Canon 300D won't autofocus

[chinggoy]

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hey guys.
just recently i tried using a cheap flash (forgot the brand) for a day with my 300d. it worked fine, but when i got back, i noticed that my camera had a hard time auto focusing. usually half clicking would be fine, now i'd have to really press it hard. sometimes it wouldnt even work and it'll just shoot.

i've tried resetting the cam but it'll only work for a couple shots.
is it possible to re-install the firmware? will that work?
any advice? thanks!!!

[Edited on 3-27-2005 by chinggoy]

[Kenneth]

What were the lighting conditions? When and where were you trying to shoot? If you were shooting in dim light, any camera would have problems autofocusing. There has to be just enough light so that the camera can "see" a contrast point, or else try and focus on a point where a visible contrast can be made out, and then recompose.

If you were using a third party camera flash that isn't compatible, then the flash and the camera body aren't "talking" to each other to exchange E-TTL info. The flash willl work, but it'll only shoot at full blast each time, resulting in inconsistent exposures.

A Canon EX speedlite would normally have the IR autofocus assist beam. Perhaps getting a 420EX or above or Sigma Super DG would be a good option.

Either that, or use the built in pop-up flash or go manual focus.

I don't think re-installing the firmware will help. Current version should be 1.1.1 I believe.

[Edited on 3-27-2005 by Kenneth]

[unintentional]

may i know what lense are you using? and yes the lighting condition is a great factor.

[Adel]

Originally posted by chinggoy
hey guys.
just recently i tried using a cheap flash (forgot the brand) for a day with my 300d. it worked fine, but when i got back, i noticed that my camera had a hard time auto focusing. usually half clicking would be fine, now i'd have to really press it hard. sometimes it wouldnt even work and it'll just shoot.

i've tried resetting the cam but it'll only work for a couple shots.
is it possible to re-install the firmware? will that work?
any advice? thanks!!!

[Edited on 3-27-2005 by chinggoy]

Chinggoy, could you be a little clearer about the circumstances when you have trouble AF'ing?

It's hard to tell, but do you mean to say that you have a hard time focusing when the cheap flash is connected, or do you mean to say that after you used the cheap flash and took it off, the camera now has trouble AF'ing, regardless of whether the flash was connected or not?

The cam needs a bit of light to enable it to autofocus, and it usually fires a pre-shot burst of IR to assist focus as Ken said. Perhaps the cheap flash doesn't have an IR AF assist, so it can't AF in poor light, and the 300D doesn't provide it because it thinks the flash is the one doing it for you.

Speculation is difficult - maybe you can give us some more specifics, like what kind or brand the flash is. I know you forgot, but all it takes is a glance at the flash's label. It might help us help you more.

[chinggoy]

the camera had a hard time autofocusing after using the cheap flash and took it off. even if there's ample light the problem still persists. this didn't happen prior to the use of the cheap flash which right now the brand escapes me (but i bought it only for P700 from mitsubishi photo). the brand is not indicated on the flash itself. sorry for not being able to provide this information, but i'll try to call the store where i bought it from.

just to add, sometimes it will autofocus but after 5 or 6 shots the problem will come back. most of the time the problem persists.

[acaspillera]

had the same problem this afternoon, of all times, during a wedding shoot! i was using a 50mm lens. when i slapped on the 18-55 kit lens, the kit lens wouldn't autofocus! then i went back to the 50mm, and it did AF. when i went back to the kit lens, again it wouldn't AF. i took out the lens, cleaned the electronic contacts on both the body and the lens, slapped it back on, and it worked perfectly. try cleaning the contacts. maybe it's just dirty.

if it doesn't work, maybe the cheap flash fried something inside the camera. that's one of the major problems of electronic cameras. sometimes the syncing voltage of the camera isn't compatible with the syncing voltage of the flash. a couple of friends of mine had to bring their 10D's to the canon service center because something got messed up with the electronics. they used their cameras hooked up to studio lights via a sync cord. apparently, the studio lights' syncing voltage were not compatible with the 10D's syncing voltage. now, both of them use a remote radio trigger to sync with their studio lights.

[CooLes]

Try taking out the battery and put it back again. It worked for me. But had to set the date and time again. Hope this helps.

[randytamayo]

Aldwin's (acaspillera) and Lester's suggestions are your first aid moves...try to take out the battery for around 5 mins (i have no explanation for the length of time - mine I store my camera sans the battery whenever i don't intend to use the camera for a day at least)...works ok..

And clean the contacts...those would be the golden little squares at the mouth of the lens and body...make sure though that you dont get any dirt or whatever into the camera body. DO NOT use an eraser to clean it ( even if its steadtler ) - the same way some here clean their ibooks and even the contacts on RAM modules (another story).

I use a lint free cloth with a dab (not dripping wet, should be a tad drier than a damp cloth) of lens cleaning solution and rub on the contacts a bit more vigorously (i may be doing it wrong but so far no harm has come)... and let the contacts dry first before using the camera. And while your at it, might as well clean all the lens contacts too! But you have doubts, DON'T and may I suggest you do the one below

If still it does not work, I guess it would be time to use that warranty and bring your camera into to the Canon service center. If you're out of warranty, they'll gladly fix it for a fee (of course).

Happy shooting!
Randy