ES 102mm Triplet Apo, is this too good to be true??

[Chris]

Hi,

I'm in the market for a 4" Apo so I can enjoy some observing and medium focal length imaging in my obsy. A very kind SGLr put me onto the Explore Scientific 102mm Triplet which I've just found in stock where I buy my ES maxvion EP's from. The price for a 4" Triplet with a 2" R&P dual speed focuser works out to be around 800 pounds which is great! Seems too good to be true infact?

I was wondering if anyone had any experience with this scope or has anyone heard anything about it?

I'm very tempted by it. Its either this or a second hand Altair 115mm Triplet, or the wild card which is good quality Carbon Fibre f/4 Newt.

Any guidance on my next purchase greatly appreciated, budget as it stands is 900 pounds plus pocket change, jeez this ES triplet looks tempting!

Thanks

Chris

p.s. heres the link:

http://www.explorescientific.de/explore-scientific-apo-102mm-alu-essential-p-26858.html

[ronin]

Not sure if it is too low.

Nearest to comapare with is the WO GT-102, which is priced at $1458 = about 1130 Euro.

So the ES seems about 100 euro less.

Mind you I have just taken the straight cost and no inclusion or exclustion of VAT/Taxes.

The ES says Hoya Glass FCD001 and this is where the difference could come in.

The WO is FPL-53 and that tends to command a premium price, if the Hoya glass is the same as FPL-51 then a difference of 100 Euro is quite easily possible, maybe even more then 100 Euro. Even if the glass is the equivalent of FPL-53 then as it cannot quote Ohara FPL-53 glass I suspect it would still fail to command the price of one that could.

So I would say it is in the right area.

[Chris]

Not sure if it is too low.

Nearest to comapare with is the WO GT-102, which is priced at $1458 = about 1130 Euro.

So the ES seems about 100 euro less.

Mind you I have just taken the straight cost and no inclusion or exclustion of VAT/Taxes.

The ES says Hoya Glass FCD001 and this is where the difference could come in.

The WO is FPL-53 and that tends to command a premium price, if the Hoya glass is the same as FPL-51 then a difference of 100 Euro is quite easily possible, maybe even more then 100 Euro. Even if the glass is the equivalent of FPL-53 then as it cannot quote Ohara FPL-53 glass I suspect it would still fail to command the price of one that could.

So I would say it is in the right area.

Hi Ronin, I've just had a quick look at the WO GT102, Ian King sells them for around 1400 pounds which is around 600 pounds more than the ES102! I wouldn't half mind FPL53 at 4" but I fear its out of my price range. I did think about going for 80mm FPL53 triplet but my Meg72 already works great at f/6 and 432mm FL with FPL51 so perhaps not the need. I was thinking that 4" would be better for observing and for longer FL imaging of galaxies when I could stick the Meg72 ontop for wide field plus guiding duties. If the FCD glass is indeed FPL51 then it might be ok as a triplet?

http://www.iankingimaging.com/show_product.php?id=1501

Chris

[Chris]

f/7 is a touch on the slow side so I do have that niggle, I could reduce it down but that would bring the focal length down also. I think this is why I have the wild card at the back of my mind still f/3.9 at 800mm FL natively:

http://www.explorescientific.de/explore-scientific-pn208812-carbon-fibre-tube-p-24248.html

The above scope is about to be launched and looks interesting, might be a pain to collimate but shouls stay in for a while once done beings its CF. On the other hand a triplet would be slower but plug and play and pin point tiny stars sounds great.

[ronin]

I was looking at the price on the WO site direct where they are $1458.

Equally try looking at APM scopes a 100mm LZOS lens item is 3500 euro, so that means WO and ES are too good to be true.

Interesting point:

Looked at the ES site and there are 2 102 triplets, one at 1499 Euro and the one you link to at 949 Euro.

The 949 Euro offering is without a flattener, case, diagonal and eyepiece.

So if those bits add up to 500 euro's worth it all ties in.

If it is what you want then serach for reviews on it and decide.

[Chris]

Cheers, I will keep on searching, just speculation so far from what I've read hence I thought I would give a shout out on hear.

[dkbender]

I just recently picked up an ES ED152CF.   It has the same Hoya FCD glass and is spectacularly good.   From what I understand, the ex-Meade VP, Scott Roberts, that started ES, is setup to double check and measure all ES labeled product from JOC before it gets to the final customer.   He's trying really hard to establish ES as a high quality supplier, at reasonable prices.    I would have no reservation getting the ES ED102 Apo at that price.  

Here is an image taken by Mike Wiles with his ES ED152CF with the Hoya glass....   just "wow!" is my reaction.

http://www.astrobin.com/46647/

[Tim]

f/7 is a touch on the slow side so I do have that niggle,

The above scope is about to be launched and looks interesting, might be a pain to collimate but shouls stay in for a while once done beings its CF. On the other hand a triplet would be slower but plug and play and pin point tiny stars sounds great.

Is f7 really that slow? The answer will depend on what it is you want to image primarily?

Also, it isn't the case that CF tubes hold collimation better than steel tubes. The only real gain with CF is in the weight, and the thermal stability. It might hold focus over a longer period than a comparable steel tube, but I have found no differences in holding collimation between my CF and steel bodied scopes.

Cheers

Tim

[Chris]

I just recently picked up an ES ED152CF.   It has the same Hoya FCD glass and is spectacularly good.   From what I understand, the ex-Meade VP, Scott Roberts, that started ES, is setup to double check and measure all ES labeled product from JOC before it gets to the final customer.   He's trying really hard to establish ES as a high quality supplier, at reasonable prices.    I would have no reservation getting the ES ED102 Apo at that price.  

Here is an image taken by Mike Wiles with his ES ED152CF with the Hoya glass....   just "wow!" is my reaction.

http://www.astrobin.com/46647/

Hi, This is good to hear about the QC, very re-assuring thank you The M16 image is absolutely stunning! really detailed and well processed with nice round stars across the image. One thing I can't tell is the levels of CA as its a narrow band image so I need to hunt down one or two LRGB images taken with an ES Apo with this glass.

Chris

[Chris]

Is f7 really that slow? The answer will depend on what it is you want to image primarily?

Also, it isn't the case that CF tubes hold collimation better than steel tubes. The only real gain with CF is in the weight, and the thermal stability. It might hold focus over a longer period than a comparable steel tube, but I have found no differences in holding collimation between my CF and steel bodied scopes.

Cheers

Tim

Hi Tim, f/7 isn't massively slow but I'm thinking it would need about 2-3 times the exposure time of say an f/4 for DSO's, I don't know the exact calculation for this but I was told that an f/7.5 needs twice the exposure time of an f/5. I do notice the difference in speed between my 150p f/5 and my Meg72 @ f/6 but both scopes have there benefits

Interesting to hear that you have not seen any real differences in holding collimation between Carbon fibre and steel F/4's. This could makes things even cheaper if I went that route. I did think that the tube flexure was reduced quite a bit with CF when hanging kit off the focuser, tube flexure would but collimation out plus the heat expansion thing also, that was my thinking anyway. I see you have a GSO f/4 how do you find the primary springs for this and tube flexure? I've seen an ex display GSO carbon fibre f/4 for 450 quid! but I was worried that it would need a bit of work e.g. better primary springs and bobs knobs etc and the Quattro has tested better out of the box from the threads I've read on here and the CF one is 595 from FLO.

Jeez, I think one reason I've started this thread is because of the money I'm about to spend! its a lot for me and probably considered alot for quite a few other people so I need to get it righ. Any scope recommendations are more than welcome with the criteria below:

1) less than a grand (1000 pounds! )

2) fast or has the ability to be reduced to the f/5's

3) focal length around 800mm give or take.

4) ok for both visual and imaging (not a master of both I know this isn't possible)

[Chris]

Just found this report, he's certainly happpy with the ES102.

http://astronomy.qteaser.com/explorescientific102mm

[Joves]

Not sure if you've considered the Orion EON 110mm ED APO. I think it pushes a touch over your budget, but I just bought one and am looking through it for the first time as we speak. Looks real nice so far. It's 660mm FL and f:6. I'm currently viewing 47 Tucanae, a beautiful globular seen from here in the south through a 6mm Radian and it looks fantastic. Skies aren't entirely dark yet, either, so I'm imagining it's only going to get better.

Just a thought. I believe it sells in the UK for about 1200 pounds, so it's definitely more than you were anticipating, but it seems excellent value so far.

[Chris]

Not sure if you've considered the Orion EON 110mm ED APO. I think it pushes a touch over your budget, but I just bought one and am looking through it for the first time as we speak. Looks real nice so far. It's 660mm FL and f:6. I'm currently viewing 47 Tucanae, a beautiful globular seen from here in the south through a 6mm Radian and it looks fantastic. Skies aren't entirely dark yet, either, so I'm imagining it's only going to get better.

Just a thought. I believe it sells in the UK for about 1200 pounds, so it's definitely more than you were anticipating, but it seems excellent value so far.

Hi, is it this one for 1300 pounds?

http://www.scsastro.co.uk/catalogue/orion-eon-110mm-ed-f-60-apochromatic-refractor-telescope-10031.htm

The fit and finish look very nice congrats! Its a doublet with FPL51 glass @ f/6 so I'm wondering how well controlled the chromatic aberration is? The 110mm aperture and the f/6 makes it an appealling scope

Chris

[Skyline]

I take it entertaining a Nice Celestron 100ED is out of the question !

http://www.ebay.co.uk/itm/Vixen-Celestron-FL102-F9-Fluorite-APO-Telescope-The-best-4-lightweight-doublet-/301009803348?pt=UK_Photography_Telescopes&hash=item4615951854

[Chris]

I take it entertaining a Nice Celestron 100ED is out of the question !

http://www.ebay.co.uk/itm/Vixen-Celestron-FL102-F9-Fluorite-APO-Telescope-The-best-4-lightweight-doublet-/301009803348?pt=UK_Photography_Telescopes&hash=item4615951854

Hi Skyline, I saw that one, too slow and too expensive. I like the orange Moonlite focuser on it!

[Joves]

Hi, is it this one for 1300 pounds?

http://www.scsastro.co.uk/catalogue/orion-eon-110mm-ed-f-60-apochromatic-refractor-telescope-10031.htm

The fit and finish look very nice congrats! Its a doublet with FPL51 glass @ f/6 so I'm wondering how well controlled the chromatic aberration is? The 110mm aperture and the f/6 makes it an appealling scope

Chris

Thanks Chris.

That's a great question. I'll let you know in an hour or so when Jupiter comes into view.

I've been viewing recently through my TV-76, which provides beautiful views, and was just a little concerned now that the new scope doesn't provide pinpoint stars anywhere near the same calibre as the Televue. I then remembered that I had been viewing through the TV-76 with Ethos EP's, not the Radian which I have also just acquired and currently had in the new scope, so changed to the 21 Ethos. Massive difference. The Radian is nice but changing to the Ethos just made a huge difference. I'd have to say that my current view of the Pleiades is right up there with what I see through the TV-76.

Will let you know how it fares on Jupiter CA wise.

Cheers,

Aaron

[Joves]

And yep, that's the scope. Sorry, was 100 pounds off.

[Joves]

Also, the focuser on this one is an absolute belter. 11:1, fully rotatable and holds up to 8kg's. It's a sturdy beast and very smooth to use so far!

[Chris]

I look forward to hearing how it performs on Jupiter Joves

[Joves]

Let's hope the patchy clouds behave and remain just that... Patchy!

[Skyline]

What you really need is an RGB image, something like a star cluster to see how it handles those Blues.

[Joves]

True. I know there are far better scopes out there and that this will perform accordingly, but i'll be using mine predominantly for visual and for hooking up a Mallincam Xtreme, so I can handle it not being perfect. Will be interesting to see how it goes though.

[Chris]

What you really need is an RGB image, something like a star cluster to see how it handles those Blues.

Absolutely, a good test, someone kindly posted up a pic taken with the 150mm version of the ES scope which looks stunning, but its narrow band so won't show how well it handles CA. I've not had much luck finding an LRGB image or DSLR image yet unfortunately. Maybe these scopes haven't been on the seen for very long?

[dkbender]

Absolutely, a good test, someone kindly posted up a pic taken with the 150mm version of the ES scope which looks stunning, but its narrow band so won't show how well it handles CA. I've not had much luck finding an LRGB image or DSLR image yet unfortunately. Maybe these scopes haven't been on the seen for very long?

Re: Hoya FCD glass... ES ED152CF

Here's another one Mike Wiles did of M101, that is done RGB+Ha.

http://www.astrobin.com/full/45867/0/

and then an RGB only of vdb 141 Ghosts of Cephus....

http://www.astrobin.com/63132/

Maybe you can see what you need re: CA Blue on these, hopefully.

Best!

Dave

[Chris]

Thanks Dave thats very helpful indeed! Such good images, the core of m101 looks amazingly detailed, great resolution, and the Ghosts are just jumping out the screen at you, wonderful images Looking at the stars very closely there is just the tiniest film of blue on the brighter stars which I'm quite pleased about, certainly no halos like on some of the cheap doublets I've seen so I think these scopes are doing a great job for the price bracket! I'm going to research one or two more options over the next few days just to make absolutely sure but I think the ES102 triplet could be a winner for sure!