Clarification on CP5700 low light AF


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CYRN

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#1
Actually, it isn't as bad as what many people thinks.

To dispel the over-emphasis on it's low light AF take a look at the below pic.

I've got AF lock on the subject before she was even aware of it.



1/6o sec @ f6.3. The exposure setting can give you an indication on the "brightness" of the place when you compare the background.

Hope this clears the air. ;)
 

Zerstorer

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#2
Originally posted by CYRN
1/6o sec @ f6.3. The exposure setting can give you an indication on the "brightness" of the place when you compare the background.
IMO this shot is taken with flash and hence cannot be an accurate indicator of the ambient light level as the subject would be correctly exposed and the background underexposed.

This makes the surroundings look darker than what it actually was.
 

CYRN

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#3
What I ment is that the background is out of flash range, thus will give an indication of the brightness of ambient lighting since it's not affected by flash. Therefore it implied if there is no flash used, the foreground would be as dark as the background in the same exposure setting.

*** I'm not saying the ambient light is as dark as the photo shows, the shot was compensated for the flash brightness.***

The exposure setting is just for people to try out themselves to achieve the same "darkness" then see for themself the relative ambient light.

Cuz my digicam cannot compansate enough for eyes that have adapted to low light situation. Read somewhere human eyes have a range of 1,000,000,000 from adapted darkness (dim moonlight scene?) to adapted brightness (bright daylight snow?) and flim a range of 1000 only.

Maybe I'm still not experienced enough to show ambient light "as seen" by human eye.


BTW I left out the iso setting in my previous post, it's 200
 

Zerstorer

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#4
Originally posted by CYRN
What I ment is that the background is out of flash range, thus will give an indication of the brightness of ambient lighting since it's not affected by flash. Therefore it implied if there is no flash used, the foreground would be as dark as the background in the same exposure setting.
This is true only if the shutter speed used is the same as a shot taken with solely ambient light.

This is obviously not so, or a flash would not have been used.

To show the actual ambient lighting, a shot would have to be taken without flash, or the settings are meaningless.

Do note that a shot taken with flash is only metered to be correctly exposed for the main subject. Anything out of flash range will definitely be underexposed and thus be shown as darker than what it really is.
 

CYRN

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#5
Juz to satisfy the no flash scene.

Below exposure is 1/2 sec @ f4 iso 200 focused on the glass. But I doub't you can see the focus with the camera shake.

 

roygoh

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#6
Did you actually get a focus lock indication from the camera?

For my CP995, if it cannot get a focus lock and the flash is on, it will set the focus to somewhere around 5 feet if the user insist on pressing the shutter release.

With the flash on, it makes the assumption that the subject is not too far away.

Your first picture could have come out focused because of this feature, instead of it actually focused on the subject correctly.

Hope you can clarify.

Thanks!
 

jOhO

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#7
er i dun see how this shows that the cp5700 isn't bad at low light focussing, altho i can sorta tell where u're coming from.

i'm using a cp5700 too and to be honest sometimes i dunno wat to compare to. cannot compare to my brother's SLR that one comfirm is faster. maybe compare to G3 or 602?

anyway slow is better than CANNOT focus at all. i sometimes get that and it's irritating. especially in pubs and frequently in ktv where lights are dim. sometimes i get my friends to use a lighter to illuminate their faces and when i get a lock i will ask them to off the lighter.

dun even talk about focusing, even if it DOES focus i sometimes cannot frame my shot becos the whole LCD/EVF is black! :confused:
 

MaGixShOe

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Apr 16, 2002
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#8
hehehe
i kena that kind of situation before

u can try this

set ur lens to the widest, point it at the centre of the subject and whack

go back crop siew siew...
 

espn

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Dec 20, 2002
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#9
Yep I face that problem also the whole EVF is black, happened to me when I was at sentosa on Sat night, I can't see a thing just cross fingers and press the shutter.

Sad thing is even with an external flash, it cannot use the external infra-red AF sigh.

This is still a great cam no matter the slow AF... nothing's perfect.
 

CYRN

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#10
roygoh: Yes I got the AF lock confirmation on both instances.

In fact I'm the main photg for that wedding event. Got AF lock confirmation for ALL tables group shots. Muz get AF lock, else the groom will kill me if I screw up. :D Of the whole place, this table (first pic) had the worst possible lighting.

MaGixShOe: The pic is not cropped nor altered except for re-size in PS.

jOhO: I trying to prove that CP5700 can achieve AF lock in lowlight situation AND achieve it fast enough for candid shots (as seen on the first pic, fast enough to capture the shocked look).
 

CYRN

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#11
Originally posted by espn
Yep I face that problem also the whole EVF is black, happened to me when I was at sentosa on Sat night, I can't see a thing just cross fingers and press the shutter.

Sad thing is even with an external flash, it cannot use the external infra-red AF sigh.

This is still a great cam no matter the slow AF... nothing's perfect.
Just re-read the manual... I said to tune up the EV compansation and the EVF/LCD will brighten up. Haven't try myself though.
 

espn

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#12
Yep, when you up or down the EV compensation, the LCD follows you and gets brighter or darker.
 

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