What am I doing wrong

[Neil H]

Hi everyone last night I was looking at Saturn and it was nice and sharp using my MAK 180 pro so I pop on my planetary camera 224 mc  with sharpcap 4 but could not focus , it went from out of focus to blurry to out of focus 

What am I doing wrong ? 

[Same old newbie alert]

Probably nothing... Seeing, altitude and the Jetstream position all play a vital role in getting a decent image..all of which are out of your hands

Some things that could cause the issues you suggest is more likely air thermals in the tube, do you store the scope inside? As it needs the reach thermal equilibrium with the dropping temps.. so needs a decent amount of time to do this

[vlaiv]

Probably exposure length

It needs to be very short - maybe even same as capture exposure - that would be around 5ms.

Planet will be dim at that sort of exposure even if you up the gain - so don't try to make the planet brighter by using longer exposure - that will just give enough time to seeing to blur the view. You want planet to jump around from seeing but not to blur from it - if that makes sense.

 

[Neil H]

Hi guys I do store the MAK in a shed and always give it an hour or more to cool down , I won't give in so may be I will try a focus grabber  programme , I will so try it on a day time target to make sure it will focus , I will fit a duel speed focuser to it as well and see if this helps 

Thanks guys 

 

[sorrimen]

A few things will be at play. First, at the high ‘magnifications’ (wrong word but you get the point) focus will be very sensitive. With my electronic focuser on the slowest setting, holding the button for anything more than a second will send me way out of focus.

Second thing is seeing, as others have mentioned. It will make it very hard to get good focus with poor seeing. It’s not so much about getting a crisp view, rather locating the midpoint between the two out of focus ranges. At that point you’re in focus, even if it’s still jumping about and blurring from seeing. 

Another thing is focus travel. It doesn’t sound like this applies to your situation, as you’re finding a blurry midpoint. If it were to apply, a barlow normally fixes things.

Final thing is collimation. A camera will naturally be a bit more sensitive to collimation issues. Chances are this isn’t a big issue as you had good views visually, but if you’re out of collimation enough things will never appear crisp in focus. 

[Neil H]

Collimation is spot on I do a star test every time I use the MAK 

[alacant]

3 hours ago, Neil H said:

blurry to out of focus

Our cat guy says something like this...

Assuming you're in focus with an eyepiece, the camera needs to be between 10cm to 15cm from the rear face of the telescope, probably nearer the latter. You may need an extension tube.

HTH

 

[Neil H]

That's Funny you say that I just got the phone with wookie1965 and he said same thing so I will try that I know on my refractor I need the 2 extra extension that came with it to focus