a few imaging questions

[roger jerome]

Hello folks

it has been a few years since I last was out imaging (getting old and my observatory roof was too heavy to flip open....but have finally fixed that).  I would like to image Jupiter.....I have a ZWO ASI 120mc camera, a 9.25 Celestron SCT and some Barlows.  I am having senior moments (again)understanding the following:

I capture the sequence in Raw?  Then before stacking would i have to debayer...in PIPP or in Autostakkert?  Also if my polar alignment is a bit off does Sharpcap or Firecapture have in their program a feature that will help keep Jupiter from drifting out of view?

Thank you for any suggestions and it's great to be here again

Cheers

Roger

 

[Cosmic Geoff]

6 minutes ago, roger jerome said:

..I have a ZWO ASI 120mc camera, a 9.25 Celestron SCT and some Barlows. 

That'll do (as they say in Yorkshire).

Capture a .ser video In (IIRC) Raw8, and that will save you the bother of debayering it afterwards.

It probably will not matter if the polar alignment is a bit off, if you are using a GoTO mount that has been star aligned.  If you are not, expect some drift during a session.

More detailed procedures should be findable online.

[roger jerome]

Thank you so much........Not sure what IIRC is though(?)

[vlaiv]

Hi and welcome to SGL.

Use raw format and SER file in SharpCap. You'll need x1.5 barlow to match ASI120 to your C9.25.

Any x2 barlow can be made to operate at x1.5 - by adjusting barlow element to sensor distance. You can do it during daytime on any far object that you can measure on your screen. First use just camera without barlow and record size of object (church tower, high building, bridge, wall - whatever you can comfortably measure in pixels). Then add barlow and tweak sensor / barlow element distance until you get x1.5 larger image.

Don't debayer in PIPP. AutoStakkert will do it for you using bayer drizzle algorithm which is best for this type of imaging. Just tell it your camera is color and select bayer matrix order (there is menu option for that):

Don't worry too much about polar alignment. As long as you have it in the ball park - planets will stay in FOV for the duration of capture. Remember, Jupiter rotates and if you don't want to use derotation (in WinJupos) - limit your runs to about 3-4 minutes.

Use very short exposures - about 5ms. Don't try to get good histogram. That is not sound advice for planetary imaging. Histogram plays no part (except to tell you if you are over exposed and clipping - but that rarely, if ever, happens with proper exposure lengths).

[vlaiv]

1 minute ago, roger jerome said:

Thank you so much........Not sure what IIRC is though(?)

Not sure myself, but it does sound like short for "If I recall correctly" - so I assume that is the meaning of that abbreviation

 

[Steve Ward]

If I recall correctly ... 😉

[roger jerome]

wow....thank you again for your detailed advice....from a grateful old guy