- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
The T-mount is a universal thread developed by Tamron which allows various adapters to couple a lens to a wide variety of camera brands. If a lens is listed as having a T-mount, it means that the lens can be coupled to your camera if you have a T-mount adapter for your camera.
A 2X teleconverter (often called a doubler) enables a lens of a specific to be doubled. For example, the lens referenced above actually is a 650-1300 lens but with the 2X teleconverter the focal length can be doubled to a maximum focal length of 2600.
I have an Opteka 600-1200 telephoto lens which I consider to be a decent lens for its very low price. I also have a doubler which came with my camera kit. That means I can increase the focal length of my lens to 2400 but I cannot imagine any reason to do so. At it's full zoom 1200mm focal length, this lens is very difficult to handle and must be used on a tripod with a remote shutter release.
It is extremely time consuming to focus and must be focused very accurately because it has almost no depth of field. At 1200 mm, the slightest breeze or vibration will cause the picture to go fuzzy from movement.
The lens is also large and does not fit conveniently in a camera bag so it rarely goes with me unless I know for sure that I will need it. It is not particularly good for sports action shots because the action will be over before you are ready to shoot the picture. With very bright light (such as the mid-day sun) and pre-planning and pre-focusing you might be able to get some interesting sports action shots. Say you're at an automobile race and you know a car will be coming into view at a certain spot, you can set up for that spot then trip the shutter when the car pops into view.
All that being said, I think this is a good lens to have in my bag without spending $10,000 plus for a really good lens of this size.
Quantaray makes lenses with a variety of mounts for a variety of cameras. A lens with a Sony mount, for example, will not fit onto a Nikon camera. Assuming the lens has a Nikon mount, it will fit on the D5100. However, the D5100 requires the lens to have an autofocus motor. If the lens does not have such a motor then it will not autofocus. It will still work fine as a manual focus lens.
You haven't stated which body you have but the AF will not work with the extender if the effective lens aperture is too low (remember that a 2x extender doubles the focal length but halves the effective aperture).
Canon's own website states: "Autofocusing does not operate if the effective maximum aperture is
greater than f/5.6 (greater than f/8 on the EOS 1V and EOS 3)."
A 2X adapter is an item attached between your lens and camera body. It's AF (which is good) and N (most likely a Nikon). They make what ever zoom lens 2X the focal length. So a 135mm becomes a 270mm. So you get a bigger tele lens. They add extra glass, so the image is not as good without it, they eat up an F/stop. So outdoors in bright sunlight, no problem. It's shady and you have ASA 200 and you are going to have a slow shutter speed that can cause blur. Plus the viewfinder gets darker due to the extra glass. So in dim light, it may not AF and be hard to manual focus.
First of all, tele-multipliers or tele-converters do not have the greatest optics in the world, and are usually fine for close up images but not much else. Secondly, they do restrict the amount of light coming into the camera which could interfere with the internal metering. Third, you have additional lens surfaces to get dirty. To fix the problem, start with the easy one, and clean all lens surfaces meticulously with a soft lint free cloth. If that doesn't fix it, try shooting non-moving objects in brightly lit areas. If you are still getting blurry pictures, try using the tele-converter on a close-up image within the focal length of the lens combination. If that doesn't work, give the teleconverter to someone you don't like and go buy a good quality 50-135mm zoom lens. Vivitar, Sigma, or other similar lenses are good quality and are very reasonably priced.
Usually mounts are unique to a camera manufacturer. There are exceptions. Sony has the Alpha; lenses for the Konica-Minolta are the same mount. Your AF (autofocus) lens will work on it. You might also consider picking up a Konica Minolta 5D or 7D.....they're no longer made and hence are cheaply had.
The MD and Rokkor lenses won't work on the Sony Alpha.
THIS IS A CHEAP LENS (<$50 VALUE) SO I WOULDN'T LET IT DRIVE YOUR DECISIONS!!