Huge image on screen

[CornwallBob]

Hi - I'm trying to capture an image of the sun, which when I'm looking through a 25mm eyepiece appears fine (Celestron 9.25). When I exchange the eyepiece for my ZWO ASI120MC-S and try to use SharpCap, the image is huge on screen - I can only see a small section.

What am I missing/doing wrong?

Thanks

 

[Ibbo!]

The 120 is too small a sensor to get the whole sun on with the 9.25

not sur ethere is a webcam with big enough sensor to do it with the 9.25.

Try a DSLR

 

[Cornelius Varley]

57 minutes ago, CornwallBob said:

Hi - I'm trying to capture an image of the sun, which when I'm looking through a 25mm eyepiece appears fine (Celestron 9.25). When I exchange the eyepiece for my ZWO ASI120MC-S and try to use SharpCap, the image is huge on screen - I can only see a small section.

What am I missing/doing wrong?

Thanks

 

You are doing nothing wrong. The sensor of the ZWO120 is quite small and the field of view you get with it will be a lot less than a 25mm eyepiece.

see here: for comparison. The larger circle represent the fov of a 25mm eyepiece and the rectangle that of the ZWO camera.

 

[cjdawson]

Try pointing at the moon, you'll be able to make a mosaic that's fantastic quality.  You'd need to reduce the focal length that you are using with the webcam be a huge amount to be able to get the whole sun in.  I don't think that a FR exists that could do it.  Switching to a DSLR should give you the ability to fit the whole sun in the image because of the much larger sensor.

[D4N]

You may want to get some mosaic helper software as you are going to have a lot of tiles, it sucks to spend hours on a mosaic and then find that you missed a bit.

 

Even with a 0.33 reducer you would need a 6 pane mosaic to get the whole sun.

[johnfosteruk]

2 hours ago, cjdawson said:

Try pointing at the moon, you'll be able to make a mosaic that's fantastic quality.  You'd need to reduce the focal length that you are using with the webcam be a huge amount to be able to get the whole sun in.  I don't think that a FR exists that could do it.  Switching to a DSLR should give you the ability to fit the whole sun in the image because of the much larger sensor.

And he'll be able to capture some wonderful AR closeups!

[MattJenko]

Ah, the tortuous pain that is mosaics. This is my effort with an ASI120M on the moon a little while ago with a much smaller focal length than your C9.25, so you will have even more tiles to yours! If you commit to such a project and it works, you will have a simply awesome lunar/solar image though, the resolution would be astounding!

[uhb1966]

great mosaic but isnt there a tiny edge missing...upper left?B)

 

[cjdawson]

12 minutes ago, uhb1966 said:

great mosaic but isnt there a tiny edge missing...upper left?B)

 

There's where Wallace and grommit went for their Grand day out.

[uhb1966]

OMG!!! I LOVE that movie