F2.8, looking good...

[ollypenrice]

Just first lighting my Canon EF200L lens wide open, having tried it two stops down. Looks promising. Without rocking the PC boat by opening too many programmes I seem to have almost perfect corner stars on the 15mm Atik 4000 chip. Great to think that a five minute sub at this F ratio is almost like a 20 minute sub at F5, which is itself a good F ratio.

For fun I am hammering away at the Virgo Cluster, aiming for nine panels at 40 mins per panel.

Wheee..... Of course it might turn out to be lousy!

Meanwhile, over at F7 the 20 minute subs are crawling in for my last desperate attempt to get some IFN around M81/82.

F ratio rules in imaging.

Olly

[rocketandroll]

I'm currently using that lens at f2.8 to grab a widefield of M101. Hazy cloud isn't helping but at least I have the LP filter in there now!

The nine panels on Virgo should be awesome. At ISO800 I got reasonable detail in that galaxy cluster using 40sec subs and only half an hour of data total.

Good luck!!! Looking forward to seeing the results!!!

Ben

[ollypenrice]

Thanks. Good luck to you too.

Olly

[rocketandroll]

Kinda thinking the south of France might be warmer and clearer than it is here tonight :-)

I'm really going for it now, sky is much clearer and up to about 50 x 100sec subs so far. Gonna see if I can get an hour and a half plus of useable data.

Ben