Quote:
Originally Posted by avandonk
I even doubt your ability as you said yourself you could not be bothered guiding!.........
Drivel about a lack of resources smacks of bias or at best incompetence.
I won't waste any more time. I have better things to do.
The sad thing is a fair comparison would be very informative.
Bert
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Bert, I find it odd how my small experiment could be turned in to such scathing rant.
I suspect the physics was lost on you.
Think of it this way. We have two rain gauges. One catches a constant amount of rain for 30 seconds. The strength of the rainfall is then reduced by 2/3rd's. To get the same amount of rain we have to collect it for 3x longer i.e total rain, or in the case of a mono sensor in my experiment, total flux is equivalent.
How the sensors (or pavement, roof-top, back of your head...whatever) deal with the incoming flux does not change the amount of energy hitting the sensor.
For the mono cameras I used a CS filter set, so there was little leakage from the I/R or U/V....but do concede there may be an overlap between RG&B filters that may add 20% or so to the actual energy received....but certainly not 300%.
Energy considerations aside, in a practical sense, you can indeed get 90 (or more) seconds of exposure into a DSLR in the same time it takes to get 3 by 30 second exposures from a mono camera....and is probably worth investigation.
As I personally have 2 DSLR's and will be buying a 3rd soon, I have no problem/agenda here. They are great pieces of kit. If you are prepared to put the time into deep exposures you can still get great results.
This however does not change the fact there is patently a significant difference in raw sensitivity and dynamic range between DSLR's and a dedicated astro-cam....frankly more than I expected, hence the demo.