Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

sgl_imaging_challenge_banner_lunar_landings.thumb.jpg.b50378d0845690d8a03305a49923eb40.jpg

TenBears

Sky-Watcher ED80 or ED100??

Recommended Posts

I am getting ready to order my first AP rig.

Getting the Celestron Advanced VX EQ mount.  

The OTA is my question for you guys.

Are there any disadvantage of getting the Sky-Watcher ED100 over the ED80?

The 80mm is 600mm focal length f/7.5

The 100mm is 900mm focal length f/9

To me, I would think the faster 80mm scope would be more desirable.  But didn't know if the larger aperture with the 100 would be beneficial in other areas? 

I've only experience with 35mm camera's when it comes to photography, so I'm not as familiar with this.

I currently just use a 12" dob, and have been itching to get into AP.

The price difference between these two OTA's is only $100US, so I thought I'd make sure.

I'm more interested in DS than planets...  though I do want to photograph Jup/Sat, naturally.

I'm most interested in galaxies, nebulae, planets - in that order.

What I was thinking was, the 80mm would be perfect for nebulae, and down the road a longer/larger scope for galaxies?   Like the SW ED120?  Or even perhaps an 8" SCT?

Thanks

Share this post


Link to post
Share on other sites

I am getting ready to order my first AP rig.

Getting the Celestron Advanced VX EQ mount.  

The OTA is my question for you guys.

Are there any disadvantage of getting the Sky-Watcher ED100 over the ED80?

The 80mm is 600mm focal length f/7.5

The 100mm is 900mm focal length f/9

To me, I would think the faster 80mm scope would be more desirable.  But didn't know if the larger aperture with the 100 would be beneficial in other areas? 

I've only experience with 35mm camera's when it comes to photography, so I'm not as familiar with this.

I currently just use a 12" dob, and have been itching to get into AP.

The price difference between these two OTA's is only $100US, so I thought I'd make sure.

I'm more interested in DS than planets...  though I do want to photograph Jup/Sat, naturally.

I'm most interested in galaxies, nebulae, planets - in that order.

What I was thinking was, the 80mm would be perfect for nebulae, and down the road a longer/larger scope for galaxies?   Like the SW ED120?  Or even perhaps an 8" SCT?

Thanks

Hi,

I have both of these and to be honest they are both slow for imaging, ED 100 even more so. The  ED 80 will get down to about F6 with the help of an FF/FR and will give a wider field of view for a given sensor size. I have used the ED100 for planetary imaging and some of the more popular galaxies,  the ED 100 has the better optics but the ED 80 is also fine. I have now purchased an Altair Astro  0.6 FF/FR and I am awaiting a suitable night to test it with the ED 80, if it works then @ f4.5 it will be fast enough imaging scope.

Reagrds,

A.G

Edited by lensman57

Share this post


Link to post
Share on other sites

I have read on this forum time and again that with the right mount and auto guiding, that the ED80 is a fab scope.

It is on my wish list, unfortunately for me and as a great testimony to the scope nobody sells them and just upgraded my mount.

So I am going to wait for post x-mas regret to see if anybody wants to part with one.

Share this post


Link to post
Share on other sites

I'd recommend the ED80 - this has to be the best value imaging 'scope ever made! The 600mm focal length is great for deep sky imaging and gets even better when you use a focal reducer/field flattener and you DO need to use a field flattener so be sure to budget for this too.

Share this post


Link to post
Share on other sites

I'm a happy ED100 owner, but I'd have to say, DSO imaging is not its main strength, so out of the two, it would have to be ED80 for me.

Share this post


Link to post
Share on other sites

+1 for the ED80 a fabulous scope for the money.

With the dedicated x0.85 FR/FF it becomes an excellent

imaging scope.

cheers

Steve

Share this post


Link to post
Share on other sites

How does the ED120 compare to the 80 and 100? OK it's more expensive but there's twice the aperture (2.25 if we're being picky) and it is still at f7.5 like the 80 so it doesn't sacrifice the speed as the ED100 would.

The only downsides I could see would the increased weight and smaller FOV but against that is theoretically better resolution and limiting magnitude.

Share this post


Link to post
Share on other sites

How does the ED120 compare to the 80 and 100? OK it's more expensive but there's twice the aperture (2.25 if we're being picky) and it is still at f7.5 like the 80 so it doesn't sacrifice the speed as the ED100 would.

The only downsides I could see would the increased weight and smaller FOV but against that is theoretically better resolution and limiting magnitude.

Aperture size on its own has very little bearing on imaging, the crucial factors are the F ratio which affects the exposure length and then FL that detemines the image scale or how wide your FOV is as far as DSO nebulea  imaging is concerned . The size of the sensor then detemines how much of the sky is imaged. Have a look at the imaging section and you'd notice that most of the imaging is done with 60~80 mm scopes with fast Fratios F4~F5. SW ED 80 is a good first scope but I still maintain that at F 7.5 it is a little on the slow side, by upping the budget a little and looking around there are much better alternatives.

A.G

Edited by lensman57
  • Like 1

Share this post


Link to post
Share on other sites

How does the ED120 compare to the 80 and 100? OK it's more expensive but there's twice the aperture (2.25 if we're being picky) and it is still at f7.5 like the 80 so it doesn't sacrifice the speed as the ED100 would.

The only downsides I could see would the increased weight and smaller FOV but against that is theoretically better resolution and limiting magnitude.

At three times the price, not sure it is in the same league, many people compare the 120ED Frac to a 190Mak-Newt. 

These are IMHO not beginner scopes and really in a different league, not sure if it is worth comparing?

Share this post


Link to post
Share on other sites

How does the ED120 compare to the 80 and 100? OK it's more expensive but there's twice the aperture (2.25 if we're being picky) and it is still at f7.5 like the 80 so it doesn't sacrifice the speed as the ED100 would.

The only downsides I could see would the increased weight and smaller FOV but against that is theoretically better resolution and limiting magnitude.

For DSO imaging (though I am more into webcam these days), I prefer my ED80 (Celestron F6.25) over my ED120 for two main reasons:

(1) The ED80 copes better in wind. Mine has been out taking images in gusts of up to about 40mph. My 120 can start to get a bit shaky at 20mph+. I have no observatory and where I image is a bit exposed to the wind. It's pretty frustrating if a bit of wind can stop you imaging, when the dark clear nights are in short supply!

(2) I prefer the focal length of the ED80 to the ED120 for imaging. There are some very nice DSO's that suit the shorter focal length (though the size of the imaging sensor also affects how wide your shot is).

Some people say (though I don't quite agree) that a 120 is a bit neither here nor there in terms of focal length. Neither short enough to neatly frame some of the big nebuale, nor long enough to show the smaller galaxies reasonably close up. As said, I don't fully agree with that, partly because I have seen some really inspiring images that are not neatly framed, that chop a bit of the DSO off/are in a little bit closer. I mean, someone could have a poster of someone famous on their wall that does not show the entire person :) But as said, I prefer the shorter focal length generally. You can use programs like SkyChart/Cartes du Ciel and enter your scope and camera details to check out how the various DSO's would fit into the image frame. Don't forget to factor in a reducer if used.

The 120 for me is a useful addition to the 80 for DSO imaging, but I'd get the 80 first and consider if I want a much bigger second scope than the 120 - though long focal length imaging is much more demanding than short focal length! ...

Also, if any imaging newbies are reading, I think there can be a tendency to assume a larger scope is better for imaging. That's exactly what I used to think.

Then one day, when I went into my local astro shop, Green Witch, I was amazed by some astrophotos on display. And I was almost as amazed by the fact that they were taken with a very small telescope! As far as I remember, it was with a 66 or 70mm aperture scope, or thereabouts.

Imagine you take two normal life photos with a regular camera. One is of someone's face, who is sitting opposite you at the dinner table. The other shot is of a bird in a tree 50m away.

You need a short focal length for the face shot, and a long focal length for the bird shot to get in close. It's not a case that one focal length is better than the other one, just because it's bigger. The best one depends on what you are imaging. For this reason, some imagers have a few different scopes to use depending on what they want to image.

As already said by lensman, the aperture alone is not really the big thing with DSO imaging. It's more the speed that helps (the lower the F number, the better), which is determined by the combined effect of the focal length and aperture. And the focal length is important for affecting the image scale. Some people find F7.5 too slow to image with. I was fine with it, but do not have the highest expectations. Images taken at F10 already blow my mind! :shocked::laugh:

Hope the thoughts help.

Edited by Luke
  • Like 3

Share this post


Link to post
Share on other sites

Aperture size on its own has very little bearing on imaging, the crucial factors are the F ratio which affects the exposure length and then FL that detemines the image scale or how wide your FOV is as far as DSO nebulea  imaging is concerned . The size of the sensor then detemines how much of the sky is imaged. Have a look at the imaging section and you'd notice that most of the imaging is done with 60~80 mm scopes with fast Fratios F4~F5. SW ED 80 is a good first scope but I still maintain that at F 7.5 it is a little on the slow side, by upping the budget a little and looking around there are much better alternatives.

A.G

Yes I agree f4 - f5 scopes are better than f7.5, but at what cost? The faster scopes in the ED80 price range do suffer from CA 

particularly in the blue spectrum and yes you can process this, but it's a pain. Still say the ED80 at f6 with the dedicated reducer is the best value bar none.

cheers

Steve

Share this post


Link to post
Share on other sites

Aperture size on its own has very little bearing on imaging, the crucial factors are the F ratio which affects the exposure length and then FL that detemines the image scale or how wide your FOV is as far as DSO nebulea  imaging is concerned . The size of the sensor then detemines how much of the sky is imaged. Have a look at the imaging section and you'd notice that most of the imaging is done with 60~80 mm scopes with fast Fratios F4~F5. SW ED 80 is a good first scope but I still maintain that at F 7.5 it is a little on the slow side, by upping the budget a little and looking around there are much better alternatives.

A.G

Indeed, easy to see when you see pictures taken with a DSLR sized sensor and a nifty fifty! Only 50mm focal length :)

As for the original question, an ED80 would certainly be easier, but do consider the Equinox 80 as it is natively faster than the ED80.

Share this post


Link to post
Share on other sites

Guys, really appreciate the comments.  Very helpful.

With all that's been said, I looking hard at this now

Explore Scientific 80mm f/6 Air-Spaced Triplet ED Apochromatic

Anyone had any experience with this scope?  I can imagine nebulae could be imaged quite good with this.

My question though, is for galaxies.  At what FL would you consider "minimum" to do some descent galaxy imaging?  I'm thinking 480 wouldn't be enough?

Share this post


Link to post
Share on other sites

Guys, really appreciate the comments.  Very helpful.

With all that's been said, I looking hard at this now

Explore Scientific 80mm f/6 Air-Spaced Triplet ED Apochromatic

Anyone had any experience with this scope?  I can imagine nebulae could be imaged quite good with this.

My question though, is for galaxies.  At what FL would you consider "minimum" to do some descent galaxy imaging?  I'm thinking 480 wouldn't be enough?

If its M31 then 200-400mm fl is ideal much longer and you cant fit it in without going corner to corner.

  • Like 1

Share this post


Link to post
Share on other sites

If its M31 then 200-400mm fl is ideal much longer and you cant fit it in without going corner to corner.

M31 is a given when it comes to AP...  Yea, I'll be taking pics of that with my camera lenses.  :grin:

But it's like XXxxx (way) Huge compared to all other galaxies out there.

I was mostly referring the others, with LY measurements with a few more zero's.

When I haul my gear out to dark sky sites, it will be these I will be gathering light from. :kiss:

  • Like 1

Share this post


Link to post
Share on other sites
imaging

Guys, really appreciate the comments.  Very helpful.

With all that's been said, I looking hard at this now

Explore Scientific 80mm f/6 Air-Spaced Triplet ED Apochromatic

Anyone had any experience with this scope?  I can imagine nebulae could be imaged quite good with this.

My question though, is for galaxies.  At what FL would you consider "minimum" to do some descent galaxy imaging?  I'm thinking 480 wouldn't be enough?

Hi,

Explore Scientific, as far as my knowledge goes, are a US  based optical device manufacturer, reseller.. If I am not mistaken  then their APO triplet is of more than acceptable quality but please do your research in the  more US based forums. If you are primarily interested in imaging galaxies rather than wide field capture of nebulea then neither of the scopes you mention  are suitable. With the exception of the two nearby giants from our local group of galaxies and because of their proximity and size,  for any other galaxy you'd need a fast scope with a long focal length,  this means that you either have to opt for a NEWT of huge proportions or opt for an SCT of some sort with a 0.63 FF/FR to bring the focal ratio down. Regretably there are no universal imaging scopes. BTW SW ED80 is not F6 but F7.5, with the help of the SW 0.85 FF//FR it   bcomes  an F6.4 scope The Equinox 80 is a doublet of F6.25  Native, very different scopes.    

A.G

Edited by lensman57

Share this post


Link to post
Share on other sites

Man, I've just reached the end of my own personal 'which small frac for imaging' journey. I feel your pain!!!

  • Like 1

Share this post


Link to post
Share on other sites

Thanks A.G.  So photographing galaxies is going to have to move down the priority list then... I'm not ready to drop the bucks for that kind of aperture.

A small APO is going to have to suffice for now, maybe in a year or so I will get an larger SCT rig for it (I'm not messing with a huge newt on an EQ).  We'll see.

Share this post


Link to post
Share on other sites

With a smallish frac you will have loads of targets, you will not be disappointed.

Must admit I do like clusters, when the clouds allow I nearly always do a cluster or two. :grin:

M35

m35.jpg

Share this post


Link to post
Share on other sites

Well, what a jump I made...  went from considering these two scopes...  to "purchasing" an Esprit 100.  :D

I'm very excited and can't wait for delivery on Monday (hopefully!)

Share this post


Link to post
Share on other sites

Sounds like a no brainer then, ED80 it is.   Thanks!

Totally. Grabbed about half an hour with a rubbish eyepiece in my newly acquired 80mm apo and it was just amazing how much difference there was from my star travel 102. Smaller aperture but way faster and the better glass was immediately apparent.

Share this post


Link to post
Share on other sites

Well, what a jump I made...  went from considering these two scopes...  to "purchasing" an Esprit 100.  :D

I'm very excited and can't wait for delivery on Monday (hopefully!)

You have made the right choice, the Esprit 100 is  a very appealing proposition.

A.G

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.