SXVF-M25

A large-format, 6 megapixel, single-shot colour camera!

Features | vs. DSLRs | Specifications | Sample Images

A view of the APS film-sized CCD installed in a prototype camera.

Features:

• Very large, high resolution 'SuperHAD' CCD chip, with 6,000,000 x 7.8µm square pixels in a 23.4 x 15.6mm array. Size equivalent to APS film.
• Single-shot colour, using a Bayer matrix of R, G and B on-chip filters. No filter wheel required.
• High sensitivity, equivalent to 60% QE at peak of green filters.
• Exceptionally low dark signal -- no dark frames necessary for most deep sky objects.
• Exceptionally effective anti-blooming with minimal effect on linearity and no lost active area.
• Built-in very high speed USB 2.0 interface (USB 1.1 compatible) for approx. 3½ second downloads.
• Built-in autoguider interface and output -- compatible with the optional dedicated external guide camera
• Built-in dual serial ports for accessory control -- directly drive filter wheels, GOTO 'scopes etc.
• Single USB cable control for all features - get rid of that dangerous cable tangle!
• Only ONE computer needed to control all of the devices and functions.
• Very low power consumption. Less than 1 amp at 12v DC.
• Compact and lightweight -- only 75mm in diameter x 100mm long - less than 500 grams load on the 'scope!

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SXVF-M25 vs. DSLRs

There are several important features of the large format SXVF cameras that make them better than DSLRs for astronomy:

1. The cooling of the CCD is important and makes low noise exposures much more practical.
2. The slower optimised readout of the SXVF CCD gives less readout noise.
3. The images are downloaded as raw 16 bit data, so the full dynamic range and sensitivity are maintained.
4. The SXVF does not incorporate an infrared blocking filter and so the full near IR and H-alpha performance is available.
5. The SXVF is compatible with the SXV guide camera and AO unit.
6. The 'T' thread mount with adjustable CCD tip/tilt permits the camera to be accurately aligned with the optics.
7. The cylindrical profile makes it compatible with prime focus optical systems.

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The SXVF-M25 camera specification:
CCD type:	Sony ICX413AQ SuperHAD CCD with ultra low dark current, Bayer RGB matrix and vertical anti-blooming.
CCD pixel data (full res):	Pixel size: 7.8µm x 7.8µm, image format: 3000 x 2000 pixels
CCD size:	Image area: 23.4mm (horizontal) x 15.6mm (vertical).
CCD quality:	Grade 1 or better -- no bad columns, no dead pixels, no more than 50 'hot' pixels (saturated in <10 seconds).
Spectral Response:	QEmax at 540nm (~60%), 50% roll-off at 400nm and 650nm.
Readout noise:	Less than 12e RMS -- typically ONLY 7 electrons!
Full-well capacity:	Greater than 25,000 e- (unbinned)
Anti-blooming:	Overload margin greater than 800x.
Dark current:	Dark frame saturation time greater than 100 hours. Less than 0.02 electrons/second @ +10C ambient.
Data format:	16 bits
System gain:	0.4 electrons per ADU
Computer Interface:	Built-in very high speed USB 2.0 compatible interface. Also works with USB 1.1.
Image download time	Typically 3½ seconds full resolution using USB 2.0, approximately ~8 seconds with USB 1.1.
Power requirements:	115VAC / 240VAC @ 12VA, or 12VDC @ 750mA max.
Cooling system:	Regulated constant current cooling supply with single stage thermoelectric cooler to give a CCD temperature of approximately -30C below ambient.
Size:	75 x 100mm black anodised aluminium barrel with 'T2' thread at the CCD window end & input/output plugs at rear. CCD alignment screws are provided for setting the chip parallel to the focal plane.
Weight:	Approximately 400g.

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These images were all taken by Terry Platt through a Takahashi FSQ106 with a Hutech light pollution filter and did not have any dark frames subtracted. Imaging conditions were quite poor, with considerable light pollution at his site in the south of England.

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