Recommend me a decent frac!

[david_taurus83]

It's time to thin out the astro closet. It is literally a closet under the stairs. The only part of the house I have to myself. I'll be selling a few bits that I don't get much use out of now. 200p is on the list. I know these are hard to shift but it will be cheap!! I sometimes still enjoy to observe with the 200p but it needs mounting on my AZEQ6 but this is more likely to be in use with my imaging setup if the skies are clear. So I was thinking of getting a decent inexpensive frac on a decent inexpensive alt az mount with any sales cash I generate. Used preferably or new if the price is right. I have a full set of BST eyepieces, UHC and Oiii filters so ok in that respect. Just a scope, mount and tripod recommendations please. Budget £200/300??

 

Thanks

[vlaiv]

It would be nice to state your observing preferences. Wide field / DSO / Planetary & Lunar?

Not including second hand items, best that I could come up with would be this:

http://www.opticstar.com/Run/Astronomy/Astro-Telescopes-Opticstar.asp?p=0_10_1_1_54

+

https://www.firstlightoptics.com/alt-azimuth/sky-watcher-az-pronto-alt-azimuth-mount-tripod.html

But, if you are willing to give up wide field and concentrate on aperture (DSO) and planets/moon then I why not consider something like this:

https://www.firstlightoptics.com/maksutov/sky-watcher-skymax-102-az-pronto.html

 

[Prador]

That Opticstar looks like a very well put together achro for the money. Makes the SW equivalent look rather agricultural.

[david_taurus83]

A bit of everything vlaiv! Refractor preferably. I'd like peoples experiences from scopes they have and use now or kit used in the past. Have you used any Opticstar scopes yourself? They seem well priced but that might not be a good thing!

[vlaiv]

7 minutes ago, david_taurus83 said:

A bit of everything vlaiv! Refractor preferably. I'd like peoples experiences from scopes they have and use now or kit used in the past. Have you used any Opticstar scopes yourself? They seem well priced but that might not be a good thing!

In this case, I can only offer my experience with Skywatcher ST102 and very limited Evostar 102 F/10 (not ED version).

Both are in upper parts of your budget with very little room for mount.

ST102 is very decent wide field scope, only reason I let it go was Lunar - I had to jump some serious hoops to get decent lunar performance out of it - like stopping down aperture or use Baader solar continuum filter (later one gave exquisite performance in terms of sharpness and clarity, but due to modest focal length of 500mm I had trouble going for high magnification and view was not satisfactory for casual viewing due to green tint - it is good for teasing out lunar features though).

It's replacement came last fall, and unfortunately I just had a brief first light with it - with mixed results. I was surprised on CA performance - was not expecting what I saw. Moon had less CA than I expected, while stars had a bit more than I expected - maybe this is just my individual sensitivity to CA or wrong expectations. It was mounted on AZ4 and that combination just did not work for me - too much shake and long settle time. Don't know if that will be the case in general - after the session I discovered that crews that hold the focuser were loose - and whole unit moved out of position. Such thing would surely compromise OTA stiffness. Due to weather and other factors, I still did not manage second light with this scope.

I bought it as replacement for above mentioned ST102. I reasoned that longer FL and slower scope will give me better lunar and planetary performance (with Lunar views I was really happy on first light - with use of Baader contrast booster filter). I was going to sacrifice some wide field with this scope - but I have ace up my sleeve for that that I'm yet to try out. Part of my imaging gear is CCD47 x0.67 focal reducer that works with flat field scopes (or ones where curvature is minimal) - I reckon that at F/10 curvature will be very slight, and this FR will work. I plan to use it in front of 2" diagonal, so reduction factor will be a bit steeper than x0.67. This will put me back in 4" F/5 territory if it works satisfactory.

Evostar 102 F/10 is a large scope - I was surprised by its size and bulk (this seems to happen often - very few scopes made me thing - "look at that - so tiny" ) - and you will need sturdy mount for it. I would say such a scope will push your budget.

There is however "longstanding" recommendation for second hand frac in this class - TAL100 - have a look at that.

Above scope that I mentioned - Opticstar 80mm just happens to tick all the boxes for what you might be looking for - not very fast to hinder planetary/lunar performance too much, not too slow for wide field, and within budget. If I remember correctly @John recently had one offered for sale, and I think he mentioned optical performance of it being very good.

[Alfian]

8 hours ago, vlaiv said:

It would be nice to state your observing preferences. Wide field / DSO / Planetary & Lunar?

Not including second hand items, best that I could come up with would be this:

http://www.opticstar.com/Run/Astronomy/Astro-Telescopes-Opticstar.asp?p=0_10_1_1_54

+

https://www.firstlightoptics.com/alt-azimuth/sky-watcher-az-pronto-alt-azimuth-mount-tripod.html

But, if you are willing to give up wide field and concentrate on aperture (DSO) and planets/moon then I why not consider something like this:

https://www.firstlightoptics.com/maksutov/sky-watcher-skymax-102-az-pronto.html

 

I have recently acquired an Opticstar 90/500 which as far as I can tell are no longer available. Bought as a smallish wide field scope I have been very pleased with it and for an f5.5 CA is much less than expected. This works OK on a Skywatcher Avant mount which is in some respects similar to the Pronto. Both have a max payload of 3Kg and the lightweight photo type tripod and pillar extension, which on the one hand makes for a good grab 'n' go set up BUT stability wise its pretty much on the limit of acceptality (imo). This is a long winded way of saying that I dont think the longer heavier Opticstar would be happy on the Pronto. However the  102Mak should be fine as I've mounted my SE4 (mak) on the Avant OK.

[Whirlwind]

If you can find a used Skywatcher ED80 or ED100 then these usually fall in this price range. They also have a good reputation.  Another option might be to consider a used Celestron C6.  Yes it's not a refractor but it does have more aperture.  Should also cover you as a decent planetary scope.

[david_taurus83]

I should have mentioned, I have a Lunt white light wedge so needs to be a refractor up to 100mm. That Opticstar AR90S looks good for the money. Looking through the sales thread there has been 1 or 2 go for just over 100 quid. Would sit nicely on a AZ5 mount?

[KP82]

If it's £300 for the whole lot, it would be quite difficult to find any ED scopes new. So you would have to settle for achros (e.g. SW ST120 on AZ3, Bresser AR-80/640 on AZ Nano). As for used SW 80ED should fall into your price bracket.

[david_taurus83]

Not aversed to an achro at all. I would describe myself as a casual observer so hopefully I would not be as overly critical as I am with my imaging setup! @parallaxerrhas that 80mm Opticstar that vlaiv has linked above and wrote a promising review. Wondering how he's still getting on with it? Its half my budget new so half budget left for a decent alt az mount head. I have a Leica tripod I used to use with a total station (advanced theodolite) at work so could retro fit to those for good stability.

[mikeDnight]

Adding another £100 or so to your budget if you can should put you in line for a better quality frac David. Sometimes there can be some nice offerings appearing on Astro By & Sell, so I'd encourage you not to rush into things. A second hand 100mm ED or long focus achromat may be found in that price bracket.. The SW 102ED immediately comes to mind, but there are several other great ED's out there that may be even more compact and user friendly. A simple gyro or AZ4 style mount makes a great grab & go set-up. If you prefer equatorial mounts then an EQ5 or better still a Vixen GP or Polaris style mount will be more than adequate.

If you'd prefer a good achromat, then you could put a wanted ad out for a 100mm Tal Refractor or a 102mm Vixen. Both are optically excellent, though the Tal's can be a bit on the rugged side with regard to engineering. Tal's and Vixens are generally better optically than the SW achromats, which have varying degrees of figure and can suffer from significant spherical aberration as a consequence!  SW ED's however are in a whole different league!!

[parallaxerr]

On 10/02/2019 at 12:06, david_taurus83 said:

Not aversed to an achro at all. I would describe myself as a casual observer so hopefully I would not be as overly critical as I am with my imaging setup! @parallaxerrhas that 80mm Opticstar that vlaiv has linked above and wrote a promising review. Wondering how he's still getting on with it? Its half my budget new so half budget left for a decent alt az mount head. I have a Leica tripod I used to use with a total station (advanced theodolite) at work so could retro fit to those for good stability.

I've managed a hand full of sessions with the Opticstar now and I'm mixed in my opinion of it. Optically, I think it puts on a pretty good show. CA is not obtrusive to my eye at all and it's proven very good at lunar viewing. I did find myself struggling a little bit when focusing on the Trapezium in Orion recently though. I felt I couldn't hit perfect focus but was unsure if it was the optics or the focuser, which I struggle more with each time I use the scope. May well have been atmospheric of course.

If I were buying again I'd consider a different scope, but my decision to buy the AR80 was 99% driven by my reluctance to upgrade the mount. As it happens I find myself considering an AZ5 now, but with that comes the ability to carry a heavier scope and so the slipping down the slope begins again! I'm still not overly bothered about going ED, a long focus achro would be next.