It is important to remember that the number of photons collected from an object is solely dependent upon the aperture of the telescope. If you are going to 'compare' images of an object made with

Hi guys, I think, at least for myself, it is much more intuitive to think of f/D as the number of photons we can catch in a pixel, i.e. f/D can be thought of as the number of photons caught per

Figure 1: Diffraction Increases as the Imaging Lens Iris is Closed (f/# Increases) In other words, it's the aperture. P.S. I suggest that we can agree to disagree and let this go. Bryan ---In

the cause of this has been identified... i use ACP/ACP Scheduler. all ASCOM scope commands are routed through the ACP ASCOM driver to the AP-ASCOM driver. when using focusmax "acquirestar", the

Brian, To follow up on my last post, here's one link that shows the Airy disk size based on

George, First, the virtual ports have nothing to do with APCC's connection to your mount. They only provide a way for the ASCOM driver and other applications to connect to APCC. If you are

Brian, The *resolution* resulting from the size of the Airy disk is a function of wavelength and aperture. The actual physical size in microns of the Airy disk is proportional to F-ratio and is

I'm just getting around to trying to run APCC & AP1200 mount with new GTOCP4 - all bought in June last year. I'm on Windows 7 Pro AP V2 5.10.02 (older versions were used previously, before I

Ray The Airy disc size is a function only of wavelength and aperture. If we consider the ability to separate (resolve) two close objects, using the Rayleigh Criteria, and make some assumptions, then

Yes, that means that despite having the same size Airy disks, the 200" F/3 scope I mentioned will out-resolve the 2" F/3 scope, as it should. But another interesting point is that at any given

I recollected the data, recreated the model and ran it again with the model on. 0.74 peak to peak! I ran 7 cycles.... Thanks for the help. BTW, this is with the latest version of PemPro3.

Thanks, makes sense to me. I guess as long as they are all basically close and there are no outliers. Any comments on criteria for which harmonics to use in the model?

I completely understand this all. My post there was not for my own edification. :) It spiraled out of control though...

Size wise the Airy disc stays the same as far as microns (or pixel size). Resolution wise it reduces in arc seconds as the aperture increases. Rolando

But, f-ratio has some importance in physics. For instance, did you know that the size of the Airy disk is not relative to aperture or focal length, but is relative to f-ratio? It gets smaller

OK - Thanks Ray, That saves me a lot of work and considerable worry. The intent was to find the “exact moment” when it suddenly died, and if“something” (besides electronics failure),

f ratio is just a calculation. You cannot turn a dial and change the f ratio, but leave everything else alone. You have to change either aperture or focal length. Bryan

I have always done 10 cycles, which seems to eliminate effects of marginal seeing fairly well. -Christopher Erickson Observatory engineer Waikoloa, HI 96738 www.summitkinetics.com

Hi Bill, This topic has certainly been a hot potato many times over the years. :-) There are two variables, aperture and focal length... In the one case you tested, keeping focal length constant

Hah! Not sure I will. With PEMPro I get less than 1" of PE and with PHD properly configured the mount pretty much slips into the background. I use Roland's method of calibrating the settings and it