Classic or ED Refracter for CG-4 mount?

[Chris]

Hi folks, 

After a brief spell with a Celestron 102 XLT f/10 I found it was great for white light solar, really good infact, but it seems over the years I've become quite fussy about chromatic aberration when observing the planets and the Moon. I've now moved the scope on plus another scope to help fund an upgrade.

I'm looking for a frac with low chromatic aberration to sit on my CG4 mount, I'd be using it mainly for solar, Lunar, and planetary observing.

I've been very tempted by the little Skylight 60mm f/16 on ABS, plus I know another forum member is selling his vintage Kenko 76mm f/16 at a good price but it's a very long scope. On the other hand I could buy a shorter ED refractor, the ES 80 triplet looks good for the money.

With the long fracs they look the part, have virtually no cool down time due to the thin low expansion lenses and great depth of focus. 

With the Short ED or triplets, they are more portable and easy to store away.

I can't decide which way to go to be honest?

I would really like peoples opinions on what to get with about 500 pounds give or take.

Cheers

Chris

[nightfisher]

Don't go for the vintage, it will disappoint you, same with the 60 mm just not enough aperture, best would be 100ED or. Tal 100rs

[nightfisher]

Another good one to use on the CG4 would be an ED80, this would give you nice widefield views and with the right ep some good planetary views, though you might struggle with image scale

[Stu]

I agree, 100ED or save a bit more and get a 120ED. Really talking then!

[nightfisher]

On the CG4 i would stick at no more than f10 and no more than 100mm so i stick by my suggestion of ED100 or near same performance from a Tal100rs and half the cost

[Chris]

Don't go for the vintage, it will disappoint you, same with the 60 mm just not enough aperture, best would be 100ED or. Tal 100rs

Oooh, don't let Neil English catch you saying that Jules But I do see what you are saying

The 60mm aspect is a little worrying, I would prefer at least 80mm (I have the C8 in the obsy for high detail views if the object is visible from there).

There are some cracking reviews of this little Carlton lens on bright object but I agree the ED100 or Tal (if I can find one) would be a very sensible option

Lots to think about, but I do enjoy just looking at the Skylight

[Stu]

On the CG4 i would stick at no more than f10 and no more than 100mm so i stick by my suggestion of ED100 or near same performance from a Tal100rs and half the cost

Fair enough Jules, getting carried away

[nightfisher]

If you can find one go for a TAL, and try to find a slightly older one, they have made a couple of changes to the latest batch and here is why....................LZOS lens, good high power views but stick a 2" diagonal in the TAL and a revelation 42mm 2" ep and sweep the heavens with a superb wide field.............................now you see why i sell a lot of my scopes but the TAL stays as a classic favorite 

[Chris]

Another good one to use on the CG4 would be an ED80, this would give you nice widefield views and with the right ep some good planetary views, though you might struggle with image scale

I remember being very surprised at the views of Jupiter through the ED80 I once owned. The main bands were a rich caramel colour and very sharp, really lovely I thought, so yes that's definately another option.

[Stu]

100mm in a decent ED scope will definitely show you some nice sharp views

[Chris]

I agree, 100ED or save a bit more and get a 120ED. Really talking then!

The ED100 comes up second hand quite often I've noticed. Can't believe I passed by the C100ED and bought the XLT102, Doh!! I think Russ bought that one, he's no fool

It might be worth me being patient and my eyes peeled.

[Chris]

On the CG4 i would stick at no more than f10 and no more than 100mm so i stick by my suggestion of ED100 or near same performance from a Tal100rs and half the cost

The 4" f/10 Celestron felt about right with the CG4 so I agree

I know the new ones aren't as good, but where can I buy a new Tal from guys? I've heard everyone should have one

[Skyline]

Go for an 100ED, 900mm Focal length, weighing around just over 5kg with tube rings and dovetail. I had a Megrez 90 side by side with a 100ED, I couldn't believe how much false colour the megrez showed viewing the moon, where no such colour was evident in the C100ED, both scopes were viewed using a Nagler eyepiece.

[Chris]

If you can find one go for a TAL, and try to find a slightly older one, they have made a couple of changes to the latest batch and here is why....................LZOS lens, good high power views but stick a 2" diagonal in the TAL and a revelation 42mm 2" ep and sweep the heavens with a superb wide field.............................now you see why i sell a lot of my scopes but the TAL stays as a classic favorite 

I'm not sure who buys and sells the most scopes out the two of us, but if you've kept the Tal whilst other scopes have passed through then you must feel about your Tal as I do about my C8 Edge, and I love that scope!

[Chris]

Go for an 100ED, 900mm Focal length, weighing around just over 5kg with tube rings and dovetail. I had a Megrez 90 side by side with a 100ED, I couldn't believe how much false colour the megrez showed viewing the moon, where no such colour was evident in the C100ED, both scopes were viewed using a Nagler eyepiece.

Thanks, I'll look at the Tal and the ED100 later when the kids are in bed, My direction has changed a bit, no votes for the classic fracs so far.

I'm going to listen to the majority vote, because the the majority know their stuff

[avtaram]

There is a Tal 100RS on Astroboot in the specials section, £149 at the moment.

I was tempted but I already have a 120ED.

Avtar

[John]

I've owned both a TAL100 and an ED100, one followed the other. I'd go for the ED100. The TAL is a great F/10 acrhomat and CA is kept to the minimum levels that it can be for that focal ratio / aperture combination in a crown / flint doublet but the ED100 is pretty much colour free for visual observing even on testing objects such as the lunar limb, Venus, Sirius etc.

I've owned Synta ED doublets in the 80mm, 100mm and 120mm apertures and reckon they really got the lenses of these scopes right   

I bought my old "blue tube" Skywatcher ED100 as an optical tube for £300 and I really wish I still had it

Luckily I do have an ED120 to enjoy.

[Chris]

There is a Tal 100RS on Astroboot in the specials section, £149 at the moment.

I was tempted but I already have a 120ED.

Avtar

Thanks for the heads up Avtar I caught the message whilst getting all the little ones sorted for bed, and I've been racking my mind as to what to do? 

I see these are 235 new, so 148 pounds (as it is now) is obviously a very good deal! The only thing is the missing original dew shield and lens cap, this is really messing with my OCD   

I'm going with the logic of - if I don't know what to do then don't do anything. This may change if the Tal's there in the morning (which I doubt).

[Chris]

I've owned both a TAL100 and an ED100, one followed the other. I'd go for the ED100. The TAL is a great F/10 acrhomat and CA is kept to the minimum levels that it can be for that focal ratio / aperture combination in a crown / flint doublet but the ED100 is pretty much colour free for visual observing even on testing objects such as the lunar limb, Venus, Sirius etc.

I've owned Synta ED doublets in the 80mm, 100mm and 120mm apertures and reckon they really got the lenses of these scopes right 

I bought my old "blue tube" Skywatcher ED100 as an optical tube for £300 and I really wish I still had it

Luckily I do have an ED120 to enjoy.

Thanks John, The 80mm I had was great visually I thought, so I can imagine the ED100 being even greater. 

One idea is that I could buy the Skylight 60mm (just because I think it's now well priced, and I would like a part of Richard Day's craft which I really do appreciate), then look out for a second hand ED100, or failing that buy a new Tal down the line.

The only problem is that my wife might just kill me if I end up with both! 

[John]

Those are all tempting choices - all are going to give a lot of enjoyment but in slightly different ways

The Skylight 60's look, and I'm sure are, beautiful scopes but personally I need a little more aperture than that in all honesty.

[Chris]

Those are all tempting choices - all are going to give a lot of enjoyment but in slightly different ways

The Skylight 60's look, and I'm sure are, beautiful scopes but personally I need a little more aperture than that in all honesty.

I hear what your saying John, I wouldn't pick the Skylight 60 as an only scope. The chap selling it dropped the price even further so I've now bought it for 200 pounds shipped. I really couldn't turn it down.

I have however listened to the advice on this thread, and I will be keeping a close lookout for an ED100 or I may even buy a Tal. I'll put together a wooden case for the little skylight so I can store it in the obsy. 

[mikeDnight]

I bought a beautiful 4" F15 achromat a few years ago and used it on many occasions alongside my ED120. Though the F15 was a super scope and its CA was in no way objectionable, I chose to sell it for the following reasons.

It wasnt as easy to use as the shorter ED, as the positions I had to get into could be quite uncomfortable, especially if observing near the zenith.

The longer scope was much more susceptible to the wind. Even a breeze could cause the image to tremor, so high powers were difficult to use successfully.

I felt there was no superiority that the F15 had over the F7.5 ED, plus the ED had the added advantage of offering a wider field of view at low powers.

To do the longer achromat justice it really needed to be mounted on a substantial equatorial, ideally with a Hargreaves Strut attached. This would make the scope far less easy to set up and therefore less likely to be used.

A small apo of up to 4" is a joy to use by comparison. The ease of setting such an instrument up means you'd be more likely to nip out and observe more often. Also, the comfort factor has a major part to play in effective observing. The more comfortable you are at the eyepiece, the better you'll be able to concentrate and the more you'll see.

Mike

[nightfisher]

I see the TAL has gone.

good luck with the carton 60mm, post some pics when you get it

[Skyline]

There is a Skywatcher ED100 on ab&s at the moment.

http://www.astrobuysell.com/uk/propview.php?view=97227

[orley]

The 100ED is a cracking scope. Especially at 2nd hand prices.