I had obtained a Sigma 150mm APO lens recently. This image is actually first light (astronomy target) for this optic. As you can see from the bright stars in the image, the FStop iris is nine vane (producing 18 spikes). This lens on an APS-c size sensor gives about 8 degrees in vertical portrait. Full image and processing details are at:
http://www.jthommes.com/Astro/DSLR/Rho_Ophi.htm
Scope - Sigma APO 150 mm lens at f3/3.5
Camera - Canon 350D (Baader ACF modified), no filters, ISO 800 and 1600
Mount - Celestron CG-5 GOTO
Guiding - Home made guide scope 180mm FL, Vesta 690, K3CCDTools
http://www.jthommes.com/Astro/DSLR/Rho_Ophi.htm
Scope - Sigma APO 150 mm lens at f3/3.5
Camera - Canon 350D (Baader ACF modified), no filters, ISO 800 and 1600
Mount - Celestron CG-5 GOTO
Guiding - Home made guide scope 180mm FL, Vesta 690, K3CCDTools
Jim Thommes
Mak-Newt 152 mm
C8
Megrez II APO
Zenithstar 66 mm APO
G11/Gemini
ST8300M
Artemis285 Camera
Canon 350D DSLR
http://jthommes.com/Astro/