I finally decided to Learn/calculate what my equipment is best position for critical sampling.
So far I have established the following for the 6.4um pixel size of my DSI III Pro (and Canon 350d which has the same pixel size).
1. I am imaging wavelengths of say 680 nm avge with my ED80 at f6
2. The focul length is 480mm
3. Using the formula of aperature x (pixel um/wavelength)
4. I divide the result by a factor of 2.5 for poor seeing conditions and using a meade mount!
The most appropriate FL is then given as 595mm. This is pretty close to the FL of 480mm. I can assume then that this is now going to give me critical sampling.
I also understand that sampling at 2 arc sec per pixel is considered to be the best.
So by using the formula (205 x pixel um) /Focul length, I get 2.73 arc sec per pixel. Pretty close again!
All this makes sense until I run the formulas based on my LX200. This is where I can't resolve the numbers.
When I do they same calcs for my Lx200 at f0.63 and FL 1575mm I get critical sampling at 1860mm (Still pretty close).
HOWEVER, at that critical sampling FL its only sampling at 0.83 arc sec per Pixel!
So am I right in assuming that even though you can match the FL for critical sampling to your Chip, this doesnt mean that you will achieve 2 arc sec per pixel? And if that is correct then oversampling/undersampling can still take place? And if that too is correct then my chips based on 6.4um are only really ever going to critically sample at FL of around 500mm
