View Full Version here: : Ap130gtx

Hans Tucker
20-11-2017, 05:40 PM
Anyone own a AP 130GTX? What has been your experiences, pro's and con's.

20-11-2017, 05:52 PM
Depends whether you want to do AP or visual.

I have had a look through one ... side-by-side it was optically indistinguishable from the TS 130mm f/7 triplet APO I had at the time. The only real difference was the rather more lavish hardware - focusser and rings. Whether that’s really worth another $7k is up to you. There’s nothing magical about these scopes - they are very well built but they don’t break the laws of physics when it comes to resolution, nor are they comparable to a Questar 7 which could be had for not much more.

I also had the chance to look through an Intes 150mm mak-newtonian on the same night. IMHO the Intes was the better scope visually.

For medium and high power visual observing a larger SCT or Mak is better, frankly.

20-11-2017, 05:55 PM
I don’t own one and probably never will, but from what one can read on the net, it is about as good as a 130mm f/6.3 triplet can be in terms of optics (in particular for imaging) and mechanics. Cons? Price and a very long wait to get a brand new one.

20-11-2017, 07:06 PM
An AP130GTX would be totally awesome. It has the quad corrector available and it would probably match a Tak FSQ130 for imaging and perhaps surpass it in terms of no problems with focuser sag etc and considerably cheaper.

I have had 2 AP scopes and they are the top of the game. Tak is very good, AP is arguably better but probably splitting hairs. Where AP tends to be better is the engineering is more heavy duty and things like focusers never sag under load etc.

For visual, 130mm may be a tad small for bright views so yeah a compound scope may be better but for AP it would be at the top of its class almost for sure.


Peter Ward
20-11-2017, 08:34 PM
I have one and the quad corrector.

It's been relegated to being my solar telescope....a very undeserving role....as it is a sublime piece of glass.

Every AP scope I have owned has run out of light
when pushed to extreme magnifications, as opposed to lesser instruments which invariably show aberrations in one form or another.

Telescopes are not just optical beasts either.

Unless the mechanicals keep things where they need to be, the image can be very average. AP have few rivals there.

I they are indeed magical IMHO.

20-11-2017, 09:51 PM
Sounds like someone’s name came up on the waiting list😎

20-11-2017, 10:06 PM
Peter I agree they’re very very good - but they’re not alone. Frankly these run out of puff at 260X (X2 per mm of aperture). But you can’t beat the physics of limited aperture vs diffraction.

The snag is, would you drop north of $10k on a 130mm scope vs other choices at that price ? My 9” Santel cost half as much as these scopes and it likewise runs out of light before you see any aberrations. And it totally slays these small refractors - 440X is fine if seeing permits.

Likewise anyone with a Questar 7 would not sniff at this, nor the buyer of the SW 180 mak I sold recently.

Similar a well made Dob with a good mirror - say a Zambito or Royce - is a far better instrument.

Aperture and long focal length rule if you want serious magnification. There’s nothing better than a really long FL reflector or cat with small obstruction. Zero, if you are prepared for a schiefspiegler at f/23.

Peter Ward
20-11-2017, 11:57 PM
Have to say I was singularly unimpressed by the Questar 7. Nicely made, but the bugger would never thermally stabilise...

As for the price of an AP...it matters not to me....as well looked after I can get what I paid and then some should I ever want to sell it.

Sure for visual use, there are plenty of options. But if you want a fully corrected field with a 16803 sensor, and a focuser than doesn't behave like a lump of play-dough, choices rapidly narrow.

If time/weather permits, I'll see if I can grab some 130GTX + Quad compressor and Taka FSQ106 test images , and put then up on a web page...it should make interesting reading.

21-11-2017, 02:28 AM
I for one would love to see that comparison, Peter

21-11-2017, 10:40 AM
I wouldn't. I have an fsq and I can honestly say I'm unlikely to buy a 130mm AP. So I'd rather live in ignorance! But I think the earlier suggestion was this scope is comparable to the 130mm FSQ, and I can't recall ever seeing an image taken with one of those.
I do agree that the FSQ focuser arrangement leaves something to be desired. With the D810a on the back I see some tilt, but when I add the reducer and all the fittings are threaded, there is no tilt at all (yes I know it's shorter fl). I suspect the culprit is actually the 2" camera adapter, though.

Hans Tucker
21-11-2017, 08:28 PM
Nope...but know someone whom has been notified. I'm culling the heard at the moment.

25-11-2017, 10:05 PM
I've got one.

Pros: It's one of the best 130mm scopes you'll ever look through.

My thoughts and experiences? Everything just works - beautifully. Every detail of its mechanics and figure is superlative - and you do pay for that. it's pretty breathtaking at 317mag (XO 2.58), but only if the atmosphere is up to it - and that's not often at all. People always seem to forget that on the forums. Had a view of Uranus with the XO the other night that was either better or indistinguishable from all of the larger scopes that i looked through that night (up to 10" mirrors). Same night, an old and very respected observer came by and had a look at 47-Tuc through it commenting that it was possibly the best view of it he had ever seen. An imager (whose mount costs more than my OTA, if you want to talk about money!) had a look at a few globs with me and commented along the lines of "S**T...the detail all the way to edge". The reason I'm quoting others is that everyone has a bias towards their own instrument and, hey, i wouldn't believe my own press if i read it either! But in nearly 20 years of astronomy i've never had so many positive comments about the view through a scope. And i have to concur with them.

Cons: Everyone wants to look through it (not really a con - but a real pleasure actually).

If you're up for one, and money isn't an issue for you, then go for it. You'll never really have to wonder again if your scope is the problem.

It's the scope that brought me back to astronomy, which makes it a very powerful one indeed. Don't listen to the AP130GTX haters on this forum (their science is dubious). Buy it despite them.


27-11-2017, 12:01 PM
I have owned one AP scope, and I must say, it has a certain "feel" that is hard to describe. I absolutely loved it (well, OK, the 1990 focuser really could have been upgraded to the FT new version).

The image it puts up is distinctly "different" to other scopes I have owned (you all know how many that is now!!!) - a pure clrity, totally devoid of ANY artifacts, and incredibly immersive - and mine was a 1990 doublet!

Whilst I adore the Takahashis, and perhaps the Taks have SLIGHTLY better contrast, the distinction between them is simply...hard to describe! The AP made objects somehow look VERY 3 dimensional and deep, compared to the Tak's ALMOST 3D feel. The Tak's are clinically correct, the AP's to me give a more aesthetic view, whilst also being unbelieveably sharp.

I'd buy that AP back in a heart beat.

27-11-2017, 01:43 PM
You sold it ???

Seems like U just brought it!

27-11-2017, 04:36 PM
I had it a few months. I deeply regret moving it on, but I needed the funds to finance something Takahashi HA HA

27-11-2017, 07:32 PM
Unfortunately these things happen - Lewis is not alone in assembling a nice kit only to find a “dream scope” becomes available which can result in a total rethink of your gear.

In my case I’d seen images from this scope but knowing production ceased many years ago I never dreamt I could own one. But I do, now :)

29-11-2017, 01:55 PM
Dang, you're right about the wait list! Did you know that every now and then I see one brand-new in a European vendor's store. One that comes to mind recently is a dealer called www.skypoint.it - I checked with George at AP because i thought it might be a scam... He confirmed that AP sometimes sends OTAs to select premium dealers in the EU (do they still do that with Company Seven as well? - not sure). You'll pay a (Euro) premium, but it can short circuit the wait time to zero.


29-11-2017, 04:53 PM
I wasn't aware of this, thank you for sharing. However, it seems that this company adds about US$4k to what AP charges for the telescope = probably nearly AUD17k landed in Australia for a 130mm triplet...for a bare OTA without rings, flattener etc...an opportunity for true enthusiasts only for sure!

EDIT: Just checked T&C; these prices include VAT, so landing price in AU would be somehow less :thumbsup:

The Mekon
29-11-2017, 09:55 PM
Agreed, but these days there are a number of other makes that are AP's equal. 25 years ago, when I took delivery of one of the first 130EDTs there was no 5" refractor that could match it - most 6" & 8" scopes could not compete. The only scopes that were comparable were Vixen 102 fluorites and they behaved like a smaller version. Taks were never seen back then.
Nowadays, as Roland Christen himself states - you don't have to wait.
The TOA 130s are just as good. I reckon my CFF 132 is just as good - and it comes with a 3.5" Feathertouch. APMs and TECs are also in the same league.
Also have to second Peter Ward's comment on Questar 7" - not impressed when I observed through Max Gardner's scope at Wiruna many years ago. My AP 130EDT gave better views.

29-11-2017, 10:43 PM
I've looked through TOA130's, TOA150's, CFF140's and some Chinese similar sized triplets.

My pick of the lot - the TOA130. Just spot on in every respect.

30-11-2017, 07:14 AM
I believe that Hans is after an imaging scope and TOA with its 40mm imaging circle and at f/7.5 might be not the best option for DSO imaging. For astrophotography, I personally would go for a faster scope (=also shorter tube) and as large corrected circle as possible. Money permitting, for me and for imaging, it definitely would be a choice between AP 130GTX and CFF140. FSQ130 seems to be awesome too, but the cost is even higher.

30-11-2017, 08:39 PM
Yup, totally with you on the TAKs, CFFs and TECs - they're all quite awesome scopes. We're spoilt for choice at the high-end now... I've never looked through a TOA130 but i have to say i very much look forward to it, and yes, i've thought more than once about the CFF (185). Must be a wonderful view. But gee there's so much to see in the 130 first...


Hans Tucker
24-12-2017, 09:45 PM
Yay..its on its way...but it has come at a cost...I am now virtually Takless

24-12-2017, 10:13 PM
Great news! Congratulations Hans- you must be very excited. And those lucky ones that now have your Taks surely are also very happy, so a win-win situation :)

27-12-2017, 10:08 AM
I would disagree that TECs and APMs are in the same league as AP. They are simply not. TEC are no match for AP. TEC are optimised for green and red and blue are not as good. AP does not optimise just for green.

AP has a large range of imaging accessories, TEC does not. AP focusers, fittings, adapters are all heavy duty and flex and so on is simply unheard of. Not true for other brands including Tak (surprisingly). So Tak can let you down occasionally (read the large number of threads about flex in FSQ scopes). They are out to Version 4 now of the FSQ and probably still haven't gotten on top of it. They got the optics right but not the mechanicals.

AP is still the premium brand in my opinion. Roland actually images and that makes all the difference.

But yes high end 2nd tier is more fully fleshed out now.


30-12-2017, 03:28 PM
Greg (and anyone else):

What do you think of the CFF's? Are they as good optically as the AP's?

Thank you. :thanx:


30-12-2017, 06:00 PM
Lucky would be the one who could make a direct comparison :)

If we look at the cost, recent limited edition of CFF132mm was priced nearly 2000 USD less than AP130GTX. The AP has a larger claimed imaging circle (65mm vs 55mm), so that's one difference in optical performance. CFF is being hand aspherised, not sure if AP is still doing that and whether that's needed for GTX. As for polychromatic Strehl - no idea. Maybe except CFF's 105mm f/10 - apparently Strehl above 0.99 in the entire visible spectrum. No doubt AP delivers scopes as close to perfection as humanly possible within their parameters (f ratio, aperture etc).

I really look forward to reading Hans' impressions with his new baby :thumbsup:

30-12-2017, 11:05 PM
I don't really know anything about CFFs. They are probably great.
The usual weak spot though is the accessories. A weak focuser that flexes, tube currents, using carbon fibre for APO's etc.

I do know that APs have every aspect covered really well and they won't let you down.

If CFF get .99 strehl then that is extremely impressive if they can provide an interferogram to that effect.


Peter Ward
07-01-2018, 02:29 PM
For those who were interested, I managed to get some data for a quick FSQ and AP130GTX comparison.

It can be found here (http://www.atscope.com.au/ap/APGTXreview.html)

I decided against doing a full blown ramble with pictures and arrows about both instruments and simply let the test images do most of the talking.

Hope you find it useful.

07-01-2018, 06:03 PM
With reference to Greg's comments re TEC, TEC has announced that all future products will be all fluorite with the middle element. The TEC-140 recent production run is fluorite and has better blue correction than the previous ED model.

One item not specifically mentioned that needs to be considered in these choices is the back focus available when using the flattener. TEC BF for the FF is only 85mm which I personally found to be too short to accommodate gear I wanted to use.


07-01-2018, 09:07 PM
I thought the CFF scopes came with Starlight Feathertouch focusers, I wouldn't consider them a weak focuser that flexes....

07-01-2018, 09:09 PM
Yuri is going to keep the last 10 ED versions of the 140 and turn them into binoscopes by shortening their tubes to improve available back focus for the EMS-ULS visual train, maybe he would be happy to do the same for an FL version........

Hans, congratulations on the AP....

14-01-2018, 07:14 PM
I agree FT focusers are high quality. They do flex a small amount though. Yuri measured flex on the FT 3050 focuser and showed it displayed less flex when it was upside down. But I didn't ever see flex issues when using my TEC180. They are a nice focuser. I was making the comment more generally rather than specifically aimed at CFF. More something to make sure is OK as focusers are typically the weak spot for many scopes.

The strongest focusers I have seen are AP ones. They are made from a large tube of stainless steel rather than some weak aluminium like most are. AP focusers look like they could be used to change a tyre on your car!