Quote:
Originally Posted by danielsun
Just wondering if any fan vibration may have any effect on images?
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Daniel - all the best CCD's on the market employ fans of varying size and speed to aid in their cooling, most of these fans (that I've seen anyway) are no different to your standard computer fan. At least with the DSLR mod, you have the choice of what fan you want to use, and if the camera is purely for astronomy use, there is no reason why you wouldnt opt for a bigger than usual fan that runs at lower voltage to produce the same CFM (Cubic Feet per Minute) rating... There are two advantages of a larger fan, and one disadvantage...
Advantages:
1 : Larger fans can move the same amount of air and lower RPM & voltage than a smaller fan, and therefore can create less vibrations.
2 : They are quieter.. (this seems like a big case of "Who cares?" until you are sitting out on an imaging field with something like the Orion Starshoot Pro cameras. They have a 40mm fan that runs at very high RPM and sound somewhat like a dustbuster... when its happening all night on a relatively silent imaging field, it gets REALLY annoying..) An 80 to 120mm fan would be the go if you can facilitate it.
Disadvantage :
1 : It can be hard to implement a large fan into a design that looks even remotely elegant on a DSLR body...
Function over form I always say.. Who cares what it looks like as long as it does the job efficiently, quietly and satisfactorily.