Kenko 2 x Teleconverter tips

sunnybears

sunnybears

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Susan
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Hi,

I have just purchased a 'KENKO 2.0X TELEPLUS HD DGX TELECONVERTER - NIKON FIT' and I have admittedly not tinkered with it too much yet. It has autofocus that transfers through the teleconverter which I thought was handy.

I guess my query is what tips do you have for using a teleconverter? I used it with my 300mm lens and it was seeking a lot trying to focus, both on auto and manual. Manual focus was better as I could obvs focus myself. The thing with that is I am zooming to the equivalent to 600mm and the image was blurry. Can I still hand hold at that level or do I need to always tripod it?

Thanks in advance ( I did a search of the forums first - apologies if this topic has been covered)
 
You're losing 2 stops of light so your AF system is struggling/not working.

Lens handholding should be around 1.5x shutter speed v focal length.
 
twist said:
You're losing 2 stops of light so your AF system is struggling/not working.

Lens handholding should be around 1.5x shutter speed v focal length.
Click to expand...

Thank you. So shutter speed of 1/900th sec?
 
sunnybears said:
Thank you. So shutter speed of 1/900th sec?
Click to expand...

1/1000th, depends on how well you handhold, if youre still struggling then try 1/1250 etc. Just try different shutter speeds until your images are sharp, some can handhold much lower speeds, lenses have IS/VR etc which also takes it down.
 
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Which 300mm lens do you use? If it's a zoom, chances are that you'll be close to the camera's limits of autofocus capabilities, hence manual focus working better. TBH, I've never found 2x converters to be that good, unless paired with lenses that are designed to work with them - usually fast (expensive) primes and unless the extra megapixels are needed, you may well be better off with a 1.4x converter and a bit of cropping.
The general rule of thumb is that a lens can be used hand held at around the reciprocal of its focal length when converted to its 35mm equivalent. Sounds complicated but isn't really since it's a very rough guide! For your 300mm lens with the converter, it would be 1/600th on a full frame body and 1/900th on a crop body. BUT that's a very rough guide and you may well be unable to get an acceptably sharp image at those shutter speeds (or, equally possible, you may well be able to get them at slower speeds!) Try it with a static subject both on and off the tripod to see how slow YOU can go.
 
My lens is - Nikon 55-300mm f/4.5-5.6 AF-S DX VR Nikkor telephoto zoom lens 2430956
 
sunnybears said:
My lens is - Nikon 55-300mm f/4.5-5.6 AF-S DX VR Nikkor telephoto zoom lens 2430956
Click to expand...

So with the TC youre at F11 @ 300mm 'wide open', unless you have a very high end Nikon camera capable of F11 AF its not going to achieve focus (as youve discovered).
 
I have a Nikon D7500. So I can't get a more open F stop than F11? I also have a 200mm and the standard 55mm kit lens. I have a 400mm Sigma, I'm guessing that'll be impossible with the TC.
 
I may be wrong but it looks like the D7500 is rated to F8. Bascially you need a lens to be at F4 or lower aperture (+ 2 stops) in order for your AF system on your camera to AF well. So your 300mm max aperture is f5.6 (+ 2 stops) = F11.
 
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my tip is throw it in the bin.. never had any good results with any 2x converters I use the kenco 1.4 and works great
but never had much luck even when used with 500mm f4, I sometimes use the sigma 2x on my macro sigma 150mm 2.8
but only focus manually, also got the 1.7 nikon convertor and dont use that one much either.
 
I'm sorry we can't give you better news, Susan.

Personally, I wouldn't go quite as far as mark, I'd trade it in against a 1.4x teleconverter. Then again, on a 55-300 kit zoom, even that is unlikely to give great results (even the slightly better 70-300 doesn't really show its best side with a teleconverter.) IIRC the Kenko is one of the few teleconverters that will physically fit behind the "consumer" level zooms; the Nikkor telecons only fit their primes and "pro" level fast zooms.
 
Thanks for all of your feedback. I just wanted to try and teleconverter myself as I had seen mixed reviews on them. I find it far to dark to practice with in the house. I have saw some you tube videos of folk using them outside so I might have more luck that way.

The teleconverter was way cheaper than a 500mm which I can't afford. I have a 400mm.
 
Different people have different levels of expectation for their gear, and display their images in different ways.

A 2x teleconverter will not make the best posters. And they will show the limitations of a consumer grade lens so are better on professional grade ones. No least of which, because they need a wider aperture to let enough light in for autofocus, and for use in darker conditions.

But an amateur on a budget will have lower expectations that someone who can afford a long prime lens. And if it means the difference between getting the shots you want or not, a less than perfect image is still better than no image at all.

And if you are shooting mainly for web sized images, then you have a lot more scope for acceptable image quality as you will be downscaling rather than using every pixel.

The point being, first understand the limitations of what a teleconverter can do and whether that is acceptable to you. Then, if it is, try it out and see if you are happy with the results before throwing it in the bin or trading it.

It might meet your need. It might not. But your needs are not anyone else's so only you can decide.
 
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