PC23C VIDEO CAMERA
By Bill Castro
The discussion here is not too technical in nature. It is more along the lines of what is it and how to use it. Comparisons are made between the PC23C, the Astrovid camera and holding a camcorder to the eyepiece. This is a copy of a program that was presented to the Wilderness Center Astronomy Club at their meeting on November, 2000. Allthough all material presented was current at that date, it may be outdated now. Images taken with this camera are linked at the bottom. More are available in the Photo Gallery pages under Video Archive.
Glossary of Terms
- Gain- Sensitivity of the camera. Electronic gain typically boosts signal level and noise.
- Electronic Shutter- Integration time for the CCD or actual time to take picture.
- Gamma- Typically referred to as contrast.
- Minimum Scene Illumination- (in lux) the lower the better. Older camcorders ~2.0 lux, PC23C 0,04 lux and Astrovid 0.02 lux.
PC23C Modifications (Circuit modifications can be made to do the following. Modifications are only a marginal help. See references for links.)
- Image Sensor 1/3 inch monochrome CCD
- Pixels 510(H) x 492(V) 250,920
- Horizontal resolution 460 lines
- Minimum illumination 0.04 lux, f1.8
- Auto shutter 1/30 – 1/100,000 sec
- Lens C – mount
- Power Consumption 10 – 14 VDC, 200 mA
- Dimensions 2.3 x 2 x 3.77 inches
- Weight 192 g
- CCD 4.9 x 3.7mm area (7x9 micron pixels)
- Electronic shutter can be turned on/off
- BNC video output connection
- RS170 B&W video output - connects to a Video In of a TV, VCR or monitor
- Microphone built in.
RCA audio output connection
PC23C Cost and Add-ons (For use with a SCT. Prices are as of November, 2000)
- Manual gain adjustment
- Manual shutter control
- External power supply - Moving the regulator chip outside the camera box lowers chip temperature and reduces noise.
Comparison of PC23C vs Astrovid 2000
- PC23C Camera $79.95
- BNC to RCA adapter $2.95
- AC (or DC) power adapter $14.00
- Celestron T to C adapter $27.00
- Meade Variable Tele-extender $39.95
- Meade T adapter $26.95
- Clear lens $43.30
Note that a C to 1.25 inch adapter from ADIRONDACK for $35.00 can replace the T to C adapter, tele-extender and T adapter.
- Price $80 to $250 $595
- CCD area 4.9 x 3.7 mm 6.4 x 4.8 mm
- Min illum. 0.04 lux 0.02 lux
- Resolution 460 lines 600 lines
- Shutter 1/30 to 1/100,000 sec 1/60 to 1/10,000 sec
- Shutter adj. On/off or Mod Manual
- Gain adj. Mod Manual
- Contrast adj. NO Manual
- Microphone Yes No
PC23C Applications (Best with bright objects. Not good for deep sky or faint objects.)
PC23C How to use it
- Occultation timing (excellent-highly recommended by IOTA)
- Meteor strikes on the Moon (excellent)
- Moon (excellent)
- Sun (with solar filter) (excellent)
- Jupiter (tricky)
- Saturn (tricky)
- Mars (tricky)
PC23C Pros and Cons
- Prime focus, barlow or variable projection.
- Prime focus can work with most scopes
- A barlow or Variable projection may NOT work depending on the scope's focuser travel.
- Control image brightness and contrast by:
- Image size - Try to get the object to fill up as much of the screen as possible to let the cameras automatic controls make the appropriate adjustments.
- Filters - These help reduce the brightness. Color filters, nebula filters and lunar filters may be used. Solar filter is a must with the sun.
- Composition - In addition to image size, move the scope (especially the moon) to an area where there is more contrast, such as the terminator. Some of the brighter areas of the moon may bloom. The scope should be moved to show less of the moon to get better detail on the terminator.
- The required combinations of the above will depend on the scope used.
- Record to tape or display on monitor
- S-VHS, Hi-8, VHS then 8mm in order from best to lowest resolution.)
- Digitize on PC with frame grabber
- Snappy or Dazzle ($80.00)
- Occultation timing (It has a microphone)
- Excellent for eclipse, solar or lunar imaging.
- Fixed to scope compared to hand held camcorder-to-eyepiece.
- Hard to adjust picture (Astrovid or camcorder works better on planets. Modifications are only marginal.)
- Mechanical connections
Depends on what you are going to image and how often you will be using it. Works great to image moon and sun on tape or on a monitor. (Displaying it on a monitor is great for groups.) No adjustments are required. Planets are tricky. Filters and image size have to be adjusted to get the exposure and details right. This takes time in the field. The Astrovid has the neccissary manual controls to do this for you with minimal frustration.
Images (More images are available at the Photo Gallery pages under Video Archive.)
Images with 80mm refractor
Images with 8 inch f/10 LX200
- Sunspot group 9393
- Christmas 2000 partial eclipse sequence of images
- Christmas 2000 partial eclipse time lapse video (422KB requires media player)
Modifications to Supercircuits PC23C By Paul Goelz. Modifications to the video AGC (for manual gain control) and manual shutter control.
Video Capture Astrophotography By Jim Ferreira. Excellent links and references.
BNC to RCA adapter
Power supply, 12 DC 300ma adapter
From Edmund Industrial Optics
A clear lens on the camera consisting of Borofloat Window stock number K45-461 and a C-mount 20mm lens holder stock number K54-626. The clear lens keeps the dust off the camera CCD chip. Without it the chip must be cleaned for each use.
Meade and Celestron threaded adapters.
Back to Tutorials Index