as-fr-33 No no no age is in your head!!! ; )
In my case, it is my body. I can still crank out code perfectly fine, still can recite π to 60 digits (I have been using that to judge when my memory goes), although can't do as much math as when I was younger, can still do some. So, some of the analytic skills are gone.
FOA60Q to FS60 by removing the 1.7XR extender?
Without the "Q", the FOA60 still has a focal length of a whopping 530 mm (even longer than my FSQ-85 with the flattener). With the Q, it becomes an f/15 (gulp) at 900mm :-). The reason I don't use the reducer (I have the 0.73x reducer) on the FSQ-85 is that its image circle in arc seconds is no greater than the image circle with no reducer (this is typical with Optec reducers too). You get a faster scope, but don't get a wider FOV.
who owns the ASKAR300 and who is very happy with his ASI533mc pro.
Most of the stuff I have tried would work perfectly for the ASI533 sensor, too. But they all start being slightly imperfect at the corners of an APS-C frame (the ugly tilt on my WhiteCat51 can be dialed out, but hey William Optics, where is the Quality Control???).
I am perhaps overly critical of the FMA230, it is actually perfectly tolerable if I weren't so OCD.
5nm would have been perfect but you can't have it all.
The Radian Quad bands are between 4 and 4.5 nm if memory serves. And my Chroma Hα is 4 nm. But I am quite sure they both fail with the ray angle of f/1.4 optics. IDAS is the only one I have seen that has detail specs their filters at different ray angles.
And even it is not ideal at f/1.4, but at least you you are within 6 dB or so in resultant SNR (from the curve, noise goes up by perhaps 3 dB, wile signal goes down by some 3 dB with an f/1.4 system).
Because the filter passband is flat topped, it tends to be worse in SNR than a typical narrowband filter which has an approximate Gaussian shape. It probably behaves more like a 15nm filter compare to some other 10nm filter.
But hey, I am definitely keeping my NBZ for the time I can use it.
Chen
