[sjastro]

Thanks Steven - your shots look great! Good idea to go with the Pentax lenses - there is an adapter at Bintel, expensive at $449 but I guess all Ap stuff is... The lenses are under $350 though at least!

http://www.bintel.com.au/Astrophotog...oductview.aspx

http://cameraexchange.com.au/index.p...product_id=743

http://cameraexchange.com.au/index.p...product_id=742

I need to work out the FOV to decide which lens though, because your pic of ic4628 is not a great deal wider FOV than my current setup gave me last weekend. (comparison pix attached)
The 165mm 2.8 might be a better option than the 300. How long is your 'scope and which chip was that taken on?
Thanks for your input

I use an ST-X10ME CCD. The Pentax lens has a length of 260mm including the lens hood.
Your 8300 chip has a surface area 1.6X larger than my chip.
I selected the 300mm f/4 as I felt the 75mm clear aperture was a minimum requirement for "high resolution" work.

BTW your IC4628 image is excellent.

Regards Steven