Low Light Focusing

[lyncca]

I've found in really really dark environments that my camera has a hard time focusing. At first I thought it was my focusing distance, but now I know that is not the case. My lenses are fast, so that shouldn't be the problem either. Let me rephrase actually, it seems to focus, but I can't actually get the camera to take the shot.

I have the modeling flash on my SB800/SB600, but I am wondering if maybe it is the recycling time effecting this? Since it is really dark, it is obviously using more flash and taking more time to recycle, would this also effect the modeling flash?

I'm using recycleable batteries, but if this is indeed causing the problem, should I get a battery pack or lithiums (or some other option)?

My shots for the most part are right on time, but I have found that I have missed some great candids because of this and I want to fix it.

Thanks!

[texxter]

Just get a small LED flashlight and point it to your subject and use that light to focus with.

[Randy Chambers]

I get this issue sometimes too, like it will not "Lock" on the focal point and allow the camera to flash.

Anyone shed light on what the cause is?

[ldelacruz]

Even with fast lenses and pro bodies you could have issues in low light. Paco's suggestion would work or if you don't need precise focus pick another area with more contrasting lighting. I think your issue is lack of contrast because of the low light. I also remember reading in a Canon manual that there is a setting to allow the camera to fire without having precise focus. Nikon might have something similiar in the custom functions?

[bondarnes]

Is your infrared focus assist activated?

[lyncca]

Originally Posted by texxter

Just get a small LED flashlight and point it to your subject and use that light to focus with.

Ok, I will try that. I think I need a battery pack too though. The other night I couldn't get my flashes off fast enough when it did work. I take it that would fix at least that problem?

Originally Posted by Randy Chambers

I get this issue sometimes too, like it will not "Lock" on the focal point and allow the camera to flash.

Anyone shed light on what the cause is?

That's exactly what it does.

Originally Posted by ldelacruz

Even with fast lenses and pro bodies you could have issues in low light. Paco's suggestion would work or if you don't need precise focus pick another area with more contrasting lighting. I think your issue is lack of contrast because of the low light.

Yea, it was very dark and low contrast. Where the band was, there was no problem, but not out where the people were dancing (basically lit with blue string xmas lights). That stinks that there isn't a real solution besides beaming someone in the head with a flash light.

[lyncca]

Originally Posted by bondarnes

Is your infrared focus assist activated?

I'm not sure? Is that the AF activation? If so, yes.

[ldelacruz]

There are several things you can do actually. The light Paco suggested, the AF assist beam like Don said or manual focus, focus on something else and not the face of someone in the crowd and look for the custom function that will allow the camera to fire without precise focus.

[Dobick]

if the SB800 is attached to your camera you should get an af assist beam (it should be a red or green grid coming from the flash) that will aid in locking the focus.

With Canon, you need to be in a focus mode other than ai servo to have this work. Not sure if that is the case for Nikon or not

[lyncca]

Ok, so I am trying to figure this out in my hotel room since I have nothing else to do (out of town on business).

I currently have the SB600 on me, not my SB800. I found that my assist beam is not coming on. I was in C mode, which after doing a search on Google, said that it would not work, but in S mode, it still is not working. The setting is On for AF activation.

Am I missing something else? Someone said that the SB600 didn't work in spot metering, so I have that off and that it didn't work on the outside focus point, so I am on dead-center. Seriously, with all these parameters it seems a little limiting ;)

I was using the SB600 the other night when I had this problem, but I did before shooting a wedding with the SB800 as well, but that may have been because I was on C mode.

When I take the flash off, I still don't get an assist light from the camera with the onboard flash popped up.

[Randy Chambers]

I did a few tests trying to replicate this tonight. I did find that setting the glass/camera to manual focus and it will fires then.
I suppose we are probably not actually getting the subject into focus when in auto focus mode, which stops the shutter from releasing. I'd be sure that you have the focus assist lamp enabled, and AF mode set to AF-S. That helps achieve focus, but even then it will not lock in sometimes.

[ldelacruz]

Check your setting on the camera in your menu for Infared focus assist like Don mentioned. I don't have Nikon so not sure where to find it? AF activation is something different.

[lyncca]

Originally Posted by ldelacruz

Check your setting on the camera in your menu for Infared focus assist like Don mentioned. I don't have Nikon so not sure where to find it? AF activation is something different.

From Ken Rockwell, while he is normally full of crap, I figure this is at least trustworhy... I don't have my actual user manual on me.

a9 Built-in AF-assist illuminator :
This lets you deactivate the annoying AF assist light. Normally it comes on in the dark to help focus. Turn off the AF assist light if you want to keep a lower profile.

I may just have to go to Arlington camera and have them look at it. I've gone through every setting I can find to change...

[lyncca]

Ok, problem solved!

The original problem was the C mode instead of S; but I couldn't replicate it here because of the lens. Why would that cause a difference? I had in my Tokina 12-24 and when I switched to my Nikkor 24-70 it worked perfectly.

I just shot under this desk, which is nearly pitch black and it didn't even hesitate.

[ldelacruz]

Can't help you there! Not sure why the Tokina would trick it. Your persistence paid off!