120ED Typical view

[jetstream]

Here is an image (I borrowed from imaging section,not mine) that represents a typical SW120ED view of Saturn under below avg seeing.My VX struggles under the same conditions.Under better seeing the image obviously gets better(actually much better),and is awesome for this aperture.

[Mike73]

Pretty good Gerry for fairly poor seeing conditions.

The only problem that I can see of having two planetary scopes is how do you know what the seeing conditions are like before you've set up? Or do you set them both up side by side each time?

[jetstream]

Yes the refractor works,last night it was good @ 150x-200x and was sharp around 180x quite a bit.I find the LZ helps me catch the moments of good seeing-it is very close to parfocal to my eyes.The seeing last night should have been better that it was.It looked great,lighthaze,still air,but not that good.

How do I pick the scopes?I know my VX10 very well and what conditions give it problems,like my dew soaked grass by 9pm,or obs from my deck with the house brick radiating heat,getting sucked into the fan.I have had them both out,VX on patio blocks away from the house,with a ground cover on the surrounding grass to keep things at bay with the frac above things,and of course its sealed.In these humid conditions the VX goes 120-150x,the frac 150+.If I was in the quarry it would be a different story most likely-it is the most thermally stable place I've found yet,so at least it reduces the ground thermal effect.

Mike,I just play the odds,in these types of conditions I figure the odds are the 120mm will perform more consistently,but I may miss some great views the 10" could provide.The dob is usually outside,cooled and when the 120mm goes 250x+,its time to try the OOUK.

[Mike73]

Like it Gerry.

Seems you've really thought through all your planetary (and solar) needs and I reckon that will pay off next winter.

The question I asked previously was one I've asked myself when I've been tempted by a decent frac in the past. 

I did have a little 4" Lyra Optics a while ago and although it just didn't have the practical magnification needed it really was very good for home observing.

My plan for this winter is to get out of town with my OO to try and get better seeing conditions, if I do use it at home it will be with an apodizing mask. If after next winter I don't feel like that combo has worked I may well go the same route as you the year after.

[John]

My ED120 gets surprisingly close to my 12" OO dob for planetary details quite often although it runs out of puff around 250x when the 12" is just getting into its stride if the seeing is decent. Saying that, the ED120 managed to put up a decent image of Saturn even at 300x last night although dropping back to 225x made the more subtle contrast variation features such as the C ring and bands on the disk somewhat easier to discern.

Refractors often do seem to "punch above their weight" apart from DSO's where aperture always seems to win.

[ollypenrice]

If I want to watch a shadow transit on Jupiter on a blazing hot summer afternoon I have to pop round to Marc's place. He has a six million euro 0.8 metre RC knocking about somewhere. 

If I want to do likewise at home I have the inconvenience of waiting for dark  and choosing between the TEC140 and a 10 inch Meade SCT. The SCT does sometimes win but the TEC is more consistent and, somehow, more pleasing to my eye so I usually gamble on that.

Olly

[timwetherell]

Refractors often do seem to "punch above their weight" apart from DSO's where aperture always seems to win.

Yes, that's always been my experience too! 

[Marki]

Oh cool -  are you Tim Wetherell as in the Great Wetherell Refractor Tim Wetherell?

[Paul73]

I'm confused. After reading the above. Why would anyone buy a Refractor???

I had always believed them to be on a different optical level to the reflectors. There-by, outperforming them handsomely on the bright planets, doubles etc.

Paul

[John]

I'm confused. After reading the above. Why would anyone buy a Refractor??? .....

  waits for ensuing lively debate ! 

[Uplooker]

Oh cool -  are you Tim Wetherell as in the Great Wetherell Refractor Tim Wetherell?

Is this the refractor you were referring to?

http://www.wetherellart.co.uk/sculpture_greatwetherellrefractor.html

I must admit it is pretty damn cool looking.

Ian

[Marki]

Aye, thats the one. A thing of beauty!

A bit out of my reach right now though, so a nice ED120 might have to suffice in the meantime !

[timwetherell]

Oh cool -  are you Tim Wetherell as in the Great Wetherell Refractor Tim Wetherell?

One and the same sir Although the refractor and I have since parted company. It left me for a nice gentleman in the USA who was able to provide it with a more spacious home. I'm consoling myself by building a new smaller "great but not so great, but in some ways greater" refractor for our new home and small observatory in Somerset. Hopefully we'll be in the UK by the end of the year if I can make it through the myriad complications and problems of an international move. 

all the best

Tim

[timwetherell]

Aye, thats the one. A thing of beauty!

A bit out of my reach right now though, so a nice ED120 might have to suffice in the meantime !

I don't think you'll be in any way disappointed with the 120 ED! I think aperture is a law of diminishing returns, especially with refractors. I guess the resolution is linear with aperture whereas the size weight and inconvenience goes as the third power!  I was surprised how moderate the difference between the 200 and my older 140 was. There was some to be sure, but in truth, probably not enough to justify the 8000% increase in hassle of set up. In a huge observatory a big scope is great. But if you have to haul it outside every night it soon gets old. I think the old adage "The best type of scope is the one that you use" it very true

A 120ED will be a very nice and capable instrument!

all the best

Tim

[Marki]

But if you have to haul it outside every night it soon gets old. I think the old adage "The best type of scope is the one that you use" it very true

A 120ED will be a very nice and capable instrument!

all the best

Tim

True indeed. I have an Istar 150mm f10 achro - solid, robust, nice optics but massive. I'm afraid it really doesn't get to go outside as much as it should do (even taking into account the rubbish weather!) simply because of the set-up hassle.

I mostly alternate between a 100mm f13 achro and a 125mm f9 achro - much quicker to get in and take down in our changeable climate! I find the 100mm f13 punches through poor seeing pretty well and the 125mm has a pretty nice light grasp, despite some CA on brighter objects. I'd like to put the 125mm up against an ED120 sometime though.

(EDIT - by the way, welcome to the forum Tim - I hope the move to the UK goes as smoothly as possible).

[nightfisher]

True indeed. I have an Istar 150mm f10 achro - solid, robust, nice optics but massive. I'm afraid it really doesn't get to go outside as much as it should do (even taking into account the rubbish weather!) simply because of the set-up hassle.

I mostly alternate between a 100mm f13 achro and a 125mm f9 achro - much quicker to get in and take down in our changeable climate! I find the 100mm f13 punches through poor seeing pretty well and the 125mm has a pretty nice light grasp, despite some CA on brighter objects. I'd like to put the 125mm up against an ED120 sometime though.

(EDIT - by the way, welcome to the forum Tim - I hope the move to the UK goes as smoothly as possible).

Marki, 

If your thinking of acquiring a 120ED, i might not be in too much of a rush, now that the 125r is performing pretty well as it should, you might not gain much from a 120ED, it would be very interesting to see how the 2 refractors compared out in the field 

[John]

Marki, 

If your thinking of acquiring a 120ED, i might not be in too much of a rush, now that the 125r is performing pretty well as it should, you might not gain much from a 120ED, it would be very interesting to see how the 2 refractors compared out in the field 

Fair point. ED120's are not uncommon either wheras the TAL 125R is a really rare bird. In terms of character the TAL would win hands down I think. My ED120 only shows a small splash of CA around the brightest stars and thats it really. I just wish it had that nice white with black trim colour scheme that scopes should have - maybe I'll get mine re-sprayed sometime !

[nightfisher]

Fair point. ED120's are not uncommon either wheras the TAL 125R is a really rare bird. In terms of character the TAL would win hands down I think. My ED120 only shows a small splash of CA around the brightest stars and thats it really. I just wish it had that nice white with black trim colour scheme that scopes should have - maybe I'll get mine re-sprayed sometime !

John, if i were to get a 120ED, or 100ED for that matter, first thing i would do is have it sprayed white.........if you have a friendly car spray shop near you, they would probably only charge a tenner to slip it in with a white car job, i have found Mercedes white to be a good colour