400

Lens construction:	10 elements in 8 groups (1 SD glass element)
Focus distance:	2.5 m (8.2 ft.) to infinity
Angle of View:	6° 10'
Max. reproduction ratio:	1:5.8
Aperture scale:	f/5.6 to f/32
Attachment size:	72 mm
Diaphgram blades:	8
Lens hood:	built-in
Dimensions:	78.5 mm (dia.) x 202 mm (length)
Weight:	990 g

This 400 mm lens is amongst the smallest ones ever produced. Thanks to its Internal Rear Focus (IRF) system, it focuses down to 2.5 m (8.2 feet). Only the Pentax FA 400/5.6 and the AF Sigma 400/5.6 Apo Macro can focus closer, but the former is much more expensive (and cannot be mounted on my Nikon cameras!), the latter is much more heavy and obtrusive. The Table below shows a comparison between 400 mm f/5.6 lenses produced by different brands.

lens	*length* x diam. [cm]	Weight [gram]	Closest Focus Distance
Tokina AF ATX 400/5.6	202 x 78.5	990	2.5 m
Tokina SL 400/5.6 SD	207.5 x 78	980	4.0 m
Sigma 400/5.6 Apo IF	212.5 x 84	1100	4.0 m
Pentax FA 400/4.6 ED IF	199 x 83	1140	2.0 m
Nikkor AI 400/5.6 IF-ED	262 x 85	1200	4.0 m
Canon EF L 400/5.6	256 x 90	1250	3.5 m
Sigma 400/5.6 Apo Macro (HSM)	257 x 90.5	1450 (1500)	1.6 m

According to my friend John Herbst, what makes the ATX Tokina 400/5.6 so wonderful is classic Tokina quality, sharpness, and durability all put together in a compact lens. Unfortunately, Tokina is not making this lens anymore and stocks of this lens for Nikon mounts are very nearly depleted.

The ATX Tokina 400 mm f/5.6 is great for handheld action or flight shooting. On sunny days, when shooting single birds in flight and using 100 ISO film, typical shutter speeds around 1/1000 sec ensure correct exposure and allow to freeze most action.

As a result of its low weight the Tokina is easy to use handheld. One can follow a flying bird or moving animal much more smoothly with the Tokina lens, rather than with the heavier Sigma Apo Macro.

One of the first pictures I took with my Tokina 400/5.6 was the lunar eclipse (see picture below). I used a 1.4 X teleconverter (Nikon TC-14 A) to get a larger size of the moon. As a general rule, the size on film of the moon is 1/100th of the focal length. This little focal length tip also works for the sun's image. In fact they appear in the sky to be about the same diameter. Therefore, the 1.4 X allowed to increase by 40 % the size of the moon on film. To avoid image blurring due to moon orbiting, shutter speeds faster than 500 divided by the focal length must be employed. I used 1 sec (on Kodak Gold 400) to take the eclipse image, being 560 mm (400 + 1.4X) the focal length. The lens aperture was set at f/5.6 (wide open) and the (manual) exposure was set according to the spot metering of my wife's Nikon F601 camera.

Then, I have taken pictures of my City and of wildlife as well, in order to check the optical quality of my sample. Well, I was rather impressed by the very good correction of both distorsion and vignetting. The picture below was shot at f/5.6. The light fall off can be considered lower than 1/2 stop at the corners. And distorsion is really negligible.

Sharpness was very good too. However, being a light-weight long lens, the Tokina ATX 400/5.6 is very prone to camera shake and vibration and really needs to be mounted on a sturdy tripod.