Any advice on teleconverters or teleside converters.

Energize · 2 Feb 2013 at 21:31

I'm looking to purchase some teleconverters to give me some extra flexibility for my lens collection, on a Nikon D7000. Maybe a 1.4x and a 2.0x, obviously the 2.0x would be impractical for a 70-300mm but a 1.4x may be doable, 2.0x I could use with my primes.

I would then effectively have a 35mm f/1.8, 50mm f/1.4, 70mm f/2, 85mm f/1.8, 120mm f/2.5, 170mm f/3.5, maybe possibly a 240mm f/5 with stacking. And then a 70-300mm f/4.5-5.6 and 100-420mm f/6.3-8.

Which brands are suitable for my Nikon lenses?

On a somewhat related note, are there no reverse teleconverters available for aps-c cameras like there are for m4/3?

PhotoPixels · 2 Feb 2013 at 22:20

Not sure if even the 1.4tc will attach to the 70-300MM without damaging it.

Energize · 2 Feb 2013 at 23:04

Yeah Nikon's won't, but other 3rd party ones will so I'm told.

Snapshot · 3 Feb 2013 at 22:30

Energize said:
On a somewhat related note, are there no reverse teleconverters available for aps-c cameras like there are for m4/3?

I don't think it can be done as APS-C cameras have the same lens-flange to sensor distance as FX which allows FX lenses to be used without adapters. m4/3 bodies are slimmer as there's no mirror box so there's some space available for the adapter.

In answer to your original question - I think Kenko/Tele-Plus is the only worthwhile make that will fit. Make sure you buy a variant of the Pro 300 to get decent optical quality. Sigma teleconverters are equally good but I think they're restricted to Sigma lenses.

Rojin · 3 Feb 2013 at 22:39

I don't know anything about Nikon fit TC's, but don't expect to get great results with the widest aperture. There's generally a quality hit with a TC so stopping down a stop or two may be required for best results. They do give a nice flexibility though, I use a 2.0x and 1.4x occasionally with my 70-200.

Energize · 3 Feb 2013 at 22:49

Snapshot said:
I don't think it can be done as APS-C cameras have the same lens-flange to sensor distance as FX which allows FX lenses to be used without adapters. m4/3 bodies are slimmer as there's no mirror box so there's some space available for the adapter.

In answer to your original question - I think Kenko/Tele-Plus is the only worthwhile make that will fit. Make sure you buy a variant of the Pro 300 to get decent optical quality. Sigma teleconverters are equally good but I think they're restricted to Sigma lenses.

All a teleconverter does is change the size of the image circle though, I don't see why if you can increase the size of the image circle that you can't decrease the size of the image circle on an SLR.

http://www.metabones.com/sony/ef-e-speed-booster

That reverse teleconverter allows you to mount a full frame 50mm f/1.2 cannon lens on an aps-c camera and produces a 54mm f/0.90 image.

I'll check out Kenko thanks.

Ksanti · 3 Feb 2013 at 23:22

The reverse ones are just hitting the market but they are quite expensive, at least more than teleconverters would be.

http://www.dpreview.com/articles/2667195592/first-impressions-metabones-speed-booster

Looks pretty cool, particularly in terms of using smaller full frame lenses like a 50 1.8 on an APS-C body. Particularly cool if a manufacture licenses it properly to let AF work well.

D.P. · 4 Feb 2013 at 00:28

Energize said:
I'm looking to purchase some teleconverters to give me some extra flexibility for my lens collection, on a Nikon D7000. Maybe a 1.4x and a 2.0x, obviously the 2.0x would be impractical for a 70-300mm but a 1.4x may be doable, 2.0x I could use with my primes.

I would then effectively have a 35mm f/1.8, 50mm f/1.4, 70mm f/2, 85mm f/1.8, 120mm f/2.5, 170mm f/3.5, maybe possibly a 240mm f/5 with stacking. And then a 70-300mm f/4.5-5.6 and 100-420mm f/6.3-8.

Which brands are suitable for my Nikon lenses?

On a somewhat related note, are there no reverse teleconverters available for aps-c cameras like there are for m4/3?

Non of your lenses support the use of TCs!

D.P. · 4 Feb 2013 at 00:32

Energize said:
Yeah Nikon's won't, but other 3rd party ones will so I'm told.

Most of your lenses won't physically be able to support a TC from any manufacturer. The 70-300 can support some 3rd part ones, normally requir you to modify the TC a little.

But that is beside the point, the lens is just not good enough to take a TC. You a better off just cropping. I think you misunderstand what a TC does and what it is for. Their main function is for fast telephoto prime lens, not slow consumer zooms, nor fast shorter primes. The 70-200mm f/2.8 is about the only exception.

Energize · 4 Feb 2013 at 01:16

Based on the compatibility charts the Kenko Pro 300 fits all my lenses. The Nikon ones will fit the 70-300 but require modification.

I'm fully familiar with what a teleconverter does, it diverges the light coming from the lens thus increasing the image circle so the sensor effectively crops the image to a greater degree, the area of the image circle doubles for a 1.4tc so the intensity of light decreases by 1 stop.

Yes I realise what use they are designed for, but quite a large number of people use a 1.4tc with the 70-300 and the results are better than cropping based on the pictures I've seen, because the whole sensor is getting the desired light from the lens increasing the captured detail despite any aberrations introduced by the teleconverter.

Aside from that, obviously I will be adding more lenses to my collection in the future which are better suited to tc's.

D.P. · 4 Feb 2013 at 02:19

Energize said:
I'm fully familiar with what a teleconverter does, it diverges the light coming from the lens thus increasing the image circle so the sensor effectively crops the image to a greater degree, the area of the image circle doubles for a 1.4tc so the intensity of light decreases by 1 stop.

Yes I realise what use they are designed for, but quite a large number of people use a 1.4tc with the 70-300 and the results are better than cropping based on the pictures I've seen, because the whole sensor is getting the desired light from the lens increasing the captured detail despite any aberrations introduced by the teleconverter.

Aside from that, obviously I will be adding more lenses to my collection in the future which are better suited to tc's.

I have yet to see any comparison of a 1.4xtc on a 70-300 that was any better than cropping and upsizing. When shot at less than 200mm the perhaps but that is pointless, at 300mm where it counts the lens already barely provides critical sharpness without stopping down a little. Stretching that limited image over a larger area only worsens the fact.

Yes, when you use a TC you use the entire sensor, but you loose 1 stop of light gathering. More to the point you are only using a crop from the lens, thus you go back exactly where you were to begin with. Put it this way if the complete sensor is using the complete lens gathering ability we can call this 1 unit of information. Using a 1.4xtc removes information by a factor of 1.4. Cropping removes that same amount of information.

The down sides of using a TC are that you are loosing a lot of light so youare either increasing noise or blur, or both. You are also adding additional optical layers that will further reduce IQ. On the 70-300 you arloosng autofocus so will MF everything.

There is no free lunch, what you gain is mirrored by what you loose. TCs really only work on a lens that can outresolve the sensor if the camera you are using. This is rarely the case these days for anything except the best lenses.

I would save your money and buy the lens that you want, then buy the TC. I would never dream of adding my TC to my 70-300, even on my 70-200mmf/2.8 it is not my favorite setup, which is why I purchased a 300mm f4.0. Now on the 300mm f4 the TC is great so that is a double win.