Since I am not a specialist when it comes to telescopes, I appreciate the things I learn about them from reading amateur astronomers websites. However, with the knowledge I do have and 34 years of camera experience behind me, I'd like to write a little bit about them. But, before I do, I would like to offer my apologies to telescope enthusiasts. Reading what I write might be like reading a first year primer.
About the Orion 152mm F5
These are not the Orion telescopes that sell in the U.S. These are Orion products that sell exclusively in the U.K. And the 152mm and 300mm, both of which I own, do not exist on the US market.
I purchased the 152mm specifically for travel.I started to think about the small aperature telescope TV85, the one that got me the words,"hopelessly fuzzy" from an article in the newest edition of 2005's Skywatch magazine. Then I thought how nice it would be to have as large a telescope as possible to carry around with me. So I began to make a list of the most important things I needed to consider when buying one.
The carrying it around part was of concern to me and then of course I needed to think about getting it on a plane. The first thing to clear is the short length and light weight.
There might be a lot of astronomers who have a Cassegrain like the Celestron 5 or 8. But I added more qualifications. For me a big factor when it came to choosing, was the ability to easily collimate. Because settings might be changed just by movement when transporting the telescope from place to place,then re-collimation is necessary when I arrive at my site.
Another thing I was considering was a cover. As you know, any telescope like the Newton is covered by the co-mirror and then aperature size is not 100%. This is a well known dilema where size or percentage is better as a reflector. So I made my mind up to purchase a suitable Newton.
The next specification is the quality of the mirror. For me it must be 1/8 or less P-V and I need to find it at a reasonable price. The ratio is important because it amazingly effects the result which is explained on R.F.Royce's website. At this point, almost every US made telescope is off my list of possibilities. You cannot find any P-V number on the specifications of U.S. made Newtonian's in starter or middle class price structures. I'm not sure why this is so, but maybe American manufacturers think that aperature is everything. Maybe not, but these kinds of telescopes are not even manufactured in U.S. So what do you think?
Some American-made special mirrors for high level scopes are very good. But these are huge, ten inches, twelve inches or more!Try carying these overseas! via an airplane. They must be moved by car or ship like the ARMY transports a canon. It's not possible for everyone to rent a C 130 aircraft carrier, right?
I finally decided to buy the Orion 152mm f5 Newton on the UK market. It's distributed by Tele-Vue Japan. This O.T.A. has only 3.5kg weight at the 695mm lenght tube. And the second mirror is 50mm shorter in diameter.This means roughly about a 100mm aperature.The high quality, 1/8 P-V optional mirror with Hilux coating costs about 1000 dollars US. Sounds tasty, doesn't it? This is about less than half the price of great 100mm refractors. This is fantastic! If something happened to an expensive telescope, forgiving an airport baggage handler makes it tough. It's a fact that luggage is not handled with care and it would be better if we could keep our eyes on it because it has a way of dissappearing. However, from any point of view, I think I made a wise decision to buy this equipment.
So I ordered it and was patient for about three months. Then I extended my travel schedule and did 24/7/365 in 2004 and waited some more. My baggage for star watching will be Losmandy GM8 mount, TV85, Orion 152 and eyepieces plus cameras. Needless to say, heavy enough!!
My First Impression
As with the 300mm Orion, this scope uses Vixen's focuser. I know this isn't a good fit for my camera. So I switched to the Moonlight focuser that's the same as my 300mm. Maybe, I think, it's a good idea to change the tube ring mount on the telescope. It will make it more stable, but, as a trade off, it makes it heavier.
When I use the 152mm for the first time I'm amazed at what I see! It's not like the 85mm, but not like the 300mm either. It's just clear, but dark. The 300mm has so much power to gather light energy. And of course the 150mm just the opposite. However, the 152mm is good for looking at Saturn,which is too bright to look at with the naked eye at 300mm. I could see the Cassini Slit in the ring very clearly.
For the moon and nebula, this 152mm gives the ultimate view with the aperatur size and high quality mirror. What a bargain I got for less than $1000 (dependent on exchange rate).
You will see how 1/8 P-V gives great results on this web page. It's incredible! And you can imagine what's happening in my mind. Yes, now I'm thinking about updating my 300mm to the 1/8 P-V mirror!
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