problem focusing

kristlbel · 24th October 2002

I have this problem where I am sometimes unable to take my pictures because my camera refuses to lock focus on stationary object when in single focus mode. using an F80 here...

not sure if i'm doing something wrong here...

denizenx · 24th October 2002

what's the subject? too bright or too dark will have problems... or if u have dual images like reflections...

Darren · 24th October 2002

Without knowing more details, hard to give you a solution, but basically, if your subject is monochromatic or low contrast, then the AF sensors will have problem locking on.

AF sensors like the F80s work best when there is a pattern or a definite contrast on the subject eg, if the focus spot is on someones cheek, AF may not lock, but if the focus spot is on the eye, then AF will lockmon.

Also, when you are dealing with lines, make sure that the lines bisect the proper AF spot. If I am not mistaken, the middle AF spot on the F80 is of a slightly-angled cross-type sensor; the top and bottom AF spots uses a horizontal sensor; the left and right AF spots use a vertical sensor. Thus, if you are taking a shot of a fence for example, use either the centre or top/bottom sensors as the vertical fence lines will bisect the horizontal/angle placement. If you use the left/right AF spots, the vertical lines of the fence may "miss" the vertically aligned sensor and thus focus cannot be achieved. Or something like that

But basically, subjects with low contrast or not placing the AF spot on some sort of pattern/line will cause the AF problems.

kongg · 24th October 2002

Take note also of the minimum focusing distance of yr lense which u are using. If its too near, u can't focus.

roti · 24th October 2002

r u taking close-up???

kristlbel · 24th October 2002

Quote:

Originally posted by roti
r u taking close-up???

nope

kristlbel · 24th October 2002

thks all for the suggestions.

and to darren to his enlightening but cheem explanation (don't really get it

)

i'll try to remember the pts the next time i use my cam

Dagger · 24th October 2002

Quote:

Originally posted by kristlbel
thks all for the suggestions.

and to darren to his enlightening but cheem explanation (don't really get it )

i'll try to remember the pts the next time i use my cam

Why don't you join us for the next SEED on 30.10.02. It will be fun, also you could bring along you camera and could all work on your challenges in photography. Darren's a great teacher and it'a very hard to get him around. (I've been missing him for a while.) Looks like he should be there this time.

kristlbel · 25th October 2002

Quote:

Originally posted by Dagger

Why don't you join us for the next SEED on 30.10.02. It will be fun, also you could bring along you camera and could all work on your challenges in photography. Darren's a great teacher and it'a very hard to get him around. (I've been missing him for a while.) Looks like he should be there this time.

would love to. but wednesdays are one of my class days.

Dagger · 25th October 2002

Bingo! How about at one of our shoots/slide shows/etc?

24th October 2002	#1
kristlbel Member Join Date: Jun 2002 Location: somewhere over the rainbow Posts: 226	problem focusing I have this problem where I am sometimes unable to take my pictures because my camera refuses to lock focus on stationary object when in single focus mode. using an F80 here... not sure if i'm doing something wrong here...

24th October 2002	#2
denizenx Senior Member Join Date: Feb 2002 Location: L2TPYSG Posts: 4,514	what's the subject? too bright or too dark will have problems... or if u have dual images like reflections... __________________ "I'm... dreaming... of a wide... angle~ Just like the ones I used to know~"

24th October 2002	#3
Darren ClubSNAP Admin Join Date: Jan 2002 Location: ClubSNAP HQ Posts: 7,473	Without knowing more details, hard to give you a solution, but basically, if your subject is monochromatic or low contrast, then the AF sensors will have problem locking on. AF sensors like the F80s work best when there is a pattern or a definite contrast on the subject eg, if the focus spot is on someones cheek, AF may not lock, but if the focus spot is on the eye, then AF will lockmon. Also, when you are dealing with lines, make sure that the lines bisect the proper AF spot. If I am not mistaken, the middle AF spot on the F80 is of a slightly-angled cross-type sensor; the top and bottom AF spots uses a horizontal sensor; the left and right AF spots use a vertical sensor. Thus, if you are taking a shot of a fence for example, use either the centre or top/bottom sensors as the vertical fence lines will bisect the horizontal/angle placement. If you use the left/right AF spots, the vertical lines of the fence may "miss" the vertically aligned sensor and thus focus cannot be achieved. Or something like that But basically, subjects with low contrast or not placing the AF spot on some sort of pattern/line will cause the AF problems. __________________ Tweet?

24th October 2002	#4
kongg Member Join Date: Feb 2002 Location: Ang Mo Kio outskirts Posts: 784	Take note also of the minimum focusing distance of yr lense which u are using. If its too near, u can't focus.

24th October 2002	#5
roti Member Join Date: Sep 2002 Location: Sgp/China/TW Posts: 743	r u taking close-up???

25th October 2002	#10
Dagger Member Join Date: Jul 2002 Location: Singapore Posts: 1,294	Bingo! How about at one of our shoots/slide shows/etc?