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Camera test

Specifications

WAT-902H2 UltimateKPC-350BH
PC164C
KPC-650BH
PC164-EX
Signal FormatCCIREIAEIA
Image sensor1/2" B/W EXview HAD CCD1/3" B/W Sony Super HAD exView CCD1/3" B/W Sony Hi Res Super HAD exView CCD
Type de capteurICX254ALICX258AL
Pixels effectif752(H) x 582(V) 440k510(H) x 492(V) 250k768(H) x 494(V) 380k
Unit cell size8.6m(H) x 8.3 m(V)9.6m (H) 7.5m (V)6.35m (H) 7.4m (V)
Horizontal resolution
(TVL)
570 TVL 420 TVL600 TVL
Sensitivity0.0001 lux0.0003 lux0.003 lux
Electronic Shutter1/501/601/60

The data above come from technical referencesWAT-902H2 Ultimate , KPC-350BH et KPC-650BH

I check this web site for KT&C and supercircuits camera http://www.prc68.com/I/KPC350.shtml

You have all the details on the Watec 902H2 and a comparison with the Watec 120N on this excellent web sitehttp://www.kolumbus.fi/oh5iy/astro/Ccd.html

Protocol

I made the video recordings one after another by a clear night, no moon, far from lighting pollution.

Cameras were mount by Fujinon YV2.7x2.9LR4D-SA2L lens.

-VariFocal Length (mm) 2.9 ~ 8(2.7x).

-Maximum iris aperture F0.95

The field of view for each around 45, corresponding to a focal length of 8 mm sensor 1/2" and 6 mm sensor 1/3"

For the recording I use USB Dazzle DVC90 video capture device and UFOCapture software (which is very useful even in a simple registration)

- PAL (CCIR for black and white) the maximum recording resolution is 720(H) x 576(V). Notice it gives a distorted analogic video (video in 5/4 bent into 4/3).So we record it in 704 (H) x 528 (V) but we loose a little bite resolution or after resize it in 768 x 576.

Video format is 25 fps

- NTSC (EAI for black and white) the maximum recording resolution is 720(H) x 480(V). Video is also distorded. So it can directly records in 640 x 480 which is very correct with the KPC-350BH (or PC164C) or after resize the video in 720 x 540.

The rate for NTSC is 29.97 fps

Detail on UFOCapture guide (heading: Step 7 Previewing test)

Ze test


Sensitivity

Capture Settings:

(The Watec ellectronics settings are Gamma OFF and AGC Lo to have a signal noise ratio comparable to KT&C)


Below I select the best picture in 10 seconds movie
WAT-902H2U-1X.jpg KPC-350BH-1X.jpg KPC-650BH-1X.jpg

How you can see, the limit stellar magnitude is the same for the three selected images: 3.8. It's not really good to estimate the sensitivity of the cameras. Par contre sur les films on voit que la WATEC 902H2U et la KPC-350BH sont au coude coude et la KPC650BH en dea des deux autres. However on the films we see WATEC 902H2U and KPC-350BH are neck and neck and KPC650BH below two other.


30x integrated
WAT-902H2U-30X.jpg KPC-350BH-30X.jpg KPC-650BH-30X.jpg

Here the difference of sensitivity is more visible. For example, a few degrees below Alkaid, we note stars are not visible with the KPC-650BH while they are for the other two cameras.

By comparing composite image WATEC 902H2U-and KPC-350BH, we can see that magnitude limit of visible stars is the same. We might think a slight edge in brightness for the KPC-350BH, but my view,it's due to lower resolution which makes the stars appear less ad hoc on integrated image, therefore more visible.

Movies: 5 seconds of each record, not encoded, in native format. (Although the files are compressed in zip, they are heavy)

Conclusion

First KPC-650BH, on the internet some sellers posting a sensitivity 0.0003lux and others 0.003lux. Considering the tests, we may conclude that it is less sensitive than the KPC-350BH and I suspect a 0 voluntary to lure buyers...

Between WATEC 902H2U and KPC-350BH (PC164C): For me these two cameras have equivalent sensitivity. Of course the Watec have a better image resolution and allows advanced electronic settings, but for meteor detections is it worth the cost to pay 3 times more for a WATEC ($319 vs. $93 for KPC350BH)? (Knowing the CCD with time dead pixels appear...)

Up to you see according to your budget... ;-)

In any case, we can say for better resolution CCIR format is preferable to EIA (NTSC black and white) because NTSC is limited by 480 horizontal resolution while CCIR goes up to 576 pixels. It would be interesting to find KPC-350BH in CCIR format at the same price as EIA format. But I haven't found...