Exstension tubes for wildlife/birds?

Vespa · Mar 22, 2011

I have seen a couple of people that have used tubes for some really cool bird shots but I don't really understand how they work and if the $50 set on eBay are any good? I would be using them on a 70-300mm nikon zoom. Also what brands, if any, are worth buying?

Bitter Jeweler · Mar 22, 2011

You want to be looking at teleconverters.
Extension tubes are for macro work.

Big Mike · Mar 22, 2011

Mr Jeweler is right. Extension tubes allow you to focus the lens closer than they could otherwise, thus, they are good for macro. They probably don't even allow you to focus at infinity.

What you want, is a teleconverter. It goes behind the lens, like an extension tube, but has lens elements (unlike a tube, which has none).

480sparky · Mar 22, 2011

Nikon does not list teleconverters as compatible with the 70-300 I have. Perhaps there's a reason for that.

But a tc may work for the lens you have. I don't know

Big Mike · Mar 22, 2011

Nikon does not list teleconverters as compatible with the 70-300 I have. Perhaps there's a reason for that.

That's probably because using a TC on a lens like that, will likely stop the AF from working.

Teleconverters steal some light. A 2X TC takes about two stops of light. So now your F4-5.6 lens is more like an F8-F11. That makes it even harder to get good shutter speeds, but it can also stop the Auto Focus from working. The AF on most cameras, needs at least F5.6 from the lens (AF is done with the lens wide open).
In other words, with a TC and a slow lens, there isn't enough light for the AF system, so they don't consider them to be compatible.

Derrel · Mar 22, 2011

Extension tubes are often needed for close-up bird photos when using older supertelephotos like 300,400,500,and 600mm prime lenses; many older primes in this range will only focus down to 15 to 35 feet at their minimum focus distances, and so a 12 to 25mm extension tube is often needed when birds are very close. You'll see the listing of an extension tube quite often on Canon's old 500mm f/4.5-L prime lens on small-bird shots done close. That particular lens was quite popular with birders for the better part of two decades.

Bitter Jeweler · Mar 22, 2011

Ah, so some lenses still allow for focussing that far out. But not necesarily to infinity, right?

I re-read it. I get it now.

What does the focusing range become on a lens such as the 400-500mm primes?

Derrel · Mar 22, 2011

Bitter Jeweler said:
Ah, so some lenses still allow for focussing that far out. But not necesarily to infinity, right?

I re-read it. I get it now.

What does the focusing range become on a lens such as the 400-500mm primes?

Yeah...some longer telephotos only focus down to 5 meters...so when the subject is a chickadee or other small bird and the photographer is shooting from a blind or with a remote camera, the long telephoto lenses need an extension tube to allow really close focusing. My 400mm f/3.5 for example, does not focus all "that" close, so if I want to use it for backyard birding, I would most likely use it with an extension tube....which eliminates the ability to focus much beyond about 35 feet. My cheap 500mm f/8 focuses "down to" only 35 feet!!!! NOT very close!!!

Designing big telephoto lenses with closer and closer and closer minimum focusing distances (ie, better MFD) has been one of the primary improvements in 300,400,and 500mm lenses over the past 30 years. Nikon 's newest 300mm f/4 AF-S lens has a REALLY close MFD, of around 1 meter, which means that when it is paired with an extension tube, it becomes a sort of super-macro lens. An older 300mm f/4 lens would often have a MFD of 2 meters, which makes it much, much more of a pain in the butt for close-up photography.

Vespa · Mar 22, 2011

Cool. So I could use it to get some cool shots. What brands would you recommend?

Derrel · Mar 22, 2011

Extension tubes: Canon makes really NICE, solid extension tubes for its EF-mount lenses. In third-party, Kenko's DG series of autofocusing tubes are really nice, but are somewhat expensive at around $179-$149 for a set of three. A notch below them are other third parties, like Pro Optic, priced around $99 or so. Below that are really cheap, crappy tubes that have no electronic contacts, and prices like $9.99 from e-Bay....those are pretty cheezy.

But, back to the original thought---with something like a 70-300mm zoom lens of modest aperture, like an f/4~5.6 or f/4.5~5.6 variable aperture models, I think the better idea would be to get a good-quality 1.4x tele-converter; the best ones are made by Canon and NIkon, and the Kenko-Pro models are right up there as well. I really think iof you have a NIkon camera and a 70-300 of modest aperture that a $50 extension tube is only going to help you with getting better images of very small things, close-up, like say salamanders, snakes, flowers, and so on. You want to make sure that any extension tube you buy has electrical contacts that will run the lens diaphragm. I beleive that the single, 10 to 13mm or 20 to 26mm extyension tube "singles" sold at the $50 price point will have electrical contacts. I would buy a single tube that is either 12mm or 25mm; the longest of a set of three, the 36mm tube, is of limited use most of the time.