APO Telescope

[h0ughy (David)]

Originally Posted by Satchmo

Thats a very cheap price.

I've been warned off 5" triplet apos by an owner who said they take hours to thermally settle because of the insulating air layer on either side of the center lens element. With the large temp changes we have at night they don't always work well in aussie conditions.

I'm sticking with the idea of a 120mm ED Doublet when I go down the photography route.

but if you were able to keep it relatively cool or thermally equal to start with??? LOL a new use for the beer fridge?

[Astrod00d]

Hmm, I think I'd like to see some DSLR images using this scope. Just how flat is the field and is there any CA?

I read somewhere it uses FPL-51 glass rather than FPL-53 as used in the ED80. What are the implications of using FPL-51 rather than FPL-53?

[gts055 (Mark)]

Assuming the glass is of the same selected quality, ie, free of faults such as internal stresses, bubbles, color and striae, and the refractive indices of the mating elements have been selected correctly, then the only advantage in using FPL53 over FPL52 or FPL51, is that a shorter focal length can be achieved, and still give a near "color free image". High quality optical glass, of any type, comes at a premium cost. Stating FPL53 or FPL51 or whatever, means nothing, it all depends on the grade of the material. This is apart from the time taken to figure the lens set and mount them into a stable cell etc.
Regards Mark

[TrevorW]

Further to this is you just want the OTA with rings they'll sell it to you for around $750USD+ sins and shipping. Unfortunately my money don't stretch that far at the moment but this is the second enquiry I've made direct to a Chinese Manufacturer the other ones called Hi-Optics and there has been no qualms about selling direct to me. If it is the same scope that's selling for $3000 then who's ripping who off.

[Suzy_A]

Hay! have a look at some of the other items they sell!

http://www.made-in-china.com/showroo...om-Former.html

[Suzy_A]

One of my friends goes to China every month or two for business - next trip is in a week or so. I wonder if they are going anywhere near Nanjing....?

[TrevorW]

Suzy_A how rude

[gts055 (Mark)]

mmm Suzy, made out of glass too, wonder what Saturn looks like through this thing.

[Stephen65]

I've been warned off 5" triplet apos by an owner who said they take hours to thermally settle because of the insulating air layer on either side of the center lens element. With the large temp changes we have at night they don't always work well in aussie conditions.

I have a 5" triplet APO (FLT-132) and it takes no more than an hour to settle. I've also looked through three TOA-130s and I didn't notice any settling problems.

The temperature variations we have are much less than in many other parts of the world where many people use this style of telescope.

I read somewhere it uses FPL-51 glass rather than FPL-53 as used in the ED80. What are the implications of using FPL-51 rather than FPL-53?

Assuming the quality of the glass, polishing and mounting is the same, the advantage of FPL-53 is that the same degree of colour correction can be achieved at shorter focal ratios than with FPL-51. This is advantageous not only because shorter refractors are easier to handle and mount but in imaging where faster focal lengths mean shorter exposures. FPL-51 is cheaper than FPL-53.

[Astrod00d]

Originally Posted by Stephen65

I have a 5" triplet APO (FLT-132) and it takes no more than an hour to settle.

FPL-51 is cheaper than FPL-53.

I've been looking for a larger aperture refractor to upgrade from my ED80, for imaging with a DSLR-size sensor. The FLT132 looks like a great instrument but it really is beyond my price range.

So basically I've been comparing the William Optics FLT110 to the Prostar 127ED. They both cost about the same, $3100. The FLT110 has smaller aperture but boasts much higher quality. There is a field flattener designed specifically for the FLT110, no field flattener for the 127ED as far as I can determine. The FLT110 was looking like a sure thing.

Now, along comes this 127mm triplet APO for USD810.... The choice is no longer clear! Gotta check the field flatness of the 127ED!


Cheers,

Rob

[netwolf]

The other option is to get a Retialer in Aus to import these from this particular source.

Her is another source. I came accros them via the hkastro forum and while researching a 6" MN telescope they also sell (looks much like the SN6 from Meade).
http://hkastroequipment.com/fj01-38.html
This scope is rougly 860USD. So looks like the same price. Note the link to the TMB vs Mavision link indicating this is the same scope.

[netwolf]

Alan has one
http://www.iceinspace.com.au/forum/s...d.php?p=307614

[Astrod00d]

Originally Posted by netwolf

Alan has one
http://www.iceinspace.com.au/forum/s...d.php?p=307614

Thanks! I'll drop him a line and see if he's tried imaging. He sure likes it for visual, sharp and good contrast.

[prova]

any further info on this and is there a group buy going, cause if it is the same as the Prostar for that money
I'm buying one

[Terry B]

Originally Posted by prova

any further info on this and is there a group buy going, cause if it is the same as the Prostar for that money
I'm buying one

I sent a request to the co in China last night. Have to wait and see.

[prova]

Originally Posted by Terry B

I sent a request to the co in China last night. Have to wait and see.

Me too

[Satchmo]

Originally Posted by Stephen65

I have a 5" triplet APO (FLT-132) and it takes no more than an hour to settle.

That seems like a long time for a 5 inch scope. For a 'grab and go' class scope, it wouldn't suit me. I'd have gone to bed before it settled.

[prova]

Originally Posted by Satchmo

That seems like a long time for a 5 inch scope. For a 'grab and go' class scope, it wouldn't suit me. I'd have gone to bed before it settled.

Agreed, however if it is indeed legit and around the AUD1000 mark, I'm buying one to go on my HEQ5Pro that's arriving today or tomorrow.

[TrevorW]

It seems I created an interest. I'd like to buy one as well in the near future, as I live in WA they've told me it would cost $220USD for air freight & insurance. So all up $1020USD. My main concern is with warranty issues etc so if a dealer could bring them in and mark up at a realistic price not some ridiculous mark up then I'd be more than intersted buying locally even if it cost $500 or so more.

[Kokatha man]

Originally Posted by TrevorW

It seems I created an interest. I'd like to buy one as well in the near future, as I live in WA they've told me it would cost $220USD for air freight & insurance. So all up $1020USD. My main concern is with warranty issues etc so if a dealer could bring them in and mark up at a realistic price not some ridiculous mark up then I'd be more than intersted buying locally even if it cost $500 or so more.

I floated the idea of the co-op situation, which I think was slightly misinterpreted: my suggestion was that for 30 odd interested people each kicking in a lazy $30 odd, by drawing straws someone would get the scope to evaluate and then have first option to buy/keep.

Or there's another straw draw after the evaluation, to determine the lucky eventual owner, if that's deemed more equable and the test scope passes its testing.

This is predicated upon trust amongst the interested IIS members, but I'd be gullible enough at a $30 odd outlay to trust my fellow IIS brothers and sisters!?!:th umbsup:

This method lays some of the groundwork needed to import a quantity - the co-op would need to research/confirm the necessary protocols for importation.

On the other side of the coin, I have also thought of this as a "too hard" basket situation; and although loathe to bring middlemen/dealers into the equation, I am seeing Matt Lovell from Telescopes/Astronomy tomorrow and thought of passing some comments with him about this opportunity. He has the experience and ability to undertake importation of such (does it with other gear) and is not a big mark-up "rip-off" merchant to boot.

I'd be interested in others' comments re this post.

ps - I'm really interested in their possibility for my next big project: apo binoculars!

Regards, Darryl.