Live View won't autofocus

P

Palehorse

New member
Hi,

I am a new DSLR owner and have been enjoying the new pictures a lot! I love everything about the new camera, and can't wait to start experimenting...

But. I notice that with the D3100 and the kit lens (18-55mm) I can't get pictures to come into focus with Live View in low light.

I'll explain. When using the viewfinder in low light, the lens will focus in on my subject and the picture will come out looking fine, if i take the same picture over and over, the focus won't change and the picture looks great each time.

When I swap to Live View and press the shutter button half way, the lens will focus but the box will stay red. I can take a picture by pushing the shutter button the rest of the way.

If I repeatedly push the shutter button half way, with or without taking a picture, the lens will keep refocussing, even though I'm not moving the camera. So each refocus will result in a different amount of blur.

<press> *focus* - "Okay picture"
<press> *focus* - "very blurry picture"
<press> *focus* - "okay picture"
<press> *focus* - "very blurry picture"

The lens will swap between two focus results, one looks okay, the other looks like a blobby mess. This occurs no matter the mode I'm in, even Auto.

Am I missing something? Is this common? Is there more info I can provide to anyone?

Normal lighting this does not happen, and the box in Live View will go green to show a good focus.

I'm sorry if this is a no-brainer, I've looked in the manual and searched forums but I can't find anything. You Nikonites seem the friendliest so I came to you for help. :)

Thanks,
Jon
 
D

Don Kuykendall_RIP

RIP :(
Well first off Welcome to the forum

It would help if you would upload some photos to show us how low the light is. Be sure to give us the shutter speed / aperture / ISO settings.
 
D

Don Kuykendall_RIP

RIP :(
Palehorse said:
Okay I've uploaded three images, all taken in low light (a dark room with only a door cracked open)

I grabbed the settings that popped up when I took the photos on Auto mode, but the ISO only showed Auto.

1/60, 4.5

I really appreciate the assistance, let me know if there's anything I can provide.

Palehorse's Images - Nikonites Gallery @ News

Jon
Click to expand...

The ISO was shifting from 400ISO on the dark out of focus one to ISO3200 on the brightest one to 1800ISO for the middle one.
The focus problem is probably that you are in an area that really does not have enough light to focus consistently. Also there is probably not enough contrast to get a good focus.

You are probably shooting in the full Auto mode. You need to change to the one of the other modes so that you can control the ISO better. Also remember that this camera like many other cameras need light to focus. They also need something to focus on and white of white won't work most of the time.
 
R

Rexer John

Senior Member
How dark is it? You are using flash so it's hard to tell from the exif data.

​Are you at least using the inbuilt AF assist light?
 
P

Palehorse

New member
I took those sample pictures at work so the subject matter is less than inspiring. The problem cropped up last night and this morning I tried to take photos with the Live View of my kids on the couch. The contrast was there with a tan couch and red pyjamas, the only light was coming from the next room over.

When using the Live View, and pressing the shutter button to focus, the lens will actually readjust itself each time, and as the ISO was on auto I assume it's because the lens was changing length so the ISO was compensating??

I will take more samples tonight and try different ISO settings.
 
Top