Choosing between a 8"f/4 newt and a RC8 for imaging

[Gunsnroses]

Hi everyone. First post here and I'm looking for insight between the 8" f/4 newtonians and the RC8 astrographs.

At the moment I have AZ-EQG mount and a Orion ED-80.

I also have a ST-80 and ASI120MM to use for guiding. But haven't set it up yet since my AZ-EQG has been doing 3 min unguided shots so far. That seems to work well in my light polluted area with the 600mm ED80. 

But once I go up in focal length, I'm sure the guide scope will come in handy.

Anyway, I know the 8" f4 newts need a few mods out of the box. Focuser, reinforced ota around the focuser and mirror locks as well as new collimation knobs.

I haven't really read that the RC's need much modifications out of the box.

The 8"f4's seem to be critical for collimation. Much more than the RC's.

But with good collimation tools, that shouldn't be an issue I would guess.

And a Baader Coma Corrector is a must.

The only down sides I can see in the 8"f4 is that it's only 800mm, which is only 200 mm more than my ED80. So it'd still going to be pretty wide on planetary nebula and star clusters. 

And the fact that balance will be thrown off each time the mount adjusts to a new target since the focuser is on the side of the ota. Wouldn't stress that to much if I had a larger mount, but after all the equipment is mounted on the AZ-EQG, it's going to be at its limit for astrophotography and a shift in balance could throw off the tracking.

The only down sides I can see to theRC'8 is the 1600mm focal length and the fact that is an f/8.

F/8 is pretty slow. So longer exposures will be necessary. And at 1600mm, tracking will be more critical. 

Soooooo, I'm looking for insight on these two ota's from those who have used them or are using them now.

Do use barlows effectively with the 8"f/4 to magnify objects like planetary nebula?

Do you use focal reducers effectively with the RC8's to get a wider field of view and a faster f/stop?

Any insight on these ota's for imaging would be much appreciated. 

Sorry for the long post and thanks so much in advanced.

Clear skies

 

 

[Gunsnroses]

Moving this over to beginning imaging so you can delete this post.

I would, but not sure how.

Thanks.