OK, I just wrote an entire thing on this topic, and the page refreshed when hitting f5 accidentally, so lets do a TL:DR
I am stuck on understanding this.
Oversampling is good. (you just cant see as good as your camera can handle?)
Under sampling is bad.
With guide-scopes and imaging scopes, you want your guide-scope / camera to be 1/3 FL of your imaging camera? After reading further into this, I came across a lot conflicting information I need help clearing up.
Is the reason for 1/3 ratio being suggested is it is like a generalized "Good area" to be in? I read that the FL ratio between the guide and imaging don't really matter, the most important aspect is the pixel resolution being the same, if not better on the guide scope for more accurate guiding. Yes this will show many more spikes on a graph but is this due to it being tighter guiding and making more corrections? If your pixel size of your guide cam is 5, and your pixel size on the imaging cam is 2.5. This would be bad correct? It would be bad because the same star will have half as many pixels as the imaging, so the guiding will be half as accurate, but would not show as bad a graph because its a more generalized "happy area" for guiding due to it not noticing many of the corrections it should have picked up? Would this not cause the resolution/arc to be much higher because guiding is not as accurate? Everyone is talking about guides being a portion of your imaging scopes FL, but why is it not the other way? Why don't people use a imaging/guide combo if the guide was double the FL of the imaging scope?
Now in my head, I have it as nothing matters but the single star, how many pixels it takes up, how many pixels of that star your camera can see, if your guide camera, can not see more pixels or a higher pixel resolution then your imaging camera, it wont be as "good" guiding(EVEN if the FOV is tiny in comparison, its job is to guide, not show me a good view), am I correct on this aspect?
I am just a bit confused. the situation, If you have a telescope & Imaging Camera @ 2.5microns FL 625mm F/4, and a guide-scope @ 3.5microns of 625mm(Barlow 3x), I see the guide-scope is slower, but does it matter how much light you are getting if the image is going to be oversampled?) Is oversampling not the issue of having TOO much light/noise coming in?
Does this change the end resolution of pixels of the guidescope to the same if not under that of the Imaging scope. With the imaging scope at .8" and the Guide Scope at .4", I know those are unrealistic conditions, but if you had them would it not be better to over-sample on the guide scope and have twice the pixel resolution vs having less pixel resolution and not as accurate guiding? as its much easier to aim at mthe center of a star thats 10 pixels across on the guide, and only 5 on the imaging. Even though the Imaging is WAY bigger FOV, the guides FOV does not matter right?
Please someone rock my world, Slay these false notions and ideas, put me on the right path brother. I need to understand this.
I get a lot of people might wonder why even do AP if you don't have photo exp, or purchase expensive equip if you don't know the how to use it. That is why I am asking, only one way to figure this out and that is ask the Amateur/Professional community on here. I love space, I know most if not all of you do. I need to know what is out there, and this is just one step closer to getting me there.