For visual, there's nothing to beat the ol' Genesis 4" f5.
This has been with me for almost thirty years - other scopes have come and gone, but the Genesis is a 110% keeper.
In fact, I've already measured up my "box" and when I go - it goes with me.......
Morton,
Depends how much CA you'll tolerate. For a standard doublet 4", f/12 is about the minimum, and I could see CA in my f/15 4" doublet.
ED glass helps, for sure, but I still wouldn't go below f/9, personally.
Obviously, if usage is primarily lower powers, then your f/7 to f/9 range is OK. And there are a plethora of minus violet filters available for specific scopes and targets.
I just rarely meet someone using a scope like this who is not into viewing the Moon and planets.
Given the prices on decent Asian-made triplet refractors these days, there isn't really much reason to stick to doublets unless weight is an issue (doublets are considerably lighter). I'm seeing the triplet edging out the ED doublet in terms of sales since so many triplets are out there now from several companies. Also because ES is selling the 102ED triplet for $1099.99 in the States right now. Is it more than $1800AUD for you guys?
I found the CA in the SV110ED tolerable on planets. Wouldn't mind a bit less CA though, hence the thought of something with a higher spec this time.
Haven't seen many ES scopes here. There's one dealer who lists them but after hearing about some issues with their stock (of ES scopes) I'm not really interested.
I have limited experience with the Vixen f/7.7 103S-ED refractor.
The one I looked through (can't remember the brand of diagonal) was only so-so optically. I cannot say whether the owner had bothered to collimate or not, and a lot of refractors come out of the box uncollimated.
I've seen a whole bunch of these in the field over time, but all had cameras attached and weren't being used visually.
I think I agree with Larryp.
I suppose the proof of the pudding is only there in an image.
Picked at random from a row taken last moon.
I'm presuming the focus was reasonable - it's a single image.
No filtering and no adjustment at all.
Just had a look, focus isn't perfect, it's actually better with a better sky too -
It's a DSLR image @ about 1/250 sec throught the Saxon F9 100ED
Just bide your time and see what comes up in the classifieds. Apart from Tak and Vixen, WO has been putting out very nice optics in recent years and they finally have a good quality R&P focuser. I'm not so keen on ES due to sample variability.
Just bide your time and see what comes up in the classifieds. Apart from Tak and Vixen, WO has been putting out very nice optics in recent years and they finally have a good quality R&P focuser. I'm not so keen on ES due to sample variability.
Good advice, although biding my time isn't something I do well when it comes to astro gear. There's always the danger that some other expense uses up the money first.
Since I have an affinity with Stellarvue scopes I've put a wanted ad for one. There have been a few of their triplets sold here as well as the ED doublets so you never know. My dream scope used to be a Stardust Blue SV4...
What about the Explore Scientific 102mm ED APO Triplet, f7, 714mm focal length. I have the 80mm version and it is a very nice scope. Currently on sale in the US for $1099 USD.
It's not a TAK but It's solid, well built, and the optics seem very good - well at least my 80mm does.
I found the ES 80 triplet that I bought from AEC to be rather disappointing, and exchanged it a Tak FC100 DF. Admittedly, it must have an ex-demo or something that had been knocking around for a few years and so had some annoying mechanical defects & missing parts, but even allowing for this, I found the field curvature to be bothersome.
I may have been expecting too much from an 80mm f/6 Apo. It was very good on terrestrial objects and would be great birding scope, but I wanted sharper stars from a refractor. Maybe it was just a duff example!
I don't have any experience with StellarVue, but they seem to sit nicely in the price/quality curve.
I would also have a look at the Orion Eon line (Bintel have them).
I'm fairly sure Stellavue, Orion and others were assembling scopes using ED doublets in the 80-130mm range from a chinese factory mass-producing these, possibly Kunming Optical. The only question IMHO was whether all received lenses at random, or whether some (e.g. StellaVue) were paying more to cherrypick the best ones off the production line.
In any case its a pity you didn't ask when I was selling my Orion ED105 f/7 last year, optically it was as good as one could expect for an ED at that focal ratio. At high power it gave a nice Airy disk with a hint of colour inside/outside focus. Field curvature did exist - not bothersome visually, but for imaging you could nail that with a flattener, a few to choose from. You'd have to go to a triplet or alternatively an ED doublet at about f/10 to do significantly better at the same aperture.
A belated update to this thread. Having briefly been the owner of a Tak FS-102 that I couldn't really afford, I've managed to buy back my old SV110ED.
First re-light expected tonight as the forecast looks good for the weekend
Here she is awaiting darkness with my recently acquired vintage C8.
How did 'First again' light go Morton? I am taking the TOA out tonight to try out some birthday oculars.....
I may head to Medlow Bath next weekend with both scopes.....
How did 'First again' light go Morton? I am taking the TOA out tonight to try out some birthday oculars.....
I may head to Medlow Bath next weekend with both scopes.....
First light didn't really happen last night. I did take the scope out on the balcony but it was windy and the seeing was awful. Mars and Saturn were just jumping around so I canned it. Tonight is looking much more promising.
By far the best quality 4 inch class APO ( yes I class these as APO,s) is the Skywatcher 100mm ED f9 these are amazing using FPL53 for little money .
1/4 the price of a Tak but 95% of the views , a no-brainer if on a budget like most of us .
Just google Synta 100mm ED f9 reviews there are 1000,s of happy customers world wide.
Brian.
I agree. I spent a few weeks debating whether to buy my old SV or a 100ED but in the end I wanted the superior mechanics and larger aperture of the Stellarvue.
