Gunsnroses

Just to update, if anyone is still folowing, I ordered the 8"f4 today as well. So I now have both scopes coming. I will test them both with my DSLR and see if there is a focus issue.

O.k. Just ordered.... 1- 203mm f/5 ota 1- set of 235mm rings 1- cooling fan 1- Baader MPCC III Coma Corrector 1- ADM DUP 15" universal plate Next up will be Scopestuff things. New collimation knobs and a Cheshire collimation tube. Still haven't decided on the focuser yet. Also looking for a 120v plug in converter for the Dew Not controller. Any suggestions?

Custom painted CGE and 10 inch ota with Orion 80-ED.

Uranium235, the 8 inch f/5 doesn't come with rings. Only the f/4. But your right, those cheap Orion rings do work good. And I already have one of the Orion universal wide dovetails. And it's rock solid. But everyone is out of them. I had forgotten about Anthonys dovetails though. I'll have to give him a call. As for the Moonlites..6 years ago, and for many years before that, I bought Moonlites for all my scopes. I always enjoyed them. But back then, I only done visual observing. And only dabbled in astrophotography. I talked to Ron again yesterday and we discussed a CR2 with 2" compression ring drawtube with tri-knob reduction and a shaft lock. The shaft lock feature will be nice cause it will lock my focus without shifting the drawtube. But I will check out the other focusers you posted Olly. And just to be clear...I have been in visual astronomy for over 20 years. I had to sell off all my equipment when my wide and I bought our house. We needed that down payment. But all my gear was for visual only. I hade a CPC 1100 with Earth win Binoviewers and a CGE withan Orion 10 inch newtonian. But since I've gotten back around to astronomy again, this urge to image has arisen. So I want to give it a try. So far with the ED80, visually, it's been a lot of fun. Mechanically, it's been a lot of work. And the sit and wait for the camera to finish has been a bore. Lol So after I get the imaging thing going good, I'm going to have to pick up another CPC 1100 so I can do some visual stuff while I wait.

Soooo, I guess I'm going to try out the 8" f/5. It's relatively inexpensive so it won't be a big loss if it doesn't turn out to be what I want. Going to have to get tube rings, Losmandy style dovetail, Baader MPCC III and a Moonlite focuser. Also have to invest into sone collimation tools. Not sure on those just yet. Maybe Hotech or Glatter. But I do want a Cheshire to start off with so I can center the secondary once I put the new moonlite on. Guess we shall see how it goes.

This is what I'm getting now. But I want to get a bit closer to my subject to resolve more detail.

Not sure about all that "arc second" stuff or "PP" stuff, but I can answer a few of the other questions. I am imaging with a DSLR. It's a70-D crop camera. Unmodded. The reason I am/was considering a f4 Is the shorter tube length. The f/4 and RC are short. The f/4 is only 30 inches and the f/8 is 22 inches. The F/5 is almost 40 inches. The weight of the three are pretty close at around 16/18 lbs. I am looking at a focal length of around 1000mm to 1200mm. That gives me a pretty good magnification to allow me to frame things like the Orion Nebula and Horsehead, but also enough magnification to get detail on objects like the Dumbell and Ring Nebula as well as galaxies. The F/8 RC is way to long at 1600mm. And I can't find any info on what a focal reducer brings the f8 down to. The attractive things about the f/8 is how well it will hold collimation, short tube and the focuser being on the back. Unattractive thing is the focal length of 1600mm. If a focal reducer will bring that down to 1200mm or so, then that's the way to go cause I could use the 100mm for planets and the moon. The 8 inch f/4 is only 800mm. I would like a bit more magnification that the f/5 will provide. But that extends my ota almost 10 inches in length. But puts me at 1000mm. Soooooo....I guess the main question I need answered is where a focal reducer puts me with the RC. What focal length will I be working at with a good focal reducer.

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

Moving this over to beginning imaging so you can delete this post. I would, but not sure how. Thanks.

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

Thanks everyone. Will head over to a few forums in the next few days and search out some answers to my questions. Hopefully I can make a decision soon and get back to higher power/resolution imaging. Love this hobby. Clear Skies

Recently got back into astrophotography after leaving astronomy for about 6 years. When I got out of astronomy I had a CPC 1100 and a SN10 on a old Atlas mount. I recently purchased an AZ-EQG and a Orion ED-80. I'm really enjoying the wide field images of the ED-80, but it's time to get some bigger aperture to tease out more detail. I'm on the fence between a 8 inch f/4 newtonian or an RC8. So most of my questions will be directly towards that to start off. Thanks again for the add. Clear Skies