Skywatcher 80ED pro or Skywatcher 150PDS?

[Gohan75]

Is it better to get the ed80 pro or go for something with a larger appeture such as the 150pds? Ay thoughts?

[Gohan75]

Any thoughts?*

[jgs001]

Personally, I'd go with the 80ED, but then I like refractors, and own an older Celestron variant (same optics). It's a very capable scope. 

If you haven't got it already, I'd get a copy of http://www.firstlightoptics.com/books/making-every-photon-count-steve-richards.html and have a read.

[Gohan75]

i suppose with an Ed80 longer exposures will be required to get the same amount of data as say a 150mm reflector? But with the ED80 the image should have no coma ect? Is that correct?

[wxsatuser]

i suppose with an Ed80 longer exposures will be required to get the same amount of data as say a 150mm reflector? But with the ED80 the image should have no coma ect? Is that correct?

Depends on the f ratio of the reflector.

ED80 Pro with a reducer is a tad over f6

[frugal]

Depends on the f ratio of the reflector.

ED80 Pro with a reducer is a tad over f6

True, but an ED80 with a Canon 60d and a field flattener had a field of view of 2.6º, and the 150mm reflector is 1.7º. Which is the difference between the horse had nebula filling half the frame or the whole frame. Of course it depends on what you are pointing at as to whether the wider field of view is a good thing or not.

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[Gohan75]

hmm well im not sure. I want to image things such as the Orion nebula and M31 im guessing a wider field of view is better?

[jgs001]

M31 is a tight fit across the diagonal of the ED80 with a crop sensor SLR. the Orion nebula is a nice fit, as is the Pleiades. The longer focal length of the 150, means that M31 won't fit in a single image frame, and I'm not sure the others would quite...

To get a better idea, have a look at http://www.12dstring.me.uk/fov.htm

[wxsatuser]

I must admit I prefer the wider field.

[peroni]

Is it better to get the ed80 pro or go for something with a larger appeture such as the 150pds? Ay thoughts?

My vote is with the ED80 Pro. 

If you are going to get started in imaging then many people recommend a refractor like the ED80 Pro for it's simplicity and 'plug n play' nature.

I believe the 150PDS is also highly regarding and some other posts concluded that you may well end up with a reflector and a refractor.

I'm learning this art and I've had my ED80 (first scope and mount) for almost a year. I don't regret purchasing and was glad I was pointed down that route. There is lots to learn when imaging so it's a good idea to keep things like scopes as simple as possible when you start.

FOV for any scope is always going to be perfect for some targets and less than perfect for others. One size never fits all.

One other benefit of the ED80 (refractors) is that they rarely need collimating (so I've read). I've not needed to do mine. Whereas the reflectors (150PDS) often need collimating, especially if you move it in and outdoors for imaging.

[Gohan75]

Yeah, i think i will go with the ed80 to be honest as it gets such high praise. I was just wondering if a greater appeture was worth it, and the fact that the 150pds is also a lot cheaper!

[wxsatuser]

I'm well pleased with my ED80, ideal as a starter, have used it to image and general observing.

[poogle]

If you get the ED80, you should probably buy the matching 0.85x reducer/flattener for it aswell. It will reduce the scope from f/7.5 to around f/6.4 and speed up the image acquisition for you.

If you were into galaxy imaging then I would recommend the 150pds (or something with longer focal length than the ED80) over the ED80, since most galaxies will look tiny when imaged through the ED80.

/Patrik

[Gohan75]

Hmmm, that is something to consider. I do already own a 130p but can only use it for prime focus using a 2x barlow which for M31 is too high, might be ok for other galaxies though... would this be usable as an imaging scope for those smaller galaxies? Then i could use an ed80 for wider field shots?

[swag72]

The ED80 on the HEQ5 is a good match. As already said though, do get the reducer otherwise your corners will leave a little to be desired. A refractor is as easy as you can get in imaging, not that there's anything easy about it at all! The ED80 is the scope of choice for many a good imager on the forum. You'll not be disappointed.

[lensman57]

given target

Is it better to get the ed80 pro or go for something with a larger appeture such as the 150pds? Ay thoughts?

Is this for imaging or observing? If are after imaging there are a couple of points to consider.  Aperture as such is not relevant to imaging, what you need to consider is a: the folcal ratio that determines the intensity of the light that falls on the sensor, therfore the faster the scope the shorter the exposure time for a given target b: focal length that dtermines the image scale and the FOV, the shorter the FL the smaller the image scale and narrower the FOV for a given target  with the caveat that the size the sensor does not change your image scale but the larger the sensor the more of the target and the surronding sky will be recorded. The 150 PDS is a native F5 with an FL of 750mm, the ED 80 is a native F7.5 and 600mm of FL. As it stands the 150 PDS is a much faster scope considering that if you mounted the SW Coma corrector ( mandatory if you want to use anything like a DSLR to image with , with 1/4" type sensors, very small, it may not be necessary) then with reduction factor of 0.9 you have a scope with F4.5 and  675mm of FL. On the paper the 150 PDS is a clear winner but if you look around the imaging section you'd  notice that most folks are using an ED80 or simillar, I think that there are several resons for this. It is much less bulky than a 150PDS so the mount is not overloaded. It is plug and play, no adjustments, long cool down period or collimation  prior to imaging is required. It is a lot easier to move around particularly if like myself you have to set up from scratch each time. And for me atleast, the focal length of the 150 falls in no man's land, it is a little too long for widefield neblulea imaging, even reduced,  but too short to get into the galaxies that with the exception of four of them, they are all very small ( SCTs do well there ). So you need to decide what fits the bil for you. Hope this helps a bit.

Regards,

A.G

[frugal]

I don't knpw abput the original poster, but this thread is certainly giving me lots to think about.

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[PorkyB]

A lot of people seem to be worried about the fact that reflectors need regular collimation.  It really is a non-issue.  I do mine every time I use the scope.  It takes two minutes maximum and that's during cool-down time anyway.

The choice between the ED80 or the 150PDS really is down to personal preference - some people like the way images look from a refractor, some people prefer a reflector.  Both scopes need extras to make them good for imaging - the ED80 needs the field flattener / focal reducer and the 150PDS needs the coma corrector.

Personal preferences aside, the one figure that might swing it is that even with the FRFF the ED80 is f/6.3 while the 150PDS (and the 130 & 200 versions) is f/5, which is quite a significant difference in terms of exposure times.

[Gohan75]

Thanks for all your input. This setup is primarily an imaging set up as i have a dob. It is a lot to consider, one thing that also is influencing my decision is the large price difference between the two scopes. 

So from what i gather the 150PDS is a faster scope, meaning it needs less exposure times. However its focal length is higher than the ED80 which reduces its field of view somewhat? This may be a problem when imaging wide-field nebulae.  SO in other words the ED80 is a wider field imaging scope however it will need longer exposure times, it also is lighter and easier to set up ect with no need to collimate or cool down and it should be easier to guide. It has good quality optics also that do not show refraction spikes (although i do like them), how do the optics of an ED80 compare to a parabolic mirror in quality?  

Am i correct in these assumptions

[skfboiler]

Hmmm, that is something to consider. I do already own a 130p but can only use it for prime focus using a 2x barlow which for M31 is too high, might be ok for other galaxies though... would this be usable as an imaging scope for those smaller galaxies? Then i could use an ed80 for wider field shots?

I just found out last week that I can unscrew the focuser. There is threads exposed that you can screw on a typical T-ring and camera for prime focus. This may be the case with your Skywatcher as some scopes from Skywatcher & Orion Telescopes & Binoculars are made by the same company. I have yet tried taking pictures but I will at the next opportunity.

[ollypenrice]

Your assumptions are about right. The complications with imaging Newts don't stop at collimation. Collimation is easy if everything else is right, like the orientation of the secondary, the orthogonality of the focuser, the tension of the mirror clips and so on. Newts also catch the wind and the coma correctors add leverage against the focusers. Some are OK, some aren't. Fast F ratios also need finer focus. I don't think anyone would really want to argue with the idea that refractors are easier, though the extent to which are Newts are more difficult is debated regularly.

In a game with lots of complications I must say that I like imaging with refractors.

How do the optics compare? You'd probably get tighter control of the blue channel in the Newt, though the need for a coma corrector introduces some dispersion of the kind that even the very best apos produce in imaging. Bang on form, the Newt might well have it. Slightly off form and it would be the refractor.

Olly

http://ollypenrice.smugmug.com/Other/Best-of-Les-Granges/22435624_WLMPTM#!i=2277139556&k=FGgG233

[peroni]

So from what i gather the 150PDS is a faster scope, meaning it needs less exposure times. However its focal length is higher than the ED80 which reduces its field of view somewhat? This may be a problem when imaging wide-field nebulae.  SO in other words the ED80 is a wider field imaging scope however it will need longer exposure times, it also is lighter and easier to set up ect with no need to collimate or cool down and it should be easier to guide.  

I've read from others that the ED80 DS Pro quality far exceeds it's price tag. So although it is more expensive than the 150PDS you are getting good value for money.

The size of targets out there varies hugely and one scope won't be perfect for all. If you are interesting is Nebula then the ED80 would overall be better as it has a wider FOV. Even the ED80 won't capture all targets due to their size.

Imaging is a bottomless pit when it comes to kit. I only have the mount, camera, and scope so far but can see the benefits of a field flattener/focal reducer, guide scope + guide camera, CCD, ... the list goes on. If you are embarking on the imaging route, be aware that this first purchase won't be your last.

Don't worry about the longer exposure times needed in the ED80. I don't have the focal reducer/field flattener yet but I have achieved 5mins plus unguided (although that's lucky polar alignment). More achiveable is 1.5 to 3 mins subs. But with that length of exposure and careful post processing, you can achieve some admirable results.

People on this thread have recommended the FF/FR and it will be necessary ultimately but it not required first off. You can always crop you images to remove the edge imperfection.

[tonedeaf]

just wanted to add something....

as above A. G mentioned...the focal length is of issue!

with reducer the ED80 will have ~510mm which will give you good widefields...

for small/smaller galaxies you would need ~+1000mm

but:

if you are looking for the future, there will be 100% a second scope...

...knowing this, it is not unwise to choose scopes which complement themselfs

so one for widefields, and one for more "zoom", one for planets, one for....(you get the idea...)

i have the ED80 and it´s a great scope for its pricetag!

but for the small galaxies (something i love to image, didn´t know it before ) for a similar pricetag a RC 6" or a newton would be more appropriate...but the RC´s are telescopes that i wouldn´s suggest to beginn with (collmination, and other issues to tinker...)

also something to think about:

transportability!

a ED80 is set up very quick! no waiting times to cool down etc...

so if the skies clear you can have action -> visually or imaging, the later set up takes a "little" longer

(depends on the mount)

[Gohan75]

I think it makes sense to go for the ED80 given that i am new to imaging. I know i will want to get into galaxy imaging although i will be starting with M31 which can be done with the ED80. Maybe i could use the 130p with a 2x barlow for smaller galaxies? Or is imaging with a barlow not recommended? 

[tonedeaf]

please correct me if i´m wrong....

imaging with a barlow is a *cough* no-no (except for some cases -> very fast telescope, planets targets with a high mag)

cause with the barlow you "double" the focal length, therefore the scope becomes slower, therefore the exposure time climbs up (some say this may be a myth...)

but this i have to try myself out, when i get over it and buy a barlow

mostly the other way is gone -> focal reducers...such as SCT´s with a 0,6 reducer etc....