Comments on: Focus lock issue with Canon EOS 400D Digital http://www.jayceooi.com/2007/10/09/focus-lock-issue-with-canon-eos-400d-digital/ Technology, mobile, photography, gaming, programming, anything Sun, 12 Feb 2012 05:57:32 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Makeda Stravinski http://www.jayceooi.com/2007/10/09/focus-lock-issue-with-canon-eos-400d-digital/#comment-13346 Makeda Stravinski Wed, 16 Jun 2010 03:38:00 +0000 http://74.220.215.233/~jayceooi/?p=693#comment-13346 cheers for this blog. cheers for this blog.

]]> By: Jayce http://www.jayceooi.com/2007/10/09/focus-lock-issue-with-canon-eos-400d-digital/#comment-7229 Jayce Mon, 02 Feb 2009 12:12:01 +0000 http://74.220.215.233/~jayceooi/?p=693#comment-7229 @ex can-on: I am using 17-55mm f2.8 IS and 50mm f1.4. Both of the lens have focus issue on Canon 400D body. :( @ex can-on: I am using 17-55mm f2.8 IS and 50mm f1.4. Both of the lens have focus issue on Canon 400D body. :(

]]> By: ex can-on http://www.jayceooi.com/2007/10/09/focus-lock-issue-with-canon-eos-400d-digital/#comment-7148 ex can-on Sat, 24 Jan 2009 16:45:15 +0000 http://74.220.215.233/~jayceooi/?p=693#comment-7148 what lens are you using, focal 4 ? too bad in low light. i experienced that in a wedding. i was using 400D with 17-85 (f4), and another guy using another brand also kit lens. he shot like he never shot before.. and i was still struggling to get focused! by the time i got 2 shots he got all the shots he wanted. this may not be a good solution but worth to think in the long run - switch brand! what lens are you using, focal 4 ? too bad in low light. i experienced that in a wedding. i was using 400D with 17-85 (f4), and another guy using another brand also kit lens. he shot like he never shot before.. and i was still struggling to get focused! by the time i got 2 shots he got all the shots he wanted. this may not be a good solution but worth to think in the long run – switch brand!

]]> By: Jayce http://www.jayceooi.com/2007/10/09/focus-lock-issue-with-canon-eos-400d-digital/#comment-667 Jayce Wed, 10 Oct 2007 07:14:15 +0000 http://74.220.215.233/~jayceooi/?p=693#comment-667 Still ok la... ;) Still ok la… ;)

]]> By: keeyit http://www.jayceooi.com/2007/10/09/focus-lock-issue-with-canon-eos-400d-digital/#comment-666 keeyit Wed, 10 Oct 2007 07:04:16 +0000 http://74.220.215.233/~jayceooi/?p=693#comment-666 wow.. it is clear ! sure lol expensive camera lel wow.. it is clear ! sure lol expensive camera lel

]]> By: Jayce http://www.jayceooi.com/2007/10/09/focus-lock-issue-with-canon-eos-400d-digital/#comment-665 Jayce Wed, 10 Oct 2007 01:50:12 +0000 http://74.220.215.233/~jayceooi/?p=693#comment-665 I got this reply from Doug Pardee at <a href="http://forums.dpreview.com/forums/read.asp?forum=1031&message=25141654" rel="nofollow">dpreview forum</a>. JayceOoi wrote: <em>> I used ISO 800 and above in low light room. > But still failed to focus lock sometime.</em> Autofocus is separate from ISO. The autofocusing system requires a certain minimum amount of light to operate. <em>> I took wall as sample. I cannot get a focus lock with built-in flash</em> The autofocus system looks for a contrasting edge within the AF sensor area. A wall has no contrasting edges. A door frame (white wall with a dark area behind it) would be SO much better. The built-in flash won't help here. It'll add light (through that terribly annoying sputter of AF-assist flashes), but it can't create a contrasting edge. <em>> even with ISO 1600.</em> Again, ISO is irrelevant to autofocus. <em> > Same applied to plain surface.</em> Again, no contrasting edge. <em> > However, I could get focus lock easily with my Canon Speedlite 580EX II</em> The AF-assist function in the Speedlite throws lines of light onto the subject, thus creating contrasting edges. I got this reply from Doug Pardee at dpreview forum.

JayceOoi wrote:
> I used ISO 800 and above in low light room.
> But still failed to focus lock sometime.

Autofocus is separate from ISO. The autofocusing system requires a certain minimum amount of light to operate.
> I took wall as sample. I cannot get a focus lock with built-in flash

The autofocus system looks for a contrasting edge within the AF sensor area. A wall has no contrasting edges. A door frame (white wall with a dark area behind it) would be SO much better.

The built-in flash won’t help here. It’ll add light (through that terribly annoying sputter of AF-assist flashes), but it can’t create a contrasting edge.
> even with ISO 1600.

Again, ISO is irrelevant to autofocus.

> Same applied to plain surface.

Again, no contrasting edge.

> However, I could get focus lock easily with my Canon Speedlite 580EX II

The AF-assist function in the Speedlite throws lines of light onto the subject, thus creating contrasting edges.

]]> By:   Check Canon EOS 400D Digital with EF 50mm f/1.4 USM back focus issue by Jayce Ooi’s Paradise http://www.jayceooi.com/2007/10/09/focus-lock-issue-with-canon-eos-400d-digital/#comment-664   Check Canon EOS 400D Digital with EF 50mm f/1.4 USM back focus issue by Jayce Ooi’s Paradise Tue, 09 Oct 2007 14:42:57 +0000 http://74.220.215.233/~jayceooi/?p=693#comment-664 [...] Related topics: My Canon EOS 400D Digital and EF 50mm f/1.4 USM are backed! Focus lock issue with Canon EOS 400D Digital [...] [...] Related topics: My Canon EOS 400D Digital and EF 50mm f/1.4 USM are backed! Focus lock issue with Canon EOS 400D Digital [...]

]]> By:   My Canon EOS 400D Digital and EF 50mm f/1.4 USM are backed! by Jayce Ooi’s Paradise http://www.jayceooi.com/2007/10/09/focus-lock-issue-with-canon-eos-400d-digital/#comment-663   My Canon EOS 400D Digital and EF 50mm f/1.4 USM are backed! by Jayce Ooi’s Paradise Tue, 09 Oct 2007 14:42:17 +0000 http://74.220.215.233/~jayceooi/?p=693#comment-663 [...] Related topics: Check Canon EOS 400D Digital with EF 50mm f/1.4 USM back focus issue Focus lock issue with Canon EOS 400D Digital [...] [...] Related topics: Check Canon EOS 400D Digital with EF 50mm f/1.4 USM back focus issue Focus lock issue with Canon EOS 400D Digital [...]

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