robrj
Member
Posts: 248
home town/country: Escondido, CA
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Post by robrj on Mar 27, 2017 21:02:16 GMT
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Post by davy on Mar 27, 2017 21:42:11 GMT
Hi rob I had the skywatcher startravel 102mm scope and it was good,,big bit of coma but it was a new scope and was great to use,, was a learning curve getting the right Focal length for video and astrophotography, done my head in,,but got there,,,, Igor some cash and i splashed out on the skywatcher ed80,, what a difference i loved it,, i never expected such a difference between that and the st102 what a fantastic scope i added the skywatcher matched 0.85 Focal reducer/flatner and it's even better,, I'm a happy bunny with it,, i did buy a 8" skywatcher explorer to give me a bigger aperture for my lunar stuff and best of both worlds now
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Post by howie1 on Mar 27, 2017 23:26:06 GMT
And just in case you were wondering ... very close approximations ...
Magnification = (focal length in mm) / (sensor width in mm) assuming sensor width is the larger of the two dimensions quoted for a chips width and height
FOV in degrees = 57 / (magnification calculated above)
Going to an f6 compared to your old f5 = 6x6/5x5 = 36/25 = 1.4 which means if you normally shot an object with your f/5 scope in 10 secs, then with an f/6 scope you'd have to increase that to 14 secs.
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Post by ChrisV on Mar 28, 2017 0:35:17 GMT
+1 with what Howie says.
My William Optics GTF-81 really complements the newt I just got. It is 80mm with 472mm FL (F5.9). I reckon that's a great focal length, so the ES80 would be great. F7.5 is very long. Mine has a built-in field flattener - so not sure whether you need one with other scopes. And the refractor is much smaller and so easy to setup - no collimation etc. The only problem is dew (is there anmy in San Diego?) but that's easily solved with a heater and the extendable shield. I use a red dot finder on mine.
With my APS-C sensors FOV = 2.4 x 1.6deg With my 1/3" sensors FOV = 31 x 23min. But I sometimes use a bit of focal reduction. I use my meade 6.3 SCT reducer with adaptors and spacers to ~F4.9 and get FOV = 44 x 25min. That speeds things up. I'm sure your 1/2" cameras would have a nice FOV and not have much vignetting. Even if you wanted to add a bit of focal reduction later on.
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Post by Dragon Man on Mar 28, 2017 6:10:23 GMT
Rob, you will find that many telescopes companies use a bit of poetic licence when labelling their telescopes, and the two you mention are two of the scopes often wrongly labelled. Neither are true 'Apo's. You will find that they are 'ED's. Many ED scopes get labelled as Apo, or Semi-Apo (Semi-Apo is the more accurate name). A true Apo will cost anywhere from 2x to 5x the price of an ED. But to answer your question: "Another I was considering is the Orion 80mm APO. It's a bit long (f/7.5, 600mm fl) but I'm thinking I could use focal reducers to get it down"The most commonly used scope I use for Video Astronomy is my Saxon/Skywatcher/Orion f7.5 ED80 (600mm) If THIS is the Orion you are thinking of, yes it is an ED. Not a True Apo. The benefit of this scope over a standard ED80 is that it is a triplet, not a doublet like the standard ED80. As for the focal length, it is an absolutely perfect length! That's what I like about it so much. That and it's sharp stars. In my f7.5 ED80 I have used several different focal reducer and it seems most comfortable using 0.6x - 0.5x range. preferably 0.5x. But still works great with no focal reduction on small objects. Here's some of my screen grabs using a 1/2" sensor in my ED80 and 0.56x FR to show you the great FOV of around 1 degree
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robrj
Member
Posts: 248
home town/country: Escondido, CA
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Post by robrj on Mar 29, 2017 3:02:07 GMT
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Post by Dragon Man on Mar 29, 2017 7:07:27 GMT
Yes Rob, that's it. Mine has 'Saxon' printed on the side, but they are all the same scope from the same factory, 'Synta'. Synta supplies this same scope to Saxon, Skywatcher, Orion, Southern Cross, etc. All they do is paint it whatever colour scheme and whatever name on the side requested by each Dealer. Same as the Mintron Cameras. They are all Wakayama, made for Mintron, but dealers order them with Orion, Gstar, etc printed on them. GSO is another manufacturer that does the same with their scopes and gear. There's not many Astro manufacturers. Just lots of brand names, but all from only a few manufacturers. There was an interesting photo on the net about a year ago but it has since disappeared. It was in a Travel Blog, not an Astronomy site. Some tourists where visiting the Synta Optical factory in Taiwan (Suzhou Synta Optical Technology Co., Ltd.). They took some photos inside, and in one, of them on the floor, you can see thousands of near completed Meade and Celestron SCT's all lined up waiting for final assembly. To the side you could see Skywatcher, Orion, and other brand Refractors and reflectors. Nothing odd about that because many people now know that Synta make Celestron, Skywatcher, Orion,saxon, etc, but no-one knew that they made Meade too until that photo surfaced. Probably why it was removed.
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Post by Dragon Man on Mar 29, 2017 9:49:23 GMT
Another Chinese company that makes Bresser, Lunt, Meade, Celestron, Explore Scientific, National Geographic, and other brands including their own brand, is 'Maxvision' (now called Jinghua Optical). All in the same factory. Here's a pic inside one of Maxvision's assembly rooms. Notice no hair nets, the scopes are placed onto a bare floor, and the floor is dirty:
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Post by howie1 on Mar 29, 2017 11:33:16 GMT
Gawd if you look closely over on the right you can even see the weasels waiting patiently to give up their grease!
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Post by Dragon Man on Mar 29, 2017 12:03:32 GMT
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Post by fondofchips on Mar 31, 2017 13:41:35 GMT
Weasels are weaselly spotted and stoats are stoatally different!
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Post by Dragon Man on Mar 31, 2017 15:26:40 GMT
Weasels are weaselly spotted and stoats are stoatally different! . . . and Otters are an otter matter
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robrj
Member
Posts: 248
home town/country: Escondido, CA
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Post by robrj on Apr 4, 2017 14:32:40 GMT
I wound up getting an Orion ED80T CF last night. Orion had a "2nd" on clearance for $675 vs $950 for a new one (after the sale ends). The new one is currently on sale for $900.
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Post by Dragon Man on Apr 4, 2017 14:42:30 GMT
I wound up getting an Orion ED80T CF last night. Orion had a "2nd" on clearance for $650 vs $950 for a new one (after the sale ends). The new one is currently on sale for $900. Well done Rob! $950 for a new one!!!! Try $1549 here in Oz www.bintel.com.au/product/orion-ed80t-cf-apochromatic-refractor/f/6.0 design (480mm focal length) is excellent for what we do Better than a standard ED80 which is f/7.5 (600mm focal length)
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robrj
Member
Posts: 248
home town/country: Escondido, CA
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Post by robrj on Apr 4, 2017 16:44:46 GMT
Yikes! Even with straight currency conversion, it should only be $1255 new.
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Post by Dragon Man on Apr 4, 2017 18:15:05 GMT
All Astro Products are a lot more expensive down here. The dealers claim it is because of International freight costs. And they complain and wonder why so many of us buy direct from USA, or China.
And New Zealand has even higher prices than us!
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Post by howie1 on Apr 5, 2017 1:27:19 GMT
Well, having spoken to few retailers about this stuff their argument is .... US price is US$950 + $US100 shipping = $US1050 which converted to aussie is $A1370 and as thats greater than $A1000 we have to pay 10% import duty on the whole cost (item + shipping) so thats another $A137 plus $50 for the broker to do the import paperwork and stuff which makes a total of $A1557. And lo and behold it is very close to the aussie retailers price!
I've imported Astro gear, HiFi gear and car parts and the above calculation pretty much works for everything I've imported vs the cost in the local shops.
BUT .... GRRRR ....
The problem with the argument the local retailers use ... is that assumes that like you or I, they are also buying it from a US retailer!! Underline retailer! So are all our local retailers also buying from the local US retail shop??? Of course not!!!! The scumbag local retailers are buying direct from the manufacturer Orion. So in fact our local retailers are buying the said scope from Orion at less than that special deal which rob bought it for, cos the US retailer wouldnt be selling at a loss would they!?
IE the true cost of that scope direct from Orion maybe $US550. And they would buy maybe 10 as well as other Orion bits and bobs for their business. And then they'd only pay for one big delivery / box of goodies with 2 or 3 month delivery time ... ie the share of that shipping cost for every ED80 would be maybe + $US50 shipping! So that totals = $US600 per OTA! When that is converted it is $A790. And being under $1000 that is exempt from import duties!!! So thats our aussie retailers cost! So local retailer is making $A760 on every one of those sold!! Thats a 96% markup!
Like Ken says ... no wonder they complain when we see through their scam and import it ourselves from a US retailer! Trouble is they constantly lobby the Govt with that argument, and while they havent done so yet ... I wonder when the Govt will cave in. Because it is in the Govt interest to add internet fees and charges to stop us bringing stuff in as personal imports. I mean its a win-win for the Government ... more taxes and income for them if they introduce such a thing. And because the scumbag aussie retailers would raise prices even more because they would then be protected, they make more money and according to the Govt of the day, that makes higher employment! (It doesnt BTW but thats what they constantly preach). So lets make hey while the suns shines and bring in all the stuff we can! Bulk group buying power deals anyone?
Rant over! LOL
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Post by ChrisV on Apr 5, 2017 3:06:35 GMT
Good pickup on the Orion Rob. Should be great with your ultrastar. Good rant Howie, I take it you got through cyclone and ensuing rain OK?
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Post by howie1 on Apr 5, 2017 6:51:47 GMT
Yes thanks Chris. 120km/hr winds on the Bay just up the road. Spent all night with a torch looking at the newly done pergola roof as it creaked and squeaked but it was all ok. Got power back Saturday, internet back Sunday and phone back Monday. Still crap weather up here though! Cloudy and windy. Or sunny all day and cloudy and windy all night. Havent had the scope out for ages! I reckon I've forgotten how to set it all up! No wonder I'm cranky!! LOL
Did have a chuckle when dealing with Telstra re no phone and no internet. Got passed to two groups to deal with that - of course! And even though the internet came back on Sunday morning, when I got the landline back on Monday there were three messages on the Telstra messagebank from the internet blokes asking when they could book an appointment to come and fix the internet service! So (a) they had no idea that some other Telstra guys had already fixed the internet; and (b) no idea that the landline phone was down even though their internal systems must have shown two faults registered against my account. LOL
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Post by Rick in NWArk on Apr 12, 2017 16:59:54 GMT
I wound up getting an Orion ED80T CF last night. Orion had a "2nd" on clearance for $675 vs $950 for a new one (after the sale ends). The new one is currently on sale for $900. I have an Orion EDT80 CF that I got used for $500 about 2 years ago. It's f/6 (480mm) and I just love it. When I replace my AVX, it will be very heavily used again. Great for Solar, Lunar, and DSO. Planetary, not so much unless you want that wide field flying into the planet's general vicinity type of shot.
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