magnitude more sensitive, probably just because the Watec has a 1/2-inch CCD while the PC-164C has a 1/3-inch CCD, like the PC-23C. If you have a Schmidt-Cass telescope, I highly recommend using it with a focal reducing lens, especially the Meade Series 4000 CCD f/3.3 focal reducer, available for $145 from http://www.focuscamera.com and probably other Meade dealers. It will increase your field of view by a factor of 9, and since any star's seeing disk falls on fewer CCD pixels with the focal reducing lens, each pixel sees more of the star's light and the star appears brighter, in spite of some loss with the additional optics. The gain is nearly a magnitude. Neither the PC-164C nor the Watec 902H cameras have built-in microphones, like the PC-23C. If you have a PC-23C, you can use it for the audio, in which case, you need to have two power cables and two small batteries (or one with a "Y" connector, with which I have always had problems). Otherwise, you need to either patch the radio signals directly to your VCR or camcorder, or use a microphone and mixer (to boost the weak microphone signal) for audio. However you connect your video components, as Scotty Henderson has stressed many times, good cables and firm connections should solve most of any problems that arrise; a spare cable is always welcome if one fails in the field. The PC-164C is just Supercircuits' designation of this camera for their distribution within North America (NTSC version). On the camera itself, it only says "KT&C CCD Camera" and "Exview". Anton Paschke searched and found that KT&C = Korean Technology & Communication (a South Korean company) but he could not find a web page for them. He found the camera mentioned on Web sites in Ukraine and Russia, so a SECAM version must exist, but I don't know about PAL. It is possible that will come later; the NTSC version has been sold in the USA for only a month now. In any case, this rather inexpensive camera should encourage more observers to videorecord asteroidal occultations, providing more robust imaging and more accurate timing than can be done visually. Eliminating errors of reaction time estimates helps analysis of observations of most asteroidal occultations considerably. And the camera can record many more lunar events. Hopefully, they will encourage more observations of grazing occultations by making it possible to make good recordings of grazes of fainter stars. Hence, there will be more opportunities closer to you, making it easier to find events that fit your schedule. Good luck with your observations, which are always welcome, however they are made. David Dunham, IOTA
Dear persons; I am working on a hack of a SuperCircuits PC-23C I recently puchaced. I've seen photos on the web of pictures of the planets taken with this camera atteached to different telescopes, and would like to be able to do something similar. The problem I've run into with another board camera (Circuit Specialist cheapie with a SHARP chipset) was that the automatic controls (iris, shutter, blah-blah,) tend to reference to 'black' (or optically black pixels) and the 'subject', a simple bright object with a mostly black background, becomes 'clipped', or over exposed. Loss of surface detail on the planets was the end effect. The PC-23C appears to handle such objects better, but I figure if I can control shutter speed or iris manually, videos of this nature could be improved. So, here's where I am so far; I've determined the manufacture's chipset (Sony) and part numbers (CXD2400R Timing controller, CXA1310AQ Processing chip, and CXD1250M/N Vertical clock driver,) and picked up the data sheets form Sony's web site. (I believe it was at http://www.sel.sony.com ) While reading the data sheets I detemined that GAMMA, AGC and White clip are controlled by the A1310 Processor, while the D2400 Timing chip controls electronic shutter and iris. I opened the camera to find that it has a simple board camera mounted on the CS-mount end. On that board are five connections that are wired-out to the other end of the encloser and the control board. Gound (black), VCC (red), Video output (green) Lens Iris control output (lt blue), and Electronic shutter On/Off (yellow). In addition, there are nine other points to which wires could be connected; three at the end of the row of made connections, and six along edge at 90 degrees to the others. With an vom I detemined that two of the three next to the other connections are Horizontal drive output and Vertical drive output from the D2400R chip, respectively as you move away from the made connections. I have not determined what the third connection is yet; it most likely goes to some discrete control. As for the other six, they are (as you move AWAY from the edge with made connections, and ALL related to the D2400R,) LCOUT (Pin 47 oscillator inverter out,) VR/SYNC (Pin 39 Vertical drive in/composite sync input,) Ground, SPUPV/ED0 (Pin 23 Iris shutter speed up/Shutter speed setting,) SPDNV/ED2 (Pin 22 " " / " " ,) IRIN/ED1 (Pin 17 " " / " ".) (Note: These connection points may just be test points for manufacturing) (Note: Pins 23,17, and 23 can be used to directly set the shutter speed OR directly control the auto-iris, which indirectly controls the shutter.) From the data sheet and voltage measurements, I've determined that when the external electronic shutter switch is placed in the OFF position, the shutter speed may be locking at 1/100 sec., and when placed in the ON position, the Iris control signal output by the A1310 is placed in effect, adjusting the iris/shutter timing automatically. So, here's the part I need the help on; Because of the circuit design Topica (or whoever made the camera board,) used, I will be stuck to controling the electronic iris. The problem I'm having is that the data sheet shows an 'Application' example (using these three chips) that uses two variable resistors to set the set points to tell the D2400 when to increase/decrease the shutter speed. On the camera board, (it appears) that they have used a pair of resistors as a voltage divider to fix those set points. What I need help with is deciding whether or not to remove (read as; crunch!) those resistors before I add my external controls. These are comparator inputs, and my external controls should never come too close to each other and NEVER cross each other, as well. Does anybody have any advice/comments/flames on these problems? Am I on the right track, or did I derail somewhere along the line? Thanks in advance, Dana C. Lawson email@example.com
Hi Alan, Referring to the graph, it seems the ExViewHAD device is a bit over twice as sensitive as a 'normal' device for all wavelengths between 1000nm (IR) and 550nm (Green). It has maximum sensitivity to Green light, whereas a normal device appears to peak at the blue end of the spectrum. However the ExViewHAD device is in general more sensitive to all wavelengths. I chose to use the IR filter because I've noticed that some astronomical (and indeed terrestrial) objects look significantly different when IR is included - it penetrates dust better so dust lanes in galaxies tend not to be so apparent for example. However, in the event my results were not good enough to warrant having used the filter. There is a great website that shows various Messier objects imaged at different wavelengths including near IR, at http://sirtf.jpl.nasa.gov/Education/Messier/tie.html Jon. PS - the device is rated at 0.003 Lux, not 0.03! > -----Original Message----- > From: Alan Daly [mailto:alan.daly@b...] > Sent: 23 November 2001 09:53 > To: QCUIAG@yahoogroups.com > Subject: Re: [QCUIAG] Re: The Camera is dead! Long live the Camera! > > > Jon, you mentioned you used an IR blocking filter, according > to Sony's specs for the EXViewHAD CCD it is rated at 0.03 lux because: > "(The EXviewHAD) .is capable of detecting with great sensitivity near > infrared light region which is unable to be discerned by the naked > eye. Light in the near infrared light region which has long wavelengths is > converted into photoelectricity deep in the semiconductor's silicon, so in > conventional CCD structure, sensors were incapable of efficiently gathering > the charge which has undergone photoelectric conversion. This "EXview HAD CCD" > structure has made it possible to use as video information the charge of near > infrared light which was hitherto invalid. This resulted in a dramatic region > improvement in sensitivity. This in turn made it possible to film in the > dark by radiating near infrared light which is invisible to the naked eye onto > the object being filmed, which opens up applications in a broad range of > applications, such as surveillance cameras, on-board cameras and scientific > measurement cameras.". > > According to this chart - > http://www.sony.co.jp/en/Products/SC-HP/SG/CCD/image/exviewhad-03b.gif > The CCD's sensitivitity is lowest at the 500nm wavelength (1 > lux) and highest at the 900-1000nm wavelength (0.1 - 0.03 lux). > > Maybe you would have better results without IR blocking? Or am I > misunderstanding something basic? (Possible, I'm a newbie > cramming as much into my head as I can *grin*) > > Alan. > > Jon Grove wrote: > > > I had a chance to try the camera out last night, > > piggybacked (i.e stuck with tape) on my motor-driven Europa 150, coupled > > to a 70mm lens from an old SLR camera, which was not ideal but I wanted to > > try some 'wide' shots. I recorded the output to a VHS recorder and later > > captured frames using a Hauppauge WinTV card. > > > > I took various exposures of M45 and M31, ranging between a > > couple of seconds up to about 30 seconds. I had an IR blocking filter in > > front of the CCD as well. > > > > The results show that the long exposure works OK, and the images were not > > too noisy - probably helped by it being a cold evening. > > However in the longer exposures there was a significant amount of what I > > guess must be amplifier glow (although it may be the AGC trying to > > compensate for a sudden bright frame after a period of dark), so I'll need to work > > on that. I managed to get a 'reasonable' image of M45 from the tape, > > but no nebulosity was visible. Maybe I was hoping for too much, particularly > > with the moonlight and the small aperture lens. M31 showed up as an > > elliptical fuzzy blob but no detail visible, and lots of artefacts caused > > by the VHS recording. > > I think I'll give up on the SLR lens idea for now and try using the camera > > through my scope until I've got a better feel for how it behaves. I'll > > investigate the amplifier glow/AGC problem, and cooling techniques, when I > > get the opportunity. Naturally I'll keep the group informed of my progress! > > > > Clear Skies, > > Jon. > > > > > -----Original Message----- > > > From: Dr. S.J. Wainwright [mailto:astrabio@n...] > > > Sent: 22 November 2001 17:50 > > > To: QCUIAG@yahoogroups.com > > > Subject: Re: [QCUIAG] Re: The Camera is dead! Long live > the Camera! > > > > > > > > > Dear Jon, > > > I think that your camera mod has great potential. > > > I would greatly appreciate details of your modification. > > > Best wishes > > > Steve > > > Dr. S.J. Wainwright > > > www.digital-astronomy.org.uk > > > FAX: UK: 0870 1641692 > > > International : +44 870 1641692 > > > ----- Original Message ----- > > > From: "Jon Grove"
> > > To: > > > Sent: Thursday, November 22, 2001 4:24 PM > > > Subject: RE: [QCUIAG] Re: The Camera is dead! Long live > > > the Camera! > > > > > > > > > The camera is a monochrome CCTV device available in the UK from > > > http://www.rfconcepts.co.uk/ model number 1004X. It's a bare > > > board camera, > > > suitable for mounting in your own project box or > > > whatever. They stock similar cameras ready-housed for a bit more money, > > > but for my purposes the bare board was ideal. It cost £52 inclusive of VAT > > > and P&P, and arrived the day after I ordered it. > > > > > > The modification for long exposures is quite straightforward in principle, > > > although rather tricky in practice. It effectively involves putting a > > > normally-closed switch in series with pin 5 of the CXD2463R > > > controller chip. > > > With the switch closed, the camera behaves like a normal video camera. When > > > the switch is opened the camera starts integrating, and when > > > it is closed again a single integrated frame of video is produced > > > before resuming 'normal' operation. At the moment it is entirely manually > > > controlled. If anyone wants to try the mod they are obviously welcome to - > > > but it might be worth waiting until I've verified that it works on > > > astronomical objects. The previous (defunct) camera used the same controller > > > and worked fairly well in long exposure mode, so I don't anticipate too many > > > problems other than hot pixels caused by the CCD being so warm. For results > > > from the previous camera, look at my folder in the files section of the QCUIAG site. > > > > > > If these clouds clear up for a while I'll try and have a go with it tonight. > > > > > > Jon. > > >