40D's new AF experience......

^^Gord^^ · 13 Sep 2007 at 20:31

Got a chance to play with my 40D tonight and the AF is a different beast to my previous 20D and current 30D.

I used my 50mm f/1.8 as it would allow me to use the double sensitive centre point at f/2.8, the cross point at f/5.6 and it's also has slow AF.

I've been playing it low light conditions mostly and the AF is quicker and hunts less than the 30D but hits the centre point a lot less. At first this confused me and I started to wonder if I have a bad copy until I worked out the more sensitive outer AF points were locking onto things that my 30D wasn't picking up.

For example, shooting down a corridor my 30D would almost always go centre point, even if I had an outer AF point on a high contrast item like a door frame. With the 40D if I don't have anything in the centre point and the outer point is touching a door frame it will lock that point.

This is going to take some adjustment for me as I've got lazy and expect the centre point to lock on.

I'm going to try to get out tomorrow and see if this behaviour only occurs in low light conditions or not.

Have other 40D owners noticed this?

Johnny|lucidcomposure · 13 Sep 2007 at 20:34

I don't think on here you will come across many other 40D users. I am fairly sure you are one of the 1st.

Try POTN or Talk for more 40D Af questions.

^^Gord^^ · 13 Sep 2007 at 21:05

Mmmh, you might be right about that. I'll open a thread on TP.

Jase · 13 Sep 2007 at 21:05

First, grats on the new camera I remember you saying it was coming in a few days.

When I got my 40D last week I did notice a differnce in the AF although I can't say I had any problem adjusting to it, in fact I thought it was spot on. I went straight from a 20D to 40D though so don't know how the 30D handled things.

I haven't had as much time to play with the 40D as I'd hoped as I had to go to London for a few days this week. My intention was to bring the 40D with me to pass time at night and utilise the time in London, but I left in a hurry and forgot the camera

Let me know how you get on.

Jase

SDK^ · 14 Sep 2007 at 12:10

Canon do claim a 30% improvement in AF on the 40D over the 20/30D.

Felix · 14 Sep 2007 at 12:23

I have just had a go on a 40D and the focusing is a big improvement from the others I have tried perhaps even the 5D.

^^Gord^^ · 14 Sep 2007 at 12:28

I did wonder how it compared to the 5D and if people moving from the xxD range to the 5D noticed anything similar.

^^Gord^^ · 14 Sep 2007 at 16:39

Some more playing today and the outer AF points are more sensitive than the 30D. It isn't as noticeable outdoors as it is in low light conditions but it is there.

I've also done some burst testing today.....

14:48:31 (7 frames)

IMG_0021
IMG_0022
IMG_0023
IMG_0024
IMG_0025
IMG_0026
IMG_0027

14:48:32 (6 frames)

IMG_0028
IMG_0029
IMG_0030
IMG_0031
IMG_0032
IMG_0033

14:48:33 (5 frames)

IMG_0034
IMG_0035
IMG_0036
IMG_0037
IMG_0038

14:48:34 (4 frames)

IMG_0039
IMG_0040
IMG_0041
IMG_0042

That's 22 RAW shots and it took 16 seconds to write those from the buffer to the CF.