Telescope Reviews: Philips SPC900NC Being Discontinued

When I bought my first telescope, and was contemplating guiding with a webcam, the telescope store didn't have the NexImage I wanted in stock, they sold me the orion solar system imager II. Attempting to use it in that role, I discovered it was not very sensative, and rather limited in a few ways, so it went in the 'junk' pile. After I moved to vancouver island last year, I bought an NexImage from the local dealer here. That worked out ok, but, I was still unhappy with sensativity, and bought a QHY5 for guider, love it.

A few weeks ago, I got thinking, the QHY5 is an MT9M001 sensor, 1280x1024 monochrome, the SSSI is the MT9M001 with a bayer matrix. In theory, they should be similar in terms of sensativity, and I revisited that original webcam. The real difference between it and the QHY5, the webcam drivers do not expose all of the modes of the sensor, so, the longest exposure it can do is 0.13 seconds, whereas on the QHY5 it can do much longer exposures. I did a little measuring, and it turns out at 0.1 second exposures, the cameras _are_ somewhat similar.

So, on to the next step of the detailed look, after all, I have the camera in the junk pile, it would be 'nice' if it turns out to be not junk at all. I've got programs that capture data from webcams which i wrote myself, I started using them to poke a little closer into the SSII data. In one of the settings dialogs, you can turn off color, and get a monochrome data stream from it. I started looking closely at that, because typically in a webcam YUV data stream, you get the Y (luminance) in that mode, but no color data. Turns out, when you click that checkbox in the SSII configuration panel, what you get is still RGB data frames, but, it appears to be the actual raw bayer data. They have populated the entire RGB triplet with the raw bayer data, so it 'looks like' greyscale.

I haven't really had a chance to look carefully at it shooting planetary objects yet. Due to our location, jupiter never comes above our southern horizon (mountain in the way), and during the last lunar cycle we have been unable to use our normal telescope shooting location, we have renovations in progress. So I am not finished looking into this camera in detail, but, my preliminary conclusions on the 'revisit' are this.

- 1280x1024 frames, using 5.2 micron pixels, it has much better resolution than my NexImage based on a philips sensor.

- My experience with the QHY5 suggests that the Mt9M001 sensor doesn't have sensativity problems, and in that package which enables longer exposures, it's actually quite a decent sensor.

- The SSII drivers dont do longer exposures, but they do allow for exposures up to 0.13 seconds according to documentation, which suggests those drivers only use the rolling shutter mode of the sensor. Shooting planetary objects at 0.13 seconds still results in overexposure, so, there is a LOT of potential for this camera doing saturn, jupiter, and lunar shots as the exposure times dial down below 0.1 seconds. Probably more potential than the Philips sensor, particularily for lunar shots, considering the larger chips size and smaller pixel size.

- When you tick the 'enable color' checkbox to 'off', it seems the data is a modified raw frame being spit out from the windows drivers. Conversion from that RGB format to a proper Y8 format is trivial.

I have made derogatory comments regarding this particular camera in the past, mostly with regard to the sensativity, or more specifically, the lack thereof. In my re-visit of this camera, it's still got the issue of sensativity if one is attempting to use it in the role of autoguider, but, if one moves it from that role (for which it was never intended) to the role of 'planetary imager', it actually has a lot of potential. The exposure time limit of 0.13 seconds is NOT an issue for planetary imaging.

When we were on Mt Kobau at the star party this summer, i played with it one evening for a while, aimed at jupiter. It was my _first_ attempt at planetary imaging, the SSII was in my 5 inch mak, and I shot with and without barlow. When I went to try processing the next day on the resultant avi files captured with AmCap, I realized that I didn't quite nail the focus, that's a challenge in the dark, using a red screen on the laptop, doing it for the first time.

The software that originally came with the SSII is (my opinion) basically junk. It has caused numerous bsod experiences on my notebook. On the other hand, using other software to access it as a plain old windows WDM camera has never caused a problem. It only allows for RGB24 color settings on the data, but, again, once one understands that the RGB24 frames it emits, are actually not bayer decoded when you set it to monochrome, programs that understand raw data from the philips cams should be able to digest the data from this one with only minor modification.

By the next lunar cycle, we should have our renovations finished, and, I should be able to set up the telescopes out back again reqularily. I am planning to give this camera a much better test run then, doing lunar shots thru the C8. If that works out, then I'm going to do a little more work on some software for dealing with it's data formats, and be ready for the onset of saturn season with it.

For now, the jury is still out, but, it's starting to look like my orion starshoot solar system imager II is going to replace my NexImage as the weapon of choice for my planetary imaging attempts. I've got them both, and in theory the MT9M001 sensor of the SSII is superior to the sensor on the philips. When I first got it, that didn't seem to be the case, but, now after looking at it in more detail, using software i wrote myself, it appears that the camera itself was not the problem, but rather the junk software that came with it. Preliminary tests here on daylight objects, comparing it side by side to the QHY5 suggest indeed this camera is only really limited by the 0.13 second exposure time, and can indeed produce 1280x1024 raw frames at a rate of 7.5 frames per second. AmCap will indeed capture avi files using this camera, and, they do have potential to be far superior to the data captured with a philips sensor.

Compared to a $60 webcam, the orion solar system imager II looks like a spendy little beast. But, it comes with the 1.25 inch nosepiece attached, so no extra stuff to order there. The 5.2 micron pixels are smaller than 5.6 micron pixels on my philips based NexImage. The chip itself is somewhat larger, with the 1280x1024 matrix. My only two real complaints now, the 0.13 second shutter speed maximum, and that STUPID bright blue LED on the back that lights up the whole area when you plug it in.

If they fixed the WDM driver so that it could/would use all the modes of the MT9M001, including exposures longer than 0.13 seconds, and told the folks actually assembling it to leave the blue led off the circuit board when assembling the orion variant (the same camera/housing is also sold by other vendors with a lens, as a webcam), then this particular camera could, and probably would, become the imager of choice for low end planetary work.

A long time ago, I saw a link here on cloudy nights to another vendor selling essentially the same camera, and also selling what I believe was a 3 or 5 4 megapixel variant. After playing with the SSII2 again, I've actually become interested in the larger variant, and for the life of me, cannot find the link back to that alternate source...