This is one of a series of articles describing in depth the product that we sell. The reason for these articles is to help you make a more informed decision when purchasing accessories for your photographic needs. If you still have questions about this product after reading this article please feel free to contact us.
The T-Mount system was developed by Tamron in 1957. A common misconception is that the T stands for thread or threaded, but it actually stands for Tamron. The system was developed with the idea of standardizing the mount for 35mm SLR (Single Lens Reflex) cameras lenses. It was thought that the system would reduce costs because photograpers would need only a few lenses and a number of inexpensive adapters to be able to use these lenses on different brands of cameras.
While the idea sounded good on paper, it did not gain wide popularity among lens manufacturers, most likely because they did not like the prospect of selling fewer lenses. The system did catch on however as a way to attach SLR cameras to telescopes, microscopes, enlargers, and bellows attachments.
The thread used on T-Mounts, refered to as the T-thread, is a metric thread 42mm in diameter and having a pitch of 0.75mm. This diameter and pitch have become the industry standard. It should be noted the the T-Mount conection is only a mechanical connection; electronic connections such as autofocus ar not transmitted through a T-Mount adapter.
The T-Mount system is a two part adapter to attach your camera to a telescope or microscope. The first piece is specific to your camera and the second piece is specific to the piece of equipment you are attaching the camera to. Where the two peices join is the standardized 42mm thread. At Plumtree Photo we carry the first piece for your camera. It is recomended that you contact the manufacturer of your telescope or other equipment to find the part you will need to attach to that.
9.12.08
Beware to buy eyepiece items
I just find out one seller separate one eyepiece accessory kit to 3 different items for sale. ( eyepiece, filter and case ). I can buy in store about 109.00 plus free shipping. Those items sell for over 250.00 if you buy from him. I already found too many used items sold for over street price. Pls check the price before bid your maximum price
What Telescope is the best
What telescope is the best one for me?
Although there may not be a definitive answer to the question, the choice can be narrowed down. First examining the available options, and then matching one telescope design to the desired applications may achieve this.
Quite often, the purchase of a first telescope is based on little or no information. Unfortunately, the consumer usually ends up with an inadequate telescope. That is, it will not perform to expectations due to its size, poor optical quality, and inadequate mounting. They are very frustrating to use, and can quash any interest the user may have in exploring the night sky. Generally, these are the typical telescopes found in department stores or camera shops. On the other hand, some people “bite off more than they can chew” when purchasing a first telescope. That is, they may purchase a scope that is too big and cumbersome, or too complicated. Invariably, in both circumstances, the telescope often ends up collecting dust in a closet. To help avoid either of the previous scenarios, consider the information and guidelines listed below when searching for a first scope. Although it is true that larger telescopes will amplify the sky-glow in light-polluted areas more so than smaller scopes, they will also amplify the light emitted from the object itself more, thus providing a better view. Essentially, image contrast is the key issue. Larger telescopes can utilize special filters (known as Light Pollution Reduction filters) more effectively than smaller telescopes, the contrast between the sky background and the object is further improved.Larger telescopes will amplify the sky-glow in light-polluted areas more so than smaller scopes, they will also amplify the light emitted from the object itself more, thus providing a better view. Essentially, image contrast is the key issue. Furthermore, because larger telescopes can utilize special filters (known as Light Pollution Reduction filters) more effectively than smaller telescopes, the contrast between the sky background and the object is further improved. What objects do you want to observe?For those who are interested primarily in viewing the brighter objects, such as Jupiter, Saturn, and the Moon, a small telescope is adequate. For example, a 70mm diameter refractor will provide a pleasing view. If fainter, deep space objects, such as galaxies, nebulae, and star clusters are the objects of choice, a telescope with greater light-gathering ability (larger aperture size) is needed. In such instances, common choices by the novice are 4.5" to 6" diameter reflectors, or 90mm to 100mm diameter refractors, which will provide better views. Overall, however, all things being equal, the larger the aperture size, the brighter and more detailed the object will appear.
Although there may not be a definitive answer to the question, the choice can be narrowed down. First examining the available options, and then matching one telescope design to the desired applications may achieve this.
Quite often, the purchase of a first telescope is based on little or no information. Unfortunately, the consumer usually ends up with an inadequate telescope. That is, it will not perform to expectations due to its size, poor optical quality, and inadequate mounting. They are very frustrating to use, and can quash any interest the user may have in exploring the night sky. Generally, these are the typical telescopes found in department stores or camera shops. On the other hand, some people “bite off more than they can chew” when purchasing a first telescope. That is, they may purchase a scope that is too big and cumbersome, or too complicated. Invariably, in both circumstances, the telescope often ends up collecting dust in a closet. To help avoid either of the previous scenarios, consider the information and guidelines listed below when searching for a first scope. Although it is true that larger telescopes will amplify the sky-glow in light-polluted areas more so than smaller scopes, they will also amplify the light emitted from the object itself more, thus providing a better view. Essentially, image contrast is the key issue. Larger telescopes can utilize special filters (known as Light Pollution Reduction filters) more effectively than smaller telescopes, the contrast between the sky background and the object is further improved.Larger telescopes will amplify the sky-glow in light-polluted areas more so than smaller scopes, they will also amplify the light emitted from the object itself more, thus providing a better view. Essentially, image contrast is the key issue. Furthermore, because larger telescopes can utilize special filters (known as Light Pollution Reduction filters) more effectively than smaller telescopes, the contrast between the sky background and the object is further improved. What objects do you want to observe?For those who are interested primarily in viewing the brighter objects, such as Jupiter, Saturn, and the Moon, a small telescope is adequate. For example, a 70mm diameter refractor will provide a pleasing view. If fainter, deep space objects, such as galaxies, nebulae, and star clusters are the objects of choice, a telescope with greater light-gathering ability (larger aperture size) is needed. In such instances, common choices by the novice are 4.5" to 6" diameter reflectors, or 90mm to 100mm diameter refractors, which will provide better views. Overall, however, all things being equal, the larger the aperture size, the brighter and more detailed the object will appear.
Celestron Powerseeker 60EQ Telescope
As soon as I brought it home I took it out of the box and gasped in awe. It was a high quality peice that looked great. This model has an equatorial mount so you can synchronize it with the celestial pole(poloaris) and it gives you the ability to track objects across the sky.It has a large solid tripod that can be adjusted easily. The two lenses it comes with can magnify objects either 45 or 125 times. When I first took the telescope out with my dad we found the moon and I was amazed at what I could see on the lunar surface at just 45 times magnifacation! The moon took up nearly the entire field of vision at lowest magnifacation and the detail was amazing!Using the other lens was even better I could see craters the maria and all sorts of amazing things. Just a few days ago I used my Night Sky magazine(which is a great magazine by the way) and was able to find Saturn for it is high in the sky right by the beehive cluster and close to Gemini right now. After a few minutes of searching through the low power eyepiece I found it. A bright blob of golden light in the eypiece.Hands trembling I carfully adjusted the focusing nobs and I saw it. Saturn in all its glory was in my eypeice. I could just make out the rings and though it was small it was clear and sharp. I hurredly popped that lens out and put in the more powerful one and I saw Saturn in even more detail. I could see the Cassini division! Fortunetly the atmosphere was coraperating so I could see somthing most would need a large reflector to see. I was amazing and I could see it with so small a telescope. And in my Night Sky magazine it says in the March/April issue that you can see nebulae,galaxies,clusters and amazing things in just low magnifacations such as 30 or 50 times. I can even see M41(the beehive cluster) in just binoculars! I saw that cluster when I was looking for saturn.So if you see this telescpope even at 50 or a 100 dollars buy it and you wont be disapointed.
TELESCOPES
The key to purchasing a good telescope is understand what a telescope really does - not what it does not do. Telescopes do not use magnifying lenses to make distant stars and planets visible. Magnifying lenses do nothing to help you see the sky. A telescope does one thing only - it gathers light! The sun is so bright even distant planets get a good dose of light and they reflect it back. So much reflected light, it makes them appear as stars. The larger the opening of a telescope the more light it gathers and the better the image a person can see when the light is concentrated into one spot. A telescope concentrates this light in one of two ways. Light is gathered either through a lense in the front of it (Refractor type), or via a mirror in the end of it which is curved in such away it reflects it back onto a concentrated spot on a smaller second mirror which then sends it out through the eye piece (Reflector type).
Astronomy items listed anonimously foreign countries
Buying telescope accessories and other optics on Ebay can be a great way to get excellent equipment at low prices. But beware of listings that have all the "look and feel" of a USA seller when in fact they are foreign. Recently I bought an item that was listed as being in Buffalo, NY. When I won the auction, I was directed to send my $$ to a Canadian address. When I did so, the merchandise arrived with postage and origination in Hong Kong!
I am not implying that anything shady was ongoing. My item was as advertised. But I would have been up the creek without a paddle if the auction was a scam. You cannot reclaim lost money from a seller on the other side of the world. Ebay has no rule requiring foreign sellers to disclose their product's shipping point or where their office is located.
My advice? If the item is more money than you can afford to lose, let's say $50. Email the seller before you bid and ascertain that it is in the USA. If not, and you have a very high feedback rating, insist the seller send you the merchandise first, and then pay when it arrives.
Afterall, it is not carved in stone than payment must precede shipping of goods. Mutual trust is what keeps Ebay working.
I am not implying that anything shady was ongoing. My item was as advertised. But I would have been up the creek without a paddle if the auction was a scam. You cannot reclaim lost money from a seller on the other side of the world. Ebay has no rule requiring foreign sellers to disclose their product's shipping point or where their office is located.
My advice? If the item is more money than you can afford to lose, let's say $50. Email the seller before you bid and ascertain that it is in the USA. If not, and you have a very high feedback rating, insist the seller send you the merchandise first, and then pay when it arrives.
Afterall, it is not carved in stone than payment must precede shipping of goods. Mutual trust is what keeps Ebay working.
Telescope Buying Guide
1. As the observer you will need to answer the following questions
What do I want to use the telescope for? Daytime? Nightime? Sun? Planets? Comets? Stars? Galaxies?
Where will I be using it? City? Suburbs? Country?
Will I be carrying it often? Will I be transporting it often?
Will I be taking night-time pictures with it?
Will I be using it mostly for fun or for some amateur scientific exploration?
2. Background for the questions
If you will be carrying it often you will need to decide how much weight is sufficient to tire you out. Twenty-five pounds is enough to tire out anyone if it's more than 30 yards from the car or home. If you want it for sports events or nature photography then it better be very light.
The fainter the object is that you want to observer the larger the primary lens or mirror should be. Also if there is a fair amount of light pollution, there might be too much light scatter to make some object visible at all.
The mount and optical design are important, but these are secondary to the light gathering capabilities of the telescope and the magnification capabilities of the eye-piece system.
Decide whether you will be carrying the telescope once a day or evening or whether you can keep it setup in one place for a while. Setting up a telescope takes a bit of time.
Galileo had a telescope that was weaker than some of the small finder scopes attached to the larger telescopes - so any telescope on the market today can be used for fun or science.
3. How to make your choice
Observing Sun Spots (indirectly!!!) can be done with a small refractor (1 1/2" - 40x) bought at a children's store - provided you have a good projector attached.
Most night-time observing requires less than 200x magnification, so if you plan to carry your telescope and mount around go for the largest telescope and mount you can carry. For the average person this would be in the 3" to 5" range for the primary mirror. Some of the lower end telescopes are named "sporting" scopes.
If you plan to do a lot of night-time city observing and you won't be travelling regularly with your telescope, buy the largest telescope you can. This would be anywhere in the range of 6" to 16".
4. New or used
You can find some great deals for used equipment, but you can also find some great deals for broken used equipment. Even new equipment might have bolts that are too tight or too loose, or a mount where one leg doesn't slide out properly. You need to be aware of all the moving pieces and make sure the system works as a complete tool. Purchasing without touching should be discouraged. And at least there needs to be full disclosure of problems and a return policy.
When buying it, remember to ask: Can I carry it as I will during my viewing sessions? Is it powerful enough for the viewing I want to be doing? Is it easy to setup and take down if I am not leaving it in one place?
5. Eye-pieces
The eye-piece is what gives you the magnification. You calculate the magnification of the system by dividing the focal length of the primary telescope mirror/lens by the focal length of the eye-piece . For example a telescope primary with a 2000 mm focal length and an eye-piece with a 20 mm focal length with produce a magnification of 100x.
NOTE WELL: Unless you have bought a super-scope and you will be observing from the top of a mountain beside a tranquil body of water, during a power-grid failure, don't waist your money on an eye-piece that promises to deliver more than 300x magnification with your primary mirror/lens.
6. Having fun
I promise you that once you look at Jupiter or Saturn, or look at a projection of a Sun spot you will be hooked on Astronomy. Don't kill the passion that you have by going overboard with a top-of-the-line system right off the bat. A system that takes too long to setup or is too heavy to move or carry, or even one that is too expensive may be a quick reason to stop observing. There stars have been there for a billion years - they'll wait for you to make a good decision on a first telescope.
7. Checklist
main telescope (size based on carrying, viewing)
several lenses giving you some maginfication possibilities for 40x, 80x, 120x
a rugged mount like Alt-Az for viewing or Equatorial for star tracking or photography
What do I want to use the telescope for? Daytime? Nightime? Sun? Planets? Comets? Stars? Galaxies?
Where will I be using it? City? Suburbs? Country?
Will I be carrying it often? Will I be transporting it often?
Will I be taking night-time pictures with it?
Will I be using it mostly for fun or for some amateur scientific exploration?
2. Background for the questions
If you will be carrying it often you will need to decide how much weight is sufficient to tire you out. Twenty-five pounds is enough to tire out anyone if it's more than 30 yards from the car or home. If you want it for sports events or nature photography then it better be very light.
The fainter the object is that you want to observer the larger the primary lens or mirror should be. Also if there is a fair amount of light pollution, there might be too much light scatter to make some object visible at all.
The mount and optical design are important, but these are secondary to the light gathering capabilities of the telescope and the magnification capabilities of the eye-piece system.
Decide whether you will be carrying the telescope once a day or evening or whether you can keep it setup in one place for a while. Setting up a telescope takes a bit of time.
Galileo had a telescope that was weaker than some of the small finder scopes attached to the larger telescopes - so any telescope on the market today can be used for fun or science.
3. How to make your choice
Observing Sun Spots (indirectly!!!) can be done with a small refractor (1 1/2" - 40x) bought at a children's store - provided you have a good projector attached.
Most night-time observing requires less than 200x magnification, so if you plan to carry your telescope and mount around go for the largest telescope and mount you can carry. For the average person this would be in the 3" to 5" range for the primary mirror. Some of the lower end telescopes are named "sporting" scopes.
If you plan to do a lot of night-time city observing and you won't be travelling regularly with your telescope, buy the largest telescope you can. This would be anywhere in the range of 6" to 16".
4. New or used
You can find some great deals for used equipment, but you can also find some great deals for broken used equipment. Even new equipment might have bolts that are too tight or too loose, or a mount where one leg doesn't slide out properly. You need to be aware of all the moving pieces and make sure the system works as a complete tool. Purchasing without touching should be discouraged. And at least there needs to be full disclosure of problems and a return policy.
When buying it, remember to ask: Can I carry it as I will during my viewing sessions? Is it powerful enough for the viewing I want to be doing? Is it easy to setup and take down if I am not leaving it in one place?
5. Eye-pieces
The eye-piece is what gives you the magnification. You calculate the magnification of the system by dividing the focal length of the primary telescope mirror/lens by the focal length of the eye-piece . For example a telescope primary with a 2000 mm focal length and an eye-piece with a 20 mm focal length with produce a magnification of 100x.
NOTE WELL: Unless you have bought a super-scope and you will be observing from the top of a mountain beside a tranquil body of water, during a power-grid failure, don't waist your money on an eye-piece that promises to deliver more than 300x magnification with your primary mirror/lens.
6. Having fun
I promise you that once you look at Jupiter or Saturn, or look at a projection of a Sun spot you will be hooked on Astronomy. Don't kill the passion that you have by going overboard with a top-of-the-line system right off the bat. A system that takes too long to setup or is too heavy to move or carry, or even one that is too expensive may be a quick reason to stop observing. There stars have been there for a billion years - they'll wait for you to make a good decision on a first telescope.
7. Checklist
main telescope (size based on carrying, viewing)
several lenses giving you some maginfication possibilities for 40x, 80x, 120x
a rugged mount like Alt-Az for viewing or Equatorial for star tracking or photography
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