Quote:
Originally Posted by Outcast
First of all, I assume you are not running out of travel on your focuser?
Are you trying to focus the object by eye or are you using a Bhatinov mask?
If you are looking at lunar surface or planet, the object will look soft even if in focus, this is a factor of seeing & why the best approach is to shoot video & then use Autostakkert to stack the best images. Unless you are extremely lucky, single exposure images on planets & lunar rarely result in a sharp image. A Bhatinov mask can be used for planetary imaging as well, just focus on a bright star first using the diffraction spikes generated by the mask & then slew to your target of choice. However, even without a bhatinov mask, you should be able to achieve good focus, it just won't look like good focus on your screen, this is a factor of seeing.. your eye/brain is able to deal with this (organic adaptive optics... lol) & you will see your image flutter in & out of focus. Your camera sensor well, on a still shot, you just have to be lucky whereas with video, 30 seconds will capture you a thousand or so frames & give you plenty of in focus frames to stack. You can then further sharpen using wavelets in Registax.
If you are trying to focus on a deep sky object, you really need to be using either a bhatinov mask on a bright star or alternatively, capture software that features a focusing component.'
I have found that trying to focus stars in a camera by eye is very hit & miss, generally more miss...
If you are running out of travel on your focuser, well, that's a different issue..
Hope this helps
|
The focuser definitely isn't running out of travel, there is plenty either side of the focus.
Visually the Moon is razor sharp through any of my eyepieces, Jupiter is the same, stars are pin point sharp. The issues are when imaging, and the Bhatinov mask doesn't help. Using my 7D, I can throw it into liveview and zoom in on screen to a star and get the focus to where it "appears" to be right, only to have any imagery come up soft.
I'm beginning to think the camera might be the issue, it could be over-sampling. And pixel binning to counter it is something I don't even know if it's possible in the Canon 7D.