Mr Mars' Tamron 70-300mm f4-5.6 Review

All shots are 100% crop with some jpg compression to keep the size down.

I really wanted to like this lens. After reading various reviews I decided to buy it rather than the kit lens when I bought my 400D earlier this year. It had the range, quality and PRICE that I wanted.

From the beginning it exhibited unacceptable front focus. The lens was sent back and 2 weeks later a fresh copy appeared. Same problem. The camera body was then sent off to Canon for calibration. 2 weeks later it returned. Same problem. I was livid. Obviously someone was letting me down but was it the lens or the camera? I bought the Canon nifty fifty and it focused largely ok although it still exhibited some focusing issues.

Purple Swamp Hen - front focus is obvious.
Canon 400D, 300mm, 1/350 s, f5.6

Purple Swamp Hen

Snail Rock ornament used as a focus target - front focus is obvious.
Canon 400D, 119mm, 1/200 s, f4

Rock Snail

I decided to try the lens offset screw twiddle, as detailed elsewhere on the net. Success! The Tamron lens then focused much better.Unfortunately, in order to get the Tamron lens focusing properly the necessary mirror offset now caused both my Canon lenses to back focus badly. The evidence against Tamron was compelling. I reset the mirror to its correct position and sent the lens back to Tamron with a letter detailing the situation and a selection of photos.

Cabbage White Butterfly before the mirror offset twiddle.
Canon 400D, 300mm, 1/500 s, f7.1

Cabbage White before

Cabbage White Butterfly after the mirror offset twiddle.
Canon 400D, 300mm, 1/500 s, f5.6

Cabbage White after

Pied Cormorant before the mirror offset twiddle.
Canon 400D, 300mm, 1/1000 s, f8

Cormorant before

Pied Cormorant after the mirror offset twiddle.
Canon 400D, 300mm, 1/500 s, f8

Cormorant after

To their credit Tamron's Australian distributors: Maxwell, made a real effort to fix the problem. The lens was sent to Japan for analysis by the mother company. Unfortunately they could find no fault with it despite the clear evidence of front focus. They offered to set up the lens to suit the camera if I would just send my 400D off to Japan. I declined and got my money back.

I hesitate to apportion all the blame for my bad experience to Tamron. Other experience with various Canon bodies has led me to the conclusion that Canon have a real problem with their autofocus units. Nevertheless Tamron ought to be aware of any such issues, and the time wasting nightmare that I went through trying to get to the bottom of the problem simply should never happen. It is not good enough Tamron!

On the positive side however, IFF the lens focuses properly in your camera, then you have a bargain. During the brief period when I had the camera set up to work with the lens I got lovely images: sharp, contrasty and colourful. The lens felt good in my hand and the zoom ring didn't slip. The focusing motor is a little rough & noisy but worked well enough.

This lens is really sharp at 70mm, even wide open, and pretty damn good at 300mm at f8. Even at 300mm at f5.6 it is still acceptable. This lens is MUCH sharper than the Canon equivalent that comes in the twin lens kit (provided you can get it to focus...).

I found though, of course, that a 300mm lens needs IS, you can shoot at f8 in bright daylight at ISO 400, but when the light is weaker you'll get camera shake blur unless you open it up to f5.6 and/or use ISO 800. Still, you can't expect IS in a $200 lens. Or can you...

The macro facility sounds great but isn't as useful as one might think. At 300mm at closest approach the depth of field is only a few mm. This is ok for flat objects but not enough for insects etc. At 180mm it is more useful, but again the DoF is a bit narrow. It would have been much better if they had let the lens extension come out for the entire focal range, not just 180-300. And again, IS is really needed for anything handheld at 300mm. The business of changing into and out of the macro mode is rather fiddly as people have mentioned and there are no instructions to advise you. You can't switch out of macro mode while the lens is hyper-extended. To correct this, just focus on some distant object and the lens will retract, allowing you to change back to normal mode.

Chromatic Aberration is BAD when it occurs. Still, it only happens occasionally during normal shooting and for this price you can live with it.

This was my first experience with Tamron and it was mostly bad. Since I believe Canon are partly to blame I may try another Tamron lens on the Nikon D60 that I have just bought but I will only buy if I have a cast iron money back guarantee for any reason.