80mm refractor is easier though ... shorter focal length (my refractor and newt are 470 and 1000mm) and less fiddle with the refractor. No collimation and quick to set up. More time to worry about other things that go wrong !!!
Start with the refractor for imaging, everyone must have an ED80 somewhere? Use the newt for visual. When you are ready for some punishment, grab a cheap f/4 newt and image with that....
Use what you have. There is a learning curve with imaging, and a lot of it has to do with processing. Most folks start with a DSLR. Btw, not all newts are setup for imaging, if it is a visual Newt the camera may not reach focus. An imaging newt is preferred as they are designed for camera focal lengths, and usually require extension tubes to focus some eye pieces if used visually.
I too say start with what you have. Don't worry about corrector this or flattner that. Get going and the learning curve will address everything in time and turn. You have a little Vixen Newt that is made for imaging - GREAT! You won't gain anything more or less than with a refractor. Ok, there's collimation, but big deal! It is easy to solve
F5 newt from as small as 130/150mm upwards is great for DSO. The EQ-mount has to be stable enough to support the weight. With newts you get more mm per kg than with refractors.
Tube and focusser need to be able to handle the weight of you camera, as well, so I'd rather not buy a cheap 80mm refractor if you plan to dangle a heavy Canon from its end.
Following on from Kevin's remark, here's a single frame of 40secs taken
with my 8"SW f/5 Newt on HEQ5, unguided, Canon 1100D. Try that with an 80mm refractor.
It's not a quality image, but it shows what you can get with just a single shortish exposure with an 8" scope.
Best viewed at about 75% screen.
raymo
Last edited by raymo; 22-09-2018 at 12:05 AM.
Reason: more text
I totally agree with Raymo and Kevin as well
I have a 6” f6 Bintel GSO reflector on a HEQ5 mount unguided
and have captured some great images this year with up to 60 second exposures
I’m using my wife’s old stock canon 600D no adapters needed reaches focus perfectly
Here’s my single image of Eta Carinae Nebula ISO1600 with a 60 sec exposure
By the way my 6” newt only cost me $299
Thank you all for the advice. I had the Newt out the other night and sorted out the camera and focusing with it. A single shot at Alpha Cent was crystal clear, I couldn't see any coma at the edges
What's the difference between a big Newt or a small refractor? I find the smaller one is easier to set up, and doesn't vibrate so much in wind. Do you have to take longer exposures with a small refractor? An 8 inch Newt has 7 times the light-gathering power of a 3 inch refractor - does that mean you have to have 7 times the exposure with the smaller scope
What's the difference between a big Newt or a small refractor? I find the smaller one is easier to set up, and doesn't vibrate so much in wind. Do you have to take longer exposures with a small refractor? An 8 inch Newt has 7 times the light-gathering power of a 3 inch refractor - does that mean you have to have 7 times the exposure with the smaller scope
With that 7 times, you also have to factor in focal length. The big Newt gives you more focal length and a fast F ratio. Focal ratio is what it's all about. Focal ratio = focal length / diameter of the objective. Your typical ED80 has 80mm objective with 600mm focal length. So 600 / 80 = F7.5. A typical 8" F5 is 1000mm FL / 200 (diameter) = F5. So the big fat Newt has both a longer focal length AND a faster F ratio.
If we even it out and make the focal length of the ED80 1000mm, the same as the 8" F5 Newt, the ED80 would have a focal ratio of F12.5. Which is very slow photographically.
Bottom line, DSLR's like fast scopes, up to about F7. You can get away with slower focal ratios but you have to acquire enormous amounts of capture time to make up for it.
On the other hand, yes a little ED80 is so much easier to handle with vibration, tracking and wind etc. It's much more forgiving in that respect.
I actually have a 100mm Esprit f5.5, a Bintel 200mm Newt f4 and a XLT 150mm refractor f5
I am using the XLT150 and Bintel 200mm for planets with barlow, and Moon. This is because I can set them up on tripod with clock drive and exposures are all video files - very short exposures, so no problem with tracking.
For DSO's using a few long exposures (ie 30 - 90sec so far) I am using my concreted-in pier with HEQ5 Pro and 100mm Esprit with corrector. Unguided at moment, but experimenting with Synguider 2 .
Would there be any advantage in putting the Bintel 200mm f4 on the pier for DSO?
My cameras are all ZWO 224 or 183 colour. No DSLR. Advantage being imaging time, I guess, or will I get better resolution (crisper photos) with the Esprit?
Maybe the 150mm refractor will be better than the Esprit 100 as it is bigger?
DECISIONS.....DECISIONS AAAAAAAAGGGGGGGGHHHHHHH
Would there be any advantage in putting the Bintel 200mm f4 on the pier for DSO?
My cameras are all ZWO 224 or 183 colour. No DSLR. Advantage being imaging time, I guess, or will I get better resolution (crisper photos) with the Esprit?
There should be.... but.... if you search/read in the forums about fast newts and imaging you'll get a taste for the trials that await with collimation/tilt/flexure and collimation. Did I mention collimation? When the fast newts sing, they are brilliant and quick. Getting them singing is tricky.