There are a points to elaborate, as follows:
Firstly, my (personal) choice of choosing firewire over USB2.0 is the fact that i have a mac laptop that has the 6-pin firewire port. In the case of the usage of a PC laptop incase of 'emergencies', i have ones already with the firewire port available as well. Now, another reason for this choice is that even though firewire has a bit transfer rate of 400Mbits/s which is slower than USB2.0 (480Mbits/s), firewire still has a faster transfer rate when it comes to sustained throughput which i feel (personally) it is relevant here since we will be capturing the video file and it is streaming through into the laptop within a reasonable sustained time period. The reason for firewire being faster in this case is due to the differences in transfer architecture that the two transfer models adopt. Firewire employs a P-to-P architecture whereby the peripherals have some form of intelligence and can negotiate bus conflicts to determine which device can best control a data transfer. On the other hand, USB2.0 uses a master-slave architecture where the laptop handles all arbitration functions and dictates data flow to and from, and between the connected peripherals. This will result in a consequence that adds additional system overhead and results in slower data flow control.
Note that in this form of imaging that we are interested in, it is sometimes important that we transfer at high frame rates (for example in planet and lunar imaging), and henceforth, since the performance of sustained throughput is proven to be more reliable (and higher) via firewire, the choice speaks for itself.
I am not saying that USB2.0 is definitely a bad choice, it isn't, but I cannot say that it is an optimum solution either. Of course, if one were to decide based on convenience and compatibility between your exisiting laptops/desktops, you may perhaps like to choose USB2.0 version instead. For myself, I already have the firewire ports available, so the choice is very clear here for my case.
As for Sensor Technologies, I have made an error, it should be Sentech Technologies. You may google it on the net to find out more. At this point in time, I am coming closer to choosing Imaging Resource cameras (over Lumenera, Pt Grey, Sentech) because it is less costly, and I do not find it absolutely necessary to have a 12 bit camera, since I am not into solar imaging very much. One would probably got for the higher end 12 bit cameras like the Lumenera line if you would like to go into hydrogen alpha solar imaging for example. Another reason for my choice would be to save some money to get a decent filter wheel and colour filters to complete the imaging solution.
Wee Nghee: As for the current issue, yes, I am a little concerned if the camera is extracting all the power from the laptop as well, since at this point in time, I do not have extra laptop batteries. Anyway, if I am imaging from home, which I plan to, there's electricity available. Don't see a need to go to a remote dark sky for this form of imaging, unless u want to capture Pluto....;P
Will make the DMK purchase tomorrow (Saturday) evening, if nothing unforseen crops up.
Imaging Source planetary cameras
Well, I'm embarrassed to say that I have not tried it out yet as I got it during the rainy season... will try soon and post some pics.wucheeyiun wrote:How does it compare to the starshoot....post some pictures?Tachyon wrote:21wucheeyiun wrote: andrew , you got the 21 or 41...
[80% Steve, 20% Alfred] ------- Probability of Clear Skies = (Age of newest equipment in days) / [(Number of observers) * (Total Aperture of all telescopes present in mm)]
very interesting. i just read about the review of the camera in OCT issue 2007 S&T. the company even have their own Yahoo group to discuss about their products. you might wanna check them out Remus. strangely the camera doesn't come with the firewire nor usb2.0 cable. hm..... anyway does anyone ever do a comparision between Toucam, Vesta pro camera, Dmk and Lumera camera on planetary imaging??? just like to know the result of it.
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universe24
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