2.5-3 minutes unguided?

[Galen Gilmore]

Hi all

I have an EQ5 and 130pds, and I have been getting 120 second subs easily, and very consistently. I was wondering if it's even realistic to try and go for 180 seconds or even just 150?

Let me know what you guys (and gals) think.

[MarsG76]

I had a similar experience with my CGEM.. 120-180 seconds were quite consistent, of course 120 seconds gave me more keepers but I had usable 180 sec subs unguided. so I say try it and see the percentage of the keepers.

Really it's until I started using autoguiding where I really have no sub time limit and high 90% of keepers. 

[MarsG76]

Another thing to add is that the unguided sub time will also be dependent on the focal length of the scope used.

When I said that I was getting keepers at 120-180s subs this was through my 8" SCT with a f6.3 focal reducer (1280mm)... so if you expose at say 500mm focal length than your unguided sub exposure can be longer... 5 minutes and longer perhaps...

[Galen Gilmore]

1 hour ago, MarsG76 said:

Another thing to add is that the unguided sub time will also be dependent on the focal length of the scope used.

When I said that I was getting keepers at 120-180s subs this was through my 8" SCT with a f6.3 focal reducer (1280mm)... so if you expose at say 500mm focal length than your unguided sub exposure can be longer... 5 minutes and longer perhaps...

Very interesting, my 130pds is 650mm with a 0.9x reducer. I will try for 3 minutes next time I'm out. 

Thanks

[newbie alert]

I've noticed with my setup that beyond 5 mins you get a enormous amount of more detail..guiding is only the real 100% way to get those long exposure times..