Teleconverter

SnEm

SnEm

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Hi,

Does anyone have any info on how to chose a teleconverter?
I'm considering to buy one, not sure about the results, would use it on my Sony slt57 to shoot birds, will use a 300mm 3.5-6.3 (I know, but that's all I've got)
Looks like a cheaper option than having to buy a 600mm..

thx,
 
A 2* TC will add 2 stops to your lens , your first question is will the camera AF at that f stop ( which I think is f11), if it won't , and very few will, you have a manual focus lens with probably poor image quality.
Then you need to find out if your lens/body will take a TC not all will.
 
OK thanks! Will need to look for another solution....
 
SnEm said:
OK thanks! Will need to look for another solution....
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It would appear that Sigma do a 50-500 f4.5-6.3 in Sony A mount ,cheap it is not but that would be a viable option, if you can find a used one so much the better
 
You might like to check out the Sony or Minolta 500mm f8 AF reflex lens, now only available second hand. It's half the weight, half the size, and half the price of the competition, because it's a mirror reflex lens. These lenses used to be offered by all the big camera makers, but they got a bad reputation because nobody could make them AF -- except Minolta, and they have nasty "doughnut" bokeh. But as Isaac Newton predicted -- he invented this kind of lens -- there is no chromatic aberration at all. If you want a cheap 500mm that's small and light enough to drop in your gear bag just in case a 500mm shot happens to turn up, and is probably sharper than any other lens with a teleconverter boosting its focal length, then there's no competition.
 
chris malcolm said:
You might like to check out the Sony or Minolta 500mm f8 AF reflex lens, now only available second hand. It's half the weight, half the size, and half the price of the competition, because it's a mirror reflex lens. These lenses used to be offered by all the big camera makers, but they got a bad reputation because nobody could make them AF -- except Minolta, and they have nasty "doughnut" bokeh. But as Isaac Newton predicted -- he invented this kind of lens -- there is no chromatic aberration at all. If you want a cheap 500mm that's small and light enough to drop in your gear bag just in case a 500mm shot happens to turn up, and is probably sharper than any other lens with a teleconverter boosting its focal length, then there's no competition.
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Just bear in mind they are quite fragile and it's easy to knock the mirror out of alignment.
 
Thanks for the tips, but I will try and get the best out of my 300mm :-)
 
MatBin said:
Just bear in mind they [Sony/Minolta 500mm reflex] are quite fragile and it's easy to knock the mirror out of alignment.
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I didn't know that. Interesting! That could explain the oddly conflicting reports I've seen of the image quality of this lens -- mine was bought new when Sony still sold it, and is distinctly better than some of the reviews and posted images I've seen. The other explanation of course is unfamiliarity with long lens photography -- it takes a while to learn how to get sharp images out of any long lens, just one of the problems being that the DoF on a 500mm lens is smaller than the range of AF error tolerance to which at least some DSLRs are made.
 
I too have been looking for a teleconverter. The kenko teleplus pro 300 after looking at the reveiws on Amazon seems to work on my NIkon d3200 ok so check out Amazon and B&H photography for your camera and teleconverter combination.The reviews seem to be real people to me.
 
al 2000 said:
I too have been looking for a teleconverter. The kenko teleplus pro 300 after looking at the reveiws on Amazon seems to work on my NIkon d3200 ok so check out Amazon and B&H photography for your camera and teleconverter combination.The reviews seem to be real people to me.
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It's if ateleconverter will work with a camera or not, it's dependant in the lens it's being attached to. If the lens is a constant f2.8, f4 or even one of the newer f5.6 adding a teleconverter will degrade IQ and AF speed/accuracy. Generally zoom lenses that are variable aperture like f4.5-5.6 don't take teleconverters well. Nikon limits which lenses it feels work ok with a teleconverter by adding a tab to the mounting. I gather the kenko gets around the mounting issue but won't get around the performance drop.

A couple of years ago I wrote a blog on my old website about teleconverters because they came up so much on here. A copy of it can be found here:

https://spark.adobe.com/page/pemWGeihe1GJz/
 
Thanks for the info. What or where is this tab on nikon lenses?
 
al 2000 said:
Thanks for the info. What or where is this tab on nikon lenses?
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It’s a tiny metal tab (abou 3mm by 3mm) on the inside of the teleconverter mount on the side which mounts onto the lens. It’s there to stop teleconverter being mounted onto incompatible lenses. The front element of Nikon teleconverters sits slightly proud of the teleconverter body. This means the protruding front element needs to sit inside the lens. Compatible lenses leave room of this, but some non compatible lenses don’t and their rear element moves back and forth during focusing or whilst zooming. That means there is potential for the teleconverter front element and lens rear element to collide. I’ve never seen a Kenko teleconverter, I’m guessing it doesn’t have a protruding front element. I have heard of people filing off the tab but I don’t think it’s a great idea as it’s there to stop lenses being damaged by a teleconverter.
 
Another hint if using a TC and it's over the F stop your camera will autofocus on is to use live view (if you have it) and zoom in for critical focus.
 
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