Looking at AF and manual focus for the 7D

A few tests of AF and AF tracking for the Canon EOS 7D

As I’ve mentioned before, I don’t do sports photography, or photograph animals/birds very often, so my looking at AF performance with the 7D is not going to be an exhaustive study ;-)

That said, the AF system in my 1Ds3 is no slouch – all those AF points work very nicely as long as I remember to pick the right ones.

In some brief tests with the 7D and a 70-200 2.8L IS I tried some bursts of shots of approaching cars when I was out. Apart from those that slow down when you point a camera at them, most were doing 40-50mph and passed quite close to me.

Here’s a typical set of shots.

a burst of shots of an approaching Car - EOS 7D

a burst of shots of an approaching Car - EOS 7D

I’ve plenty more like this, but they can stay in the archives…

After trying a few combinations, I found that AI Servo mode, with a single focus point (+ expansion) gave the most reliable results where I was tracking the oncoming car.

The only blurred shots in other sets came from the lateral motion of the car when it passed me, or where the AF point was pointing at a nondescript close up shiny bit of bodywork.

My main discovery was just how many combinations of AF settings and tracking options there were. I’m sure there are optimum settings for this particular type of shot, but I didn’t find the manual overly helpful in knowing where to start experimenting.

I was left feeling that photographers who expect everything to work ‘out of the box’ and don’t take the trouble to learn about their new AF system are going to be the ones on the forums complaining that the AF is no good. If you do see examples of AF performance being discussed, be sure not to automatically equate the ability to take some good pictures with an ability to critically evaluate the performance of different AF adjustments.

Keep a look out for well written guides as to how to get the best from AF for -your- style of photography.

If your photography -does- rely on speedy AF then expect to do some serious experimenting. I’m afraid my interest in photographing cars heading towards me rapidly wanes on a cold day :-)

BTW If anyone comes across any really good AF test articles, then please do let me know and I’ll add them to the resources on the main 7D page.

Manual focus

7D with Zeiss 20mm lens

7D with Zeiss 20mm lens

I’ve tried a few manual focus lenses on the 7D.

Focus confirm works with Canon TS-E lenses, but with the 20mm Zeiss Flektogon I was back to using the distance scale or liveview.

The focusing screen is really not designed for focusing, since it actually gives the impression of a bigger DOF than you really have.  Exposure was no real problem, metering with the lens stopped down.

The Flektogon is an M42 screw fit lens and the adapter is not an AF confirm one.

At f/8 the image is good and sharp, with residual chromatic aberration easily cleaned up in RAW development.

This lens does show up the advances in coating development , since the 1970’s) and is prone to patches of lowered contrast – but it didn’t cost me anything :-)

Trees and lane, December morning

Trees and lane, December morning 7D + Zeiss 20/2.8

Some of the original detail (slight sharpening in processing)

100% crop at centre of frame

100% crop at centre of frame

There are some other articles on the site about using old lenses on cameras

  • http://markphillips.eu Mark

    Thanks Keith, that was actually pretty handy info.

    I’m sold on a 7D. Shall be getting one in the new year I reckon.

  • http://www.northlight-images.co.uk Keith

    I’ve posted some sample images – hope that helps

  • Jan Trussler

    Hia Kieth,

    Can you try and look at the image quality (OOf issues) at F6.3 against your 1Ds?

    That might clear up a lot of the poor resolution issues posted all over the net.

    Jan Trussler