Over 5" refractor

[Gary70]

Much as I am wanting to lay out for a TAL 125R, my enthusiasm to send money across the continent is waning due to poor communication with a supplier.

Anyway I am still wanting a larger aperture refractor,

I have read good reports on the quality of the Lyra but I really want to be in the 5" realms or maybe 6" (you don't so many 6's it seems)

Is the Bresser Messier AR-152L/1200 or its smaller 127 cousin worth a look? I am not sure if it is, but I guess it would be a meade pretty much?

So it should have some credentials.and is in a similar price area as the TAL (which I am still hankering after)

[damnut]

Hi There,

One of my current copes is the 152mm Meade short tube, if you get the long tube it is a beast!. Had the 127 mm bresser badge long tube and that was excellent with little ca. The 152 is a petzval design and resultant f5, I love it.

Needs a sturdy mount, but if there is ever a classic picture of a telescope its this on a mount..Treat yourself to a pier extension, it will save your back!.

Enjoy

[John]

The 6" F/8's are great for deep sky and not bad for lunar / planetary but that aperture / focal ratio combination does produce a fair amount of chromatic aberration (in my opinion) which bothers some folks more than others. I got lucky and was able to use a device called a Chromacor to remove 90% of the CA and much of the spherical aberration that these scopes produce. This has quite a dramatic effect on their performance, taking it close to an ED doublet. Rare as hens teeth though, the Chromacors.

The 5" F/9.4's (eg: Meade AR5, Bresser 127L) show noticeably less CA but can still suffer a bit from spherical aberration. I've had one very nice one (a Bresser) and an average one (a Meade). Personally I did not feel the need for a CA filter / corrector with these scopes as the CA was not obtrusive. Both came from the same factory I reckon.

Neil English's report on his TAL 125 acknowledges that a decent example of the chinese 5" F/9.4 rivals the TAL in performance terms although I'd agree that the TAL is a more interesting and perhaps more characterful scope.

The 5" scopes are easier to mount than the 6" ones - the latter are really pretty hefty I found. Both sizes need a tall mount unless you enjoy being on your knees when viewing the zenith area !

I would not pay a lot of money for the above though. I've picked the ones I've owned on the used market for quite low prices as optical tube assemblies.

[nightfisher]

There is always the celestron omni 120, combined with a CA filter it could turn out to be a decent scope

[Brian Nordstrom]

Check out 'Istar Optical' in the USA , I have one of their nice 127MM F/8 doublets in my home made scope , they hand make great lenses up to 250mm ( 10 inches ) and then some .

They also sell fully made up OTA's , have a google I am sure you won't be dissapointed .

There customer service is really good , my lense took 10 days to reach my front door here in Darwin Australia from the USA , good after sales service as well .

Brian.

[John]

I was in discussion with Istar for a while over one of their F/12 127mm achromats with an R30 objective lens. The price was not unreasonable at around £1,300 but the weight of the tube was around 40 lbs and would have needed a much more substantial mount than I have access to - something like a Losmandy G11 I think was the recommendation !

I've also looked into a D&G 6" F/12 which was actually lighter than the above Istar but would still need a very heavy duty mount. This is one of the main issues when considering a larger aperture refractor.

[Marki]

John, as a matter of interest, how much did the 150mm weigh? Looks massive in the photos.

Edit - the skywatcher, I meant.

[John]

John, as a matter of interest, how much did the 150mm weigh? Looks massive in the photos.

Edit - the skywatcher, I meant.

The Skywatcher 150mm F/8's weigh around 20lbs with finder / diagonal attached. The Meade AR6 was around 26lbs.

[Gary70]

Guys as usual, we get the kind of advice and shared experience you can't even pay for, thanks

I wish I could afford Istar, or any of the other "bespoke itmes" on peak to valley,

John out of interest roughly how many scopes have you owned? you seem to have have limitless knowledge of so many. so helpfull.

[John]

....John out of interest roughly how many scopes have you owned? you seem to have have limitless knowledge of so many. so helpfull....

Thats nice of you to say but I sometimes fear it's a bit boring

I've got a list of those I've owned and the total stands at 35 at the moment, including the 4 I currently have. I have been in the hobby for 30+ years though. I have slowed down a lot in the past couple of years, honestly

[Gary70]

Thats nice of you to say but I sometimes fear it's a bit boring

Not a bit, if it wasn't for people like you this forum would be pretty empty I think. my wife would say this whole hobby is boring but each to their own

I am liking the bresser more and more for a large ap scope,not that i don't trust technosky but it is arisk.

whatever happened to Celestrons 150? I remember checking those out a while back but they seem to have gone from the market,

[Gary70]

I saw a TS 127 - 1200 a bit pricey but on paper it looks coser to a TAL than the bresser smaller ap than bresser can offer but not a crisis I was wondering if 6" would have too much ca.

What is the Fraunhofer design compared to Petzval?

[AndyH]

I personally would pick a well made, simple Fraunhofer doublet over a Petzval any day of the week. Unless the Petzval was made by TeleVue

Be aware my views are clouded by having used, years ago, a small petzval refractor. I still shiver, when I hear the 'P' word.

[ollypenrice]

I have, languishing unused, a 6 inch Helios F8 (aka all the other names!) It's a bit scruffy but when in use people did enjoy it. Cheap and very cheerful. I must take it out for a spin. When I bought it I star tested it first and it gave an excellent result. SInce it competes with our TEC140 for mount space it doesn't win but it does deserve more outings.

Olly

[John]

I agree with Andy - keep it simple, although the Vixen NA140SSF is quite interesting:

http://www.firstlightoptics.com/vixen/vixen-na-140-ssf-flat-field-refractor.html

Off the top of my head, the options for conventional chinese 5" F/9-ish achromats seem to be:

- Meade AR5 LXD55

- Meade AR5 LXD75 (collimatable objective cell)

- Bresser 127L (clone of the Meade AR5 LXD75)

- Phenix 127mm F/9.4 (possibly made by the same manufacturer as the Meade AR5 LXD55 ??)

- Telescope Services Elite 127 (a clone of the Meade AR5 LXD55 I think)

In the USA Antares used to sell a clone of the TS Elite as well.

Can anyone think of some more ?.

[damnut]

The Bresser / Meade 6" I have has a Petzval corrector built in, this shortens the focal length and reduces the CA considerably to the point i do not use a uhc / -v filter that I used to on my ar127L. It has a fully collimatable front cell too.

I would echo some comments re the petzval design above, however this is a 3-4" element rather than the common correctors that manufacturers like Seben put into the focusser tube. However the Fraunhofer design is the most common in achro doublets and these in general deliver ca.

Cheers

[twotter]

Can anyone think of some more ?.

Does the SW Evostar 150 qualify?

[Gary70]

The 127 TS elite is more costly than the bresser and others is it considered superior or is it just more expensive because it is............ more expensive?

Almost sure to drop onto a 127 now, seems the CA can be an issue over that (well acording to reviews and so on)

[John]

I think the TS Elite is a bit overpriced - it's basically the same scope as the Bresser 127L minus the collimatable objective cell. To be honest I'd never buy a new chinese large aperture achromat, they are just too pricey. I've bought all the ones I've owned on the used market for between £125 and £200 for the optical tube. That includes the 6" F/8's as well.

Actually I've only ever bought 2 brand new scopes in my life and lost rather a lot when I came to sell them so it's used all the way for me now.

[allcart]

I'm looking at 6" refractors myself. There doesn't seem to be a lot of choices and used ones seem a bit on the thin side. Lyra optics have a recent 152mm short tube refractor added to their list of scopes. maybe a bit too pricey for what I want it for, but it does seem to have good optics.

[John]

Those 152mm f/5.9's got a lot of air time on the Cloudynights forum for a while. I reckon they would make great wide field scopes but I was a bit skeptical about their abilities as high power scopes because of the chromatic aberration that any 6" F/5.9 achromat will produce.

For ages I lusted after 6" and larger refractors but their mounting requirements can get severe and the CA gets more apparent as the aperture goes up unless you go for an ED and then the price takes a huge hike.

[allcart]

You're not kidding about the prices.

I'd settle for a SW 150, or even ST 150. I only want it for solar work so ca isn't really a problem.. Still can't find a used one though.

[00110111]

I have the ST 150 f/5 and the CA isn't as bad as I thought it might be. It gives a great wide view and decent power when you need it, and it's a lot more manageable than the versions with more focal length. This scope is held rock steady on an EQ5.

[Patrice Lanteigne]

Explore Scientific offer a 6" f/6.5 achromat. It's a well made and solid telescope. It's a long way from the top of the 6" refactor heap but at less than $1000 for a scope, diagonal, rings and a finder its also pretty easy to get it past the minister of finance. I totally enjoy mine for what it has to offer. Sure it does have some colour on Jupiter and the moon does have a little fringe but there is no way I can justify the thousands of dollars needed to get a significantly better instrument in this aperture.

[Rossco72]

With great size comes great cost... Or significant compromise.

I would seriously suggest you try and look through one of these "fast" big refractors to see if you like or can live with the view and the physical size of the scope.

Cheers

Stuart