Guiding or ED80?

[Herzy]

Here is my current equipment and I will give you two options as to how I could improve my imaging setup.

An AVX Mount, C6-N Optical tube (The focuser doesn't have room for a field flattener or any filters), Nikon D3200 and $550.

Options:

1) Buy an ED80 APO Refractor. This thing will give me longer exposures with a wider field of view and it is lighter. The optics are much better then my current tube so thats a plus. It also has room for both a field flattener and a LP filter unlike my other tube. However, the focal ratio is f/7.5 vs the focal ratio of my current optical tube f/5. If my thinking is correct, that means that this scope would require longer exposures to achieve the same results.

2) Get into guiding. I bought a small guide scope and guide camera and a 40 foot long USB cord I could guide off my desktop computer (I don't have a laptop). This would work but it would be really heavy on my mount. I have no experience with guiding so this will take a lot of trial and error.

Ideas?

 

[Joel Shepherd]

Well, both. :-)  It probably will be pushing it weight-wise, but I'd probably lean towards getting a guider package. Get your GOTO and rough polar alignment dialed in -- cut or mark spots in whatever location you ordinarily put your mount so that you can drop it on those marks and be within a degree of polar alignment -- then replace your visual finder with a RDF and a 50mm guidescope, and get to work. I no longer use a visual finder for aligning my AVX: I drop it on the dimples the legs have carved into the bricks and can do the 2+4 GOTO alignment and the All Star polar alignment without a finder.

I put a guider on a scope similar to yours before getting an ED80, and regretted not getting a guider a good six months earlier. You will figure out how to guide that scope and you'll see a huge improvement in your photos from the longer, steadier exposures. An ED80 makes guiding easier, but it is definitely doable with your scope. If I had to choose, I'd rather do the work to get a stack of 5-minute exposures from a 6" Newtonian, than a stack of 60-second exposures from an unguided ED80.

If you've made it this far, you'll figure guiding out.

[Herzy]

18 minutes ago, Joel Shepherd said:

Well, both. :-)  It probably will be pushing it weight-wise, but I'd probably lean towards getting a guider package. Get your GOTO and rough polar alignment dialed in -- cut or mark spots in whatever location you ordinarily put your mount so that you can drop it on those marks and be within a degree of polar alignment -- then replace your visual finder with a RDF and a 50mm guidescope, and get to work. I no longer use a visual finder for aligning my AVX: I drop it on the dimples the legs have carved into the bricks and can do the 2+4 GOTO alignment and the All Star polar alignment without a finder.

I put a guider on a scope similar to yours before getting an ED80, and regretted not getting a guider a good six months earlier. You will figure out how to guide that scope and you'll see a huge improvement in your photos from the longer, steadier exposures. An ED80 makes guiding easier, but it is definitely doable with your scope. If I had to choose, I'd rather do the work to get a stack of 5-minute exposures from a 6" Newtonian, than a stack of 60-second exposures from an unguided ED80.

If you've made it this far, you'll figure guiding out.

One thing I forgot to mention that is really important: The ED80 is used. It's a limited-time offer that comes with a whole bunch of extras ($650 worth for only $450) It comes with dew heater bands and it comes with a nice dual speed focuser (A huge upgrade on the original ED80 focuser). It's a great deal that I won't get again any time soon. I agree with you that guiding will get me the results I want sooner but eventually I am going to want both upgrades and in the future I won't have this great deal. 

Does that piece of info change your mind on what you would do or are you sticking with the plan to guide?

Also, how long do you think it will take to get set up? It's summer now but during the school times I don't have all that much time to image. I'm usually confined to only weekends on school nights unless everything goes perfectly and I don't have to do an ASPA four times just to get 60 second subs.

[Herzy]

It's essentially just thinking short-term and getting amazing results sooner or thinking long-term and getting the equipment I want sooner.

[Thalestris24]

Hi

I'd recommend getting a laptop! A cheap, low-spec second hand one will do. Not sure you could guide ok via a 40ft usb cable! With an ed80 you'll want a field flattener/reducer which will also speed it up. With phd2 guiding software you can drift align using its built-in tool. Using Stellarium + Astrotortilla for platesolving will enable you to quickly centre a target . 

Louise

[PeterCPC]

+1 for getting a laptop. I guide my ED80 and ED120 on my AVX. However, I don't use Stellarium or Astrotortiila but that's for you to ponder. I just use the handset and Backyard EOS.

Peter

[Waldemar]

+ for the laptop. Long USB cables are bound to make trouble!
2e hand equipment goes normally for ± 60% of the new price, so 450 is on the high side. The guy probably expects you to bargain. Personally I would go for the ED80, but I love refractors because of the obstruction free optics and no collimation (normally)
A reducer/flattener will improve the images and gives you about the same fl as your Newtonian
An off axis guider may work for you as well, keeps the weight lower and no flexure problems.

Make a wise decission and have fun!

Waldemar

 

[Herzy]

If I bought a laptop I wouldn't be guiding. The laptop would take up all of the money and K would have to wait to get more money for a guide scope and guide camera.

Guiding off a desktop will work perfectly well. I had some friends that do that and it works great. It would also allow me to be inside. Don't get me wrong eventually I want a laptop because a desktop can't be brought to observatories or dark skies but for now I don't see why I need it.

[Joel Shepherd]

What kind of ED80 is it? Do you have the make and the model? That does sort of change the equation, though my bias would still lean towards the guider ... but I can understand not wanting to pass a good deal. You'd want to be certain, though, that the ED80 is going work well for imaging. Have you seen or used it first-hand?

Not sure where the laptop discussion popped up (another thread?) and they do make things more convenient, but if you're managing without it, okay. One way to potentially cut down on the number of cables is to run a single high quality cable from your inside computer to a powered hub near the telescope, and fan short cables out from there.

[Herzy]

40 minutes ago, Joel Shepherd said:

What kind of ED80 is it? Do you have the make and the model? That does sort of change the equation, though my bias would still lean towards the guider ... but I can understand not wanting to pass a good deal. You'd want to be certain, though, that the ED80 is going work well for imaging. Have you seen or used it first-hand?

Not sure where the laptop discussion popped up (another thread?) and they do make things more convenient, but if you're managing without it, okay. One way to potentially cut down on the number of cables is to run a single high quality cable from your inside computer to a powered hub near the telescope, and fan short cables out from there.

It is unfortunately not the triplet one. It is the Orion ED80 it comes with the following

Orion Dual Speed focuser

2 Dew heater bands 

13" dovetail plate

Tube rings for the scope

All of that together would make a really good deal for only $450. It's online but it's from a friend of mine that moved away so I can trust him. He said its in good condition and he is only selling it because he had a baby and is giving up the hobby for a while not because there is anything wrong with it. No I don't know how well it would work for astrophotography but it was recommended as a good buy in my price range for AP.

What you said was the plan I had in mind. I would run a long cable out my window to a powered hub that connects to everything.

[Joel Shepherd]

I'd do some research on this site and the interwebs on that scope and see if folks comment on its suitability for AP. It may be great -- I don't know -- but do some research first. You're getting it for AP, right?, so make sure it's going to be up to job, especially in terms of chromatic aberration. It won't be a great deal if you aren't happy with the results.

Also, it will add time to get the guider going each night, but it is worth it. I usually do a2-4 alignment, an ASPA and maybe a second 2-4 if the polar alignment was off much. With the indents in the bricks, it's usually not. You won't need to do multiple ASPA exercises once you get a routine dialed in.

[Thalestris24]

There are quite a few good images made with the Orion ed80 on Astrobin

[Herzy]

2 hours ago, Joel Shepherd said:

I'd do some research on this site and the interwebs on that scope and see if folks comment on its suitability for AP. It may be great -- I don't know -- but do some research first. You're getting it for AP, right?, so make sure it's going to be up to job, especially in terms of chromatic aberration. It won't be a great deal if you aren't happy with the results.

Also, it will add time to get the guider going each night, but it is worth it. I usually do a2-4 alignment, an ASPA and maybe a second 2-4 if the polar alignment was off much. With the indents in the bricks, it's usually not. You won't need to do multiple ASPA exercises once you get a routine dialed in.

Yea I did a lot of research. I asked around on forums and even on bright stars the CA isn't really visible. Dew is a major problem but the package comes with dew heater bands. There have been hundreds of complaints about the focuser but the guy includes a better one. There are some small problems but I think it's a good fit. Would you go for it or would you guide sooner?

[Joel Shepherd]

I'd probably go for it ( the ED80). Maybe you can pick up a guider at a discount as well. :-)

[uhb1966]

please note that you cant use such long normal  usb cables w modern computers! youd need an active cable w repeater ... but the prices have come down for them just 35 eur for a quality active usb2 cable so no big deal...

[Uranium235]

Do you have a PC in the house?

Keep the lappy outside (safely stashed in a crockbox), then use powerline networking and teamviewer to control it from the comfort/warmth of your house.

As for guiding or 80ED, thats a tough one since you really could do with both. But.... how about a 130pds? Its roughly the same FL as the 80ED, its light, has a 2" dual speed focuser, and operates at f5. That and guiding could be gotten for the same cost as a new 80ED:

 

 

[Herzy]

3 hours ago, Uranium235 said:

Do you have a PC in the house?

Keep the lappy outside (safely stashed in a crockbox), then use powerline networking and teamviewer to control it from the comfort/warmth of your house.

As for guiding or 80ED, thats a tough one since you really could do with both. But.... how about a 130pds? Its roughly the same FL as the 80ED, its light, has a 2" dual speed focuser, and operates at f5. That and guiding could be gotten for the same cost as a new 80ED:

 

 

No I don't have a single PC and I don't have any laptops that work. I've thought about the 130pds but eventually I'm still going to want a refractor despite how good the 130pds. I know it's quite good but I'd rather spend big money now instead of delaying and just slightly upgrading. Don't get me wrong I'm sure I could get great results with the 130pds, I just don't think it's the right upgrade atm.

After reading through the thread it is better than I thought. :/ I'm faced with a tough decision. Does the tube pick up wind and cause vibrations? That's what my Newtonian does now because it's so big it acts like a sail.

3 hours ago, uhb1966 said:

please note that you cant use such long normal  usb cables w modern computers! youd need an active cable w repeater ... but the prices have come down for them just 35 eur for a quality active usb2 cable so no big deal...

I don't know anything about usb or what an "active cable w repeater" is, could you explain? I was just told that it is possible to guide off a desktop so assumed I could do it. It is a mac and it's fairly new.

[Uranium235]

The 130 really is a dinky, small telescope and does not pick up any breeze or vibrations. Put it this way, I had both the 80ED and 130pds at one point - and guess which one sat in corner for a year collecting dust rather than photons? (it wasnt the 130!). To get a good refractor that operates at f5, youve got to pay silly money.

The only advatages the 80ED has is that it is instantly plug & play and is uber-reliable with no tinkering required. But I would not use it without the 0.85x FF/FR (so it operates @ f6.3) - that pushes the cost up further.... its native f7.5 is just too darn slow

[alacant]

I've always wondered why the slow ed80s in varying degrees of apo-ness were recommended so much. They're miserably dark for taking astro snaps, everything appears small and they distort stars even a little way from the centre. I dunno though. I'm not sure whether the alternative of having hideous spikes sticking out from stars is the lesser of the evils!

[Uranium235]

12 hours ago, alacant said:

I've always wondered why the slow ed80s in varying degrees of apo-ness were recommended so much. They're miserably dark for taking astro snaps, everything appears small and they distort stars even a little way from the centre. I dunno though. I'm not sure whether the alternative of having hideous spikes sticking out from stars is the lesser of the evils!

I think thats a bit of a negative view of what for many, is a very reliable telescope. If you have distorted stars, then you need the flattener/reducer.... what else do you expect from a doublet? Show me a doublet with a flat field, and I will show you a shot of the pope on Mars I took a few weeks ago with the Hubble telescope.

Now...lets see just how "bad" these 80ED and 130pds telescopes are...

80ED:

 

130pds:

 

Nuff said....

[RikM]

If you have to prioritise, the most important component is the mount. It has to be stable and pointing in the right direction during the exposures. Guiding is a huge plus in keeping things on track.

Since you are imaging with a DSLR, you need the fastest optics you lay your hands on.

I would agree with Rob that a 130pds and a finder guider would give you better potential.

The ED80 is an outstanding imaging telescope, when fitted with a flatner/reducer and coupled with a sensitive CCD camera. 

[Uranium235]

Agreed Rik, mount is #1... optics come 3rd place.

But either the 80 or 130 should work within the limits of the AVX mount the OP is using. As long as he keeps the overall load below 7.5kg, he should be fine.

[alacant]

Negative, yes. I was trying to keep the reply specific to the thread in what is the beginner's section. I apologise for posting a negative comment. Please delete if this is not allowed. TIA.

[Herzy]

 

2 hours ago, Uranium235 said:

Agreed Rik, mount is #1... optics come 3rd place.

But either the 80 or 130 should work within the limits of the AVX mount the OP is using. As long as he keeps the overall load below 7.5kg, he should be fine.

So at the end of the day the question is does the reliability and ease of use that comes along with an ED80 counteract the price and slow f ratio? I was super hyped that I would be able to take longer exposures with it (wider FOV) but it seems that the pictures would be the same because the slow f ratio would counteract the longer exposures giving a similar image.

I guess my concern is that it just seems so strange to buy a 130mm newt when I have a 150mm newt sitting right next to me. I mean the quote "don't fix what isn't broken" kind-of applies here. My images aren't bad... they aren't necessarily good but I am getting by. If I am going to upgrade I want to go all in. I've spent thousands of dollars on buying things that I don't even use today. The things that I eventually sold or just have lying around because there are problems with them that I hadn't realized when I originally bought them. Buying the 130pds is certainly an upgrade, but is it an "all out" upgrade? Would it help me so much that I wouldn't need to upgrade again for years? I don't know about that one. Is there possibly another refractor in my price-range that I could buy that has a fast f ratio that you know of? I'm leaning towards refractors because they are simple and really easy to use (and light!!).

[Uranium235]

Well, the 80ED is about as cheap as it comes in regard to reliability and colour correction..... it really is hard to beat at that price point. Im pretty sure your AVX should be able to swing 10min subs on a regular basis if you have autoguiding. Perhaps a scour of the 2nd hand market might be in order? Gear is pretty well looked after and the going rate is about 60% of new price for an 80ED... but you need to be quick as they get snapped up pretty sharpish. The only reason I sold my 80ED is because I needed the money, and at one point I had two of them! (dual shooter)

The problem with fast refractors is colour correction and field flatness - its hard to get that on the cheap. If youre looking for fast & flat then you need to be investing in a triplet + FF/FR or multi-element refractor (eg: 4 or 5 elements) - and those are difficult to manufacture, hence the price tag.

Another idea would be just to replace the focuser on your existing newt.

Or, you could for now just get some guiding in and master that while you save up for new optics nobody gets their gear all in one lump, its accumulated over a number of years.