What 2x extender is recommended for the Nikon D70, 70-300 lens (62 mm)?

I have seen a Kenko and a Tamron advertised. Please advise best one. Thanks.
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Drwritelight

... but 1.4x works very well with primes and ok with decent zooms.

I use the cheapest Tamron 1.4x, which I find razor sharp:
D70s, Sigma 105mm 2.8, Tamron 1.4x
6s, f18, 105mm



D70s, Nikon 70-210 f4, Tamron 1.4x
1/160s, f7.1, 210mm
Through plexiglass ....



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http://letkeman.net/Photos

First off, I believe that the Kenko and Tamron tele-extenders are different brandings of the same item.

Yo do not mention which 70-300 that you are talking about; however, I do not think that any of the 70-300 lenses, that I am aware of, will work well with an extender. In order to auto-focus, the camera needs a lens whose widest aperture is no less than f/4. If your lens' widest aperture is smaller than f/4, you willl likely have auto-focus problems with a telextender.

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Cliff

http://www.pbase.com/cliffb

If I am not mistaken, Kenko is from Tokina.

To the OP...you will be very unhappy with a 2X telextender, 1.4X would be better and a maximim of 1.7 would be the most.

Remember that you loose a stop for a 1.4X and about 2 stops for a 2X. Then you need to close down about 2 stops to get a sharp photo. Add all that to the maximum lens aperature and you will see that it adds up.

A telexender will magnify any faults you have in your lens so, a lens that is marginally acceptable will be unacceptable with it added. Telextenders are best used with professional quality glass with fast (2.8) maximum aperatures.

If you have AF-S pro glass (e.g. 17-200 2.8, 300 2.8, that sort of thing) then the Nikon extenders (1.4, 1.7, 2.0) will all work very well and will retai a high degree of image sharpness.

My original post was about augmenting consumer glass.

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http://letkeman.net/Photos

GroundGlass said:

If I am not mistaken, Kenko is from Tokina.

Click to expand...

I understand that Kenko and Tokina are both names used by THK Photo Products, Inc.; and, that Tamron is a totally different manufacturer. However, this would not be the first time that manufacturers have shared product lines. I have read, from several sources, that these two companies share tele-extenders. I have never done a jans-on comparison, however, if looking on-line, the specs of the Tamron "SP AF Pro" extenders and the Kenko "Pro 300 DG" extenders are exactly the same. Also, in on-line photos of each, other than the name and color, the photos appear identical.
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Cliff

http://www.pbase.com/cliffb

Cliff,

The kenko 1.4 works with my 70-300G (yes the cheapest one) It can focus at 300mm but the trick I learned is to quickly focus at 70mm then zoom to 300m then hold the shutter down. It will be so close to the focus piont that it will easily find the focus then take the picture. If you try to focus at 300m too often it will turn the focus ring in the wrong direction, so it will focus completely one way then turn back then find focus. Some people mistakenly call this hunting. I call hunting when the lens goes past the focus point back and forth a couple of times. I have a 15 year old Tamrom 28-200 that truly hunts. The 70-300 doesn't hunt, it just makes a wrong guess which forces it to turn the wrong way t start with.

Whether it is hunting or not, it can be an eternity to wait for the lens to finish turning. That's why the trick I learned is cool. It also works without the TC.

Guy Moscoso

Also take into account Nikon’s statement regarding auto focus. “A minimum effective aperture of f 5.6 is required for auto focus to function.” When you add a 1.4x TC you louse 1 stop so a f 5.6 lens combined with the TC becomes f 8 and with a 2x TC it’s a 2 stop penalty.

Morris

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http://qcpages.qc.cuny.edu/~morris/POD

Morris,

If you could be so kind, I have the kenko and use it with the cheap 70-300G (also 80-200 f2.8) and it works. Ask Nikon why they insist about f5.6, but If you want to quote someone who uses one you can feel free to quote me.

I've also tried it with all of my lenses, from 18-55dx to 28-200G and they all work.

Guy Moscoso.

morris said:

Also take into account Nikon’s statement regarding auto focus. “A
minimum effective aperture of f 5.6 is required for auto focus to
function.” When you add a 1.4x TC you louse 1 stop so a f 5.6 lens
combined with the TC becomes f 8 and with a 2x TC it’s a 2 stop
penalty.

Morris

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Click to expand...

Nikon's limit of f/5.6 is not a "hard limit". The AF system will attempt to work beyond f/5.6. Certainly, I've used a couple of f/6.3 lenses over the years and they were able to autofocus. In good lighting, you may be able to achieve AF at f/8 with a converter, but there are no guarantees. At f/5.6, Nikon AF is guaranteed to function normally.

As for teleconverters, I know that for whatever reason the Sigma TCs will disable AF above f/5.6. I've never been able to figure that one out-- Sigma claims it is the Nikon body shutting it off, but I've used other TCs not seen AF disabled.

There are several challenges when you use teleconverters, and AF is only one of them. First of all, you need to be careful when using a TC to remember that your effective focal length is that much longer and thus proper support is a must. With APS-C sensors, the general rule I employ is to use a shutter speed of 1/(2x FL). If I'm using a 300mm lens, that means I'd want to shoot at 1/600th if possible. Add a 2x TC, and you'll want to shoot at 1/1200th or so. With the loss of light, this can create a challenge.

The other big challenge which ties into the shutter speed issue is that for optimal performance, you should usually avoid shooting wide-open with a TC. There are a couple of exceptions (I get very good performance with at TC-14E and 200-400VR), but even the Nikon 2X TCs need to be stopped down about two full stops for optimal performance.

My advice is to use a TC only when it is absolutely necessary, get the best TC you can, and employ them on good glass, such as a telephoto prime. The 300mm f/4 AFS is an excellent example of a Nikkor lens that handles a 1.4X TC very nicely.

-Jason

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Jason P. Odell, Ph.D.
Author, 'The Photographer's Guide to Capture NX'
http://www.luminescentphoto.com/capturenx.html
Holiday discount for dpreview readers:
http://www.luminescentphoto.com/dpreview.html

Co-host, 'The Image Doctors' at Nikonians Podcasts
http://podcasts.nikonians.org

Thanks, especially for the pix. The parrot is priceless
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Drwritelight

Thanks, for a very thoughtful and factual response.
--
Drwritelight

Thanks, for the great tip. I will try it as soon as I get the extender. --
Drwritelight