Focus RASA on moon compared to Sigma 150-600 lens

[Datalord]

So, had a few days of vacation where I brought my Canon 6D with a Sigma 150-600 lens. On a clear night I went out to take some pictures handheld with the combo and was surprised at how good a result I could get:

 

Then I thought "wow, I'm looking forward to what I can do with the RASA!".

Well, disappointment. I mucked about with the focuser for the better part of an hour and the best I could get was this:

Is there something fundamental about the difference between a reflector and a refractor that I'm missing here? Or is it the low aperture of the RASA? I took well over 100 pictures while I was just trying to get the focus good.

EDIT: these pictures have only been debayered and made B/W. No other processing done.

[Galen Gilmore]

You may want to wait until the moon is in its 1st or last quarter. A full moon is not very good for viewing or photographing.

[Datalord]

2 hours ago, Galen Gilmore said:

You may want to wait until the moon is in its 1st or last quarter. A full moon is not very good for viewing or photographing.

Is it going to get me better focus?

[wxsatuser]

15 minutes ago, Datalord said:

Is it going to get me better focus?

No!
Less contrast at full moon.

Both could have been well focused but what was the seeing like on each occasion?

 

 

[Datalord]

5 hours ago, wxsatuser said:

No!
Less contrast at full moon.

Both could have been well focused but what was the seeing like on each occasion?

 

 

Ah, so there is an explanation. 

The seeing was pretty bad on the RASA night, I just didn't think it would affect a moon shot. 

[MarsG76]

I see what you mean.. the C11 would perform better when stacked and waveleted, but so would the Sigma.... but I see how it would be assumed that the C11 would deliver more detail and yet....

 

[wxsatuser]

1 hour ago, Datalord said:

Ah, so there is an explanation. 

The seeing was pretty bad on the RASA night, I just didn't think it would affect a moon shot. 

That's why most planetary imagers use video to capture ' lucky seeing'.
Lots of frames at a fast speed to capture the odd frames where seeing is very good.
Stack a few of them and process, normally gets a good result.

[Datalord]

3 minutes ago, wxsatuser said:

That's why most planetary imagers use video to capture ' lucky seeing'.
Lots of frames at a fast speed to capture the odd frames where seeing is very good.
Stack a few of them and process, normally gets a good result.

Interesting. My qhy definitely is not a fast camera, so that is off the table.

Always stuff to learn.

[wxsatuser]

It can be done with a dslr but the video needs to be as near as 1 to 1 as possible.
Normally recording Liveview is close to 1 to 1, most other video modes are interpolated and don't get close to 1 to 1.
Canon 550D and 60D have movie crop mode which is true 1 to 1 from the centre 640x480 pixels.

[rahuljp]

Sorry to intrude. Just trying to get Datalord's attention. Sent you a pm!