Frame & Focus

[GerryDi]

Hello,

I have been using BYEOS for sometime and am still have difficulty in using the "Frame & Focus" section.  Problem is I cannot get an image on the computer screen or the LCD screen of the camera (EOS 70D).  I have tried just about every camera setting to acquire an image, but with no luck.  I have this issue if I'm using the camera/lens combination or the camera attached directly (prime focus) to the telescope.  I end up taking numerous blind shots in order to see and image and in focus, and that is not working very well.

Any and all help suggestions would be greatly appreciated.

Thank you,

Gerry Di 

[astroman133]

Live View exposures are very short, on the order of 10 milliseconds long. Only the brightest stars will show up at all at prime focus.

BYE has a Maximum Sensitivity setting. Be sure to select that before using Live View for focusing. Then point at the brightest star available, like Vega or Arcturus.

If you have a lens on the camera then even the Maximum Sensitivity setting may not show stars because they are so small at the shorter focal lengths. In that case you will need to use Snap images for focusing. These should work even with exposures that are only a few seconds long.

[s3igell]

Frame&Focus is based on the same LiveView video feed as you see on the back LCD of the Camera (only displayed on a significantly larger screen).

You can base your expectations on what you see on that smaller screen.  It might be helpful to refresh yourself by checking that screen image some night before hooking up BYE.

There are a few things you can do to improve your Frame&Focus session:

1. Select the Max Sensitivity setting in BYE
2. Ensure that your Lens or Scope is as close to In-Focus as you can manually set.  If a Lens, set it to where you know Infinity Focus should be.  If a Scope, set the Focuser to a Pre-Determined "In-Focus" mark (test in Daytime against a distant Pole or Tree and mark or record the graduated scale number if your Focuser Drawtube has such).
3. Start with something extremely Bright or Large (Moon, Vega, Jupiter, Venus) to get Focus, then move to your Target Area to set Framing.
4. Expect only Bright Stars (Mag 2+) to show - Brighter Magnitudes only when using Longer Focal Ratio Lens or Scope

And when all else fails, revert to snapping Short Exposures at High ISO (just remember to reset everything to your Planned Exposure Settings before executing your Capture Plan).

(This last may be an Imaging Session "Saver", in any case, as LiveView works to Overheat your DSLR Sensor which in turn adds Thermal Noise to the Captured Images until the Sensor has had time to Cool.)