exmoorjim

Hi All, I know the method for calculating the image magnification ratio when using eye pieces, but what is the calculation when using a camera instead of an eyepiece.

I use an Sky Watcher Evostar 150 (150mm objective lens) and an ZWO ASI485 colour camera.

Thanks for any help.

Hi, Thanks for the tips. I have marks on the edge of both lenses, ("9 - 9 - 8") hand written, If I have the writing on both up the same way I guess the two lenses will be orientated correctly.

thanks again.

Good Evening All,

I've just bought a "spare" Evostar 150, it was very cheap mainly because the previous owner had taken the lenses out of the lens cell for cleaning!!!!

and then lost interest so sold it off cheap. "All the bits included but loose" I thought how hard can it be to re assemble!!!

I have......

1 x main lens (bevel ground on one edge, square on other edge with three stuck-on plastic spacers) (Inner lens I'm presuming -nearest eyepiece)

1x second (outer) lens

1x thin plastic spacer ring

1x thick plastic spacer ring

1x rubber O ring

1x threaded retaining ring

So, I'm not totally sure of the correct sequence / position of the parts.

Any suggestions please.

Thanks

 Just getting my gear all set up and talking to each other and testing on clear nights (few at the moment) so fully operational is taking time.

It was a short clear spell the other night and I had my finder scope Sky Watcher ED50/camera ZWO120/computers working (just) and thought I would get onto Orion Nebula with the finder  scope, a 4 second exposure revealed a smudge, so I did a 15 second exposure and got (to me) an amazing image, attached. I didnt have time to get better focus or exposure etc so it is pretty raw (not RAW !)

The image was taken via a smart phone off the computer screen

I was shocked that a 2" scope could give such an image.

Location

1000ft above sea level on Exmoor, Devon, UK.

Home made 6.5m x 2.5m Observatory/control room / day bed/tea drinks area plus Pulsar 2.2m dome.

Hardware

Sky watcher Evostar 150mm refractor plus ZWO 485 colour camera plus focus motor

Sky watcher ED50 50mm finder scope plus ZWO120 colour camera plus diy focus motor

Sky watcher EQ6 R mount

Stellarium

Sharpcap